title: Human immunodeficiency virus reactivation by phorbol esters or T-cell receptor ligation requires both PKCalpha and PKCtheta.
abstract: Latently human immunodeficiency virus (HIV)-infected memory CD4(+) T cells represent the major obstacle to eradicating HIV from infected patients. Antigens, T-cell receptor (TCR) ligation, and phorbol esters can reactivate HIV from latency in a protein kinase C (PKC)-dependent manner; however, it is unknown which specific PKC isoforms are required for this effect. We demonstrate that constitutively active (CA) forms of both PKCtheta, PKCthetaA148E, and PKCalpha, PKCalphaA25E, induce HIV long terminal repeat (LTR)-dependent transcription in Jurkat and primary human CD4(+) T cells and that both PKCthetaA148E and PKCalphaA25E cause HIV reactivation in J1.1 T cells. Suppression of both PKCalpha and PKCtheta with short hairpinned (sh) RNA inhibited CD3/CD28-induced HIV LTR-dependent transcription and HIV reactivation in J1.1 T cells. Both prostratin and phorbol myristate 13-acetate induced HIV LTR-dependent transcription and HIV reactivation in J1.1 T cells that was blocked by shRNA against either PKCalpha or PKCtheta. Since suppression of PKCalpha and PKCtheta together has no greater inhibitory effect on HIV reactivation than inhibition of PKCalpha alone, our data confirm that PKCalpha and PKCtheta act in sequence. The requirement for PKCalpha and PKCtheta for prostratin-induced HIV reactivation and the ability of selective PKCalpha or PKCtheta agonists to induce HIV transcription indicate that these PKC isoforms are important targets for therapeutic drug design.
authors: Division of Infectious Diseases and Progam in Translational Immunology and Biodefense, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
authors: Sergey A
authors: SA
authors: Trushin
authors: Gary D
authors: GD
authors: Bren
authors: Susana
authors: S
authors: Asin
authors: Kevin N
authors: KN
authors: Pennington
authors: Carlos V
authors: CV
authors: Paya
authors: Andrew D
authors: AD
authors: Badley
mesh_terms: D002478:Cells, Cultured; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D019169:Jurkat Cells; D010703:Phorbol Esters / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D000074121:Protein Kinase C-theta; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D014775:Virus Activation; D017735:Virus Latency
chemical_list: D007527:Isoenzymes; D010703:Phorbol Esters; D011948:Receptors, Antigen, T-Cell; C496628:PRKCA protein, human; C076233:PRKCQ protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D000074121:Protein Kinase C-theta