| Abstract: | A new model for the generation of specific antitumor cytotoxic T-lymphocytes (CTL) was proposed. In contrast to other models, it allows to generate effector CTL without immunization in vitro. C57BL/10 mice or/and C57BL/6 mice were immunized by injection with gamma-irradiated syngeneic tumor cells into the footpads. For estimation of cytotoxic activity, chromium-51 release assay was used. It has been shown that effector CTL were absent in the lymph nodes in 1-fold as well as 2-fold immunization. Cytotoxic cells have not been found in 1-fold immunization even after maturation of the lymphocytes in monoculture. Specific CTL were detected only after secondary immunization and subsequent cultivation in vitro. Effector cells had Thy1.2+, Lyt2+, L3T4- phenotypes. Presence in vitro of exogenous IL-2 was needed for the generation of CTL against MX-11 sarcoma but not against EL4 lymphoma. We suggest that the release of IL-2 from lymphomas cells could stimulate generation of the effector cells through activation of the endogenous production of IL-2, or due to some other factors. |
