The interaction of recombinant IL-2 with human resting lymphocytes: blocking effects of monoclonal antibodies to IL-2 receptors.
Several lines of evidence suggest that subsets of resting lymphocytes naturally express interleukin-2 receptors (IL-2.R). Recombinant IL-2 (rIL-2) induced the enhancement of natural killer (NK) activity, the generation of activated killer (AK) cells, the proliferation of resting lymphocytes, and the production of interferon-gamma (IFN-gamma) in lymphocyte cultures. The subsets of lymphocytes mediating these responses appeared to be heterogeneous, but reside predominantly in nylon wool-passed non-T, non-B cells ("null cells" or T3- cells); in response to rIL-2, only Leu 11+T3- cells showed enhanced NK activity, and both Leu 11+T3- and Leu11-T3- cells showed predominantly AK activity, proliferation and production of IFN-gamma. These findings suggest that the T3- fraction (null cell fraction) contains predominantly cells expressing IL-2.R at the resting state. Unlike the case with activated T cells, however, none of these responses was blocked by any of three monoclonal antibodies to IL-2.R, including anti-Tac antibody at any dilution. These results indicate that IL-2.R on the resting T3- cells possess unique biological features compared to those on activated T or B cells. A most likely explanation is that T3- cells possess higher affinity IL-2.R than activated T or B cells. Other possibilities are also discussed.
D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006801:Humans; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008215:Lymphocytes, Null / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology*; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D007371:Interferon-gamma