the effect of injection of heat shocked tumor cell lysate on splenocytes proliferation and nitric oxide production in balb/c mice with fibrosarcoma tumor

introduction: the aim of this study was to investigate the effect of the hsp-70 (heat shock protein-70) induction in the lysate of heat shocked tumor cells on splenocyte proliferation, nitric oxide production by peritoneal macrophages, and fibrosarcoma tumor size reduction in balb/c mice. material and methods: wehi 164 cells (mouse fibrosarcoma cell line) were injected subcutaneously into the right flank of syngeneic balb/c mice to establish a tumor model. then the lysate of heat shocked (42°c, 1 h) and non heat shocked wehi 164 cells, were prepared by 5 times freezing and thawing. then we immunized test group mice with lysate of heat shocked tumor cell (at days 0, 7 and14). in the control groups we injected the lysate of cells without heat shock and pbs. in this study we detected hsp-70 expression by immunoblot. tumor volume was measured every 5 day. we detected the proliferation of mouse spelenocyte by using mtt test. we also detected the nitric oxide (no) production by mouse splenocytes and normal macrophages. results: in this study we detected increases in hsp-70 expression in the lysate of heat shocked cell in comparison with non heat shocked cells, by immunoblot. tumor volume was significantly decreased and the proliferation of splenocytes increased in test group. we also observed that immunizing with heat shocked tumor cell lysate resulted in a significantly increased no production. conclusion: these results indicated that the lysate of heat shocked tumor cell is more potent than non heat shocked tumor cell in inducing anti tumor immunity. the dual roles of hsps as molecular vehicles for antigen cross-priming and as activation signals for the innate immune system cell, make them particularly useful for tumor immunotherapy. these findings provide a useful therapeutic model for development of novel approaches to cancer treatment.