Contribution of follicular dendritic cells to persistent HIV viremia.

HIV-1 infections cannot be completely eradicated by drug therapy, as the virus persists in reservoirs. Low-level plasma viremia has been detected in patients treated for over 7 years, but the cellular compartments that support this low-level viremia have not been identified. The decay of HIV-1 during treatment appears to occur in four phases, with the 3rd and 4th phases occurring when the virus is below the limit of detection of conventional assays. Here, we focus on the 3rd phase of decay, which has been estimated to have a half-life of 39 months. We show that follicular dendritic cells (FDC), which have been identified as an HIV reservoir, can be the main source of the low-level viremia detected during the 3rd phase of decay and contribute to viremia at even longer times. Our calculations show that the kinetics of leakage of virus from FDC is consistent with three types of available clinical data.