MDDC involvement in HIV infection

The main role of monocyte-derived dendritic cells (MDDCs — part of the dendritic cell family) is to capture antigens for later processing and presentation to T lymphocytes. MDDCs can also efficiently transfer HIV infectivity without themselves becoming infected, but the mechanisms involved in this process have been unclear. In the May 2 Sciencexpress, David McDonald and colleagues from University of Illinois at Chicago, show that MDDC–T cell contact facilitates transmission of HIV by locally concentrating virus, receptor, and coreceptor during the formation of an infectious synapse (Sciencexpress, DOI:10.1126/science.1084238, May 1, 2003).

McDonald et al. used live-cell microscopy and observed that HIV was recruited to sites of cell contact in MDDCs. In addition, they showed that in the absence of antigen-specific signaling, the HIV receptors CD4, CCR5, and CXCR4 on the T cell were recruited to the interface, while the MDDCs concentrated HIV to the same region....