Laboratory of Molecular Microbiology, NIAID, NIH, Bethesda, MD 20892, USA.
J Virol. 2011 Sep;85(17):8702-8. doi: 10.1128/JVI.00332-11. Epub 2011 Jun 29.
Many species of African nonhuman primates are natural hosts for individual strains of simian immunodeficiency virus (SIV). These infected animals do not, however, develop AIDS. Here we show that multiple species of African nonhuman primate species characteristically have low frequencies of CD4(+) T cells and high frequencies of both T cells that express only the alpha-chain of CD8 and double-negative T cells. These subsets of T cells are capable of eliciting functions generally associated with CD4(+) T cells, yet these cells lack surface expression of the CD4 protein and are, therefore, poor targets for SIV in vivo. These data demonstrate that coevolution with SIV has, in several cases, involved downregulation of receptors for the virus by otherwise-susceptible host target cells. Understanding the genetic factors that lead to downregulation of these receptors may lead to therapeutic interventions that mimic this modulation in progressive infections.
许多种非洲非人灵长类动物是灵长类免疫缺陷病毒（SIV）个别毒株的天然宿主。然而，这些受感染的动物不会患上艾滋病。在这里，我们表明，多种非洲非人灵长类动物的特征是 CD4(+) T 细胞的频率较低，而只表达 CD8 链的 T 细胞和双阴性 T 细胞的频率较高。这些 T 细胞亚群能够引发通常与 CD4(+) T 细胞相关的功能，然而这些细胞缺乏 CD4 蛋白的表面表达，因此是体内 SIV 的不良靶标。这些数据表明，与 SIV 的共同进化在几种情况下涉及到病毒的受体下调，而这些受体在其他情况下是易感宿主靶细胞。了解导致这些受体下调的遗传因素，可能会导致模仿这种调节的治疗干预措施，从而改善进行性感染。
