LOW-LEVELS OF DEOXYNUCLEOTIDES IN PERIPHERAL-BLOOD LYMPHOCYTES - A STRATEGY TO INHIBIT HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 REPLICATION

Human immunodeficiency virus type 1 (HIV-1) viral DNA synthesis in qui escent and activated peripheral blood lymphocytes (PBLs) was studied. Incomplete viral DNA (previously demonstrated to be associated with HI V-1 virions) is carried by HIV-1 virions into quiescent and activated PBLS, contributing to the formation of an early viral DNA pool in thes e cells. The viral DNA is subsequently completed but only extremely sl owly and inefficiently in quiescent PBLs compared to that in stimulate d PBLs. We find that this correlates with significantly lower levels o f dNTP substrates in quiescent compared to activated PBLs. At these lo w dNTP concentrations, HIV-1 reverse transcriptase acts in a partially distributive manner. Increasing dNTP concentrations from the levels o f quiescent PBLs to the levels of activated pBLs the processive action of reverse transcriptase, which in turn stimulates rapid and efficien t formation of full-length DNA. Furthermore, hydroxyurea treatment of stimulated PBLs decreases the dNTP levels and the DNA synthesis rate t o levels comparable to quiescent PBLs. Our data therefore indicate tha t low levels of dNTP may explain why HIV-1 DNA is synthesized slowly a nd inefficiently in quiescent PBLs and suggest that pharmacologic indu ction of low dNTP levels represents a therapeutic approach for inhibit ion of HIV-1 replication.