Lack of in vivo compartmentalization among HIV-1 infected naïve and memory CD4+ T cell subsets.

Viral compartmentalization between naïve and memory CD4(+) T cell subsets has been described, but only for individuals who were receiving antiretroviral therapy (ART). We present here an extensive analysis of the viral quasispecies residing in the naïve, central and effector memory CD4(+) T cell subsets in a number of therapy naïve individuals and representing an array of HIV-1 subtypes. We longitudinally analyzed subset-specific infection and evolution in a subtype B infected individual who switches from CCR5 to dual CCR5/CXCR4 coreceptor usage. We show that the central memory subset, the predominantly infected subset, harbors a more diverse viral population compared to the others. Through sequence analysis of the env C2V3 region we demonstrate a lack of viral compartmentalization among all subsets. Upon coreceptor switch we observe a pronounced increase in the infection level of the naïve population. Our findings emphasize the importance of all CD4(+) T cell subsets to viral evolution.