COMPARATIVE INVESTIGATION OF THE CROSS-RE ACTIVITY OF T-LYMPHOCYTES WITH CYTOTOXIC AND SUPPRESSIVE ACTIVITIES SPECIFIC OF THE EPITOPES OF MEMBRANIC HISTOCOMPATIBILITY CLASS-II MOLECULES

C57Bl/6(B6) mice were immunized by intravenous (i.v.) or intra foot pa d (f.p.) injection of 2000 rad-irradiated B6.C-H-2bm12 (bm12) mouse sp lenocytes. Immune lymphocytes of the recipients were tested simultaneo usly for the specific cytotoxic and suppressive activities of T-lympho cytes on the fourth day after immunization. To answer the question whe ther T-suppressors (Ts), in contrast to cytotoxic T-lymphocytes (CTL), can recognize antigenic (AG) determinants, similar to serological one s, the cells of mouse strains with different haplotypes were used as t argets and stimulators. The mouse cells both expressing and not expres sing the mutant sequence, corresponding to 67-71 aminoacids (AA) of A( beta)bm12 chain in the context with their own MHC class II molecules, i.e. in an altered (in comparison with I-A(bm12) molecules) context an d donor strain cells were also used. No principal differences have bee n found between the patterns of recognition for CTL and Ts. No correla tion have been observed between the presence of the sequence correspon ding to 67-71 AA of A(beta)bm12 chain in the context with MHC class II molecules, expressed on the stimulator surface membrane, and the abil ity of the immune B6 anti-bm12 Ts population to recognize the stimulat ors. The results obtained do not give any reasons to suppose that Ts A G-specific reseptors (TCR) and CTL show different pattern of recogniti on.