Human cytomegalovirus binding to fibroblasts is receptor mediated.
The binding of radiolabeled human cytomegalovirus (HCMV) strain AD169 to human lymphocytes, lymphoblastoid cell lines, monocytes, and fibroblasts varied over a 20-fold range. Since maximum binding was observed with human foreskin fibroblasts (HFF), interactions of radiolabeled HCMV with this cell type were analyzed quantitatively. Binding of HCMV to HFF at 4 degrees C was specific and saturable; at low viral inputs specific binding averaged 16.4% of input and nonspecific binding was less than 1% of input. Binding curves yielded single-component linear Scatchard plots indicating an average Kd of 1.1 nM and 5,262 available virus-binding sites per cell. A two-component Scatchard curve was obtained at 37 degrees C and reflected viral internalization, since it could be converted to a single-component curve by the use of paraformaldehyde-fixed cells. HCMV strain Towne was found to bind to the receptor used by HCMV strain AD169 with similar affinity. HCMV failed to bind to protease-treated HFF or to HFF grown in the presence of inhibitors of glycosylation. Sialic acid residues, however, were not found to be important in binding. These data indicate that a single type of molecule, likely a glycoprotein, on the surface of HFF serves as a specific receptor for the virus.
Taylor
H P
HP
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, California 92037.
Cooper
N R
NR
D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000502:physiology*; D005347:Fibroblasts / Q000382:microbiology; D006031:Glycosylation; D006801:Humans; D019158:N-Acetylneuraminic Acid; D011991:Receptors, Virus / Q000502:physiology*; D012794:Sialic Acids / Q000502:physiology; D014357:Trypsin / Q000494:pharmacology
D011991:Receptors, Virus; D012794:Sialic Acids; D014357:Trypsin; D019158:N-Acetylneuraminic Acid