title: Identification of functional T cell subsets and surface antigen changes during activation as they relate to RT6.
abstract: The functional and phenotypic heterogeneity of the rat peripheral T lymphocyte antigen RT6 has been examined. The in vivo popliteal graft-vs-host reaction (GvHR), in vitro MLR, and the generation and effector populations of cytotoxic T lymphocyte were used to examine the response of RT6-positive (RT6+) or -negative (RT6-) subsets of CD4 and CD8 T cells to alloantigen. T lymphocytes with the CD4+RT6+ surface phenotype are necessary and sufficient for inducing a strong GvHR. T lymphocytes with the CD4+RT6-, CD8+RT6+, and CD8+RT6- surface phenotypes do not contribute or induce a strong GvHR. Both the CD4+RT6+ and the CD4+RT6- T cells proliferate in the MLR assay. CTL precursors are a mixture of CD8+RT6+ and CD8+RT6- phenotypes, but only cells bearing the RT6- phenotype are potent CTL effector cells. Data presented in this paper also demonstrate that the RT6.1 alloantigen, present on the majority of rat T cells, modulates on cortisone-resistant thymocytes (CRT) and peripheral T cells. Although freshly isolated CRTs do not express the RT6.1 epitope, RT6+ cells develop when CRTs are placed into culture. Peripheral T cells that are RT6- will also become RT6+ in culture. Stimulation of T cell cultures with a mitogen causes the loss of the RT6.1 antigen, as detected by the DS4.23 mAb. The effect is more pronounced in cultures of CRTs than peripheral T cells. Following a return to a nonactivated state, the T cells reexpress RT6. The loss and reexpression of RT6 may be related to activation and/or differentiation of T cells.
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City.
authors.forename: H D
authors.initials: HD
authors.lastname: Hunt
authors.forename: D M
authors.initials: DM
authors.lastname: Lubaroff
mesh_terms: D036002:ADP Ribose Transferases; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis*; D002469:Cell Separation; D003348:Cortisone / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D006649:Histocompatibility Antigens / Q000032:analysis*; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008562:Membrane Glycoproteins; D051381:Rats; D011919:Rats, Inbred Strains; D016176:T-Lymphocyte Subsets / Q000502:physiology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006649:Histocompatibility Antigens; D007519:Isoantigens; D008562:Membrane Glycoproteins; D036002:ADP Ribose Transferases; C090163:Art2b protein, rat; D003348:Cortisone