HELPER ACTIVITY OF CHICKEN V-BETA-1-BETA-2+ ALPHA-BETA T-CELLS FOR IN-VITRO IGA ANTIBODY-SYNTHESIS( AND V)

Chickens have only two T cell receptor variable beta gene families: V beta 1 and V beta 2 (1). In our previous work we found that IgA produc tion was almost completely suppressed in chickens depleted of V beta 1 (+) alpha beta T cells by treatment with a TCR V beta 1-specific monoc lonal antibody (2), while IgM and IgG production was not affected. Our present results indicate that, in vitro, both V beta 1(+) and V beta 2(+) chicken cecal tonsil T cells provide help for the differentiation of cecal tonsil IgA B cells, suggesting that the failure of V beta 1( +) T cell-depleted chickens to produce IgA is not caused by the inabil ity of V beta 2(+) T cells to provide help for IgA production by B cel ls, but rather by the scarcity of these T cells in mucosal tissues (3) , where most IgA responses are induced (4).