title: Inhibitory effects of anti-CD2 monoclonal antibodies on interleukin 2 production and interleukin 2 receptor expression in anti-CD3-induced T cell activation.
abstract: The effects of anti-CD2 monoclonal antibodies (mAb) on anti-CD3-driven interleukin 2 (IL2) production and IL2 receptor (IL2R) expression were investigated. Two anti-CD2 mAb, which had previously been shown to inhibit in vitro anti-CD3-induced T cell proliferation, also inhibited anti-CD3-induced IL2 production. However, it seemed unlikely that this was the crucial mechanism in the inhibition of anti-CD3-driven proliferation, since anti-CD2 mAb also partially inhibited T cell proliferation induced by the anti-CD3 mAb 446 which does not induce detectable IL2 levels. Anti-CD2 mAb also inhibited anti-CD3-induced surface IL2R expression as measured by immunofluorescence staining with an anti-IL2R mAb against the p55 chain. Inhibition of IL2R expression paralleled inhibition of proliferation. This anti-CD2-mediated inhibition involved a block in the generation of normal numbers of IL2R+ cells rather than a direct inhibitory effect on the IL2R+ cells themselves, since IL2R+ cells isolated from anti-CD2-containing cultures responded normally to IL2. Exogenous IL2 and IL4, singly or in combination, could reverse neither the anti-CD2-mediated inhibition of anti-CD3-induced proliferation nor the anti-CD2-mediated inhibition of anti-CD3-induced IL2R expression. Taken together, these observations suggest that anti-CD2 mAb inhibit anti-CD3-driven proliferation by inhibiting the generation of IL2R+ cells at a maturational stage proximal to their expression of surface IL2R. This inhibition cannot be overcome by exogenous IL2 or IL4, suggesting that the underlying biochemical mechanism involves an IL2- and IL4-independent pathway.
authors.affiliation: Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033.
authors.forename: W
authors.initials: W
authors.lastname: Stohl
authors.forename: M
authors.initials: M
authors.lastname: Linker-Israeli
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000276:immunology*; D018801:CD2 Antigens; D017252:CD3 Complex; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000494:pharmacology; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011971:Receptors, Immunologic / Q000032:analysis / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D007378:Interleukins; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D015847:Interleukin-4