Recent origin of human immunodeficiency virus type 1 variants in resting CD4+ T lymphocytes in untreated and suboptimally treated subjects.

Resting CD4(+) T lymphocytes are an important reservoir for human immunodeficiency virus type 1 (HIV-1) in treated patients with undetectable viremia. The knowledge of viral persistence in these cells is limited, however, for patients without treatment or patients for whom treatment is failing; therefore, this reservoir in such patients was characterized. Virus variants were characterized in 3 subjects who were followed-up from primary HIV-1 infection and 5 treatment-experienced subjects. No founder viral sequences and only a minority of the earlier identified drug-induced mutations were found in the resting T lymphocytes. Instead, the viral sequences were closely related to those detected simultaneously in plasma, except in 2 treatment-experienced subjects. Thus, a turnover and replenishment of this virus reservoir in peripheral blood is likely to occur in most persons with detectable viremia. However, infrequently the virus variants in plasma and resting T cells seem to be derived from independent sources.