Type I and II insulin-like growth factor receptors on human phytohemagglutinin-activated T lymphocytes.
Human T cells activated with mitogens, antigens, or antibodies to the T-cell receptor complex acquire a cascade of new receptors, including the receptors for interleukin-2, transferrin, and insulin. We investigated whether receptors for insulin-like growth factors (IGF) also were expressed on activated T cells. Based on competitive binding studies, immunoprecipitation of labeled cell surface receptors and blocking of radiolabeled peptide binding by a specific monoclonal antibody (alpha IR-3) to the type I IGF receptor, as well as affinity crosslinking of radiolabeled peptides to their receptors, we concluded that both type I and type II IGF receptors are expressed on activated T cells. A specific binding site for IGF-II also was observed on the type I IGF receptor which was not inhibited by alpha IR-3. Receptors for IGF were more numerous on activated T cells than on resting T cells, and their peak expression appeared by the peak of DNA synthesis. Thus, human activated T cells were shown to express both type I and II IGF receptors which could potentially play a role in the regulation of T-cell proliferation, differentiation, and function.
D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D007700:Kinetics; D008213:Lymphocyte Activation; D014066:Palatine Tonsil / Q000276:immunology; D011972:Receptor, Insulin / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D017451:Receptors, Somatomedin; D012397:Rosette Formation; D013002:Somatomedins / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin