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Comparison of biological effects of modulated electro-hyperthermia and conventional heat treatment in human lymphoma U937 cells.
Aug. 2016 | Andocs, G; Rehman, M U; Zhao, Q-L; Tabuchi, Y; Kanamori, M; Kondo, T
Loco-regional hyperthermia treatment has long history in oncology. Modulated electro-hyperthermia (mEHT, trade name: oncothermia) is an emerging curative treatment method in this field due to its highly selective actions. The impedance-matched, capacitive-coupled modulated radiofrequency (RF) current is selectively focused in the malignant cell membrane of the cancer cells. Our objective is studying the cell-death process and comparing the cellular effects of conventional water-bath hyperthermia treatment to mEHT. The U937 human histiocytic lymphoma cell line was used for the experiments. In the case of conventional hyperthermia treatment, cells were immersed in a thermoregulated water bath, whereas in the case of mEHT, the cells were treated using a special RF generator (LabEHY, Oncotherm) and an applicator. The heating dynamics, the maximum temperature reached (42 °C) and the treatment duration (30 min) were exactly the same in both cases. Cell samples were analysed using different flow cytometric methods as well as microarray gene expression assay and western blot analysis was also used to reveal the molecular basis of the induced effects. Definite difference was observed in the biological response to different heat treatments. At 42 °C, only mEHT induced significant apoptotic cell death. The GeneChip analysis revealed a whole cluster of genes, which are highly up-regulated in case of only RF heating, but not in conventional heating. The Fas, c-Jun N-terminal kinases (JNK) and ERK signalling pathway was the dominant factor to induce apoptotic cell death in mEHT, whereas the cell-protective mechanisms dominated in case of conventional heating. This study has clearly shown that conventional hyperthermia and RF mEHT can result in different biological responses at the same temperature. The reason for the difference is the distinct, non-homogenous energy distribution on the cell membrane, which activates cell death-related signalling pathways in mEHT treatment but not in conventional heat treatment. PMID 27551529

NK Cell Activation in the Antitumor Response Induced by IFN-α Dendritic Cells Loaded with Apoptotic Cells from Follicular Lymphoma Patients.
Juli 2016 | Lapenta, Caterina; Donati, Simona; Spadaro, Francesca; Castaldo, Paolo; Belardelli, Filippo; Cox, Maria C; Santini, Stefano M
Follicular lymphoma (FL) is the most common form of indolent non-Hodgkin lymphoma. This malignancy is considered virtually incurable, with high response rates to therapy but frequent relapses. We investigated the ability of monocyte-derived dendritic cells generated in the presence of IFN-α and GM-CSF (IFN-DC) and loaded with apoptotic lymphoma cells to activate immune responses against FL cells, with the ultimate goal of designing novel patient-specific vaccination strategies for the treatment of FL. In this article, we show that apoptotic tumor cell-loaded IFN-DC from FL patients, which were cultured for 2 wk with autologous lymphocytes, led to Th1 response skewing, based on significantly higher levels of IFN-γ production and a remarkable increase in CD8(+) and NK cell frequency, consistent with the detection of enhanced cytotoxic effector function toward autologous FL cells. IFN-DC were found to promote efficient NK cell activation, increased expression of cytotoxicity receptors, and extensive IFN-γ production in the virtual absence of IL-10. Moreover, direct recognition and killing of primary autologous lymphoma cells by activated NK cells from FL patients was also demonstrated. A critical role was demonstrated for MHC class I-related chain A and B and membrane-bound IL-15 in IFN-DC-mediated NK cell activation and early IFN-γ production. The overall results indicate that IFN-DC loaded with autologous apoptotic FL cells represent a valuable tool for improving the potency of therapeutic cancer vaccines through the efficient induction of NK cell activation and promotion of CD8(+) T cell antitumor immunity. PMID 27357153

Newcastle Disease Virus: Potential Therapeutic Application for Human and Canine Lymphoma.
Dez. 2015 | Sánchez, Diana; Pelayo, Rosana; Medina, Luis Alberto; Vadillo, Eduardo; Sánchez, Rogelio; Núñez, Luis; Cesarman-Maus, Gabriela; Sarmiento-Silva, Rosa Elena
Research on oncolytic viruses has mostly been directed towards the treatment of solid tumors, which has yielded limited information regarding their activity in hematological cancer. It has also been directed towards the treatment of humans, yet veterinary medicine may also benefit. Several strains of the Newcastle disease virus (NDV) have been used as oncolytics in vitro and in a number of in vivo experiments. We studied the cytolytic effect of NDV-MLS, a low virulence attenuated lentogenic strain, on a human large B-cell lymphoma cell line (SU-DHL-4), as well as on primary canine-derived B-cell lymphoma cells, and compared them to healthy peripheral blood mononuclear cells (PBMC) from both humans and dogs. NDV-MLS reduced cell survival in both human (42% ± 5%) and dog (34% ± 12%) lymphoma cells as compared to untreated controls. No significant effect on PBMC was seen. Cell death involved apoptosis as documented by flow-cytometry. NDV-MLS infections of malignant lymphoma tumors in vivo in dogs were confirmed by electron microscopy. Early (24 h) biodistribution of intravenous injection of 1 × 10(12) TCID50 (tissue culture infective dose) in a dog with T-cell lymphoma showed viral localization only in the kidney, the salivary gland, the lung and the stomach by immunohistochemistry and/or endpoint PCR. We conclude that NDV-MLS may be a promising agent for the treatment of lymphomas. Future research is needed to elucidate the optimal therapeutic regimen and establish appropriate biosafety measures. PMID 26703717

Clinical outcomes of a novel therapeutic vaccine with Tax peptide-pulsed dendritic cells for adult T cell leukaemia/lymphoma in a pilot study.
Apr. 2015 | Suehiro, Youko; Hasegawa, Atsuhiko; Iino, Tadafumi; Sasada, Amane; Watanabe, Nobukazu; Matsuoka, Masao; Takamori, Ayako; Tanosaki, Ryuji; Utsunomiya, Atae; Choi, Ilseung; Fukuda, Tetsuya; Miura, Osamu; Takaishi, Shigeo; Teshima, Takanori; Akashi, Koichi; Kannagi, Mari; Uike, Naokuni; Okamura, Jun
Adult T cell leukaemia/lymphoma (ATL) is a human T cell leukaemia virus type-I (HTLV-I)-infected T cell malignancy with poor prognosis. We herein developed a novel therapeutic vaccine designed to augment an HTLV-I Tax-specific cytotoxic T lymphocyte (CTL) response that has been implicated in anti-ATL effects, and conducted a pilot study to investigate its safety and efficacy. Three previously treated ATL patients, classified as intermediate- to high-risk, were subcutaneously administered with the vaccine, consisting of autologous dendritic cells (DCs) pulsed with Tax peptides corresponding to the CTL epitopes. In all patients, the performance status improved after vaccination without severe adverse events, and Tax-specific CTL responses were observed with peaks at 16-20 weeks. Two patients achieved partial remission in the first 8 weeks, one of whom later achieved complete remission, maintaining their remission status without any additional chemotherapy 24 and 19 months after vaccination, respectively. The third patient, whose tumour cells lacked the ability to express Tax at biopsy, obtained stable disease in the first 8 weeks and later developed slowly progressive disease although additional therapy was not required for 14 months. The clinical outcomes of this pilot study indicate that the Tax peptide-pulsed DC vaccine is a safe and promising immunotherapy for ATL. PMID 25612920

