I-J epitopes are adaptively acquired by T cells differentiated in the chimaeric condition.
I-J has been defined as a locus mapped in the murine major histocompatibility complex (MHC) which encodes serological markers found primarily on the surface of suppressor T cells (TS) and soluble suppressor factors (TSF). Recent studies have, however, revealed that there is no such specialized locus within the MHC at the DNA level. As the existence of I-J determinants at the protein level on functional T cells, T-cell clones and hybridomas has been confirmed by several serological and biochemical studies, this contradiction has raised serious arguments in the immunological community concerning the nature, origin and expression of I-J determinants. We have raised a number of monoclonal antibodies against the polymorphic structure of I-J molecules, and have studied the expression of I-J epitopes on T cells derived from irradiated bone marrow chimaeras in which stem cells of different genotype differentiated into T cells under the foreign host MHC environment. The results, presented here, indicate that I-J epitopes are not primarily determined by the MHC genes of the stem cells themselves, but are adaptively acquired by T cells differentiated in the chimaeric condition according to the environmental MHC phenotype. Thus, the serologically detectable I-J epitopes are found to be associated with inducible T-cell receptors recognizing self class II MHC antigens.
Uracz
W
W
Asano
Y
Y
Abe
R
R
Tada
T
T
D000818:Animals; D002454:Cell Differentiation; D002678:Chimera; D002874:Chromosome Mapping; D000939:Epitopes / Q000235:genetics*; D006183:H-2 Antigens / Q000235:genetics; D007959:Lymphocyte Culture Test, Mixed; D008285:Major Histocompatibility Complex; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D000939:Epitopes; D006183:H-2 Antigens