Antitumor enhancement by adoptive transfer of tumor antigen primed, inactivated MHC-haploidentical lymphocytes

• Haploidentical lymphocytes could induce tumor specific CTL against recipient tumor by MHC identical molecules.
• Haploidentical lymphocyte mismatched molecules can play a role of adjuvant.
• Inactivated haploidentical CTL can be accumulated to the tumor tissue to take effect.
• Host innate, adoptive and memory immune responses to tumor could be induced by transfer of inactivated haploidentical CTL.

The present study investigated the antitumor effects by adoptive transfer of tumor antigen primed, inactivated MHC-haploidentical lymphocytes in TC-1 lung cancer mouse model. Our studies revealed that the inactivated MHC-haploidentical effecter cells display the antitumor activity in vitro and target the tumor in vivo. After adoptive transferring these effecter cells, the Th1 cytokines such as IL-2 and IFN-γ are elevated in the serum; the recipient tumor-specific cytotoxic T-cells and natural killer cells are activated; tumor specific memory T cells are induced; tumor growth is inhibited and mouse survival is prolonged. The results indicate that MHC-haploidentical lymphocytes provide both effecter cells which can target the tumor cells through the identical MHC molecules and an adjuvant effects through the unmatched allogeneic MHC molecules which induces endogenous innate and adaptive antitumor immune responses.