Vaccination of diffuse large B- cell lymphoma patients with antigen-primed dendritic cells.
Juni 2013 | Abediankenari, Saeid; Janbabaei Mollae, Ghasem; Ghasemi, Maryam; Yousefzadeh, Yousef; Bahrami, Masoud; Alimoghaddam, Kamran
Dendritic cells (DCs) are professional antigen presenting cells that have a potential role in the initiating of immune responses. The cell vaccination is a new strategy in treatment of infectious diseases and cancers. In this study, we have generated monocyte-derived dendritic cells of lymphoma patient's peripheral blood mononuclear cells then; these cells were used as vaccine in lymphoma patients. We generated dendritic cell vaccine from lymphoma patient's blood monocytes with human interleukin-4, granulocyte monocyte colony stimulating factor and then, antigen-primed Dcs were administrated subcutaneously close to the inguinal lymph nodes after maturation of dendritic cells. After 7 days, we analyzed immune response in lymphoma patients with determining of LDH, Beta 2 Microglobulin, CD4+T cell percent, CD8+ Tcell percent and Tumor size before and after vaccination. Furthermore, phenotypic and functional analysis of dendritic cells was performed using anti CD83-FITC monoclonal antibodies. Before vaccination, the mean ± SD of LDH was 530.62±140.65 but after vaccination it was 459±109.45 that significantly different between experimental groups (P=0.002). In addition, the CD8+ T cells percentage significantly different between two groups (P=0.002). We concluded that the use of dendritic cell probably is one of the suitable noninvasive treatments for lymphoma patients that they have not response to chemical drugs. PMID 23737309

Enhanced therapeutic effect of B cell-depleting anti-CD20 antibodies upon combination with in-situ dendritic cell vaccination in advanced lymphoma.
Nov. 2012 | Manzur, S; Cohen, S; Haimovich, J; Hollander, N
The present standard of care for B cell non-Hodgkin's lymphoma includes the anti-CD20 monoclonal antibody rituximab. Although combination treatments with chemotherapy and rituximab improved the duration of remissions and overall survival in indolent B cell lymphoma, the disease is essentially incurable. Thus, new therapeutic approaches are needed. One such approach is active immunization. Given that rituximab depletes both malignant and normal B cells, it is expected to impair humoral immune responses in vaccinated patients. Hence, optimal vaccination strategies for rituximab-treated patients require induction of effector T cells, which can be achieved by dendritic cell (DC) vaccines. We have demonstrated in a mouse model that chemotherapy combined with DC vaccines was therapeutically effective. However, efficacy was related to tumour size at the onset of treatment, decreasing in correlation with increasing tumour burdens. We therefore examined whether, in spite of its low efficacy in advanced disease, DC vaccination may synergize with anti-CD20 antibodies to enhance therapy. Lymphoma-bearing mice were treated with cyclophosphamide, anti-CD20 antibodies and an intratumoral DC vaccine. Results clearly demonstrated the enhanced therapeutic effect of this combination treatment. Thus, under conditions of disseminated disease, when either anti-CD20 antibody treatment or vaccination showed insufficient efficacy, their combination resulted in synergism that mediated long-term survival. We demonstrated further that the combination of antibody and vaccine induced T cell-mediated anti-tumour immune responses with long-term memory. Combination treatments including tumour cell-loaded DC vaccines may therefore provide a strategy for enhancing therapy in rituximab-treated patients. PMID 23121670

Dendritic cells and cutaneous T-cell lymphomas.
Apr. 2011 | Ni, X; Duvic, M
Dendritic cells (DCs) are potent antigen-presenting cells that help orchestrate the innate and adaptive immune systems to induce tolerance and immunity. They are diversified in their phenotypes, stages of maturation, degrees of activation, and functions. Several subtypes of DCs exist among human lymphoid tissues, non-lymphoid tissues, and in peripheral blood. In the skin, three types of DCs are described: Langerhans cells (LCs), dermal dendritic cells (DDCs), and plasmacytoid dendritic cells (pDCs). In the peripheral blood, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells are well described. Dysfunctional DCs are found in many autoimmune disorders, allergies, and cancers. In this paper, we focus on DCs as related to cutaneous T cell lymphomas (CTCLs). Abnormal DC number and defective DC function are found in the blood of patients with advanced stage Sézary syndrome (SS), a leukemic variant of CTCLs. Extracorporeal photopheresis (ECP), an effective therapy for erythrodermic CTCLs, is thought to work by inducing apoptosis of tumor cells and monocytes-derived DCs. DC vaccination has been carried out successfully in some patients with CTCLs when combined with immune modifiers like toll like receptor agonists, which may enhance the function of DCs. However, DCs may perform a dual role in the pathogenesis of CTCLs. Immature DCs (langerhans cells) could promote the survival of malignant T cells. Further understanding of DCs and their role in CTCLs can help us to uncover the pathogenesis of this disease and to further explore the therapeutic uses of DCs. PMID 21505396

Improved clinical outcome in indolent B-cell lymphoma patients vaccinated with autologous tumor cells experiencing immunogenic death.
Nov. 2010 | Zappasodi, Roberta; Pupa, Serenella M; Ghedini, Gaia C; Bongarzone, Italia; Magni, Michele; Cabras, Antonello D; Colombo, Mario P; Carlo-Stella, Carmelo; Gianni, Alessandro M; Di Nicola, Massimo
Increasing evidence argues that the success of an anticancer treatment may rely on immunoadjuvant side effects including the induction of immunogenic tumor cell death. Based on the assumption that this death mechanism is a similar prerequisite for the efficacy of an active immunotherapy using killed tumor cells, we examined a vaccination strategy using dendritic cells (DC) loaded with apoptotic and necrotic cell bodies derived from autologous tumors. Using this approach, clinical and immunologic responses were achieved in 6 of 18 patients with relapsed indolent non-Hodgkin's lymphoma (NHL). The present report illustrates an impaired ability of the neoplastic cells used to vaccinate nonresponders to undergo immunogenic death on exposure to a cell death protocol based on heat shock, γ-ray, and UVC ray. Interestingly, when compared with doxorubicin, this treatment increased surface translocation of calreticulin and cellular release of high-mobility group box 1 and ATP in histologically distinct NHL cell lines. In contrast, treated lymphoma cells from responders displayed higher amounts of calreticulin and heat shock protein 90 (HSP90) compared with those from nonresponders and boosted the production of specific antibodies when loaded into DCs for vaccination. Accordingly, the extent of calreticulin and HSP90 surface expression in the DC antigenic cargo was significantly associated with the clinical and immunologic responses achieved. Our results indicate that a positive clinical effect is obtained when immunogenically killed autologous neoplastic cells are used for the generation of a DC-based vaccine. Therapeutic improvements may thus be accomplished by circumventing the tumor-impaired ability to undergo immunogenic death and prime the antitumor immune response. PMID 20884630

Synergistic effect of dendritic cell vaccination and anti-CD20 antibody treatment in the therapy of murine lymphoma.
Apr. 2009 | Gadri, Zohar; Kukulansky, Tova; Bar-Or, Eyal; Haimovich, Joseph; Hollander, Nurit
Indolent B-cell lymphomas are characterized by repeated remissions and relapses with most patients eventually dying of the disease. Although combination treatments with chemotherapy and the anti-CD20 antibody rituximab improved duration of remissions and overall survival, the disease is essentially incurable. Thus, novel therapeutic approaches are needed. One such approach is active immunization with dendritic cells (DCs). Given that rituximab depletes patients of normal B cells, optimal vaccination strategies for rituximab-treated patients require induction of effector T cells. We have previously demonstrated in a murine model that idiotype (Id)-keyhole limpet hemocyanin-pulsed DCs induced Id-reactive CD8 T cells and protection against tumor challenge in the absence of anti-Id antibodies. On the basis of these results, we investigated vaccination in a therapeutic model, in which mice carrying advanced tumors of the highly aggressive 38C-13 lymphoma were treated with chemotherapy and anti-CD20 antibodies combined with a DC-based vaccine. As a rule, cytoreduction by cyclophosphamide was required in each regimen of combination treatment, and vaccination with tumor cell-loaded DCs was more effective than vaccination with Id-keyhole limpet hemocyanin-loaded DCs. We demonstrated that under conditions of large primary tumors that had already spread to lymph nodes, when anti-CD20 antibody treatment showed minimal effect and DC vaccination had no effect, synergism between anti-CD20 antibodies and DC vaccines resulted in significant long-term survival that did not involve active antitumor antibody production. Combination treatments including tumor cell-loaded DC vaccines may therefore provide a strategy for enhancing the potency of therapy in rituximab-treated patients. PMID 19342972

