Blockade of the interleukin-2 receptor by anti-Tac antibody: inhibition of human lymphocyte activation

J Immunol. 1983 Aug;131(2):690-6.


We have previously shown that monoclonal anti-Tac antibody inhibits the proliferation of interleukin-2 (IL-2) dependent human continuous T cell lines. Further, we have shown that anti-Tac specifically blocks greater than 95% of the binding of radiolabeled II-2 to a continuous T cell line. In view of these data, we suggested that anti-Tac antibody may bind to and block the human T cell receptor for IL-2. We now report the effects of anti-Tac on the activation of human peripheral blood T lymphocytes. We find that anti-Tac: 1) blocks T cell proliferation induced by soluble antigens (80-90%), autologous antigens (90%) and alloantigens (75-90%); 2) partially inhibits T cell proliferation induced by mitogenic lectins, including Concanavalin A (50-88%), pokeweed mitogen (40-87%), and phytohemagglutinin (20-80%); 3) abrogates (greater than 95%) the generation of cytolytic T lymphocytes in allogeneic cell cocultures, but does not inhibit killing by cytolytic T lymphocytes once formed; 4) and inhibits T cell dependent pokeweed mitogen activated B cell immunoglobulin production (78-95%). We further demonstrate that anti-Tac inhibition of proliferation is not secondary to diminished production of IL-2. Finally, in antigen induced T cell proliferative assays, we demonstrate that the addition of highly purified IL-2 reverses the inhibitory effects of anti-Tac. These data are consistent with the hypothesis that anti-Tac recognizes the human IL-2 receptor and illustrate ways in which this antibody can be used to modulate the human immune response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology*
  • B-Lymphocytes / immunology
  • Cell Division
  • Concanavalin A / pharmacology
  • Humans
  • Isoantigens / immunology
  • Lymphocyte Activation*
  • Lymphocyte Cooperation
  • Phytohemagglutinins / pharmacology
  • Pokeweed Mitogens / pharmacology
  • Receptors, Immunologic / immunology*
  • Receptors, Interleukin-2
  • T-Lymphocytes / cytology
  • T-Lymphocytes, Cytotoxic / immunology
  • Time Factors


  • Antibodies, Monoclonal
  • Isoantigens
  • Phytohemagglutinins
  • Pokeweed Mitogens
  • Receptors, Immunologic
  • Receptors, Interleukin-2
  • Concanavalin A