Amino Acid 324 in the Simian Immunodeficiency Virus SIVmac V3 Loop Can Confer CD4 Independence and Modulate the Interaction with CCR5 and Alternative Coreceptors
| Autor: | Steffen Lorenz, Claas Otto, George J. Leslie, Silke Meister, Frank Kirchhoff, Bridget A. Puffer, Mandy Krumbiegel, Armin Papkalla, Jacqueline D. Reeves, Jan Münch, Stefan Pöhlmann, Robert W. Doms, Carl W. Davis, Andrea Marzi |
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| Rok vydání: | 2004 |
| Předmět: |
Virus genetics
Receptors CCR5 Receptors Peptide viruses Immunology V3 loop Biology medicine.disease_cause Microbiology Macaque Cell Line Receptors G-Protein-Coupled Cell Fusion Viral Envelope Proteins Virology biology.animal medicine Animals Humans Tropism chemistry.chemical_classification Cell fusion virus diseases Simian immunodeficiency virus biology.organism_classification Macaca mulatta Virus-Cell Interactions Amino acid Amino Acid Substitution chemistry Organ Specificity Insect Science CD4 Antigens Lentivirus Receptors Virus Simian Immunodeficiency Virus HeLa Cells Protein Binding |
| Zdroj: | Journal of Virology. 78:3223-3232 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.78.7.3223-3232.2004 |
| Popis: | The V3 loop of the simian immunodeficiency virus (SIV) envelope protein (Env) largely determines interactions with viral coreceptors. To define amino acids in V3 that are critical for coreceptor engagement, we functionally characterized Env variants with amino acid substitutions at position 324 in V3, which has previously been shown to impact SIV cell tropism. These changes modulated CCR5 engagement and, in some cases, allowed the efficient usage of CCR5 in the absence of CD4. The tested amino acid substitutions had highly differential effects on viral infectivity. Eleven of sixteen substitutions disrupted entry via CCR5 or the alternative coreceptor GPR15. Nevertheless, most of these variants replicated in the macaque T-cell line 221-89 and some also replicated in rhesus macaque peripheral blood monocytes, suggesting that efficient usage of CCR5 and GPR15 on cell lines is not a prerequisite for SIV replication in primary cells. Four variants showed enhanced entry into the macaque sMagi reporter cell line. However, sMagi cells did not express appreciable amounts of CCR5 and GPR15 mRNA, and entry into these cells was not efficiently blocked by a small-molecule CCR5 antagonist, suggesting that sMagi cells express as-yet-unidentified entry cofactors. In summary, we found that a single amino acid at position 324 in the SIV Env V3 loop can modulate both the efficiency and the types of coreceptors engaged by Env and allow for CD4-independent fusion in some cases. |
| Databáze: | OpenAIRE |
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