Vaccination with autologous tumor-loaded dendritic cells induces clinical and immunologic responses in indolent B-cell lymphoma patients with relapsed and measurable disease: a pilot study.
Jan. 2009 | Di Nicola, Massimo; Zappasodi, Roberta; Carlo-Stella, Carmelo; Mortarini, Roberta; Pupa, Serenella M; Magni, Michele; Devizzi, Liliana; Matteucci, Paola; Baldassari, Paola; Ravagnani, Fernando; Cabras, Antonello; Anichini, Andrea; Gianni, Alessandro M
Eighteen relapsed patients with measurable indolent non-Hodgkin lymphoma (NHL) were vaccinated with dendritic cells (DCs) loaded with killed autologous tumor cells. Six patients had objective clinical responses including 3 continuous complete responses (CRs) and 3 partial responses (PRs), with a median follow up of 50.5 months. Eight patients had stable disease, whereas 4 had progressive disease. Clinical responses were significantly associated with a reduction in CD4(+)CD25(+)FOXP3(+) regulatory T cells, an increase in CD3(-)CD56(dim)CD16(+) natural killer (NK) cells, and maturation of lymphocytes to the effector memory stage in either postvaccination peripheral blood or tumor specimen samples. In partial responding patients, vaccination significantly boosted the IFN-gamma-producing T-cell response to autologous tumor challenge. In one HLA-A*0201(+) patient who achieved CR, IL-4 release by circulating T cells in response to tumor-specific IgH-encoded peptides was also documented. Immunohistochemical analysis of tumor biopsies using biotin-conjugated autologous serum samples revealed a tumor-restricted humoral response only in the postvaccination serum from responding patients. Collectively these results demonstrate that vaccination with tumor-loaded DCs may induce both T- and B-cell responses and produces clinical benefits in indolent NHL patients with measurable disease. This study is registered with the Istituto Superiore di Sanità: with protocol number 7578-PRE 21-801. PMID 18809757

Therapeutic vaccines for non-Hodgkin B-cell lymphoma.
Sep. 2008 | Briones, Javier
Despite current therapeutic strategies for B-cell lymphoma, including chemotherapy and transplantation, the majority of patients are not cured. The characterisation of several tumour antigens has made immunotherapy an interesting approach to the treatment of patients with lymphoma. The idiotype region in the immunoglobulin expressed by the tumour B cells is not only a clonal marker but also a tumour-specific antigen. For this reason, the idiotype is an ideal target for immunotherapy. Extensive studies of idiotype vaccination have been done in murine lymphoma models and some of these strategies are now being tested in clinical trials. In the last few years, new strategies to improve the immune response against lymphoma cells have been studied, including the use of DNA or recombinant viruses encoding tumour-antigens, genetically modified tumour cells and a number of immune adjuvants targeting dendritic cells, T cells or NK cells. PMID 18796371

Dendritic cells and T lymphocyte interactions in patients with lymphoid malignancies.
Juni 2008 | Pytlík, R; Hofman, P; Kideryová, L; Cervinková, P; Obrtlíková, P; Sálková, J; Trnený, M; Klener, P
Dendritic cell (DC) vaccination is an attractive approach to the treatment of patients with lymphoid tumors. To evaluate its feasibility, we have tested the functional properties of DC and T-lymphocytes in patients with treated and untreated chronic lymphocytic leukemia (CLL) and follicular lymphoma (FL). Healthy volunteers were used both as controls and as a source of cells for allogeneic mixed leukocyte reaction (MLR). In these reactions, dendritic cells from both untreated and treated patients were comparable to dendritic cells from healthy volunteers. In all the untreated patients studied, autologous dendritic cells promoted the survival and proliferation of both CD4 and CD8 lymphocytes (though the proliferation response was much better in the CD4 subset), whereas only 3 out of 5 treated patients were able to mount this response with CD4 lymphocytes and 4 out of 5 with CD8 lymphocytes. In 3 out of 5 untreated patients, pulsing of DCs with tetanus toxoid promoted a better CD4 response than was achieved with unpulsed DCs, while none of 5 treated patients had an additional response after pulsing with tetanus toxoid. None of patients studied, either treated or untreated, had a better CD8 response to pulsed DCs than to unpulsed ones. During CD4 lymphocyte proliferation, more CD4(+)CD25(hi) lymphocytes were generated in both treated and untreated patients than in healthy controls. Poor proliferation of cytotoxic cells and preferential proliferation of CD4(+)CD25(hi) T-regulatory cells in response to self and/or foreign antigens might be one of the mechanisms responsible for immunosuppression and impaired tumor surveillance in patients with lymphoid malignancies. PMID 17552881

Immunotherapy of hematological malignancies using dendritic cells.
Apr. 2008 | Van de Velde, Ann L R; Berneman, Zwi N; Van Tendeloo, Viggo F I
The arsenal of therapeutic weapons against hematological malignancies is constantly growing. Unravelling the secrets of tumor immunobiology has allowed researchers to manipulate the immune system in order to stimulate tumor immunity or to bypass tumor-induced immunosuppression. An area of great interest is active specific immunotherapy where dendritic cell (DC)-based therapeutic vaccines for cancer have definitely grabbed the spotlight. DC are intensively investigated as cellular adjuvants to harness the immune system to fight off cancer by augmenting the number and effector functions of tumor-specific CD8+ cytotoxic T lymphocytes. In the present review we present a comprehensive synopsis and an update of the use of DC in hematological malignancies. In the future, more basic research as well as more clinical trials are warranted to fully establish the value of DC vaccination as an adjuvant therapy for modern hematological oncology. PMID 18390412

Dendritic cells loaded with apoptotic antibody-coated tumor cells provide protective immunity against B-cell lymphoma in vivo.
Jan. 2008 | Franki, Suzanne N; Steward, Kristopher K; Betting, David J; Kafi, Kamran; Yamada, Reiko E; Timmerman, John M
The in vitro priming of tumor-specific T cells by dendritic cells (DCs) phagocytosing killed tumor cells can be augmented in the presence of antitumor monoclonal antibody (mAb). We investigated whether DCs phagocytosing killed lymphoma cells coated with tumor-specific antibody could elicit antitumor immunity in vivo. Irradiated murine 38C13 lymphoma cells were cocultured with bone marrow-derived DCs in the presence or absence of tumor-specific mAb. Mice vaccinated with DCs cocultured with mAb-coated tumor cells were protected from tumor challenge (60% long-term survival), whereas DCs loaded with tumor cells alone were much less effective. The opsonized whole tumor cell-DC vaccine elicited significantly better tumor protection than a traditional lymphoma idiotype (Id) protein vaccine, and in combination with chemotherapy could eradicate preexisting tumor. Moreover, the DC vaccine protected animals from both wild-type and Id-negative variant tumor cells, indicating that Id is not a major target of the induced tumor immunity. Protection was critically dependent upon CD8(+) T cells, with lesser contribution by CD4(+) T cells. Importantly, opsonized whole tumor cell-DC vaccination did not result in tissue-specific autoimmunity. Since opsonized whole tumor cell-DC and Id vaccines appear to target distinct tumor antigens, optimal antilymphoma immunity might be achieved by combining these approaches. PMID 17993615

Immunotherapy in mantle cell lymphoma: anti-CD20-based therapy and beyond.
Jan. 2008 | Zhou, Yuhong; Zhang, Liang; Romaguera, Jorge; Delasalle, Kay; Han, Xiaohong; Du, Xin; Kwak, Larry; Yi, Qing; Wang, Michael
Mantle cell lymphoma (MCL), an aggressive non-Hodgkin's lymphoma characterized by t(11; 14)(q13; q32) chromosomal translocation and overexpression of cyclin D1, has the worst prognosis among all lymphomas. Recent advances in biology, genetics, and immunology have supported the development of immunotherapy in MCL. Rituximab monotherapy in MCL has limited activity. It is more effective when used in combination with chemotherapy such as R-CHOP, R-hyperCVAD/MTX-Ara-C, or R-FCM as front-line or salvage therapy for mantle cell lymphoma. Maintenance with Rituximab was shown to prolong response duration. Although most results have suggested that combining autologous stem cell transplantation with Rituximab may lead to durable remission, the sample size was not sufficient to declare survival benefit. Anti-CD20 radioimmunoconjugates (RICs) (90)Yttrium-ibritumomab tiuxetan and (131)Iodine-tositumomab have been used in mantle cell lymphoma even when patients are relatively resistant to Rituximab-based therapy. Allogeneic stem cell transplantation is a treatment modality in advanced or relapsed MCL, particularly using reduced-intensity conditioning. MCL may have high response rates and sustained remissions after donor lymphocyte infusion. Dendritic cells (DCs) fused with MCL cells for immunostimulation have preliminarily shown anti-lymphoma effects as well. Idiotype vaccination in MCL patients following Rituximab-containing chemotherapy induced tumor-specific T-cell immunity in the absence of B cells. Other immunotherapy, such as the combination of thalidomide with Rituximab, has shown substantial antitumor activity. A Phase I/II study is ongoing to determine the maximum tolerated dose (MTD) and the efficacy of lenalidomide in combination with Rituximab for relapsed/refractory MCL. This review summarizes the latest and exciting advances in MCL. PMID 17722077

