Manifestation of allo H-2-restriction specificity by self H-2-restricted T cells.

Previous study has demonstrated that a considerable number of antigen-specific, allo H-2-restricted CTLPs could be recovered from normal lymphocytes. Experiments were conducted to examine whether antigen-specific, self H-2-restricted T cells could also manifest allo H-2-restriction specificity. Non-H-2-specific, self H-2-restricted CTLs were induced in the microcultures with a limited number of responder spleen cells from B10(H-2b) mice that had been primed with C3H.SW(H-2b) spleen cells. Two hundred thirteen non-H-2-specific CTLs generated in limiting dilution culture condition were assayed for cross-reactivity against TNP-modified and unmodified allogeneic targets of 10 different H-2 haplotypes. Of these CTLs, 29 (14%) were cross-reactive to a TNP-modified allogeneic target and seventeen (8%) to an unmodified allogeneic target. The quantitative analysis for cross-reactivity of non-H-2 specific, self H-2-restricted CTLs reveals a significant number of CTLs that were cross-reactive with either alloantigen or antigen (TNP) plus allo H-2. Furthermore, CTL clones with triple specificities including self H-2-restriction specificity, allo-reactivity, and allo H-2 restriction specificity were also found. These results indicate that antigen-specific, allo H-2-restricted T cells are distinct not only from alloreactive T cells but also from antigen-specific, self H-2-restricted T cells. Significance of the manifestation of allo H-2 restriction specificity by self H-2-restricted T cells is discussed in regard to the generation of T cell repertoire.