Measles virus receptors and tropism.

Measles virus (MV) is a member of the Morbillivirus genus in the Paramyxoviridae family. Human signaling lymphocyte activation molecule (SLAM) acts as a cellular receptor for MV. SLAM is expressed on immature thymocytes, activated lymphocytes, macrophages and mature dendritic cells. This distribution of SLAM is in accord with lymphotropism and immunosuppressive nature of MV. Canine distemper and rinderpest viruses, other members of the Morbillivirus genus, also use SLAM as receptors. Laboratory-adapted MV strains often use ubiquitously expressed CD46 as an alternative receptor through the amino acid change(s) in the receptor-binding hemagglutinin. Furthermore, MV can infect various cultured cells, albeit with very low efficiency, via SLAM- and CD46-independent pathway, which may also account for MV infection of SLAM(-) cells in vivo.