Tachykinins Mononuclear Phagocytes and HIV-1 Infection

描述（由申请人提供）：本研究的首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-IR（NK 1 R）作为免疫系统和神经系统相互作用的中枢介质调节HIV免疫发病机制的机制。我们的主要假设是，改变SP和NK 1 R，在HIV发病机制中是重要的，并且这种受体及其配体与HIV感染者的神经认知变化、生活压力和抑郁症相关。我们发现非肽SP拮抗剂（CP-96，345）通过下调趋化因子受体CCR 5（HIV进入巨噬细胞的主要辅助受体）以及通过NK 1 R拮抗剂抑制内源性SP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病毒增强了SP在人类免疫细胞中的表达，引发了“前馈循环”。我们发现，细胞在体外从单核细胞分化为巨噬细胞表型（THP细胞）导致NK 1 R-T（截短的）和NK 1 R-F（全长）的表达，而单核细胞仅表达NK 1 R-T。NK 1 R及其截短形式（NK 1 R-T）和全长形式（NK 1 R-F）的定性和定量表达对巨噬细胞中的钙通量具有功能性影响。在大脑扣带皮层中，NK 1 R-T和NK 1 R-F的mRNA表达在HIV感染者中减少。我们将使用来自免疫和CNS系统的细胞，包括外周单核细胞-巨噬细胞和从选择的人脑区域获得的细胞来检查这些机制。我们将研究NK 1 R（NK 1 R-F和NK 1 R-T）与HIV和趋化因子受体之间相互作用的细胞生物学。目的：（1）研究NK-1 RF在单核细胞源性巨噬细胞中的表达及其与CCR 5、CD 4、Fractalkine和IL-8的关系。(2)我们将研究NK 1 R-T，NK 1 R-F受体和CCR 5之间的物理和功能相互作用。(3)我们将探索胞质Ca 2+增加在NK 1 R-F、NK 1 R-T和CCR 5之间的串扰中的作用。(4)我们假设NK 1 R-T或NK 1 R-F mRNA和蛋白质或受体功能水平的改变与HIV-1/AIDS感染者认知功能的改变有关，这些影响改变了CCR 5-NK 1 R相互作用。与公共卫生的相关性：这些研究将进一步了解HIV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.