Identification of a putative receptor for subgroup A feline leukemia virus on feline T cells.
Retrovirus infection is initiated by the binding of virus envelope glycoprotein to a receptor molecule present on cell membranes. To characterize a receptor for feline leukemia virus (FeLV), we extensively purified the viral envelope glycoprotein, gp70, from culture supernatants of FeLV-61E (subgroup A)-infected cells by immunoaffinity chromatography. Binding of purified 125I-labeled gp70 to the feline T-cell line 3201 was specific and saturable, and Scatchard analysis revealed a single class of receptor binding sites with an average number of 1.6 x 10(5) receptors per cell and an apparent affinity constant (Ka) of 1.15 x 10(9) M-1. Cross-linking experiments identified a putative gp70-receptor complex of 135 to 140 kDa. Similarly, coprecipitation of 125I-labeled cell surface proteins with purified gp70 and a neutralizing but noninterfering anti-gp70 monoclonal antibody revealed a single cell surface protein of approximately 70 kDa. These results indicate that FeLV-A binds to feline T cells via a 70-kDa cell surface protein, its presumptive receptor.
Ghosh
A K
AK
Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305-5402.
Bachmann
M H
MH
Hoover
E A
EA
Mullins
J I
JI
D000818:Animals; D000911:Antibodies, Monoclonal; D002415:Cats; D002460:Cell Line; D002846:Chromatography, Affinity; D003432:Cross-Linking Reagents; D007700:Kinetics; D005256:Leukemia Virus, Feline / Q000378:metabolism*; D007942:Leukemia, Experimental / Q000378:metabolism*; D011233:Precipitin Tests; D011991:Receptors, Virus / Q000737:chemistry*; D015682:Retroviridae Proteins, Oncogenic / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D011991:Receptors, Virus; D015682:Retroviridae Proteins, Oncogenic; D014759:Viral Envelope Proteins; C074548:feline leukemia virus receptor; C073723:glycoprotein gp70, Feline leukemia virus