CD3/Ti gamma A: a functional gamma-receptor complex expressed on human peripheral lymphocytes.
We have recently developed a mAb designated anti-Ti gamma A, which was found to immunoprecipitate from the well characterized CD3+ TCR alpha/beta- F6C7 fetal clone a CD3-associated disulfide-linked gamma-glycoprotein. This antibody recognizes approximately 3% of adult peripheral lymphocytes and delineates a CD2+ CD3+ TCR alpha/beta- CD4- NKH1- subset where expression of CD8 appears to vary widely from one individual to another. In the present study, we have used anti-Ti gamma A mAb to assess whether gamma-chains expressed on these adult lymphocytes are used as functional R. The two activities which have been associated thus far with TCR gamma+ cells, that is, IL-2-dependent proliferation and non-MHC-restricted cytotoxicity, were investigated here by using either resting or activated Ti gamma A+ lymphocytes. On the resting state, these cells (which appear as a very homogeneous population of granular lymphocytes) mediate little if any NK activity that could not be augmented by anti-Ti gamma A mAb. In contrast, after initial stimulation by PHA plus rIL-2 and subsequent culture in the presence of IL-2, activated Ti gamma A+ lymphocytes were strongly lytic against a series of conventional NK target cell lines. This cytotoxic function was either blocked or enhanced by anti-Ti gamma A mAb, depending upon experimental conditions. With respect to proliferation, it was possible to induce responses of resting Ti gamma A+ lymphocytes with antibody-coated CNBr beads only in the presence of exogenous IL-2, whereas, in culture, the same cells proliferated directly and secreted IL-2 after treatment by anti-Ti gamma A beads. Taken together, these data demonstrate that a major subset of circulating CD3+ TCR alpha/beta- lymphocytes use protein products of T cell gamma rearranging genes as functional R structures.
Faure
F
F
Département de Biologie Clinique, Institut Gustave-Roussy, Villejuif, France.
Jitsukawa
S
S
Triebel
F
F
Hercend
T
T
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D002460:Cell Line; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007376:Interleukin-2 / Q000494:pharmacology; D007399:Interphase; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008863:Microspheres; D011233:Precipitin Tests; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D011961:Receptors, Fc / Q000032:analysis*; D017452:Receptors, IgG; D011994:Recombinant Proteins / Q000494:pharmacology; D012685:Sepharose; D013601:T-Lymphocytes / Q000032:analysis / Q000166:cytology / Q000378:metabolism*
D000945:Antigens, Differentiation, T-Lymphocyte; D007074:Immunoglobulin G; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D011961:Receptors, Fc; D017452:Receptors, IgG; D011994:Recombinant Proteins; D012685:Sepharose