title: Functional analysis of T-cell antigen 4-1BB in activated intestinal intra-epithelial T lymphocytes.
abstract: The 4-1BB antigen has been recently demonstrated to be a 30 kDa inducible T-cell antigen and is expressed on the cell surface of activated splenic T cells and thymocytes. This novel T-cell antigen also associates physically with the T cell-specific protein tyrosine kinase, p56lck. We show here that the inducible T-cell antigen 4-1BB is expressed on activated intestinal intra-epithelial T lymphocytes (IEL). After activation, or in the presence of IL-2, the activated IELs showed higher levels of 4-1BB. Functional studies revealed that the activated IELs triggered with anti-4-1BB monoclonal antibody could enhance the level of IEL cytotoxicity against anti-CD3-secreting hybridoma cells. Cross-linking of anti-4-1BB antibody also enhanced the proliferation of IELs. These results suggest that the inducible antigen 4-1BB has broad biological functions which not only play a role in activated splenic T cells and thymocytes but also in the mucosal immune system.
authors.affiliation: Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202-5120.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: K E
authors.initials: KE
authors.lastname: Pollok
authors.forename: K K
authors.initials: KK
authors.lastname: Kim
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: B S
authors.initials: BS
authors.lastname: Kwon
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis / Q000276:immunology* / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D015151:Immunoblotting; D007376:Interleukin-2 / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology*; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D017252:CD3 Complex; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin