Abstract: Objective To evaluate the therapeutic effect of MHSP65-TCL on melanoma and its effect on the activity of the
immunocytes. Methods MHSP65-TCL was prepared by mixing MHSP65 with TCL derived from B16 melanoma cell lysate by
repeated freezing and thawing. The MHSP65-TCL vaccine was administered in mice bearing B16 melanoma, and the changes
in melanoma growth was observed. To investigate the influence of TCL in MHSP65-TCL on the activity of the immunocytes,
we co-cultured TCL and mouse spleen cells in vitro, and analyzed CD69 expression on the cells, cell apoptosis, and levels of
IL-10 and IFN-γ in the cell culture supernatant. Results The MHSP65-TCL vaccine showed an anti-melanoma effect in the
tumor-bearing mice. In the in vitro experiment, TCL in MHSP65-TCL strongly stimulated the activation of mouse spleen cells
while causing apoptosis in some of the immunocytes and promoting cellular IL-10 secretion, but not IFN-γ. Conclusions
MHSP65-TCL derived from B16 melanoma cells has an anti-melanoma effect mediated by the activation of immunocytes. TCL
in MHSP65-TCL also has immunosuppressive effect on immunocytes possibly due to the presence of suppressive components
in TCL, and identifying and eliminating these components may potentially improve the anti-tumor actovoty of MSHP65-TCL
vaccine.