Dendritic Cell Restriction and Innate Immune Sensing of HIV Infection

HIV 感染的树突状细胞限制和先天免疫感应

• 批准号: 7841122
• 负责人: Dan Littman
• 金额: $ 25.35万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7841122
• 关键词: Acquired Immunodeficiency Syndrome; Affect; Antigens; Bioinformatics; Bone Marrow; CD4 Positive T Lymphocytes; Cell Communication; Cell Culture Techniques; Cell Maturation; Cell Surface Receptors; Cell physiology; Cell surface; Cells; Chimeric Proteins; Coculture Techniques; Dendritic Cells; Dendritic cell activation; Detection; Early Diagnosis; Gene Expression Profiling; Genes; Goals; HIV; HIV Infections; HIV-1; HIV-2; Hand; Heart; Helper-Inducer T-Lymphocyte; Heterophile Antigens; Human; IRF3 gene; Immune; Immune response; Immune system; Individual; Infection; Interferon Type I; Investigation; Maps; Mediating; Microbe; Mus; Mutation; Natural Immunity; Natural Resistance; Nature; Pathway interactions; Primate Lentiviruses; Production; Proteins; RNA Interference; Resistance; Resistance to infection; Retroviridae; Reverse Transcription; Role; SIV; Sentinel; Signal Induction; Signal Pathway; Signal Transduction; Staging; System; T cell response; T-Cell Activation; T-Lymphocyte; Transcript; Transgenic Mice; Vaccination; Vaccine Design; Vaccines; Viral; Viral Genome; Viral Proteins; Virus; Virus Diseases; Virus Inhibitors; Virus Replication; Virus-like particle; antimicrobial; chemokine; cyclin T1; cytokine; immune activation; improved; inhibitor/antagonist; microbial; microorganism; monocyte; mutant; novel strategies; pathogen; prophylactic; public health relevance; receptor; response; therapeutic vaccine; tool

DESCRIPTION (provided by applicant): Dendritic cells (DCs) have essential roles in early detection of pathogens and in subsequent activation of both innate and adaptive immune responses. The role of DCs in infection with HIV-1 remains poorly understood, even though these cells are likely to be of critical importance in developing new strategies for protective HIV vaccination. The goal of this proposal is to gain a better fundamental understanding of how HIV-1 interacts with DCs and how this interaction affects the ability of the DCs to coordinate an anti-viral immune response. Even though DCs express cell surface receptors for HIV-1 entry, they are resistant to productive viral replication due to a block that occurs before reverse transcription of the viral genome can be completed. However, DCs have a unique ability to "hand-off" the virus to CD4+ T cells, and thus greatly enhance the infectivity of these cells. HIV-1 can be coaxed into infecting DCs if the cells are first exposed to virus-like particles (VLPs) that deliver the Vpx protein of the related primate lentivirus, SIVmac. Vpx inactivates a dominant restriction for HIV-1 replication in DCs and can therefore be used to determine how the immune response is affected if HIV-1 can productively infect DCs. In preliminary studies, we have found that MDDC infected with HIV-1 (using SIVmac VLPs containing Vpx) up-regulate co-stimulatory molecules involved in the activation of T cells as well as a type I interferon response, suggesting that viral infection triggers an innate immune signaling pathway in these cells. Specific Aim 1 will be to determine how HIV-1 infection of monocyte-derived DC (MDDC) triggers innate immune signaling pathways. Gene expression profiling will be performed on MDDC to provide a bioinformatics guide for the pathways to be investigated, and RNAi approaches will then be employed to identify host cell molecules involved in induction of costimulatory molecules and other innate immunity genes. The stage of HIV-1 replication at which the host innate immune response is activated will be determined by using a combination of HIV replication inhibitors and viral mutants. Specific Aim 2 will examine the consequence of DC infection with HIV-1 on the spread of virus in cultures of DC and T cells and on anti-viral and other anti-microbial T cell responses. The spread of HIV-1 (encoding Vpr or a Vpx-Vpr fusion that permits replication in DC) and the induction of antigen-specific T cell responses will be investigated in co-cultures of MDDC and CD4+ T cells. By comparing infection under conditions that permit or restrict infection of DCs, it will be possible to determine if natural resistance of DC to infection with HIV-1 is beneficial to the host or to the virus. Together, these approaches will provide new tools for studying anti-HIV immune responses and for developing more effective vaccine strategies. PUBLIC HEALTH RELEVANCE: Understanding the nature of the immune response in the HIV-infected individual lies at the heart of our efforts to develop effective prophylactic or therapeutic vaccines for AIDS. Our proposal is to better characterize the interaction of HIV-1 with dendritic cells, which make up the early microbial detection system in the body. Results of these studies may provide new approaches for inducing strong protective immune responses against the virus.

描述（由申请人提供）：树突状细胞（dc）在病原体的早期检测和随后的先天和适应性免疫反应的激活中具有重要作用。dc在HIV-1感染中的作用仍然知之甚少，尽管这些细胞可能对开发保护性HIV疫苗接种的新策略至关重要。这项建议的目标是更好地了解HIV-1如何与dc相互作用，以及这种相互作用如何影响dc协调抗病毒免疫反应的能力。尽管树突状细胞表达HIV-1进入的细胞表面受体，但由于在病毒基因组逆转录完成之前发生阻断，它们对病毒的多产复制具有抗性。然而，树突状细胞具有将病毒“传递”给CD4+ T细胞的独特能力，从而大大增强了这些细胞的传染性。如果细胞首先暴露于传递相关灵长类慢病毒SIVmac的Vpx蛋白的病毒样颗粒（vlp）， HIV-1就可以被诱导感染dc。Vpx灭活了dc中HIV-1复制的主要限制，因此可以用来确定如果HIV-1能够有效感染dc，免疫反应是如何受到影响的。在初步研究中，我们发现感染HIV-1的MDDC（使用含有Vpx的SIVmac VLPs）上调参与T细胞激活和I型干扰素反应的共刺激分子，这表明病毒感染触发了这些细胞中的先天免疫信号通路。特异性目的1将是确定HIV-1感染单核细胞源性DC （MDDC）如何触发先天免疫信号通路。将对MDDC进行基因表达谱分析，为待研究的途径提供生物信息学指导，然后采用RNAi方法鉴定参与诱导共刺激分子和其他先天免疫基因的宿主细胞分子。宿主先天免疫反应被激活的HIV-1复制阶段将通过使用HIV复制抑制剂和病毒突变体的组合来确定。特异性目标2将检查DC感染HIV-1对DC和T细胞培养物中病毒传播的影响，以及对抗病毒和其他抗微生物T细胞反应的影响。HIV-1的传播（编码Vpr或Vpx-Vpr融合，允许在DC中复制）和抗原特异性T细胞反应的诱导将在MDDC和CD4+ T细胞共培养中进行研究。通过比较允许或限制DC感染的条件下的感染情况，将有可能确定DC对HIV-1感染的自然抗性是对宿主还是对病毒有益。总之，这些方法将为研究抗艾滋病毒免疫反应和制定更有效的疫苗战略提供新的工具。