The fusion protein of wild-type canine distemper virus is a major determinant of persistent infection.
The wild-type A75/17 canine distemper virus (CDV) strain induces a persistent infection in the central nervous system but infects cell lines very inefficiently. In contrast, the genetically more distant Onderstepoort CDV vaccine strain (OP-CDV) induces extensive syncytia formation. Here, we investigated the roles of wild-type fusion (F(WT)) and attachment (H(WT)) proteins in Vero cells expressing, or not, the canine SLAM receptor by transfection experiments and by studying recombinants viruses expressing different combinations of wild-type and OP-CDV glycoproteins. We show that low fusogenicity is not due to a defect of the envelope proteins to reach the cell surface and that H(WT) determines persistent infection in a receptor-dependent manner, emphasizing the role of SLAM as a potent enhancer of fusogenicity. However, importantly, F(WT) reduced cell-to-cell fusion independently of the cell surface receptor, thus demonstrating that the fusion protein of the neurovirulent A75/17-CDV strain plays a key role in determining persistent infection.
Plattet
Philippe
P
Institut de Biotechnologie, University of Lausanne, Bâtiment de Biologie, CH-1015 Lausanne, Switzerland.
Rivals
Jean-Paul
JP
Zuber
Benoît
B
Brunner
Jean-Marc
JM
Zurbriggen
Andreas
A
Wittek
Riccardo
R
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D019921:Biotinylation; D002522:Chlorocebus aethiops; D004216:Distemper / Q000821:virology*; D004217:Distemper Virus, Canine / Q000472:pathogenicity*; D004285:Dogs; D019084:Fluorescent Antibody Technique, Indirect; D014162:Transfection; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000032:analysis / Q000737:chemistry / Q000502:physiology*
D000596:Amino Acids; D014760:Viral Fusion Proteins