PERIPHERAL NEUROPATHY IN LENTIVIRUS INFECTIONS: EARLY VIRAL AND HOST DETERMINANTS

描述（由申请人提供）：周围神经系统（PNS）疾病已成为工业化世界中HIV感染患者中最重要的神经系统并发症。疼痛、感觉异常和步态障碍是人类免疫缺陷病毒（HIV）诱导的远端感觉多神经病变（DSP）的临床特征，并发治疗，特别是高活性抗逆转录病毒治疗（HAART）可加重这种症状。慢病毒包括HIV-1和猫免疫缺陷病毒（FIV）引起免疫抑制和由DSP发展定义的神经系统疾病。其发病机制尚不明确。特别是，导致DSP的初始致病事件是未知的，包括损伤的主要解剖部位、事件的时间序列和DSP的分子决定因素。我们的总体工作假设是，导致慢病毒诱导的远端感觉多神经病变的早期事件代表了巨噬细胞和淋巴细胞感染/激活的趋同效应，随后导致背根神经节神经元的致病结果。为了验证这一假设，我们将使用离体和体内模型研究DSP的表型和机制特征，包括背根神经节（DRG）培养和我们实验室开发的猫模型，其中慢病毒感染会导致DRG感觉神经元和轴突损伤。我们将在这些模型中使用病毒或从已建立的HIV-1和FIV毒株中衍生的克隆基因来定义导致DSP的早期事件，重点关注蛋白酶激活受体(PAR)-1和CD154:CD40信号之间的相互作用。利用FIV感染的体内模型，我们将对猫的伤害性和其他感觉模态反应进行神经行为分析，并评估病毒感染的全身影响。形态学分析将允许表征DSP的不同特征，包括轴突和DRG损伤。这些研究还将通过分析宿主基因对感染的反应来补充。我们将通过使用独特的细胞培养室来扩展我们对来自人类PNS制剂的hiv感染DRG培养物的研究。我们还将研究病毒负荷在不同神经和非神经组织中的影响，并检查FIV编码的反义转录物的作用。综上所述，我们将重点研究神经元损伤的初始部位和DSP的潜在分子机制，以及评估特定PNS和循环细胞对疾病过程的贡献。此外，我们将研究DRG感觉神经元在病毒复制过程中的损伤机制。相关性：超过三分之一的艾滋病毒/艾滋病患者受到周围神经病变的影响，导致慢性疼痛、身体残疾、生活质量下降和一些抗逆转录病毒疗法的使用受阻。本建议的目的是阐明导致周围神经病变的疾病相关过程，从中可以开发合理的治疗方法。在这里描述的实验中使用的许多科学技术和模型都是这个研究小组的实验室所独有的，他们在一起工作了多年。

DESCRIPTION (provided by applicant): Peripheral nervous system (PNS) disorders have become the foremost neurological complications among patients with HIV infection in the industrialized world. Pain, paresthesiae and gait disability characterize the clinical features arising from human immunodeficiency virus (HIV)-induced distal sensory polyneuropathy (DSP), which can be exacerbated by concurrent therapies, especially highly active antiretroviral therapy (HAART). Lentiviruses including HIV-1 and feline immunodeficiency virus (FIV) cause immunosuppression and neurological disease defined by the development of DSP. The mechanisms underlying the development of DSP remain uncertain. In particular, the initial pathogenic events leading to DSP are unknown including the primary anatomical site of injury, the temporal sequence of events and the molecular determinants underlying DSP. Our overall working hypothesis is that the early events resulting in lentivirus-induced distal sensory polyneuropathy represent convergent effects of infection/activation of macrophages and lymphocytes with ensuing pathogenic outcomes in dorsal root ganglion neurons. To test this hypothesis, we will investigate the phenotypic and mechanistic features of DSP using both ex vivo and in vivo models, including dorsal root ganglion (DRG) cultures and a feline model developed by our laboratories in which lentivirus infections cause damage to DRG sensory neurons and axons. We will define the early events leading to DSP in these models using viruses or cloned genes derived from established strains of HIV-1 and FIV, concentrating on the interactions between proteinase-activated receptor (PAR)-1 and CD154:CD40 signaling. Using an in vivo model of FIV infection, we will perform neurobehavioral analyses characterizing nociceptive and other sensory modality responses in cats together with evaluating the systemic effects of viral infection. Morphological analyses will permit characterization of different features of DSP including axonal and DRG injury. These studies will also be complemented by analyses of expression of host genes in response to infection. We will extend our studies of HIV-infected DRG cultures derived from human PNS preparations through the use of unique cell culture chambers. We will also investigate the impact of viral burden in different neural and non-neural tissues together with examining the effects of an antisense transcript encoded by FIV. In summary, we will focus on the identification of the initial site of neuronal injury and the underlying molecular mechanisms of DSP, together with assessing the contributions of specific PNS and circulating cells to the disease process. In addition, we will investigate the mechanisms by which DRG sensory neurons are injured in relation to viral replication. Relevance: Over an third of all individuals with HIV/AIDS are affected by peripheral neuropathy, which results in chronic pain, physical disability, reduced quality of life and the preclusion of the use some antiretroviral therapies. The purpose of the present proposal is to elucidate the disease-associated processes leading to peripheral neuropathy from which rational treatments can be developed. Many of the scientific techniques and models to be employed in the experiments described herein are unique to the laboratories of this team of investigators who have worked together for many years.