Monocyte derived dendritic cells generated by IFN-alpha acquire mature dendritic and natural killer cell properties as shown by gene expression analysis.
Nov. 2007 | Korthals, Mark; Safaian, Nancy; Kronenwett, Ralf; Maihöfer, Dagmar; Schott, Matthias; Papewalis, Claudia; Diaz Blanco, Elena; Winter, Meike; Czibere, Akos; Haas, Rainer; Kobbe, Guido; Fenk, Roland
Dendritic cell (DC) vaccines can induce antitumor immune responses in patients with malignant diseases, while the most suitable DC culture conditions have not been established yet. In this study we compared monocyte derived human DC from conventional cultures containing GM-CSF and IL-4/TNF-alpha (IL-4/TNF-DC) with DC generated by the novel protocol using GM-CSF and IFN-alpha (IFN-DC). PMID 17894866

Comparison of dendritic cell-mediated immune responses among canine malignant cells.
Okt. 2007 | Tamura, Kyoichi; Arai, Hiroyoshi; Ueno, Emi; Saito, Chie; Yagihara, Hiroko; Isotani, Mayu; Ono, Kenichiro; Washizu, Tsukimi; Bonkobara, Makoto
Dendritic cell (DC) vaccination is one of the most attractive immunotherapies for malignancies in dogs. To examine the differences in DC-mediated immune responses from different types of malignancies in dogs, we vaccinated dogs using autologous DCs pulsed with keyhole limpet hemocyanin (KLH) and cell lysate prepared from squamous cell carcinoma SCC2/88 (SCC-KLH-DC), histiocytic sarcoma CHS-5 (CHS-KLH-DC), or B cell leukemia GL-1 (GL-KLH-DC) in vitro. In vivo inductions of immune responses against these tumor cells were compared by the delayed-type hypersensitivity (DTH) skin test. The DTH response against SCC2/88 cells were observed in dogs vaccinated with autologous SCC-KLH-DC, while the response was undetectable against CHS-5 and GL-1 cells in dogs vaccinated with autologous CHS-KLH-DC and GL-KLH-DC. Skin biopsies taken from DTH challenge sites were then examined for immunohistochemistry, and recruitment of CD8 and CD4 T cells was detected at the site where SCC2/88 cells were inoculated in dogs vaccinated with SCC-KLH-DC. By contrast, neither CD8 nor CD4 T cell infiltration was found at the DTH challenge site in the dogs vaccinated with CHS-KLH-DC or GL-KLH-DC. These findings may reflect that the efficacy of immune induction by DC vaccination varies among tumor types and that immune responses could be inducible in squamous cell carcinoma. Our results encouraged further investigation of therapeutic vaccination for dogs with advanced squamous cell carcinoma in clinical trials. PMID 17917377

Induction of protective CTL immunity against peptide transporter TAP-deficient tumors through dendritic cell vaccination.
Sep. 2007 | Chambers, Benedict; Grufman, Per; Fredriksson, Vanoohi; Andersson, Kenth; Roseboom, Marjet; Laban, Sandra; Camps, Marcel; Wolpert, Elisabeth Z; Wiertz, Emmanuel J H J; Offringa, Rienk; Ljunggren, Hans-Gustaf; van Hall, Thorbald
A large proportion of human cancers show deficiencies in the MHC class I antigen-processing machinery. Such defects render tumors resistant to immune eradication by tumoricidal CTLs. We recently identified a unique population of CTL that selectively targets tumor immune-escape variants through recognition of MHC-presented peptides, termed TEIPP (T cell epitopes associated with impaired peptide processing), expressed on cells lacking functional TAP-peptide transporters. Previously, we showed that vaccination with TEIPP peptides mediates protection against TAP-deficient tumors. Here, we further explored the concept of TEIPP-targeted therapy using a dendritic cell (DC)-based cellular vaccine. Impairment of TAP function in DC induced the presentation of endogenous TEIPP antigens by MHC class I molecules, and immunization with these DCs protected mice against the outgrowth of TAP-deficient lymphomas and fibrosarcomas. Immune analysis of vaccinated mice revealed strong TEIPP-specific CTL responses, and a crucial role for CD8(+) cells in tumor resistance. Finally, we show that TEIPP antigens could be successfully induced in wild-type DC by introducing the viral TAP inhibitor UL49.5. Our results imply that immune intervention strategies with TAP-inhibited DC could be developed for the treatment of antigen processing-deficient cancers in humans. PMID 17875682

Specific targeting of whole lymphoma cells to dendritic cells ex vivo provides a potent antitumor vaccine.
März 2007 | Adam, Christian; Mysliwietz, Josef; Mocikat, Ralph
Dendritic cells (DC) pulsed with tumor-derived antigenic material have widely been used in antitumor vaccination protocols. However, the optimal strategy of DC loading has not yet been established. Our aim was to define requirements of optimal DC vaccines in terms of in vivo protection in a murine B-cell lymphoma model. PMID 17359532

Generation of functional dendritic cells (DC) in adult acute lymphoblastic leukemia: rationale for a DC-based vaccination program for patients in complete hematological remission.
Feb. 2007 | Maggio, Roberta; Peragine, Nadia; Calabrese, Elisabetta; De Propris, Maria Stefania; Intoppa, Stefania; Della Starza, Irene; Ariola, Cristina; Vitale, Antonella; Foà, Robin; Guarini, Anna
The capacity to generate effective dendritic cells (DC) from adult acute lymphoblastic leukemia (ALL) patients in complete remission (CR) and off-therapy was investigated. Monocyte-derived DC cultured in the presence of granulocyte-macrophage colony-stimulating factor, interleukin (IL)-4 and tumor necrosis factor (TNF)-alpha expressed maturation markers, produced IL-12 and loaded apoptotic bodies to a similar extent to normal DC. Patients' circulating T and NK lymphocytes were normally represented and, after stimulation, were capable of producing TNF-alpha and interferon-gamma to a similar extent to control lymphocytes. DC loaded with leukemia-derived apoptotic bodies increased their ability to stimulate both allogeneic and autologous lymphocytes, and to generate specific anti-leukemic CD3 + cells. These findings offer a rationale for the design of DC-based vaccine programs for adult ALL patients in CR with the aim of controlling/eradicating the disease. PMID 17325890

Gene expression in enhanced apoptosis of human lymphoma U937 cells treated with the combination of different free radical generators and hyperthermia.
Dez. 2006 | Wada, Shigehito; Tabuchi, Yoshiaki; Kondo, Takashi; Cui, Zheng-Guo; Zhao, Qing-Li; Takasaki, Ichiro; Salunga, Thucydides L; Ogawa, Ryohei; Arai, Toshiyuki; Makino, Keisuke; Furuta, Isao
The effects of various free radicals derived from 6-formylpterin (6-FP), alpha-phenyl-tert-butyl nitrone (PBN) and 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) combined with hyperthermia, on gene expression in similarly enhanced apoptosis of human lymphoma U937 cells were investigated using cDNA microarrays containing approximately 16,600 genes and computational gene expression analysis tools. When the cells were treated for 10 min at 44 degrees C (15% apoptosis level), 39 up-regulated and 3 down-regulated genes were identified. In the up-regulated genes, apoptosis- and unfolded protein response-associated genes were contained. The combined treatment with heat and either chemical enhanced apoptosis level (approximately 30%) and showed a chemical-specific gene expression pattern. Furthermore, the expression levels of selected genes were confirmed by a real-time quantitative PCR. The present results will provide a basis for further understanding the molecular mechanisms in enhancement of heat-induced apoptosis by different intracellular oxidative stress. PMID 17164180

