T-cell activation influences initial DNA synthesis of simian immunodeficiency virus in resting T lymphocytes from macaques.
The relationship between T-cell activation and early events in the replication cycle of simian immunodeficiency virus (SIV) was analyzed in resting T lymphocytes from macaques. We used the polymerase chain reaction to detect an early product of reverse transcription (R/U5) and almost complete viral DNA (long terminal repeat/gag). We found that SIV can enter resting T lymphocytes and initiate replication but that the reverse transcription process is not efficient and proceeds slowly in resting cells. Cross-linking the CD3/T-cell receptor complex with monoclonal antibodies, unlike cross-linking either the CD28 or CD2 accessory receptor and like phorbol myristate acetate, induced a rapid increase in viral R/U5 DNA detected within 3 to 6 h postinfection. Anti-CD3 or phorbol myristate acetate induced replication of full-length viral DNA within 6 to 9 h postinfection, but full-length SIV DNA was not detectable at earlier time points. We then compared various inhibitors of T-cell activation for their effects on viral initiation and complete replication. Cyclosporin A, an inhibitor of a distal step in T-cell activation, blocked anti-CD3-induced T-cell proliferation and completion of SIV DNA replication but had no effect on induced increases in SIV R/U5 DNA. By contrast, initial SIV DNA synthesis was partially blocked by inhibitors of very early steps in T-cell activation, including herbimycin A, an inhibitor of protein tyrosine kinases, and by two different inhibitors of protein kinase C, H7 and staurosporine. Since resting T cells do not efficiently complete SIV DNA synthesis and cyclosporin A can block the formation of complete viral DNA induced in activated T cells, a cellular factor(s) present in activated T cells appears to be required for the formation of full-length SIV DNA.
Polacino
P S
PS
Regional Primate Research Center, University of Washington Medical Center SJ-50, Seattle.
Liang
H A
HA
Firpo
E J
EJ
Clark
E A
EA
D000818:Animals; D016227:Benzoquinones; D017252:CD3 Complex / Q000378:metabolism; D002455:Cell Division; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D004279:DNA, Viral / Q000096:biosynthesis*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D047029:Lactams, Macrocyclic; D008213:Lymphocyte Activation / Q000187:drug effects; D008254:Macaca nemestrina; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011809:Quinones / Q000494:pharmacology; D011946:Receptors, Antigen / Q000378:metabolism; D017828:Rifabutin / Q000031:analogs & derivatives; D015398:Signal Transduction; D015302:Simian Immunodeficiency Virus / Q000254:growth & development*; D013601:T-Lymphocytes / Q000382:microbiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D016227:Benzoquinones; D017252:CD3 Complex; D004279:DNA, Viral; D007376:Interleukin-2; D047029:Lactams, Macrocyclic; D011809:Quinones; D011946:Receptors, Antigen; D017828:Rifabutin; C020754:herbimycin; D016572:Cyclosporine; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate