A preclinical model to assess the antigenicity of an HLA‐A2 melanoma cell vaccine

Background. The authors have demonstrated that immunization with melanoma whole‐cell vaccine (MCV) augments T‐cell responses to melanoma and that cytotoxic T‐cells (CTL) recognize allogeneic melanoma‐bearing shared HLA‐A antigens. A preclinical model was developed to assess CTL activation in vitro using melanoma lines as stimulators. HLA‐A2 expression is predominant in melanoma patients and plays a role in HLA class I restricted CTL killing of melanomas. The authors hypothesized that a MCV consisting of allogeneic HLA‐A2 melanomas may be as good as autologous melanoma MCV for HLA‐A2 patients. Methods. CTL were generated from peripheral blood lymphocytes of patients with HLA‐A2 melanoma by stimulation with autologous melanoma, allogeneic melanoma (HLA‐A2 or non‐HLA‐A2), or allogeneic MCV (mixed HLA‐A2 and non‐HLA‐A2 melanomas). Results. HLA‐A2 MCV and autologous melanoma were similar and significantly better stimulators than the others. Specificity also was supported by CTL killing and mixed lymphocyte tumor reaction assays. Conclusions. These studies provide important information for the studying immunization of patients with HLA‐A2 melanoma with an allogeneic HLA‐A2 MCV in a Phase I clinical trial.