DC-SIGN and DC-SIGNR: helping hands for HIV

The ability of dendritic cells (DCs) to promote HIV infection of T cells ef ficiently has been linked to the C-type lectin DC-specific intercellular ad hesion molecule (ICAM)-grabbing nonintegrin (DC-SIGN). DC-SIGN and its homo log DC-SIGN-related (DC-SIGNR) capture and transmit human and simian immuno deficiency viruses to a wide variety of receptor-positive cells. The expres sion patterns of DC-SIGN and DC-SIGNR suggest that they might play roles in both horizontal and vertical transmission, as well as dissemination of vir us within the host. In vivo experiments are required to prove these hypothe ses and might pave the way for the development of new inhibitors of viral e ntry.