MRS OF NEUROPROTECTION IN AN SIV MODEL OF NEUROAIDS

描述（由申请人提供）：在艾滋病流行的早期，由艾滋病毒引起的神经系统疾病被认为是该疾病的重要临床表现。尽管HAART取得了成功，但艾滋病感染的神经认知并发症仍然是一个重要且可能日益严重的问题。这项研究的长期目标是证明米诺环素，一种耐受性良好，廉价的抗生素，可以预防神经元损伤，并促进神经元在加速的neuroAIDS动物模型中的恢复。米诺环素已被测试在各种神经元疾病，包括neuroAIDS。然而，其作用机制仍然未知。我们的研究旨在产生初步的数据，以了解米诺环素的机制。我们建议连续评估血液、CSF和脑中的神经元健康、单核细胞/巨噬细胞活化和病毒产生，以揭示米诺环素的神经保护、抗炎和/或抗病毒特性。为此，七只SIV感染的CD 8+细胞耗尽的猕猴将在接种后28天开始接受每日剂量的米诺环素，并将使用磁共振光谱（MRS）、免疫学、病毒学和病理学收集数据。他们的结果将与一个未感染的队列、两个SIV感染的CD 8耗尽的未治疗的队列和一个用联合抗逆转录病毒疗法（CART）治疗的队列进行比较。这四个队列已在单独的R 01中得到资助。将通过MRS在体内定量神经元标志物，并通过免疫组织化学（IHC）和离体MRS进行尸检，以收集初步数据，阐明米诺环素治疗在SIV感染期间的神经保护作用（具体目的1）。当通过神经元标记物NAA的显著降低鉴定出神经元损伤时，开始治疗，以确定米诺环素是否仅防止进一步损伤或实际上是否能够促进神经元恢复。使用突触体蛋白（突触前完整性的标志物）和微管相关蛋白2（MAP 2，树突完整性的标志物）进行的死后IHC将用于确认体内发现。由于预期神经元恢复是米诺环素抗炎作用的结果，因此NAA的变化将在推定的神经胶质代谢物标志物胆碱（Cho）和肌醇（MI）的减少之前，通过体内MRS测量（具体目标2）。将在死后评估这些动物中巨噬细胞/小胶质细胞和星形胶质细胞活化的相对程度。巨噬细胞标志物的IHC包括CD 68、CD 163和主要组织相容性复合物（MHC）II类，而胶质细胞酸性蛋白（GFAP）将用作星形胶质细胞增生标志物。最后，将在接受米诺环素治疗的动物和接受抗逆转录病毒治疗的动物之间比较SIV感染的病毒学标志物（具体目标3）。将使用定量SIV RNA PCR、原位杂交和IHC评估CNS和感染的相关细胞类型的SIV感染。将进行NAA与血液、CSF和脑中病毒水平之间的线性回归分析，以进一步揭示米诺环素的抗病毒特性。项目叙述：相当多的艾滋病毒感染者会出现神经系统症状，从轻微的认知障碍到严重的痴呆（neuroAIDS），这被认为是大脑神经元损伤的结果。米诺环素是一种耐受性良好的廉价抗生素，已在多种神经元疾病中进行了测试;然而，其作用机制尚不清楚。本研究的重点是解开米诺环素的潜在功能，通过连续访问体内神经元的健康，以及单核细胞/巨噬细胞活化和病毒载量，利用加速动物模型neuroAIDS。

DESCRIPTION (provided by applicant): Early in the AIDS epidemic, neurological disorders produced by HIV were recognized as an important clinical manifestation of the disease. Despite the success of HAART, the neurocognitive complication of AIDS infection continues to be an important and possibly increasing problem. The long-term goal of this study is to show that minocycline, a well-tolerated, inexpensive antibiotic, can prevent neuronal injury and promote neuronal recovery in an accelerated animal model of neuroAIDS. Minocycline has been tested in a variety of neuronal diseases including neuroAIDS. However, its mechanism of action is still unknown. Our study seeks to produce preliminary data to understand the mechanism of minocycline. We propose to serially assess neuronal health, monocyte/macrophage activation and viral production in the blood, CSF and brain to reveal minocycline's neuroprotective, anti-inflammatory and/or antiviral properties. To this end, seven SIV-infected CD8+ cell depleted macaques will receive daily doses of minocycline beginning 28 days post inoculation, and data will be collected using magnetic resonance spectroscopy (MRS), immunology, virology and pathology. Their results will be compared to an uninfected cohort, two SIV infected CD8 depleted untreated cohorts and a cohort treated with combination antiretroviral therapy (CART). These four cohorts are already funded in a separate R01. Neuronal markers will be quantified in vivo by MRS and post mortem by immunohistochemistry (IHC) and ex vivo MRS to collect preliminary data elucidating the neuroprotective effect of minocycline treatment during SIV infection (specific aim 1). Treatment will be initiated when neuronal damage has been identified by a significant decrease in the neuronal marker NAA, in order to determine if minocycline merely prevents further injury or if in fact it is able to promote neuronal recovery. Post mortem IHC using synaptophysin (a marker of pre-synaptic integrity) and microtubule associated protein 2 (MAP2, a marker of dendritic integrity) will be used to confirm the in vivo findings. Since it is expected that neuronal recovery is a result of minocycline's anti- inflammatory effect, changes in NAA will be preceded by a reduction in the putative glial metabolite markers, choline (Cho) and myo-Inositol (MI), measured by in vivo MRS (specific aim 2). The relative degree of macrophage/microglia and astrocyte activation in these animals will be assessed post mortem. IHC for macrophage markers include CD68, CD163, and major histocompatibility complex (MHC) class II, while glial fibrillary acidic protein (GFAP) will be used as an astrogliosis marker. Finally, virologic markers for SIV infection will be compared between animals that receive minocycline therapy and those that undergo antiretroviral therapy (specific aim 3). SIV infection of the CNS and relative cell types infected will be assessed using quantitative SIV RNA PCR, in situ hybridization and IHC. Linear regression analysis between NAA and the viral levels in the blood, CSF and brain will be performed to further reveal the antiviral properties of minocycline. PROJECT NARRATIVE: A significant number of HIV-infected patients develop neurological symptoms ranging from minor cognitive impairment to severe dementia (neuroAIDS), which are thought to be a result of injury to neurons in the brain. Minocycline, a well-tolerated, inexpensive antibiotic has been tested in a variety of neuronal diseases; however the mechanism of how this works is unknown. The focus of this study is to unravel the underlying function of minocycline by serially accessing neuronal health in vivo, as well as monocyte/macrophage activation and viral loads, utilizing an accelerated animal model of neuroAIDS.