带瘤小鼠IL—2R表达减少机理的初步研究

Preliminary Study on Mechanisms of Diminished Interleukin-2 Receptor Expression in Tumor-bearing Mouse

The present study was performed to elucidate the relationship between the H22 hepatoma growth and the decreased ability of mouse spleen cells to secrete Interleukin-2 (IL-2) and to express IL-2 receptor(IL-2R).The results showed that the spleen cells from tumor-bearing mouse(TBM) produce less IL-2 than those of their normal counterparts. However, addition of exogenous IL-2 only partially improved the impaired concanavalin A(ConA) responsiveness of lymphocytes of the TBM. The absorption investigation indicated that the ConA-activated spleen cells from the TBM were less receptive to IL-2,which suggested the defect of IL--2R expression. We therefore analyzed the percentage of IL-2R positive cells. The results demonstrated that the number of lymphocytes induced to express IL-2R decreases with increasing tumor burden. The further study indicated that the prostaglandine ( immunosuppressive factors secreted by H22 hepatoma cells and the suppressor T lymphocytes inhibite the lymphocytes to express IL-2R in TBM. Our data suggested that the reduced ability to secret IL-2 and to express IL-2R may be one of the reasons for the impaired cell-mediated immune response in tumor bearing host.