Identification of two amino acids in the hemagglutinin glycoprotein of measles virus (MV) that govern hemadsorption, HeLa cell fusion, and CD46 downregulation: phenotypic markers that differentiate vaccine and wild-type MV strains

Abstract

We have used site-directed mutagenesis of the hemagglutinin (H) glycoprotein of measles virus (MV) to investigate the molecular basis for the phenotypic differences observed between MV vaccine strains and recently isolated wild-type MV strains. The former downregulate CD46, the putative cellular receptor of MV, are positive for hemadsorption, and are fusogenic in HeLa cells, whereas the latter are negative for these phenotypic markers. CD46 downregulation in particular, could have profound consequences for the immunopathology of MV infection, as this molecule protects the cell from complement lysis. Mutagenesis of two amino acids, valine and tyrosine at positions 451 and 481, respectively, in the H protein from the vaccine-like Hallé MV strain to their counterparts, glutamate and asparagine, in the H protein from the wild-type Ma93F MV strain (creating the V451E/Y481N double mutation) abrogated CD46 downregulation, HeLa cell fusion, and hemadsorption. The converse double mutagenesis of the Ma93F H protein (E451V/N481Y) transferred the CD46-downregulating, fusogenic, and hemadsorption functions to this protein. The data provide the first mapping study of the functional domains of MV H. The consequences of these results for MV vaccine design and the role of CD46 in MV infection are discussed.

Morbillivirus Receptors and Tropism: Multiple Pathways for Infection

“…However, strains isolated in B95a cells or human B-cell lines were shown to grow only in a limited number of lymphoid cell lines (Kobune et al, 1990;Schneider-Schaulies et al, 1995b;Tatsuo et al, 2000a). Furthermore, the H protein of MeV isolated from B-cell lines neither induced downregulation of CD46 nor caused cell-cell fusion (upon coexpression of the F protein) in CD46-positive cell lines (Lecouturier et al, 1996;Bartz et al, 1998;Tanaka et al, 1998).…”

“…From these observations, it had been postulated that B-cell line-isolated strains do not use the ubiquitously expressed CD46 but utilize another molecule as a receptor (Lecouturier et al, 1996;Buckland and Wild, 1997;Bartz et al, 1998;Hsu et al, 1998;Tanaka et al, 1998;Tatsuo et al, 2000a). Tatsuo et al (2000b) performed a screening of a cDNA library of B95a cells, in which a non-susceptible human kidney cell line, 293T, was transfected with the cDNA library and then screened with a vesicular stomatitis virus pseudotype bearing the H protein of MeV isolated from B-cells and F protein from the Edmonston strain.…”

Hemadsorption Expressed by Cloned H Genes from Subacute Sclerosing Panencephalitis (SSPE) Viruses and Their Possible Progenitor Measles Viruses Isolated in Osaka, Japan

“…It binds cellular receptor such as CD46 (7,20,27). Recenly, two amino acids at positions 451 and 481 ofthe H protein have been proposed to be associated with hemadsorption (HAD), syncytium formation, and CD46 downregulation (17). According to a recent report by Xie et al (34), Tyr at position 481 of the H protein did not appear to be critically involved in the interaction with the receptor for wild type MV, although this residue is indispensable for the interaction between H protein and CD46.…”

Specificity switching in virus–receptor complexes

“…Another example is the canine parvovirus, which has emerged as a new pathogen of dogs by gaining the ability to recognize the canine transferrin receptor [5]. Finally, measles virus and the SARS coronavirus are also established models for receptor specificity switching as a result of subtle amino acid changes in their viral attachment proteins [6,7]. A number of well-resolved structures of viruses or viral proteins in complex with cellular receptors are available, and several of these have already contributed to our understanding of parameters that can alter ligand specificities [7-22,23 ,24,25 ,26 ,27 ,28 ,29 ,30 ,31 ,32, 33 ,34 ].…”