Tachykinins Mononuclear Phagocytes and HIV-1 Infection

描述(申请人提供)：本研究的主要目标是了解速激肽神经肽P物质(SP)及其首选受体神经激肽-LR(NK1R)作为免疫和神经系统相互作用的中心介质调节艾滋病毒免疫病理机制的机制(S)。我们的主要假设是，改变的SP和NK1R在HIV的发病机制中具有重要作用，并且该受体及其配体的改变与HIV感染者的神经认知变化和生活压力和抑郁有关。我们发现，非肽SP拮抗剂(CP-96,345)通过下调趋化因子受体CCR5，以及NK1R拮抗剂抑制内源性SP的产生，抑制HIV在人单核巨噬细胞中的复制。SP自分泌环路在调节细胞因子和炎症反应中起着重要作用。HIV反过来增强了人类免疫细胞中SP的表达，引发了一个“前馈循环”。我们发现，从单核细胞向巨噬细胞表型(THP细胞)的体外分化导致NK1R-T(截短)和NK1R-F(全长)的表达，而单核细胞仅表达NK1R-T。NK1R及其截短形式(NK1R-T)和全长形式(NK1R-F)的定性和定量表达对巨噬细胞的钙流动有功能影响。在大脑扣带回，HIV感染者NK1R-T和NK1R-F的mRNA表达均降低。我们将使用来自免疫系统和中枢神经系统的细胞，包括外周单核-巨噬细胞和从选定的人脑区域获得的细胞来研究这些机制。我们将研究NK1R(NK1R-F和NK1R-T)与HIV和趋化因子受体相互作用的细胞生物学。我们的目标是：(1)研究NK-1RF在单核细胞来源的巨噬细胞中的表达及其与CCR5、CD4、Fractalkine和IL-8的关系。(2)我们将研究NK1R-T、NK1R-F受体与CCR5之间的物理和功能相互作用。(3)探讨细胞内钙离子升高在NK1R-F、NK1R-T和CCR5之间的相互作用。(4)我们推测，NK1R-T或NK1R-F或受体功能的改变与HIV-1/AIDS感染者认知功能的改变有关，这些影响改变了CCR5-NK1R相互作用。与公共卫生的相关性：这些研究将进一步导致了解艾滋病毒疾病神经认知变化的发病机制，并导致独特和新颖的治疗干预措施。

DESCRIPTION (provided by applicant): The overarching goal of this investigation is to understand the mechanism(s) whereby the tachykinin neuropeptide, substance P (SP), and its preferred receptor, Neurokinin-lR (NK1R) modulate the immunopathogenesis of HIV as central mediators in the interaction between the immune and nervous systems. Our major hypothesis is that altered SP and NK1R, are mechanistically important in HIV pathogenesis and that this receptor and its ligand are altered in association with neurocognitive changes and life stress and depression in HIV-infected individuals. We showed that the non-peptide SP antagonist (CP-96,345) inhibits HIV replication in human mononuclear phagocytes through down-regulation of CCR5, the chemokine receptor, the principal co-receptor for HIV entry into macrophages and also by NK1R antagonist inhibition of endogenous SP production. The SP autocrine loop has an important role in regulating cytokine and inflammatory responses. HIV reciprocally enhances SP expression in human immune cells, eliciting a "feed-forward cycle". We discovered that cell differentiation in vitro from monocyte to macrophage phenotype (THP cells) results in the expression of both the NK1R-T (truncated) and NK1R-F (full-length), whereas the monocyte cell expresses only NK1R-T. The qualitative and quantitative expression of NK1R and its truncated (NK1R-T) and full length forms (NK1R-F) have functional consequences for calcium flux in macrophages. In the brain cingulate cortex, mRNA expression of both the NK1R-T and NK1R-F are reduced in HIV-infected subjects. We will use cells from both the immune and the CNS systems, including peripheral monocyte-macrophages and cells obtained from select human brain regions to examine these mechanisms. We will examine the cell biology of the interaction between NK1R (NK1R-F and NK1R-T) and HIV and chemokine receptors. Our aims are: (1) To investigate expression of NK-1RF in monocyte-derived macrophages and their associations with CCR5, CD4, Fractalkine, and IL-8. (2) We will investigate the physical and functional interactions between NK1R-T, NK1R-F receptors and CCR5. (3) We will explore the role of cytosolic Ca2+ increase in the cross-talk between NK1R-F, NK1R-T, and CCR5. (4) We hypothesize that altered levels of either or both NK1R-T or NK1R-F mRNA and protein, or receptor function, are associated with alterations with cognitive function in HIV-1/AIDS infected individuals, and these effects alter CCR5-NK1R interaction. Relevance to Public Health: These studies will further lead to understanding the pathogenesis of neurocognitive changes in HIV disease and lead to unique and novel therapeutic intervention.