title: Characterization of subpopulations of T-cell receptor intermediate (TCRint) T cells.
abstract: CD1-autoreactive T cells of two types have been demonstrated among T cells expressing the T-cell receptor (TCR) alphabeta at intermediate levels (TCRint cells). One type constitutes a major fraction of the natural killer (NK)1.1+ TCRint population in C57BL/6 (B6) mice and carries a restricted TCR composed of an alpha-chain with an invariant Valpha14-J281 rearrangement, and a beta-chain using Vbeta8. 2, 7 or 2. The second type utilises a variety of TCR and was derived from CD4+ cells in mice lacking MHC class II. To increase our understanding of the two different CD1-reactive subsets, we have investigated and compared the populations of origin: NK1.1+ and NK1. 1- TCRint subsets from MHC class II-deficient mice and CD4+NK1.1+ T cells from B6 mice. The three TCRint populations shared a phenotype indicating previous activation, and contained low frequencies of cells expressing NK receptors of the Ly49 family. In contrast to control CD4+ cells, the three TCRint subsets produced high amounts of interleukin (IL)-4 and interferon (IFN)-gamma after activation. Importantly, no IL-10 could be detected in either TCRint population, implying a distinct function for these cells, different from those of conventional CD8+ and CD4+ cells, including the typical T-helper 2 (Th2) cell. Analysis of TCR expression indicated that the proportion of cells using the semi-invariant Valpha14/Vbeta8.2-type TCR was lower in NK1.1+ cells from MHC class II-negative mice than in CD4+NK1.1+ B6 cells. Further, usage of the Valpha14-J281 rearrangement was also demonstrated among NK1.1- TCRint cells.
authors.affiliation: Immunology Unit, Department of Cell and Molecular Biology, Lund University, Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Sköld
authors.forename: A
authors.initials: A
authors.lastname: Rytter
authors.forename: F
authors.initials: F
authors.lastname: Ivars
authors.forename: S
authors.initials: S
authors.lastname: Cardell
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D016130:Immunophenotyping; D008297:Male; D051379:Mice; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta