In an attempt to induce an immune response against tumour antigens, several groups are transfecting cytokine and other genes into autologous tumour cells which are given to the patient as a vaccine. This process is labour-intensive, time-consuming and expensive. Allogeneic cells would offer a more convenient vehicle for the delivery of cytokines and other molecules. However, current dogma suggests that MHC-matched cells are a prerequisite for an effective immune response. Using murine melanoma models we compared allogeneic and autologous vaccination and showed that the survival of C56BL/6 mice (H-2b) was prolonged with some degree of protection achieved against an autologous B15-F10 (H-2b) cell challenge when the mice were vaccinated with allogeneic K1735-M2 (H-2k) cells but not when immunized with autologous B16-F10 cells. Both vaccination with live and irradiated allogeneic cells induced an anti-tumour effect using only one immunization and no boost or adjuvant. Protection was not observed after vaccination with another melanoma (S91; H-2d) or with a carcinoma (A9HT; H-2k). Allogeneic vaccination promoted a cytotoxic cellular response against both the allogeneic and the syngeneic melanomas. This allogeneic vaccination model will be useful for studying the underlying mechanisms of protection, in both pre- and post-challenge settings, as well as for developing whole cell vaccination systems using genetically modified allogeneic tumour cells.
Animals Cancer Vaccines