Current status of immunotherapy in B cell malignancies.
Okt. 2006 | Kofler, D M; Mayr, C; Wendtner, C-M
Conventional treatment of hematologic malignancies mainly consists of chemotherapeutic agents or a combination of both, chemotherapy and monoclonal antibodies. Despite recent advances, chemotherapeutic treatments often remain unsatisfying due to severe side effects and incomplete long-term remission. Therefore the evaluation of novel therapeutic options is of great interest. B cell malignancies, in particularly follicular lymphomas, chronic lymphocytic leukemia and multiple myeloma, represent the most immune-responsive types of all human cancer. Several immunotherapeutic strategies are presently employed to combat these B-cell malignancies. Active immunotherapies include vaccination strategies with dendritic cells (DCs) and genetically-modified tumor cell preparations as well as DNA and protein vaccination. Most of these vaccines target the tumor-specific immunoglobulin idiotype and have already demonstrated some anti-lymphoma activity in early phase clinical trials while their definitive impact is evaluated in ongoing phase III randomized trials. In contrast to these active immunizations, T cells transduced with chimeric antigen receptors and donor leukocyte infusions (DLI) represent adoptive (passive) immunotherapies. Recent advances of gene transduction technologies enabled improvement of immunotherapeutic strategies based on genetic modification of malignant cells or adoptive T cells. Current early phase clinical trials are investigating the potential of these innovative approaches. At the moment it remains unclear if the novel immunotherapeutic strategies will be able to play a similar role in the treatment of B cell malignancies than the already established antibody-based immunotherapy. PMID 17073599

Antigen targeting to endosomal pathway in dendritic cell vaccination activates regulatory T cells and attenuates tumor immunity.
Aug. 2006 | Maksimow, Mikael; Miiluniemi, Mari; Marttila-Ichihara, Fumiko; Jalkanen, Sirpa; Hänninen, Arno
Lymphoma cells are malignant cells of the T- or B-cell lineage that often express many surface markers inappropriately, yet are not recognized as abnormal by the immune system. We modeled this situation by inoculating ovalbumin-expressing E.G7-OVA lymphoma cells into mice that expressed ovalbumin as a self antigen in pancreatic islets, and investigated the efficacy of dendritic cell (DC) vaccination in these mice. Although vaccination with DC-expressing ovalbumin induced strong cytotoxic T-cell immunity, which led to clearance of E.G7-OVA lymphoma cells in naive C57BL/6 mice, DC vaccination was ineffective in mice expressing ovalbumin as a self antigen. Antigen modification to increase its processing via the endosomal processing pathway dramatically increased CD4 T-cell activation but paradoxically, impaired the protective effect of DC vaccination even in naive mice. Depletion of CD25(+) T cells (regulatory T cells [Tregs]) prior to vaccination restored the efficacy of DC vaccination and allowed eradication of lymphoma also in mice expressing ovalbumin as a self antigen. We conclude that lymphoma cells may be eradicated using DC vaccination if activation of CD25(+) Tregs is simultaneously inhibited, and that intentionally enhanced endosomal antigen processing in DC vaccines may shift the balance from CD4 T-cell help toward stimulation of Tregs. PMID 16621963

Analysis of cell proliferation and cell death during in situ hyperthermic treatment of neoplastic cells: a case report of human non-Hodgkin lymphoma.
Juli 2006 | Barni, S; Pontiggia, E; Bertone, V; Pontiggia, P; Mathé, G
In this study we observed the effects in vivo of hyperthermic treatment on the cell kinetics (cell proliferation/cell death) in one case of human non-Hodgkin lymphoma, by analyzing the following morpho-cytochemical parameters: Acridine Orange fluorochromasia, mitotic index, proliferating cell nuclear antigen (PCNA) expression, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) labeling, and ultrastructure morphology. After two hyperthermic exposures there was a significant reduction of cell growth rate (e.g. mitotic and PCNA positive cells) and an increase in cell loss by death. The cell death occurred by the typical apoptotic cascade, namely DNA fragmentation, chromatin hypercondensation and margination, karyorrhexis, ribonucleoproteins segregation and cytoplasm cleavage; in addition some necrotic cells were found. The data indicates that the hyperthermic treatments limit the cell proliferation (e.g. arrest and/or deceleration of the cell cycle) by facilitating the trigger of programmed cell death. It was concluded that thermal injury can be considered an effective inducer of antiproliferative and apoptogenic associated effects on the growth of this kind of neoplasia. PMID 16757146

Peripheral blood mobilization of different lymphocyte and dendritic cell subsets with the use of intermediate doses of G-CSF in patients with non-Hodgkin's lymphoma and multiple myeloma.
Mai 2006 | Vela-Ojeda, J; García-Ruiz Esparza, M A; Reyes-Maldonado, E; Jiménez-Zamudio, L; García-Latorre, E; Moreno-Lafont, M; Estrada-García, I; Mayani, H; Montiel-Cervantes, L; Tripp-Villanueva, F; Ayala-Sánchez, M; García-León, L D; Borbolla-Escoboza, J R
Between June 2003 and November 2004, we collected mobilized peripheral blood units from 29 patients with non-Hodgkin's lymphoma and multiple myeloma for autologous peripheral blood stem cell transplantation. They received granulocyte colony-stimulating factor (G-CSF) (16 micro g/kg/day) for a total of 5 days. Immediately before and 3 h after the fourth and fifth dose of G-CSF, we performed flow cytometry analysis to quantify: T cells (CD3+CD4+, CD3+CD8+), B cells (CD19+), NK cells (CD3-CD16+CD56+), NKT cells (CD3+CD16+CD56+), type 1 dendritic cells (DC1) (lin-HLA-DR+CD11c+), type 2 dendritic cells (DC2) (lin-HLA-DR+CD123+), regulatory T cells (Tregs) (CD4+CD25+), and activated T cells (CD3+HLA-DR+). All cell subsets were mobilized after G-CSF treatment with the exception of B, NK, and NKT lymphocytes. The median number of Treg cells before and after G-CSF was statistically different (29+/-14.9x10(6)/l vs 70.1+/-46.1x10(6)/l, P<0.02). DCs were mobilized significantly with a 5.9-fold increase in DC2 (15.1+/-30.3x10(6)/l vs 89.8+/-81.0x10(6)/l, P<0.02) and a 2.6-fold increase for DC1 (41+/-42.5x10(6)/l vs 109.5+/-58.0x10(6)/l, P<0.04). Patients received a mean of 3.1+/-1.2x10(7)/kg NK cells, 1.3+/-0.9x10(7)/kg NKT cells, 0.41+/-0.29x10(7)/kg DC1, 0.2+/-0.22x10(7)/kg DC2, and 1.8+/-1.9x10(7)/kg Tregs. In conclusion, intermediate doses of G-CSF induce mobilization of different lymphocyte subsets, with the exception of B, NK, and NKT cells. The mobilization of certain suppressive populations (DC2 and Treg) could be in theory deleterious, at least in patients with cancer. PMID 16525786

Autologous dendritic cells pulsed with eluted peptide as immunotherapy for advanced B-cell malignancies.
Mai 2006 | Ritchie, David; Hermans, Ian; Yang, Jianping; Walton, Julie; Matthews, Kate; Carter, John; Findlay, Michael; Dady, Peter; Rawson, Pisana; Ronchese, Franca
We have studied the feasibility, safety and efficacy of vaccination with autologous dendritic cells pulsed with eluted peptide in patients with advanced low-grade B-cell malignancies. This study demonstrates that autologous dendritic cell vaccines can be successfully produced from patients with advanced disease and be delivered without significant toxicity. Furthermore, we have demonstrated immunological and clinical responses in two of ten patients treated. These results provide further evidence for the use of immunotherapy in the management of B-cell malignancies, but also suggest that sustained responses may only be possible in patients with low bulk disease early in the disease course. PMID 16690526

