Interleukin 2 receptor gene expression in normal human T lymphocytes.
We have used cDNAs for the human interleukin 2 (IL-2) receptor to study IL-2 receptor gene expression in normal activated T cells. Resting T cells do not contain detectable IL-2 receptor mRNA. Within 1 hr after stimulation with phytohemagglutinin (PHA), a large, presumably nuclear precursor RNA species is seen, which then gradually disappears. Mature IL-2 receptor mRNA forms appear within 8 hr after stimulation, reach peak levels between 8 and 24 hr, and then decline. Thus, in PHA-activated lymphocytes the rise and fall in IL-2 receptor mRNA levels precede by more than 24 hr the peak and decline of IL-2 receptor protein expression occurring at the cell surface. 4 beta-Phorbol 12-myristate 13-acetate (PMA) also stimulates IL-2 receptor mRNA and protein expression by T cells. Combinations of optimal concentrations of PHA and PMA produce an additive effect on IL-2 receptor mRNA levels, suggesting that PHA and PMA may induce IL-2 receptor gene expression through different, complementary mechanisms. Nuclease S1-protection assays indicate that IL-2 receptor mRNAs may differ in length due to the use of three different polyadenylylation signals. Further, these assays demonstrate the presence of transcripts that lack a 216-base segment within the protein-coding region and thus do not encode a functional IL-2 receptor. Nuclear transcription assays indicate that the increase in IL-2 receptor mRNA is reflected at the level of transcription. Thus, IL-2 receptor gene regulation controls IL-2 receptor expression at the cell surface and is intimately linked to the control of T-cell proliferation.
D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D006680:HLA Antigens / Q000235:genetics; D015793:HLA-B7 Antigen; D006801:Humans; D007376:Interleukin-2; D008213:Lymphocyte Activation; D011061:Poly A / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000502:physiology*; D013997:Time Factors; D014158:Transcription, Genetic
D006680:HLA Antigens; D015793:HLA-B7 Antigen; D007376:Interleukin-2; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011061:Poly A; D004247:DNA