The association of CD81 with tetraspanin-enriched microdomains is not essential for Hepatitis C virus entry

• Published in: BMC microbiology Vol. 9; no. 1; p. 111
• Main Authors: Rocha-Perugini, Vera, Lavie, Muriel, Delgrange, David, Canton, Jonathan, Pillez, André, Potel, Julie, Lecoeur, Cécile, Rubinstein, Eric, Dubuisson, Jean, Wychowski, Czeslaw, Cocquerel, Laurence
• Format: Journal Article
• Language: English
• Published: London BioMed Central 28.05.2009; BioMed Central Ltd; BMC
• Subjects: Animals; Antigens, CD - metabolism; Biological Microscopy; Biomedical and Life Sciences; Biotinylation; Cell Line, Tumor; Cell Membrane - virology; Ceramides - metabolism; Cholesterol - metabolism; Gene expression; Genetic aspects; Hepacivirus - genetics; Hepacivirus - immunology; Hepacivirus - physiology; Hepatitis Antibodies - metabolism; Hepatitis C; Hepatitis C - virology; Humans; Life Sciences; Membrane Microdomains - virology; Membrane proteins; Membrane Proteins - metabolism; Mice; Microbiology; Mycology; Neutralization Tests; Parasitology; Research Article; Sphingomyelin Phosphodiesterase - metabolism; Tetraspanin 28; Virology; Virus Internalization; mCD81 Cell; Tetraspanin Enrich Microdomains; Cholesterol Depletion; HCVpp Infection; HCVcc Infection
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/1471-2180-9-111

Background Three percent of the world's population is chronically infected with hepatitis C virus (HCV) and thus at risk of developing liver cancer. Although precise mechanisms regulating HCV entry into hepatic cells are still unknown, several cell surface proteins have been identified as entry factors for this virus. Among these molecules, the tetraspanin CD81 is essential for HCV entry. Interestingly, CD81 is also required for Plasmodium infection. A major characteristic of tetraspanins is their ability to interact with each other and other transmembrane proteins to build tetraspanin-enriched microdomains (TEM). Results In our study, we describe a human hepatoma Huh-7 cell clone (Huh-7w7) which has lost CD81 expression and can be infected by HCV when human CD81 (hCD81) or mouse CD81 (mCD81) is ectopically expressed. We took advantage of these permissive cells expressing mCD81 and the previously described MT81/MT81 w mAbs to analyze the role of TEM-associated CD81 in HCV infection. Importantly, MT81 w antibody, which only recognizes TEM-associated mCD81, did not strongly affect HCV infection. Furthermore, cholesterol depletion, which inhibits HCV infection and reduces total cell surface expression of CD81, did not affect TEM-associated CD81 levels. In addition, sphingomyelinase treatment, which also reduces HCV infection and cell surface expression of total CD81, raised TEM-associated CD81 levels. Conclusion In contrast to Plasmodium infection, our data show that association of CD81 with TEM is not essential for the early steps of HCV life cycle, indicating that these two pathogens, while using the same molecules, invade their host by different mechanisms.