title: A novel subset of CD2-, CD3/T cell receptor alpha/beta+ human peripheral blood T cells. Phenotypic and functional characterization of interleukin 2-dependent CD2-CD3+ T cell clones.
abstract: It is generally believed that CD2 (T11, sheep erythrocyte receptor) is expressed on all human T cells. In the present study we have identified and characterized a minor subset of CD2- CD3/TCR alpha/beta+ T cells in the peripheral blood of healthy individuals. CD2-CD3+ T cells were enriched in PBMC depleted of plastic-adherent macrophages, E-rosetting (i.e., CD2+) T cells and surface Ig+ B cells. CD2-CD3+ T cells accounted for 0.1-0.8% of PBMC in six individuals. IL-2-dependent long-term clones of CD2-CD3+ T cells neither reacted with a panel of anti-CD2 mAbs nor expressed detectable levels of CD2 mRNA by Northern blot analysis. These clones, however, expressed a full-length TCR C beta mRNA and reacted with mAbs against TCR-alpha/beta, CD3, and CD4, and thus were mature T cells. CD2-CD3/TCR+ T cell clones could be triggered into proliferation, IL-2 production, and cytotoxic effector activity by anti-CD3 and anti-TCR mAbs. We conclude that (a) a minor subset of CD2-, CD3/TCR-alpha/beta+ T cells is present in normal peripheral blood; and (b) expression of CD2 at the level of protein and/or mRNA is not required for T cell signaling via the CD3/TCR molecular complex.
authors.affiliation: Institute of Immunology, University of Heidelberg, Federal Republic of Germany.
authors.forename: D
authors.initials: D
authors.lastname: Kabelitz
authors.forename: P
authors.initials: P
authors.lastname: Conradt
authors.forename: S
authors.initials: S
authors.lastname: Schondelmaier
authors.forename: H
authors.initials: H
authors.lastname: Wagner
authors.forename: R
authors.initials: R
authors.lastname: Haars
mesh_terms: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000502:physiology*; D015152:Blotting, Northern; D018801:CD2 Antigens; D017252:CD3 Complex; D002999:Clone Cells; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology; D008213:Lymphocyte Activation; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D011971:Receptors, Immunologic / Q000032:analysis / Q000502:physiology*; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic