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模型来解决RFA-MH-14-170在抗逆转录病毒治疗期间HIV中枢神经系统储库的建立和持久性的目标，并测试缓解神经认知疾病的新策略。我们专注于轻度HAND，神经认知障碍（NCI），其严重程度低于痴呆，称为HIV-NCI。我们已经证明，感染嗜鼠嵌合HIV （EcoHIV）的常规小鼠在慢性全身性感染中复制人类HIV- nci，诱导免疫以控制外周HIV，早期HIV神经入侵，并在行为测试中评估HIV- nci样症状性疾病的表现。该项目的总体假设是，在抑制性抗逆转录病毒治疗和恢复免疫的情况下，中枢神经系统持续HIV感染的生物学原理与外周组织的生物学原理根本不同，从而允许脑部疾病持续存在，并需要新的疾病控制策略。我们认为HIV在长寿命细胞中以生物活性形式持续存在于中枢神经系统中；尽管有抗病毒药物和抗hiv免疫反应，但病毒的表达和神经致病性产物的分泌仍然存在。该假设将在感染EcoHIV的小鼠中进行测试，使用行为测试中的认知损伤来评估我们研究的生理相关性。与H. E. Gendelman博士合作，将利用纳米art技术优化抗逆转录病毒治疗，包括中枢神经系统输送。具体目标是：1)确定与NCI诱导和暴露后ART相关的HIV CNS库建立的时间框架和机制。使用EcoHIV或EcoHIV- gfp，野生型或CCL2- ko小鼠，交错应用纳米ART或CCL2抑制剂，我们将测试大脑感染和病毒基因组形式的动力学，感染的细胞类型，突触树突状损伤，以及与抗病毒免疫，ART时间，HIV和单核细胞进入大脑相关的NCI诱导。2)确定功能性免疫、外周HIV抑制和慢性抗逆转录病毒治疗小鼠慢性感染期间CNS和NCI进展中HIV持续存在的机制。在持续、中断或仅外周抗逆转录病毒治疗的慢性感染中，在分子水平上测试NCI的程度与单核细胞进入中枢神经系统、中枢神经系统内病毒传播、大脑中的HIV Tat活性、LPS诱导的病毒表达激增、CD8 T细胞浸润和突触树突损伤的比较。3)在抗逆转录病毒治疗下，测试HIV病毒激活和沉默辅助策略对HIV脑库和慢性HIV- nci的影响的原理证明。原病毒会被HDAC抑制剂激活。原病毒沉默将包括I型干扰素和a型免疫。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EcoHIV DNA的QPCR检测、基因表达和途径分析、双染色荧光显微镜和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.