Stimulation of human T cells via anti-T cell receptor monoclonal antibody BMA031: distinct cellular events involving interleukin-2 receptor and lymphocyte function antigen 1.
We have analyzed activation of resting human T cells by anti-T cell receptor (TCR) monoclonal antibody (mAb) BMA031, a murine mAb of the G2b isotype. Human peripheral blood lymphocytes (PBL) respond to anti-TCR mAb by short-term proliferation in vitro and by acquisition of responsiveness to interleukin 2 (rIL-2) in the absence of detectable IL-2 production. Cell depletion and limiting dilution experiments indicate that anti-TCR mAb +/- rIL-2 stimulation covers a substantial portion of human T cells, including CD4+ and CD8+ cells. Enhancement by rIL-2 of anti-TCR mAb-induced proliferation is blocked by anti-IL-2 receptor (IL-2R, p55) mAb, while anti-TCR mAb-induced proliferation is not. In contrast, anti-TCR mAb-induced proliferation is blocked by anti-lymphocyte function antigen 1 (LFA-1, CD11a) mAb and is not demonstrable in PBL from two patients with severe congenital LFA-1 deficiency, not even in the presence of irradiated LFA-1+ PBL. We conclude that stimulation of resting human T cells by anti-TCR mAb BMA031 enables dissociation of distinct steps in T cell activation that specifically require participation of IL-2R (p55) and LFA-1 cell surface molecules in a mutually exclusive way.
Department of Pediatrics II University Ulm, Federal Republic of Germany.
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Knobloch
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Diamantstein
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Flegel
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Friedrich
D000911:Antibodies, Monoclonal / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins