title: Direct involvement of CD7 (gp40) in activation of TcR gamma/delta+ T cells.
abstract: In this study we reported that on T cell receptor (TcR) gamma/delta+ cells from three cell lines Peer, MOLT-13 and ICRF-1, the T cell antigen CD7 (gp40) can be directly involved in the activation process. This is shown by a rapid increase in cytoplasmic free calcium after stimulation of these cells with an anti-CD7 monoclonal antibody (mAb). Activation through CD7 was further confirmed by measuring the production of interleukin 2 in ICRF-1 cells stimulated with anti-CD7 mAb. In addition induction of mRNA for tumor necrosis factor (TNF)-alpha and TNF-beta in Peer and for granulocyte-macrophage-colony-stimulating factor in MOLT-13 was observed in these anti-CD7-stimulated cells. The same anti-CD7 antibody was unable to activate TcR alpha/beta+ Jurkat cells or normal resting peripheral blood T lymphocytes. We further showed that normal resting TcR gamma/delta+ cells were likewise activated via the CD7 molecule. TcR gamma/delta+ cells obtained from a patient with acute lymphoblastic leukemia 3 months after autologous bone marrow transplantation were induced to proliferate, as measured by [3H]thymidine incorporation after stimulation with anti-CD7 mAb but not with anti-CD3 mAb. Interestingly TcR alpha/beta+ cells from the same donor tested in parallel were not stimulated by anti-CD7 but by anti-CD3 mAb. In essence these findings contribute to the idea that on TcR gamma/delta+ cell, the CD7 antigen could play an important role during T cell differentiation.
authors.affiliation: Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Carrel
authors.forename: S
authors.initials: S
authors.lastname: Salvi
authors.forename: F
authors.initials: F
authors.lastname: Rafti
authors.forename: M
authors.initials: M
authors.lastname: Favrot
authors.forename: C
authors.initials: C
authors.lastname: Rapin
authors.forename: R P
authors.initials: RP
authors.lastname: Sekaly
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000502:physiology*; D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D006801:Humans; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium