The investigation of murine lymphocyte subsets interaction by limiting dilution analysis

Proliferative response of murine splenocytes to alloantigen was analyzed by limiting dilution analysis (LDA). S-shaped nonlinear dependencies received were interpreted as a result of interaction between two subpopulations. Using membrane antigens it was demonstrated that cells proliferating in LDA conditions have Thy1, 2⁺, L3T4⁺ and IgG^-, Lyt2^- phenotype specific for T helper cells (Th). It was suggested that Th1 and Th2 interaction is responsible for the formation of LDA-curve. This hypothesis was verified in experiments with activators of adenylate cyclase forskolin (FS) and cholera toxin (CT) which suppress productive and proliferative functions of Th1 but not Th2. Both FS and CT inhibited the proliferation of second effectors which, as a consequence, seem to be Th1. The comparative study of Th proliferation in humoral and cellular response supported this hypothesis too. Humoral response to ovalbumin requiring Th2 help correlated with the proliferation of first effectors which must be Th2. And the response to tumor antigen requiring Th1 help correlated with the proliferation of second effectors, Th1, as it was shown in previous experiment. We concluded that nonlinear LDA can be used to study the mechanism of interaction of Th1 and Th2 in this test-system.