Prostaglandin A inhibits replication of human immunodeficiency virus during acute infection

An antiviral effect of prostaglandins (PGs) of the A series on the replication of human immunodeficiency virus (HIV) has been determined. In the T cell line C8166 under single growth cycle conditions, PGA1 reduced the number of infectious progeny 1000-fold in the absence of cytotoxicity. Thus, inhibition of HIV replication by PGA1 represents a true antiviral phenomenon. The number and size of virus-induced syncytia, and the amount of viral antigen were also drastically reduced. The effect was specific for PGAs because PGA2 was also inhibitory, whereas PGB1, PGE1 and PGE2 were inactive. Virus adsorption and penetration do not appear to be targets of antiviral action because PGA1 substantially reduced virus replication, even when added 5 h post-infection. PGA1 did not inhibit viral reverse transcriptase, as determined by in vitro assays, suggesting that its antiviral action is not the consequence of a direct inhibitory effect on this enzyme. PGA1 also inhibited the replication of HIV-1 in CEM x 174 cells, but with less potency. Previously, intravenous infusion of PGA1 into human volunteers has shown no significant deleterious side-effects and thus these observations suggest that PGAs might have potential as antiviral agents in humans.