Epitopes associated with major histocompatibility complex (MHC) restriction site of T cells IV. I‐J epitopes on MHC‐restricted cloned T cells

摘要

AbstractWe studied the expression of an I‐Jkepitope on class II‐restricted cloned L3T4+T cells established from H‐2k, H‐2b, F1and semiallogeneic radiation bone marrow chimeras by the inhibition of antigen‐induced T cell proliferation andin vitrosecondary antibody response, and by the direct immunofluorescence with a monoclonal anti‐I‐Jk. Both I‐Ak‐ and I‐Ek‐restricted T cells were shown to carry the identical I‐Jkepitope regardless of their genotypic origins, antigen specificity, and helper or suppressor function. None of the I‐Ab‐restricted clones derived from similar animals showed the I‐Jkepitope. This isomorphism, regardless of the restriction specificity for I‐Akor I‐Ek, contradicts the idea that I‐J is an idiotypic determinant on class II‐restricted T cell antigen receptor (TcR). In fact, the I‐Jkepitope was not comodulated with TcR/T3 complex when incubated with an anti‐T3 antibody, indicating that I‐J is a new isomorphic receptor f