CNS Reservoirs of HIV in a Mouse Model of HIV Infection and Cognitive Impairment:

描述(由申请人提供)：本申请建议使用我们的小鼠HIV感染、突触树突损伤和认知障碍的模型来解决RFA-MH-14-170关于在抗逆转录病毒治疗期间建立和持续建立HIV CNS储存库的目标，并测试缓解神经认知疾病的新策略。我们专注于轻度的手，神经认知障碍(NCI)，没有痴呆症那么严重，称为HIV-NCI。我们已经证明，用嗜鼠的嵌合HIV EcoHIV感染常规小鼠，在慢性全身感染中复制人类HIV-NCI，在外围诱导免疫以控制HIV，早期HIV神经侵袭，以及在行为测试中评估的HIV-NCI样症状性疾病的表现。该项目的总体假设是，在抑制ART和恢复免疫的背景下，中枢神经系统中持续感染艾滋病毒的生物学与周围组织中的生物学完全不同，从而允许持续的脑部疾病，并需要新的疾病控制策略。我们认为，HIV以生物活性形式持续存在于CNS中，在长期存活的细胞中；尽管有抗病毒药物和抗HIV免疫反应，病毒表达和神经致病产物的分泌仍然存在。这一假设将在感染EcoHIV的小鼠身上进行验证，使用行为测试中的认知障碍来评估我们研究的生理学相关性。包括中枢神经系统注射在内的抗逆转录病毒治疗将利用NanoArt技术与H.E.Gendelman博士合作进行优化。具体目标是：1)确定与NCI诱导和暴露后ART相关的建立HIV CNS储存库的时间框架和机制。使用EcoHIV或EcoHIV-GFP，野生型或CCL2-KO小鼠，交错应用NanoArt或CCL2抑制剂，我们将测试与抗病毒免疫、ART时机、HIV和单核细胞进入脑内相关的抗病毒免疫相关的脑感染和病毒基因组形式、感染细胞类型、突触树突损伤和NCI诱导的动态。2)探讨功能免疫、外周HIV抑制和慢性ART小鼠慢性感染过程中HIV在中枢神经系统持续存在和NCI进展的机制。在持续、中断或仅有外周ART的慢性感染中，在分子水平上测试NCI的程度与单核细胞CNS进入、CNS内病毒传播、脑内HIV TAT活性、病毒表达激增、CD8T细胞浸润和突触树突状细胞损伤相比较。3)在存在抗逆转录病毒疗法的情况下，测试艾滋病毒前病毒激活和沉默的辅助策略对艾滋病毒脑储存库和慢性艾滋病毒-NCI的影响的原则证明。使用中的HDAC抑制剂将激活前病毒。前病毒沉默将包括I型干扰素和TAT免疫。治疗对HIV表达的影响将与突触树突损伤和HIV-NCI的改善相关。目前使用的方法包括两种互补的行为测试、小鼠组织中整合的EcoHIV DNA的QPCR检测、基因表达和途径分析、双重染色荧光显微镜和HIV免疫。

DESCRIPTION (provided by applicant): This application proposes to use our model of HIV infection, synaptodendritic damage, and cognitive impairment in mice to address the objectives of RFA-MH-14-170 on establishment and persistence of HIV CNS reservoirs during ART and testing new strategies for mitigation of neurocognitive disease. We focus on mild HAND, neurocognitive impairment (NCI) less severe than dementia, termed HIV-NCI. We have shown that infection of conventional mice with a mouse-tropic chimeric HIV, EcoHIV, reproduces human HIV-NCI in chronic systemic infection, induction of immunity to control HIV in the periphery, early HIV neuroinvasion, and manifestation of a HIV-NCI-like symptomatic disease assessed in behavioral tests. The overall hypothesis of this project is that the biology of persistent HIV infection in CNS in the setting of suppressive ART and restored immunity differs fundamentally from that in peripheral tissues, thereby permitting continuing brain disease and necessitating novel strategies for disease control. We propose that HIV persists in CNS in a biologically active form in long-lived cells; that virus expression and secretion of neuropathogenic products persist despite antiviral drugs and anti-HIV immune responses. The hypothesis will be tested in EcoHIV infected mice using cognitive impairment in behavioral tests to assess the physiological relevance of our studies. Antiretroviral treatment, including CNS delivery, will be optimized using nanoART technology in collaboration with Dr. H. E. Gendelman. The Specific Aims are: 1) Determine the time frame and mechanisms of establishment of HIV CNS reservoirs relative to induction of NCI and post-exposure ART. Using EcoHIV or EcoHIV-GFP, wildtype or CCL2-KO mice, staggered application of nanoART or CCL2 inhibitor, we will test the dynamics of brain infection and viral genome forms, cell types infected, synaptodendritic damage, and NCI induction related to antiviral immunity, ART timing, brain entry by HIV and by monocytes. 2) Determine the mechanisms of HIV persistence in CNS and NCI progression during chronic infection of mice with functional immunity, suppressed peripheral HIV, and chronic ART. In chronic infection with continuous, interrupted, or peripheral-only ART, test the extent of NCI compared to monocyte CNS entry, intra-CNS virus spread, HIV Tat activity in the brain, LPS- induced surges in virus expression, CD8 T cell infiltration, and synaptodendritic injury at the molecular level. 3) Test proof-of-principle of adjunct strategies for HIV provirus activation and silencing for their effects on HIV brain reservoirs and chronic HIV-NCI in the presence of ART. Provirus will be activated with HDAC inhibitors in use. Provirus silencing will include Type I IFN and Tat immunization. The effects of treatment on HIV expression will be correlated with improvement in synaptodendritic injury and HIV-NCI. Methods currently in use include two complementary behavioral tests, QPCR detection of integrated EcoHIV DNA in mouse tissues, gene expression and pathway analysis, dual staining fluorescence microscopy, and HIV immunization.