Dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) is a C-type lectin receptor exclusively expressed by DCs and macrophages. It has been shown to bind and internalise a variety of pathogens such as HIV-1 and Mycobacterium tuberculosis, via conserved microbe-associated glycosylated moieties. It has also been demonstrated that HIV-1 can remain in an infectious state for days following internalisation by DC-SIGN, and infectious virions can then be transmitted to CD4+ T cells in trans.