Downregulation of CD4 is required for maintenance of viral infectivity of HIV-1
| Autor: | Akinori Ishimoto, Tomomi Nakahara, Kenta Sasaki, Hiroyuki Sakai, Masakazu Tanaka, Takaharu Ueno |
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| Rok vydání: | 2003 |
| Předmět: |
CD4-Positive T-Lymphocytes
viruses Human Immunodeficiency Virus Proteins Cell Down-Regulation Biology Virus Replication medicine.disease_cause Gene Products nef Virus Downregulation and upregulation Virology medicine Humans Viral Regulatory and Accessory Proteins nef Gene Products Human Immunodeficiency Virus Receptor Gene Infectivity Mutation Virion Gene Products env virus diseases biochemical phenomena metabolism and nutrition medicine.anatomical_structure Viral replication Superinfection CD4 Antigens HIV-1 |
| Zdroj: | Virology. 311:316-325 |
| ISSN: | 0042-6822 |
| Popis: | Downregulation of virus receptors on the cell surface is considered to be important in preventing superinfection. HIV-1 encodes multiple gene products, Env, Vpu, and Nef, involved in downregulation of CD4, a major HIV-1 receptor. We found that simultaneous mutations in both vpu and nef severely impaired virus replication. We examined the involvement of CD4 downregulation mediated by Vpu and Nef in the modification of virus infectivity. The mutation in vpu increased CD4 incorporation into virions without affecting the Env content in it, inhibiting the attachment step of virions to the CD4-positive cell surface. Although a single mutation in nef suppresses virus infectivity via a CD4-independent mechanism, it could augment CD4 incorporation in virions in combination with a vpu mutation. These results indicated that CD4 downregulation was necessary for maintenance of Env function in the virion. |
| Databáze: | OpenAIRE |
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