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 immunodef iciency 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; ther efore, this reservoir in such patients was characterized. Virus variants we re characterized in 3 subjects who were followed-up from primary HIV-1 infe ction 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 re lated to those detected simultaneously in plasma, except in 2 treatment-exp erienced subjects. Thus, a turnover and replenishment of this virus reservo ir in peripheral blood is likely to occur in most persons with detectable v iremia. However, infrequently the virus variants in plasma and resting T ce lls seem to be derived from independent sources.