title: CD3Ti+ human thymocyte-derived clones displaying a differential response to activation via CD3Ti and CD2.
abstract: Previous studies indicated that, unlike peripheral T-cells, freshly isolated thymocytes show little or no proliferation to activation signals via either the antigen/MHC receptor complex (CD3Ti) or the CD2 structure, unless exogenous IL-2 or phorbol esters are added. To investigate these differences in more detail, we have studied the response of clonal populations of mature thymocyte subsets as well as peripheral T-cell clones to activation via either CD3Ti or CD2. Here we report the characterization of three clones belonging to different subsets of mature thymocytes: CD3+ CD4+ (Ti alpha/beta), CD3+ CD8+ (Ti alpha/beta), and CD3+ CD4- CD8- (Ti gamma/delta). All three clones could be induced to proliferate to insolubilized anti-CD3 mAb. In contrast, activating anti-CD2 mAbs, which induced proliferation in all peripheral T-cell clones tested, did not induce an appreciable proliferation of the thymocyte clones. The latter required additional signals provided by the phorbol ester PMA. However, anti-CD2 mAbs were able to induce early activation events such as phosphoinositide turnover and [Ca2+]i increase to an extent similar to the ones elicited by anti-CD3 mAb. These results further support previous findings suggesting that mature thymocytes are not functionally identical to peripheral T-cells.
authors.affiliation: Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: R
authors.initials: R
authors.lastname: Testi
authors.forename: A
authors.initials: A
authors.lastname: Alcover
authors.forename: G
authors.initials: G
authors.lastname: Spagnoli
authors.forename: E L
authors.initials: EL
authors.lastname: Reinherz
authors.forename: O
authors.initials: O
authors.lastname: Acuto
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000937:Antigen-Antibody Reactions; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D018801:CD2 Antigens; D017252:CD3 Complex; D002118:Calcium / Q000502:physiology; D002999:Clone Cells; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D010716:Phosphatidylinositols / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D011971:Receptors, Immunologic / Q000502:physiology*; D012995:Solubility; D013601:T-Lymphocytes / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D010716:Phosphatidylinositols; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium