GO-6976, A SELECTIVE INHIBITOR OF PROTEIN-KINASE-C, IS A POTENT ANTAGONIST OF HUMAN IMMUNODEFICIENCY VIRUS-1 INDUCTION FROM LATENT LOW-LEVEL-PRODUCING RESERVOIR CELLS-INVITRO
Ka. Qatsha et al., GO-6976, A SELECTIVE INHIBITOR OF PROTEIN-KINASE-C, IS A POTENT ANTAGONIST OF HUMAN IMMUNODEFICIENCY VIRUS-1 INDUCTION FROM LATENT LOW-LEVEL-PRODUCING RESERVOIR CELLS-INVITRO, Proceedings of the National Academy of Sciences of the United Statesof America, 90(10), 1993, pp. 4674-4678
Human immunodeficiency virus (HIV-1) infection is followed by a period
of latency or a low-level-persistent (LLP) state that results in an a
symptomatic infection of the host. Productive viral expression may be
triggered by a variety of activators including mitogens, antigens, and
cytokines. Protein kinase C (PKC) has been shown to be important in t
he intracellular cascade of signals induced by such activators. With U
1 and ACH-2 cell lines representative of an HIV-1 postintegration stat
e, the effect of Go 6976, a synthetic inhibitor of PKC was tested. Go
6976 is a nonglycosidic indolocarbazole found to potently inhibit HIV-
1 induction by Bryostatin 1, tumor necrosis factor alpha, and interleu
kin 6. Go 6976 effectively blocks viral transcription induced by Bryos
tatin 1 or tumor necrosis factor alpha that leads to the inhibition of
intracellular viral protein synthesis and viral shedding. Go 6976 als
o blocks interleukin 6-mediated posttranscriptional induction of viral
proteins. The IC50 of Go 6976 shows a 12- to 60-fold more potent effe
ct than for H-7, another PKC inhibitor with a similar mechanism. The i
nhibitory effect is reduced when Go 6976 is not added before or within
1 hr of induction by the potent PKC activator Bryostatin 1. However,
U1 cells can be grown for long periods in a nontoxic concentration of
Go 6976 (300 nM), which confers virtual inhibition of HIV-1 induction
without the development of resistance. Results indicate that inhibitio
n of HIV-1 proviral induction from latent/low-level-producing infectio
us states with potent PKC inhibitors like Go 6976 may represent an add
itional and promising antiviral approach.