Kuwata Takeo, Enomoto Ikumi, Baba Masanori, Matsushita Shuzo
Center for AIDS Research, Kumamoto University, Kumamoto, Japan
Center for AIDS Research, Kumamoto University, Kumamoto, Japan.
Antimicrob Agents Chemother. 2015 Nov 2;60(1):437-50. doi: 10.1128/AAC.02285-15. Print 2016 Jan.
Cenicriviroc is a CCR5 antagonist which prevents human immunodeficiency virus type 1 (HIV-1) from cellular entry. The CCR5-binding regions of the HIV-1 envelope glycoprotein are important targets for neutralizing antibodies (NAbs), and mutations conferring cenicriviroc resistance may therefore affect sensitivity to NAbs. Here, we used the in vitro induction of HIV-1 variants resistant to cenicriviroc or NAbs to examine the relationship between resistance to cenicriviroc and resistance to NAbs. The cenicriviroc-resistant variant KK652-67 (strain KK passaged 67 times in the presence of increasing concentrations of cenicriviroc) was sensitive to neutralization by NAbs against the V3 loop, the CD4-induced (CD4i) region, and the CD4-binding site (CD4bs), whereas the wild-type (WT) parental HIV-1 strain KKWT from which cenicriviroc-resistant strain KK652-67 was obtained was resistant to these NAbs. The V3 region of KK652-67 was important for cenicriviroc resistance and critical to the high sensitivity of the V3, CD4i, and CD4bs epitopes to NAbs. Moreover, induction of variants resistant to anti-V3 NAb 0.5γ and anti-CD4i NAb 4E9C from cenicriviroc-resistant strain KK652-67 resulted in reversion to the cenicriviroc-sensitive phenotype comparable to that of the parental strain, KKWT. Resistance to 0.5γ and 4E9C was caused by the novel substitutions R315K, G324R, and E381K in the V3 and C3 regions near the substitutions conferring cenicriviroc resistance. Importantly, these amino acid changes in the CCR5-binding region were also responsible for reversion to the cenicriviroc-sensitive phenotype. These results suggest the presence of key amino acid residues where resistance to cenicriviroc is incompatible with resistance to NAbs. This implies that cenicriviroc and neutralizing antibodies may restrict the emergence of variants resistant to each other.
塞尼洛维罗克是一种CCR5拮抗剂，可阻止1型人类免疫缺陷病毒（HIV-1）进入细胞。HIV-1包膜糖蛋白的CCR5结合区域是中和抗体（NAbs）的重要靶点，因此赋予塞尼洛维罗克抗性的突变可能会影响对NAbs的敏感性。在此，我们利用体外诱导对塞尼洛维罗克或NAbs耐药的HIV-1变体，来研究对塞尼洛维罗克的抗性与对NAbs的抗性之间的关系。对塞尼洛维罗克耐药的变体KK652-67（KK菌株在浓度递增的塞尼洛维罗克存在下传代67次）对针对V3环、CD4诱导（CD4i）区域和CD4结合位点（CD4bs）的NAbs中和敏感，而获得对塞尼洛维罗克耐药菌株KK652-67的野生型（WT）亲本HIV-1菌株KKWT对这些NAbs耐药。KK652-67的V3区域对塞尼洛维罗克抗性很重要，并且对V3、CD4i和CD4bs表位对NAbs的高敏感性至关重要。此外，从对塞尼洛维罗克耐药的菌株KK652-67诱导出对抗V3 NAb 0.5γ和抗CD4i NAb 4E9C耐药的变体，导致其恢复到与亲本菌株KKWT相当的对塞尼洛维罗克敏感的表型。对0.5γ和4E9C的抗性是由在赋予塞尼洛维罗克抗性的替代位点附近V3和C3区域中的新替代R315K、G324R和E381K引起的。重要的是，CCR5结合区域中的这些氨基酸变化也导致恢复到对塞尼洛维罗克敏感的表型。这些结果表明存在关键氨基酸残基，在这些位点对塞尼洛维罗克的抗性与对NAbs的抗性不相容。这意味着塞尼洛维罗克和中和抗体可能会限制对彼此耐药的变体的出现。