Adjuvant IL-15 does not enhance the efficacy of tumor cell lysate-pulsed dendritic cell vaccines for active immunotherapy of T cell lymphoma.
Jan. 2006 | Gatza, Erin; Okada, Craig Y
There has been a recent interest in using IL-15 to enhance antitumor activity in several models because of its ability to stimulate CD8+ T cell expansion, inhibit apoptosis and promote memory T cell survival and maintenance. Previously, we reported that C6VL tumor lysate-pulsed dendritic cell vaccines significantly enhanced the survival of tumor-bearing mice by stimulating a potent tumor-specific CD8+ T cell response. In this study, we determined whether IL-15 used as immunologic adjuvant would augment vaccine-primed CD8+ T cell immunity against C6VL and further improve the survival of tumor-bearing mice. We report that IL-15 given after C6VL lysate-pulsed dendritic cell vaccines stimulated local and systemic expansion of NK, NKT and CD8+ CD44hi T cells. IL-15 did not, however, augment innate or cellular responses against the tumor. T cells from mice infused with IL-15 following vaccination did not secrete increased levels of tumor-specific TNF-alpha or IFN-gamma or have enhanced C6VL-specific CTL activity compared to T cells from recipients of the vaccine alone. Lastly, IL-15 did not enhance the survival of tumor-bearing vaccinated mice. Thus, while activated- and memory-phenotype CD8+ T cells were dramatically expanded by IL-15 infusion, vaccine-primed CD8+ T cell specific for C6VL were not significantly expanded. This is the first account of using IL-15 as an adjuvant in a therapeutic model of active immunotherapy where there was not a preexisting pool of tumor-specific CD8+ T cells. Our results contrast the recent studies where IL-15 was successfully used to augment tumor-reactivity of adoptively transferred transgenic CD8+ T cells. This suggests that the adjuvant potential of IL-15 may be greatest in settings where it can augment the number and activity of preexisting tumor-specific CD8+ T cells. PMID 16025264

B cell tumor vaccine enhanced by covalent attachment of immunoglobulin to surface proteins on dendritic cells.
Jan. 2006 | Lou, Qiang; Conway, Thomas F; Egilmez, Nejat K; Loyall, Jenni L; Bernstein, Steven H; Kelleher, Raymond J; Bankert, Richard B
Protein antigens have been covalently linked randomly to surface proteins on immature dendritic cells (DC). This has been achieved under physiological conditions using a heterobifunctional reagent that couples antigens to free thiol groups expressed on DC surface proteins. This results in a significant increase in the amount of antigen that is bound to DC, and the antigen/membrane protein complexes that are formed are rapidly internalized. DC, loaded covalently with either beta-galactosidase (beta-gal) or a tumor-associated immunoglobulin (Ig) when injected into mice, induce a beta-gal- or Ig-specific T cell response, and a protective anti-tumor immunity for tumors expressing either beta-gal or the targeted Ig. This response is shown here to be significantly greater than that which is induced by DC that are loaded with these antigens via the conventional antigen pulse protocol. These results establish a novel, safe, and viable approach of enhancing the effectiveness of DC-based vaccination strategies for B cell lymphoma. PMID 16185929

Vaccine strategies to treat lymphoproliferative disorders.
Dez. 2005 | Radford, Kristen J; Vari, Frank; Hart, Derek N J
Lymphoproliferative disorders, including follicular lymphoma (FL), multiple myeloma (MM) and chronic lymphatic leukaemia (CLL), are slowly progressive malignancies which remain incurable despite advances in therapy. Harnessing the immune system to recognise and destroy tumours is a promising new approach to treating these diseases. Dendritic cells (DC) are unique antigen-presenting cells that play a central role in the initiation and direction of immune responses. DC loaded ex vivo with tumour-associated antigens and administered as a vaccine have already shown promise in early clinical trials for a number of lymphoproliferative disorders, but the need for improvement is widely agreed. Recent advances in the understanding of basic DC biology and lessons from early clinical trials have provided exciting new insights into the generation of anti-tumour immune responses and the design of vaccine strategies. In this review we provide an overview of our current understanding of DC biology and their function in patients with lymphoproliferative disorders. We discuss the current status of clinical trials and new approaches to exploit the antigen presenting capacity of DC to design vaccines of the future. PMID 16373232

Targeting heat shock proteins for immunotherapy in multiple myeloma: generation of myeloma-specific CTLs using dendritic cells pulsed with tumor-derived gp96.
Dez. 2005 | Qian, Jianfei; Wang, Siqing; Yang, Jing; Xie, Jin; Lin, Pei; Freeman, Muta E; Yi, Qing
To develop effective immunotherapies for patients with multiple myeloma, it is important to use novel tumor antigens. Recent studies in solid tumors show that tumor-derived heat shock proteins (Hsp) can be used as immunogen; however, no such study has yet been reported in multiple myeloma. PMID 16361569

Natural killer cells license dendritic cell cross-presentation of B lymphoma cell--associated antigens.
Dez. 2005 | Dao, Tao; Gomez-Nunez, Marta; Antczak, Christophe; Kappel, Barry; Jaggi, Jaspreet Singh; Korontsvit, Tatyana; Zakhaleva, Victoriya; Scheinberg, David A
Presentation of exogenous antigen by MHC class I molecules, or cross-presentation, is a property of dendritic cells, which is considered crucial for the priming of cytotoxic T-cell response to tumor antigens. However, the precise mechanisms of this process are not fully understood. PMID 16361564

Dendritic cells expand Epstein Barr virus specific CD8+ T cell responses more efficiently than EBV transformed B cells.
Dez. 2005 | Subklewe, Marion; Sebelin, Kathrin; Block, Andrea; Meier, Antje; Roukens, Anna; Paludan, Casper; Fonteneau, Jean-François; Steinman, Ralph M; Münz, Christian
Adoptive transfer of Epstein Barr virus (EBV) specific cytotoxic T lymphocytes (CTLs) has been successfully applied in the treatment of EBV associated post-transplant lymphoproliferative disease (PTLD). In most studies EBV transformed B cells (LCLs) have been used for the induction of EBV specific T cell lines. Application of this approach to other EBV associated tumors is difficult, because LCLs focus T cell expansion toward immunodominant EBV antigens that are not expressed in EBV associated Hodgkin's lymphoma and nasopharyngeal carcinoma. Therefore, we compared dendritic cells (DCs) with LCLs for CD8+ T cell stimulation against dominant and subdominant EBV antigens. DCs expanded tenfold more EBNA3A and LMP2 specific CD8+ T cells than LCL and also stimulated EBV specific CTL from PTLD patients. Both, DCs and LCLs stimulations led to the expansion of high affinity T cells, capable to target EBV transformed B cells. While LCLs and DCs expressed MHC class I and II products at similar levels, DCs showed a higher expression of costimulatory and adhesion molecules. This resulted in more efficient T cell conjugate formation with DCs than with LCLs. We propose the use of DCs for stimulation of EBV specific T cells in active or passive immunotherapy of EBV associated malignancies. PMID 16360833

Genetic idiotypic and tumor cell-based vaccine strategies for indolent non Hodgkin's lymphoma.
Okt. 2005 | Ruffini, Pier Adelchi; Di Nicola, Massimo; Carlo-Stella, Carmelo; Siena, Salvatore; Gianni, Alessandro Massimo
B cell malignancies express a clear tumor-specific antigen (B cell immunoglobulin variable regions) known as idiotype (Id). It is now possible to immunize patients against autologous Id generating humoral and cellular immune responses that correlate with clinical and molecular remissions and the possibility of improved disease-free survival. In its present form, however, individual vaccine preparation by generating heterohybridomas is a technical and financial challenge. DNA vaccination provides a unique opportunity to streamline individual vaccine manufacture by circumventing the need for protein purification. DNA fusion vaccines have been developed in which genetic carriers promote adaptive immunity against the attached Id. Such carriers can specifically bind receptors on dendritic cells (DC) for targeted antigen delivery, or supply high levels of T cell help. Ideally, the carrier should be able to activate innate immunity to enhance the antigen-presenting capacity of DC. The correlates of immunity may vary depending upon the genetic carrier used. Translation to patients has begun with preliminary evidence of Id-specific immune responses. An alternative vaccination strategy that allows for the potential to vaccinate against multiple tumor antigens without the need to identify individual antigens is based on tumor cells themselves to be used as vaccine. To this purpose, however, each patient's tumor cells must be genetically modified to increase their immunogenicity. To overcome the technical limitations inherent with a fully autologous approach, strategies have been devised where a universal, genetically modified bystander cells is expected to provide the immunoenhancing cytokines to allow immune recognition of unmodified patients' tumor cells. PMID 16250891

