Hongjaisee Sayamon, Braibant Martine, Barin Francis, Ngo-Giang-Huong Nicole, Sirirungsi Wasna, Samleerat Tanawan
1 Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University , Chiangmai, Thailand .
2 Inserm U966, Université François Rabelais , Tours, France .
AIDS Res Hum Retroviruses. 2017 Sep;33(9):946-951. doi: 10.1089/AID.2017.0044. Epub 2017 Jun 12.
Specific amino acids within the V3 loop of HIV-1 CRF01_AE envelope glycoprotein that are involved in the interaction with CCR5/CXCR4 coreceptors, are not well characterized. We generated V3 mutants using polymerase chain reaction (PCR)-based site-directed mutagenesis of HIV-1 CRF01_AE R5-env plasmids at specific positions. Mutant viruses were produced by env-pseudotyped virus assay, tested for coreceptor usage using U373.R5 and U373.X4 cells, and viral entry was assessed with luciferase activity measurement. All viruses, harboring either single or double mutations, used the CCR5 coreceptor. However, those containing a single substitution at positions 7, 11, 18, and 32 and those with mutations at positions 5/32 and 18/32 had reduced infectivity. Only virus with arginine substitution at position 11 seemed to be involved in CXCR4 coreceptor usage. Our results suggest that some V3 positions may be necessary for the binding to coreceptor, but not for the switch of coreceptor usage.
1型人类免疫缺陷病毒（HIV-1）CRF01_AE包膜糖蛋白V3环内参与与CCR5/CXCR4共受体相互作用的特定氨基酸尚未得到充分表征。我们使用基于聚合酶链反应（PCR）的定点诱变技术，对HIV-1 CRF01_AE R5-env质粒在特定位置进行诱变，产生了V3突变体。通过包膜假型病毒试验产生突变病毒，使用U373.R5和U373.X4细胞检测共受体使用情况，并通过荧光素酶活性测量评估病毒进入。所有携带单突变或双突变的病毒都使用CCR5共受体。然而，那些在第7、11、18和32位含有单取代的病毒以及在第5/32和18/32位有突变的病毒感染性降低。只有在第11位有精氨酸取代的病毒似乎参与了CXCR4共受体的使用。我们的结果表明，一些V3位置可能是与共受体结合所必需的，但不是共受体使用转换所必需的。
