Epitopes associated with major histocompatibility complex (MHC) restriction site of T cells. IV. I-J epitopes on MHC-restricted cloned T cells.
We studied the expression of an I-Jk epitope on class II-restricted cloned L3T4+ T cells established from H-2k, H-2b, F1 and semiallogeneic radiation bone marrow chimeras by the inhibition of antigen-induced T cell proliferation and in vitro secondary 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-Jk epitope 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-Jk epitope. This isomorphism, regardless of the restriction specificity for I-Ak or 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-Jk epitope was not comodulated with TcR/T3 complex when incubated with an anti-T3 antibody, indicating that I-J is a new isomorphic receptor for self different from TcR alpha/beta heterodimers.
Nakayama
T
T
Department of Immunology, Faculty of Medicine, University of Tokyo, Japan.
Kubo
R T
RT
Kubo
M
M
Fujisawa
I
I
Kishimoto
H
H
Asano
Y
Y
Tada
T
T
Asao
Y
Y
D000818:Animals; D000939:Epitopes / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology; D008819:Mice, Nude / Q000276:immunology; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D000949:Histocompatibility Antigens Class II