Toward personalized immunotherapy for non-Hodgkin lymphoma: targeting the idiotypic immunoglobulin.
Okt. 2005 | Armstrong, Anne C; Cheadle, Eleanor J; Hawkins, Robert E
The idiotypic determinants of B-cell lymphomas, formed by cell-specific rearrangement of the immunoglobulin genes, are unique and are therefore a suitable target against which to direct immunotherapy. Recent advances in our understanding of the fundamental mechanisms behind an effective immune response, coupled with advances in genetic engineering techniques, have led to a renewed interest in immunotherapy. Early clinical studies have confirmed the immunogenicity of the idiotypic antigen in patients with lymphoma. This review discusses the different methods of idiotypic vaccination currently under investigation in the clinic, including protein, genetic, and cellular vaccines. Protein vaccines are the most clinically advanced, with phase III trials of idiotypic protein linked to GM-CSF currently underway. DNA vaccines are easier to produce but to date only appear to be weakly immunogenic in man. Dendritic cell vaccines have shown promise but their use may be limited by the complexity of this approach. This review also highlights other approaches not yet in the clinic but that have shown promise in the laboratory, such as viral vaccines and T-cell therapy. PMID 16207070

B-cell lymphoma and myeloma protection induced by idiotype vaccination with dendritic cells is mediated entirely by T cells in mice.
Aug. 2005 | Cohen, Sharon; Haimovich, Joseph; Hollander, Nurit
Immunoglobulin idiotypes (Id) of malignant B cells are tumor-specific antigens that may be targeted for immunotherapy. Id-directed immunotherapy by immunization with autologous Id has been initiated in clinical trials to control residual disease in B-cell lymphoma and multiple myeloma. The effector mechanisms responsible for destruction of B-cell tumors are a controversial issue. The authors show that vaccination with Id-pulsed dendritic cells (DCs) or with soluble Id-KLH in adjuvant induced immune responses that eliminated both B-cell lymphoma and myeloma in tumor-bearing mice; however, the two vaccination regimens resulted in distinct immune responses. Whereas soluble Id plus adjuvant induced high levels of anti-Id antibodies, the Id-pulsed DCs did not induce anti-Id or any antitumor antibodies. Immunization with Id-pulsed DCs induced a significant increase in the frequency of Id-reactive T cells. Depletion studies in DC-vaccinated mice showed that the predominant effector cells responsible for tumor rejection were of the CD8 subset. The finding that DC-based Id vaccines elicit tumor protection, which is entirely based on cell-mediated effector mechanisms, is of particular importance for plasma cell tumors because these tumors do not express Id on the surface and hence do not bind anti-Id antibodies. PMID 16113602

Immunotherapy in multiple myeloma--possibility or probability?
Juli 2005 | Harrison, S J; Cook, G
In a small number of patients with multiple myeloma (MM), long-term disease-free survival has been achieved by harnessing the immune phenomenon, 'graft-versus-tumour' effect, induced by allogeneic haemopoietic stem cell transplantation. This has prompted many investigators to examine ways in which a patient's own immune system can be more effectively directed against their disease, with the ultimate aim of tumour eradication. In this review we assess the current understanding of immunobiology in MM, and how the different components of the immune system, such as dendritic cells, T cells and natural killer cells, may be harnessed using in-vitro and in-vivo priming techniques. We look at the clinical immunotherapy trials reported to date and whether, in light of the current information, immunotherapy for MM is an achievable goal. PMID 16042684

Immunoselection of functional CMRF-56+ blood dendritic cells from multiple myeloma patients for immunotherapy.
Juli 2005 | Radford, Kristen J; Turtle, Cameron J; Kassianos, Andrew J; Vuckovic, Slavica; Gardiner, Damien; Khalil, Dahlia; Taylor, Kerry; Wright, Sue; Gill, Devinder; Hart, Derek N J
Dendritic cells (DCs) loaded with tumor-associated antigens are a promising treatment to prevent disease relapse in patients with multiple myeloma (MM). Early-phase clinical trials have shown safety, efficacy, and immunologic responses in MM, but a key issue now is the isolation of a functional, clinically relevant DC preparation. The authors have described a unique blood DC (BDC) isolation platform based on positive immunoselection with the CMRF-56 antibody. To validate this as a feasible source of BDCs for immunotherapy, the authors undertook a quantitative and functional analysis of BDCs in MM patients and healthy donors. These data show that MM patients have similar numbers of CD11c+CD16+ and CD11c+CD16- BDCs but about half the number of CD11c-CD123+ BDCs in whole blood compared with healthy donors. BDCs could be isolated by CMRF-56+ immunoselection from all MM patients tested, with similar yields and purity to healthy donors. These BDCs could be activated ex vivo with poly I:C or LPS. Furthermore, CMRF-56+ preparations could induce potent CD4+ and CD8+ T-lymphocyte responses in both MM patients and healthy donors. These data suggest that BDCs with in vitro functional integrity can be isolated from MM patients in sufficient numbers to justify a clinical trial. PMID 16000950

Therapeutic vaccination against murine lymphoma by intratumoral injection of naive dendritic cells.
Juli 2005 | Song, Wenru; Levy, Ronald
Dendritic cells are potent antigen-presenting cells that can induce both immune responses and tolerance depending on their state of activation. Immunologic tolerance to established tumors is a major impediment for the development of effective cancer immunotherapy. Dendritic cells may be deficient in number or in function at the tumor site. To address this problem, we evaluated the ability of immature naïve dendritic cells to induce an antitumor immune response when injected directly into a murine B-cell lymphoma. Mice with advanced transplanted syngeneic tumor were given intratumoral injections of bone marrow-derived dendritic cells. Intratumoral dendritic cell injection alone had no antitumor effect. Systemic chemotherapy alone resulted in only transient tumor regression. However, the intratumoral injection of dendritic cells after chemotherapy led to complete, long-term tumor regression in the majority of treated mice. This dendritic cell-mediated antitumor effect was systemic, resulting in simultaneous elimination of the tumor at second uninjected sites. In addition, it resulted in long-term memory with resistance to tumor rechallenge. Both CD4+ and CD8+ T cells are necessary for the antitumor effect. Furthermore, tumors that occasionally recurred in mice with initial complete tumor regression could be retreated by the same combined chemoimmunotherapy approach. These results show that immunotherapy can succeed in the setting of advanced lymphoma if dendritic cells are restored and loaded with tumor antigens in situ at a single tumor site. PMID 15994975

Vaccine therapy for non-Hodgkin's lymphoma and other B-cell malignancies.
Juli 2005 | Leitch, Heather A; Connors, Joseph M
Immunity against tumor antigens, including the passive transfer of humoral (antibody-based) immunity or cellular immunity in the form of cytotoxic T-lymphocyte clones, has been exploited for the treatment of non-Hodgkin's lymphoma and other B-cell malignancies in recent years. In many strategies, the idiotype expressed on B-cell malignancies is the antigen used to induce active immunity. Early studies using purified idiotype, immune adjuvant and cytokines to induce anti-idiotype immunity have demonstrated that these methods are safe and potentially effective, and they are now being tested in prospective, randomized clinical trials. Methods for improvement include recombinant sources of idiotype, DNA vectors, enhancement of antigen delivery and presentation by using dendritic cells, boosting immune help through the use of cytokine delivery or foreign antigens, and blocking negative regulators. The goal of this approach is to induce lasting and individualized immunity against B-cell malignancies that is readily available and cost-effective. PMID 15988911

