HIV-1 infection of human peripheral blood, cord blood and tonsillar dendritic cells

The role of peripheral blood and tissue dendritic cells (DC) in the pathogenesis of human immunodeficiency virus (HIV) infection has been studied by several groups of investigators. The ability of DC to support productive HIV infection in vitro remains controversial. As reported here, low-level replication of HIV occurs in cord blood DC (CBDC), while tonsillar DC (TDC) fail to support HIV replication. It is unclear whether peripheral blood dendritic cells (PBDC) are depleted or dysfunctional in HIV-infected individuals. While several previous reports and our own data indicate that T-cell proliferation to mitogens and antigens is reduced in the presence of HIV-exposed PBDC, the exact mechanisms involved have not been elucidated. DC appear to have the ability to transfer HIV to CD4 T-cells during an immune response. This transfer leads to productive infection and apoptotic cell death. The role of DC in the pathogenesis of HIV infection requires further definition. The availability of methods for generation of DC from cord or adult peripheral blood and for improved identification of PBDC should prove to be useful in this regard.