Induction and regulation of CD2 mRNA in human lymphocytes.
Herein we studied the accumulation and decay of CD2 mRNA in human PBMC stimulated with PHA. The data show that CD2-specific messages are present in low quantities in resting PBMC and are rapidly increased by five- to sevenfold within 24 h of addition of optimal amounts of PHA. Similar induction of CD2 mRNA was seen after stimulation of PBMC with anti-CD3 mAb and PMA. Peak levels of CD2 message were maintained until 72 h post-stimulation and declined gradually thereafter. Despite stimulation with Staphylococcus aureus and PMA, purified B cells failed to demonstrate any CD2 mRNA. Unlike transferrin or IL-2R mRNA, Il-2 had no effect on the accumulation of CD2 messages in resting or PHA-stimulated PBMC. The time course of CD2 mRNA accumulation preceded lymphocyte proliferation and the appearance of additional cell surface CD2 Ag. The decay of CD2 mRNA was very rapid, with a t 1/2 of approximately 45 min. The protein synthesis inhibitor, cycloheximide, increased its half-time by fourfold to 3.5 h. The data imply the existence of a labile factor, dependent on protein synthesis that is important in the regulation of CD2 mRNA. Compared to other PHA-inducible lymphocyte genes, the kinetics of CD2 transcript accumulation are most reminiscent of the oncogenes N-ras and c-abl.
D018801:CD2 Antigens; D002352:Carrier Proteins / Q000235:genetics*; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000502:physiology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics*
D018801:CD2 Antigens; D002352:Carrier Proteins; D007376:Interleukin-2; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D003609:Dactinomycin; D003513:Cycloheximide