A cloned, antigen-specific, Ia-restricted Lyt-1+,2- T cell with suppressive activity

The correlation between cell surface antigen phenotype and function is one of the cornerstones of modern cellular and clinical immunology. It is based on the collective experience of many investigators examining populations of T cells. The availability of cloned lines of T cells now allows us to ask whether all cells sharing cell surface antigen phenotype are functionally equivalent. We have examined a large number of antigen-specific, self-Ia recognizing, cloned Lyt-1+,2- T cell lines for their ability to help B cells proliferate and secrete antibody in response to antigen. All of these lines induced antigen-specific, Ia-restricted B cell proliferation. One line did not induce antibody secretion. This line, indeed suppressed the plaque-forming cell response of B cells helped by any of the other cloned T cell lines tested. Suppression in this system had all the characteristics of classical T cell help, apart from the ultimate outcome. That is, the suppressor cell acted upon the B cell in a manner that was antigen-specific, Ia-restricted, and required hapten-carrier linkage. We interpret our results as supporting the basic paradigm of an association of cell surface antigen phenotype with function, with an important proviso. Not all Ly1, Ia-restricted T cells may be capable of helper function, and some in fact may be suppressive. Experimental conditions favoring the generation of such cells, or disease states in which such cells reside within the Ly1 or T4+ subset, may give rise to disparities between phenotype and function similar to that observed here at the clonal level.(ABSTRACT TRUNCATED AT 250 WORDS)