title: Activation-induced expression of thymic shared antigen-1 on T lymphocytes and its inhibitory role for TCR-mediated IL-2 production.
abstract: We have produced a hamster mAb, PRST1, which reacts with thymic shared Ag-1 (TSA-1), a product of the Ly6 gene family. By cross-blocking experiments, we found that TSA-1 is identical to stem cell Ag-2 (Sca-2). Using PRST1, the changes of TSA-1/Sca-2 expression on mature T cells during the activation process were analyzed. Although freshly isolated T cells did not express detectable TSA-1 on their cell surface, in vitro stimulation of T cells with concanavalin A induced a marked increase of surface TSA-1 expression. The increased expression of TSA-1 on T cells was detected from 12 h after stimulation and was associated with the increase of TSA-1 mRNA. In vivo injection of mice with staphylococcal enterotoxin B (SEB) resulted in the enhanced TSA-1 expression in splenic V beta 8+ T cells. This antigen-specific induction of TSA-1 expression in vivo preceded a detectable increase in numbers of V beta 8- T cells after SEB injection. Functionally, whereas anti-TSA-1 mAb was not mitogenic to T cells, it inhibited anti-CD3-induced IL-2 production by T cell hybridomas. These results indicate that TSA-1/Sca-2 is a unique marker for T cell activation and a signal through this molecule may have a negative feedback role to limit IL-2 production from activated T cells stimulated through the TCR.
authors.affiliation: Precursory Research for Embryonic Science and Technology (PRESTO), Research Development Corporation of Japan (JRDC), Osaka.
authors.forename: A
authors.initials: A
authors.lastname: Kosugi
authors.forename: S
authors.initials: S
authors.lastname: Saitoh
authors.forename: S
authors.initials: S
authors.lastname: Narumiya
authors.forename: K
authors.initials: K
authors.lastname: Miyake
authors.forename: T
authors.initials: T
authors.lastname: Hamaoka
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis / Q000276:immunology*; D015152:Blotting, Northern; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D011506:Proteins / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D007376:Interleukin-2; D008565:Membrane Proteins; D011506:Proteins; D011948:Receptors, Antigen, T-Cell; C084839:thymic shared antigen-1