Immune responses in patients with esophageal cancer treated with SART1 peptide-pulsed dendritic cell vaccine
ABSTRACT
Patients with advanced stage of squamous cell carcinoma of esophagus have a poor prognosis with a lethal outcome. In order to explore the feasibility and effectiveness of dendritic cell (DC)-based immunotherapy for squamous cell carcinoma of esophagus, we performed a phase I/II clinical trial of monocyte-derived dendritic cells (moDCs) pulsed with SART1 peptide in seven patients with advanced stage of this disease. Although the feasibility of this therapy was definite, the effectiveness was not clearly confirmed in advanced stage of squamous cell carcinoma of esophagus. However, in vitro study revealed that moDCs generated for this therapy possessed a potent ability of inducing SART1 peptide-specific cytotoxic T lymphocytes (CTLs). In addition, these moDCs were demonstrated to be able to produce exosomes with an antigen presenting ability for inducing SART1 peptide-specific CTLs. ELISPOT assay using cryopreserved patient’s lymphocytes demonstrated that IFN-γ ELISPOTs were increased after four times of SART1 peptide-pulsed moDC vaccinations compared with before the vaccination in a patient. The present study demonstrated that moDCs prepared from advanced stage of squamous cell carcinoma of esophagus possess a good immune function and in vivo immune responses (detected by ELISPOT assay) were evoked by the infusion of these moDCs. These findings suggest that DC-based immunotherapy could be one of the modalities applicable for squamous cell carcinoma of esophagus.