Hepatitis C virus envelope protein E2 binds to CD81 of tamarins.
Since recombinant envelope glycoprotein E2 of hepatitis C virus (HCV) binds to CD81 on human and chimpanzee cells, it has been suggested that CD81 may be a receptor for HCV. Humans and chimpanzees are the only species known to be susceptible to HCV infection. E2 has been reported not to bind to CD81 of the African green monkey, mouse, or rat, suggesting that binding of HCV to CD81 is species specific and may determine susceptibility to infection with HCV. We investigated the interaction between E2 of HCV and CD81 of tamarins, a group of small New World monkeys frequently used for the study of human viruses. Tamarins are not susceptible to HCV infection. Nonetheless, we found that three different forms of HCV E2 (intracellular, secreted, and cell surface-displayed) bound more efficiently to recombinant tamarin CD81 than to human CD81, as determined by ELISA and immunofluorescence. The affinity of the interaction was approximately 10-fold higher for tamarin than for human CD81. Binding of E2 to CD81 on cultured or primary tamarin cells was demonstrated by flow cytometry. In contrast to previous reports, there was also a low-affinity interaction between E2 and African green monkey CD81. Thus, the HCV E2 interaction with CD81 is not limited to humans and chimpanzees and does not predict susceptibility to HCV infection.
Allander
T
T
Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0740, USA.
Forns
X
X
Emerson
S U
SU
Purcell
R H
RH
Bukh
J
J
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002478:Cells, Cultured; D002678:Chimera / Q000276:immunology; D002522:Chlorocebus aethiops; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D016174:Hepacivirus / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D011991:Receptors, Virus / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012452:Saguinus / Q000276:immunology*; D013045:Species Specificity; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins / Q000276:immunology*
D015703:Antigens, CD; C554798:CD81 protein, human; C554799:Cd81 protein, mouse; C554797:Cd81 protein, rat; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011991:Receptors, Virus; D011994:Recombinant Proteins; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus