CDw150(SLAM) is a receptor for a lymphotropic strain of measles virus and may account for the immunosuppressive properties of this virus

Natural isolates of measles virus readily infect several lymphocyte cell lines. These viruses appear to use a receptor other than CD46, the molecule to which most laboratory strains or virus bind. Methods used to identify and characterize this lymphocyte receptor for measles Virus are described in this study. A binding assay with a soluble form of measles virus H protein demonstrated that B-cell lines, activated with Epstein-Barr virus, or T cells, transformed with human T-cell leukemia virus, exhibit this receptor on their cell surfaces. On the other hand, resting lymphocytes, monocytes, or immature leukocytes either failed to express or possessed reduced levels of this receptor. A cDNA library derived from B95-8 marmoset B-cell lines was used to identify this receptor through expression cloning. This molecule was shown to be CDw150, which is also known as the signaling lymphocytic activation molecule (SLAM). When the lymphocyte receptor was expressed in Chinese hamster ovary (CHOP) or human embryonic kidney (293T) cells, these cells became susceptible to lymphotropic as well as laboratory strains of measles virus. Binding assays confirmed that either lymphotropic or laboratory strains of measles virus could adhere to human or marmoset CDw150, but interaction with the mouse homolog was weak. These infections were independent of the presence of CD46 on the host cell surface. Interaction of measles virus with CDw150(SLAM) could explain the immunosuppressive properties of this virus. (C) 2001 Academic Press.