Triggering of T cell proliferation through AIM, an activation inducer molecule expressed on activated human lymphocytes.
In this report, we describe a novel activation antigen that appears very early after T cell activation and is absent in resting lymphocytes, through which agonistic proliferative signals can be triggered by mAb binding. It has been designated as activation inducer molecule (AIM) and is a disulphide-linked heterodimeric structure containing two polypeptide chains of Mr 33,000 and 27,000. The expression of AIM can be induced by different activation stimuli such as PMA, PHA, or anti-CD3 mAb, but not by the Ca2+ ionophore A23187, and it precedes the expression of other activation molecules such as 4F2 or the IL-2-R. Once AIM antigens are expressed on lymphocytes after stimulation with submitogenic doses of PMA, the binding of anti-AIM mAbs triggers a strong proliferative response. Furthermore, a comitogenic effect of the anti-AIM mAbs is exerted in the presence of either PHA or anti-CD3 mAb. The activation of lymphocytes through AIM antigens induces both IL-2 and IL-2-R receptor synthesis and is inhibited by anti-IL-2-R mAbs.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D004220:Disulfides; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000502:physiology; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D008970:Molecular Weight; D011233:Precipitin Tests; D015375:Receptors, Interleukin-2 / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000099192:CD69 Antigens
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D004220:Disulfides; D007376:Interleukin-2; D037181:Lectins, C-Type; D015375:Receptors, Interleukin-2; D013755:Tetradecanoylphorbol Acetate; D000099192:CD69 Antigens