Detachment of human immunodeficiency virus type 1 from germinal centers byblocking complement receptor type 2

After the transition from the acute to the chronic phase of human immunodef iciency virus (HIV) infection, complement mediates long-term storage of vir ions in germinal centers (GC) of lymphoid tissue. The contribution of parti cular complement receptors (CRs) to virus trapping in GC was studied on ton sillar specimens from HIV-infected individuals. CR2 (CD21) was identified a s the main binding site for HIV in GC, Monoclonal antibodies (MAb) blocking the CR2-C3d interaction were shown to detach 62 to 77% of HIV type 1 from tonsillar cells of an individual in the presymptomatic stage. Although they did so at a lower efficiency, these antibodies were able to remove HIV fro m tonsillar cells of patients under highly active antiretroviral therapy, s uggesting that the C3d-CR2 interaction remains a primary entrapment mechani sm in treated patients as well. In contrast, removal of HIV was not observe d with MAb blocking CR1 or CR3, Thus, targeting CR2 may facilitate new appr oaches toward a reduction of residual virus in GC.