In Vitro Generation of Cytolytic T Cells Against Human Melanoma Cells Overexpressing HDM2

Abstract

Background: Previous experiments have shown that tumour-associated antigens can be exploited for a successful anti-tumour immunisation. Previous reports demonstrated that oncoprotein MDM2 (HDM2) contains two highly conserved MHC class I binding motifs, MDM2₁₀₀ and MDM2₄₄₁, and that dendritic cells (DC) presenting MDM2₁₀₀ stimulate an effective CTL reaction against melanoma cells. Materials and Methods: In this study, we investigated the CTL-inducing capacity of autologous human dendritic cells pulsed with fragment HDM2₄₄₁. Results: In vitro HDM2₄₄₁-primed T lymphocytes revealed a strong proliferation activity, released Th-1-associated cytokines, and possessed an effective anti-tumour activity causing apoptosis in HDM2₄₄₁-overexpressing melanoma cells. Cytotoxic assay demonstrated that, in parallel to melanoma cells, up to 65% of primed T cells also underwent apoptosis. Conclusion: These data suggest that HDM2₄₄₁ may be exploited for broad-spectrum DC-based trials against metastatic melanomas overexpressing HDM2, and point out that the efficacy of such immunotherapeutical approaches may be limited via T cell apoptosis.