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

描述（由申请人提供）：本申请拟使用我们的小鼠HIV感染、突触树突状细胞损伤和认知障碍模型，以解决RFA-MH-14 - 170关于ART期间HIV CNS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）不如痴呆严重，称为HIV-NCI。我们已经表明，感染的常规小鼠与小鼠嗜嵌合体HIV，EcoHIV，复制人类HIV-NCI在慢性全身感染，诱导免疫力，以控制HIV在外周，早期HIV神经侵袭，并表现出HIV-NCI样症状性疾病的行为测试评估。该项目的总体假设是，在抑制性ART和恢复免疫力的情况下，CNS中持续HIV感染的生物学与外周组织中的生物学根本不同，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在CNS中以生物活性形式存在于长寿细胞中;尽管抗病毒药物和抗HIV免疫反应，病毒表达和神经致病性产物的分泌仍然存在。该假设将在EcoHIV感染的小鼠中使用行为测试中的认知障碍进行测试，以评估我们研究的生理相关性。抗逆转录病毒治疗，包括中枢神经系统的交付，将优化使用nanoART技术与博士H。e.詹德曼具体目标是：1）确定相对于诱导NCI和暴露后ART的HIV CNS储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nanoART或CCL2抑制剂，我们将测试脑感染和病毒基因组形式、感染的细胞类型、突触树突损伤的动力学，以及与抗病毒免疫、ART时机、通过HIV和单核细胞进入大脑。2)确定在具有功能性免疫、抑制的外周HIV和慢性ART的小鼠的慢性感染期间，HIV在CNS中持续存在和NCI进展的机制。在连续、中断或仅外周ART的慢性感染中，测试NCI的程度，与单核细胞CNS进入、CNS内病毒扩散、脑中的HIV达特活性、LPS诱导的病毒表达激增、CD 8 T细胞浸润、和突触树突损伤的机制。3)在ART存在的情况下，测试HIV前病毒激活和沉默的辅助策略对HIV脑储库和慢性HIV-NCI的影响的原理证明。使用HDAC抑制剂将激活前病毒。前病毒沉默将包括I型IFN和达特免疫。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，QPCR检测小鼠组织中整合的EcoHIV DNA，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.