Innate Immunity Genes In HIV-1 Transmission

这个新项目是作为我们以前工作的延伸而开始的，以前的工作证明了先天免疫和Toll样受体（TLR）在肺对环境污染物的反应中的关键作用。(It已在约翰霍普金斯进行，并将转移到NIEHS。）已知TLR是先天免疫的重要调节剂，先天免疫是抵抗HIV感染和AIDS进展的关键组成部分。在小鼠和人类中介导对革兰氏阴性细菌（例如脂多糖或内毒素）的应答的TLR 4也被认为是体外HIV感染和病毒复制的决定因素。在我们的研究中，我们验证了两个假设：（1）TLR 4的功能多态性与HIV-1感染负相关;（2）TLR 4多态性赋予HIV感染者对疾病进展的抵抗力。与多中心艾滋病队列研究（MACS）合作，我们从501名男性中获得并检测了DNA标本：402名HIV血清转换者（病例）和99名高危HIV阴性男性（对照）。在血清转换者中，379人的HIV血清转换窗口小于1年，AIDS发病窗口小于1年（明确定义的病例）。通过单链构象多态性（SSCP）分析，对赋予内毒素抗性的896 A至G（Asp 299 Gly）和1190 A至G（Thr 399 Ile）TLR 4多态性进行基因分型。通过序列分析证实了多态性。为了检验第一个假设（HIV传播），我们比较了病例和对照组之间TLR 4突变的患病率。为了检验第二个假设（艾滋病进展），对379例明确定义的病例进行了从血清转换到艾滋病的时间和血清转换后CD 4、CD 8和HIV RNA的动力学评估。我们没有发现任何TLR 4基因型的HIV阴性和阳性男性之间的HIV传播差异，因此表明TLR 4多态性与HIV传播无关。然而，与野生型等位基因纯合子（+/+）相比，TLR 4多态性杂合子（+/-）或纯合子（-/-）男性在血清转换后的前8年内对AIDS发病具有显著的保护作用（RR=0.44，95%CI =0.21-0.89）。有趣的是，两种多态性（Asp 299 Gly，n=3; Thr 399 Ile，n=4）的纯合子男性均未发生AIDS（最短随访时间= 10.7年）。与+/-和+/+男性相比，-/-男性血清转换后的中位HIV RNA较低，但数量较少，无法进行正式分析。因此，我们的研究结果表明TLR 4是HIV感染者中AIDS进展的重要决定因素，并可能为治疗AIDS提供潜在的治疗靶点。

This new project was started as an extension of our previous work that demonstrated a critical role of innate immunity and toll-like receptors (TLR) in pulmonary responses to environmental pollutants. (It has been conducted at Johns Hopkins and will be transferred to NIEHS.) TLRs are known to be important modulators of innate immunity, a critical component of resistance to HIV infection and AIDS progression. TLR4, which mediates responses to Gram-negative bacteria (e.g. lipopolysaccharide or endotoxin) in mouse and humans, has also been implicated as a determinant of HIV infection and viral replication in vitro. We have tested two hypotheses in our study: (1) functional polymorphisms in TLR4 negatively associate with HIV-1 infection; (2) the TLR4 polymorphism confers resistance to disease progression in HIV-infected individuals. In collaboration with the multi-center AIDS cohort study (MACS), we obtained and tested DNA specimens from 501 men: 402 HIV seroconverters (cases) and 99 high-risk HIV negative men (controls). Among seroconverters, 379 had a HIV seroconversion window less <1 yr and AIDS onset window <1 yr (well-defined cases). Individuals were genotyped by single-stranded conformation polymorphism (SSCP) analysis for 896 A to G (Asp299Gly) and 1190 A to G (Thr399Ile) TLR4 polymorphisms that confer resistance to endotoxin. Polymorphisms were confirmed by sequence analysis. To test the first hypothesis (HIV transmission), we compared prevalence of the TLR4 mutations between cases and controls. To test the second hypothesis (AIDS progression), time from seroconversion to AIDS and kinetics of CD4, CD8, and HIV RNA following seroconversion were assessed for the 379 well-defined cases. We found no differences in HIV transmission between HIV negative and positive men for any of the TLR4 genotypes, therefore indicating that the TLR4 polymorphisms were not associated with HIV transmission. However, men heterozygous (+/-) or homozygous (-/-) for the TLR4 polymorphism had significant protection against AIDS onset during the first 8 yr following seroconversion (RR=0.44, 95% CI=0.21-0.89) compared with men homozygous for the wild-type allele (+/+). Interestingly, all men homozygous for either polymorphism (Asp299Gly, n=3; Thr399Ile, n=4) did not develop AIDS (minimum follow up = 10.7 yr). Median HIV RNA following seroconversion was lower in -/- men compared to +/- and +/+ men, but small numbers precluded formal analysis. Our results therefore indicate TLR4 is an important determinant of AIDS progression in HIV-infected individuals, and may provide a potential therapeutic target for treatment of AIDS.