The role of idiotype vaccines in the treatment of human B-cell malignancies.
Apr. 2004 | Bendandi, Maurizio
Twelve years after the first formal demonstration that it is possible to vaccinate a cancer patient against an antigen derived from his/her own tumor, idiotype vaccines are now well into Phase III clinical trials for the treatment of follicular lymphoma. Meanwhile, their potential has also begun to be explored in other non-Hodgkin's lymphoma settings, such as that of mantle cell lymphoma. Another well known field of potential application for idiotype vaccines is that of multiple myeloma. However, the currently available results, even with the advent of dendritic cells, seem to be less promising than those obtained in lymphoma, to such an extent that idiotype vaccines are currently tested in multiple myeloma patients in the context of more aggressive therapeutic strategies. PMID 15056042

Dendritic cell-based immunotherapy in multiple myeloma.
Feb. 2004 | Yi, Qing
Most patients with multiple myeloma (MM) cannot be cured with currently available therapies. Although complete remission could be achieved in about 50% of newly diagnosed patients with high-dose chemotherapy and tandem transplantation, relapses of the underlying disease occur frequently. To realize long-term disease-free survival, it will be necessary to develop complementary therapies that are non-cross-resistant with chemotherapy. To this end, immunotherapy aimed at inducing or enhancing tumor-specific immunity that may control or eradicate remaining tumor cells may be an appealing method. Dendritic cells (DCs) are professional antigen-presenting cells and considered the best natural adjuvants for immunotherapy in malignancies. Vaccination with tumor antigen-pulsed DCs has been shown to be protective and therapeutic in animal tumor models, and induced a strong tumor-specific immunity and durable tumor regression in human solid tumors and B-cell lymphoma. As a result, clinical trials in various human malignancies have been initiated. This review will focus on DC-based immunotherapy in MM. I will discuss myeloma antigens and antigen-specific immune responses, the capacity of DCs to present myeloma antigens and induce cytotoxic T-cell responses, and clinical experience of DC vaccination in myeloma patients. PMID 14959845

Immunotherapy for lymphomas.
Juli 2003 | Timmerman, John M
A growing list of immunotherapeutic strategies is now being employed to combat lymphoid malignancies. These efforts are warranted given that B-cell lymphomas, particularly those of the common follicular subtype, are among the most "immune-responsive" of all human cancers. Although systemic cytokine therapies for B-cell malignancies have been largely disappointing to date, monoclonal antibody therapies, principally the anti-CD20 antibody rituximab, have already made enormous impact on the treatment algorithm for many B-cell lymphomas. Therapeutic vaccines targeting the tumor-specific immunoglobulin idiotype have demonstrated promising results against lymphomas in phase I/II studies and are currently being evaluated in phase III randomized trials. Additional vaccine therapies being developed include those based on dendritic cells, recombinant idiotype proteins, DNA, heat shock proteins, and gene-modified tumor cells. It is hoped that immunotherapeutic agents, used in tandem or in combination, may someday allow effective treatment of lymphoid malignancies and delay or even replace the need for conventional cytotoxic therapies. PMID 12841382

Enhancement of hyperthermia-induced apoptosis by local anesthetics on human histiocytic lymphoma U937 cells.
Mai 2002 | Arai, Yoko; Kondo, Takashi; Tanabe, Kiyoshi; Zhao, Qing-Li; Li, Fu-Jun; Ogawa, Ryohei; Li, Min; Kasuya, Minoru
The combined effects of hyperthermia at 44 degrees C and local anesthetics on apoptosis in human histiocytic lymphoma U937 cells were investigated. When the cells were exposed to hyperthermia for l0 min marginal DNA fragmentation and nuclear fragmentation were observed. In the presence of amide-type local anesthetics further enhancement was found depending on concentration. The order of the concentration required for maximum induction was the reverse order of the lipophilicity (prilocaine > lidocaine > bupivacaine). Western blotting revealed that in hyperthermia there was initial release of Ca(2+) from the intracellular store site as indicated by increased expression of the type 1 inositol-1,4,5-trisphosphate receptor. However, the combination with lidocaine did not induce any further enhancement. Lidocaine enhanced the decrease in ATP content and the increase in intracellular Ca(2+) concentration in individual cells induced by hyperthermia. In addition, superoxide formation, decrease in the mitochondrial membrane potential, and activation of intracellular caspase-3 were found in the cells treated with hyperthermia and lidocaine. All of these were suppressed in part in the presence of the intracellular Ca(2+) ion chelator BAPTA-AM (bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl). The present results indicate that local anesthetics at optimal concentrations enhance hyperthermia-induced apoptosis via Ca(2+)- and mitochondria-dependent pathways. Initial release of Ca(2+) from intracellular store sites caused by hyperthermia and followed by the subsequent increase in the intracellular Ca(2+) concentration and the additional activation of the mitochondrial caspase-dependent pathway (partly regulated by intracellular Ca(2+) concentration) plays a crucial role in the enhancement of apoptosis induced by the combination of hyperthermia and lidocaine. PMID 11861640

Anti-idiotypic vaccination in the treatment of low-grade B-cell lymphoma.
Apr. 2002 | Barrios, Yvelise; Cabrera, Rafael; Yáñez, Rosa; Briz, Montserrat; Plaza, Aresio; Forés, Rafael; Fernández, Manuel-Nicolás; Díaz-Espada, Fernando
Patients with B-cell lymphoma can be induced to mount a specific immune response against the individual idiotypic determinants expressed in their tumor cells. This form of active immunotherapy is now under evaluation in the clinical setting. We evaluated the feasibility and effectiveness of this kind of immunotherapy in a group of patients with low-grade lymphoma, which included two cases of bi/triclonal lymphoma. PMID 11940484

Effect of hyperthermia on AKR lymphoma variants differing in degree of malignancy.
Dez. 2001 | Sharabi, Y; Klorin, G; Leibovici, J
The effect of hyperthermic treatment on AKR lymphoma cells of varying malignancy was investigated. Tumor cells were pretreated at 37 or 43 degrees C and then injected to mice. The effect on the highly malignant variant, TAU-38, was compared to that on the low-malignancy variant, TAU-39, following both subcutaneous (s.c.) and intravenous (i.v.) inoculation. Hyperthermia showed no effect on the TAU-39 variant following s.c. inoculation on the primary tumors or mice survival, but the TAU-38 variant exhibited a significant delay of tumor appearance following treatment, namely, decreased tumor size and increased life span. Following i.v. inoculation, in both variants, hyperthermia caused a significant decrease in metastatic spread and an increased life span. We conclude that hyperthermia, in addition to exerting a greater effect on the high-malignancy variant, acts at the late phases of metastasis. Hyperthermia might therefore have a place in the management of cancer in its advanced disseminated phase. PMID 11768032

Tumour cell kinetics as predictors of response in canine lymphoma treated with chemotherapy alone or combined with whole body hyperthermia.
Jan. 2000 | Larue, S M; Fox, M H; Ogilvie, G K; Page, R L; Getzy, D M; Thrall, D E; Johnson, J L; Dewhirst, M W; Gillette, E L
Kinetic parameters including potential doubling time (Tpot), duration of S phase (Ts), labelling index (LI), and DNA index (DI) were obtained from 42 dogs with previously untreated lymphoma. Standard flow cytometric techniques using BrdUrd were employed. All dogs were treated with L-asparaginase and remission was induced in 26 dogs, which were then randomized to receive chemotherapy only (doxorubicin [DOX] alone or with lonidamine) or chemotherapy plus whole body hyperthermia (WBH). Dogs were treated every 3 weeks for up to five treatments and evaluated every 3 weeks for evidence of tumour recurrence. Within this subset of animals there was no difference in outcome based on treatment group. Median values for Tpot, Ts and LI were 3.4 days, 7.23 h and 12.49%, respectively. Dogs that had tumours with LI > or = 20% had a shorter time until recurrence than dogs with tumours characterized by LI < 20%. In dogs treated only with chemotherapy, dogs bearing tumours with longer than median Tpot and Ts values and lower than median LI had significantly longer remission duration than dogs with more rapidly proliferating tumours. Dogs treated only with chemotherapy, which had longer than median Tpot and Ts values and lower than median LI, had significantly longer remission duration than all other dogs in the study. The mechanisms in which kinetics are associated with response to chemotherapy are not clear and vary depending on tumour type and treatment regimen. More work is needed to understand factors involved in cell killing during in vivo hyperthermia. PMID 10598945