Initiation of therapy during primary HIV type 1 infection results in a continuous decay of proviral DNA and a highly restricted viral evolution

A latent pool of HIV-1 is established early in memory CD4(+) T lymphocytes and persists during antiretroviral therapy. Also, viral replication may con tinue in subjects despite undetectable viremia, However, it remains unclear whether this residual replication results in any significant sequence evol ution. We were therefore interested in studying the viral evolution and HIV -1 DNA dynamics in subjects with primary infection receiving or not receivi ng early potent antiretroviral therapy, In 16 subjects, HIV-1 DNA load was monitored from 1 to 23 days, up to 1253 days, after onset of symptoms. Exte nsive sequential cloning and sequence analysis of the V3 region was perform ed in four subjects. In the treated subjects a continuous decline in the pr oviral load was found, corresponding to a half-life of about 6 months. As e xpected in newly infected individuals the founder virus populations showed high intrasubject sequence similarity, Also, a limited increase in the vira l divergence was detected during the first 6 months in three treated subjec ts, Thereafter, no significant sequence changes were found despite analysis of a large number of clones. Our data thus suggest that early and successf ul therapy in compliant subjects with primary HIV-1 infection results in a highly restricted viral evolution and a decline in the proviral load close to the decay rate of human memory T lymphocytes.