Cyclopentenone prostaglandins inhibit the replication of several
DNA and RNA viruses, including retroviruses. The
antiviral activity has been associated with the induction of a 70-kDa
heat-shock protein (HSP70), via activation of the
heat-shock transcription factor (HSF) in infected cells. In the present study we investigated the effect of
prostaglandin A1 (
PGA1) on the regulation of HSP70 gene expression as well as on
viral RNA and
protein synthesis in CEM-SS cells during acute
infection with human immunodeficiency virus type 1 (HIV-1). We report that HIV-1
infection does not alter HSF activation by
PGA1, whereas it causes an increase in intracellular HSP70
mRNA levels, as a result of enhanced HSP70 mRNA stability. We also show that, as reported in studies of different virus/host cell models,
PGA1 inhibits HIV-1 replication by acting at multiple levels during HIV-1
infection. In addition to the previously reported block of HIV-1
mRNA transcription,
PGA1 was also found to inhibit
viral protein synthesis. These results, together with the fact that
prostaglandins are used clinically in the treatment of several diseases, open new perspectives in the search for novel antiretroviral drugs.