Anti-tumour activity of heat-shock protein 60-recognizing CD4⁺ T cells against syngeneic murine renal cell carcinoma

OBJECTIVES: To determine whether heat-shock protein (HSP) 60-recognizing CD4⁺ T cells show antitumour activity against renal carcinoma (RENCA) cells, as HSP is highly expressed by tumour cells and induced in cells by various stresses, including transformation. MATERIALS AND METHODS: RENCA, a renal cortical adenocarcinoma cell line of BALB/c origin, was used. Expression of major histocompatibility complex (MHC) class I, class II and HSP-60 on RENCA tumour cells was analysed by flow cytometry. BASL1.1, an autoreactive T-helper type 1 type CD4⁺ T cell clone established by us, and that recognises HSP-60, was also used for a tumour-neutralising assay. RESULTS: The RENCA cells were negative for MHC class II, but expressed intracellular HSP-60. In the tumour-neutralising assay, BASL1.1 cells significantly suppressed the in vivo growth of RENCA cells. Three of five mice rejected RENCA cells when co-inoculated with BASL1.1 cells. CONCLUSIONS: These results indicate that HSP-60-recognizing CD4⁺ T cells have the potential to eliminate renal cell carcinoma in vivo and that the eliciting of an anti-self T cell response at the tumour site can lead to regression of renal cancer.