Mechanism underlying Morphine modulation of gut barrier function in the Context o

描述(由申请人提供)：在急性HIV感染中，CD4+T细胞耗尽后肠道微生物的移位被认为是慢性HIV-1感染中免疫激活的潜在机制，也是HIV疾病进展的标志。有趣的是，与不使用毒品的艾滋病毒感染者相比，静脉注射海洛因的艾滋病毒患者的细菌载量更高。然而，这种缺陷背后的机制还没有得到很好的研究。我们在初步数据中显示，在药物滥用的小鼠模型中，与安慰剂治疗的动物相比，吗啡治疗的动物肠道细菌易位显著增加，这在注射吗啡的TATtg小鼠中进一步加剧。Toll样受体(TLRs)在肠上皮细胞上的战略性定位和表达 肠道共生细菌的过度激活，促进抗菌肽分泌到肠腔。然而，TLR激活的失调会导致屏障功能障碍、持续的细菌易位和慢性全身免疫激活。我们的初步数据显示，在TLR2KO和TLR2/4双基因敲除小鼠中，吗啡治疗导致肠上皮细胞TLR2和TLR4mRNA和蛋白水平显著增加，并且吗啡诱导的细菌易位增加显著减弱。根据我们的初步结果，我们假设吗啡调节TLR在肠上皮细胞(IEL)上的表达和分布，导致紧密连接蛋白的破坏，从而增加细菌易位。根据我们的初步数据，我们假设，吗啡诱导IEC上TLRs的激活有助于肠道屏障的破坏，导致细菌易位增加。我们进一步假设，HIV蛋白TAT将进一步加剧病理状态。在目标1中，我们将确定在HIV-1TAT的背景下，吗啡治疗和吗啡治疗导致TLR2和4表达异常，TLR2和4定位异常，并导致屏障破坏和肠道细菌易位的持续激活。目的：研究人类免疫缺陷病毒(HIV)1TAT中TLR的表达和被吗啡和吗啡激活破坏紧密连接蛋白组织和功能的机制。在目标3中，我们将确定甲基纳曲酮在氯喹存在下缓解吗啡和HIV-1 TAT对肠道屏障功能调节的治疗潜力。这些研究的结果将有助于开发新的治疗策略，以减弱艾滋病毒感染患者和艾滋病毒感染药物滥用人群的免疫激活和逆转艾滋病毒疾病的进展。

DESCRIPTION (provided by applicant): Translocation of gut microbes following CD4+ T cell depletion in acute HIV infection has been implicated as a potential mechanism for immune activation in chronic HIV-1 infection and a hallmark for HIV disease progression. Interestingly, HIV patients that use intravenous heroin have higher bacterial loads when compared to non-drug using HIV infected patients. However, the mechanism underlying this defect has not been well studied. We show in preliminary data, in a murine model of drug abuse, significant increase in gut bacterial translocation in morphine treated animals when compared to placebo treated animals, which is further exacerbated in the TATtg mice treated with morphine. Strategic localization and expression of Toll-like- receptors (TLRs), on intestinal epithelial cells prevents excessive activation by gut commensal bacterial and promotes secretion of antimicrobial peptides into the gut lumen. However, dysregulated TLR activation results in barrier dysfunction, sustained bacterial translocation and chronic systemic immune activation. We show in preliminary data that morphine treatment results in a significant increase in both TLR2 and TLR4 mRNA and protein levels in gut epithelial cells and morphine induced increase in bacterial translocation is significantly attenuated in TLR2KO and TLR2/4 double knockout mice. Based on our preliminary results we hypothesize that morphine modulation of TLR expression and distribution on intestinal epithelial cells (IEL) results in tight junction proteins disruption leaing to increased bacterial translocation. Based on our preliminary data, we hypothesize, that morphine induced activation of TLRs on IEC contributes to gut barrier disruption leading to increased bacterial translocation. We further hypothesize that HIV-protein TAT will further exacerbate the pathological state. In Aim 1: We will determine that morphine treatment and morphine treatment in the context of HIV-1 TAT results in dysregulated TLR2 and 4 expression, aberrant TLR2 and 4 localization and persistent activation contributing to barrier disruption and gut bacterial translocation. Aim 2: We will determine the mechanisms how TLR expression and activation by morphine and morphine in the context of HIV 1 TAT disrupts tight junction protein organization and function. In Aim 3: we will determine the therapeutic potential of methylnaltrexone in the presence of Chloroquine in mitigating morphine and HIV-1 TAT modulation of gut barrier function. The results from these studies will allow for the development of new therapeutic strategies to attenuate immune activation and reverse HIV disease progression both in HIV infected patients and in HIV infected drug abusing population.