Tachykinins Mononuclear Phagocytes and HIV-1 Infection

描述（由申请人提供）：本研究的总体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）作为免疫系统和神经系统相互作用的中枢介质调节HIV免疫发病机制。我们的主要假设是，SP和NK1R的改变在HIV发病机制中具有重要的机械作用，并且该受体及其配体的改变与HIV感染者的神经认知变化、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 （HIV进入巨噬细胞的主要共受体）和NK1R拮抗剂抑制内源性SP的产生来抑制HIV在人单核吞噬细胞中的复制。SP自分泌环在调节细胞因子和炎症反应中具有重要作用。HIV相互增强人类免疫细胞中的SP表达，引发“前馈循环”。我们发现细胞在体外从单核细胞到巨噬细胞表型（THP细胞）的分化导致NK1R-T（截断）和NK1R-F（全长）的表达，而单核细胞仅表达NK1R-T。NK1R及其截断型（NK1R- t）和全长型（NK1R- f）的定性和定量表达对巨噬细胞中的钙通量具有功能影响。在大脑扣带皮层中，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类大脑区域获得的细胞来检查这些机制。我们将研究NK1R （NK1R- f和NK1R- t）与HIV和趋化因子受体之间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)我们将探讨胞质Ca2+增加在NK1R-F、NK1R-T和CCR5之间的串扰中的作用。(4)我们假设NK1R-T或NK1R-F mRNA和蛋白水平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的相互作用。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。

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.