Modulation of the expression of interleukin 2 receptors of human thymocytes by recombinant interleukin 2.
The effect of purified recombinant interleukin 2 on the expression of the receptors for interleukin 2 by human thymocytes was examined. Interleukin 2 augmented the expression of interleukin 2 receptors and interferon-gamma synthesis by thymocytes activated with concanavalin A, and it was required to maintain the growth of thymocytes in vitro and the expression of interleukin 2 receptors. The increase observed in the number of receptor bearing thymocytes and in the density of receptors due to interleukin 2 occurred within the first 2 days of culture. Dexamethasone inhibited the expression of interleukin 2 receptors, the synthesis of interferon-gamma, and the early proliferation and protein synthesis of lectin-activated thymocytes during the first 2 days of culture. The inhibitory effect of dexamethasone on the expression of interleukin 2 receptors and on the synthesis of interferon-gamma was reversed by interleukin 2, whereas its effect on proliferation and on protein synthesis during the first two days of culture was not reversed by interleukin 2. Interleukin 2 induced the proliferation of thymocytes in vitro, even in the absence of activation by lectin; however, the number of cells displaying receptors which could be detected with anti-Tac remained low throughout the first week of culture and interferon-gamma synthesis was not observed. Nonetheless, interleukin 2-induced proliferation was inhibited by anti-Tac on a dose dependent manner. The results of the study document that recombinant interleukin 2, like purified natural interleukin 2, is required for the expression of interleukin 2 receptors, for interferon-gamma synthesis, and for the growth of thymocytes in vitro.
D002455:Cell Division / Q000187:drug effects; D002648:Child; D003001:Cloning, Molecular; D003208:Concanavalin A / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000235:genetics / Q000494:pharmacology*; D008222:Lymphokines / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000378:metabolism*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
D007376:Interleukin-2; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A; D003907:Dexamethasone; D007371:Interferon-gamma