Inhibiting Mucosal HIV-1 Transmission by Host Cell RNA Interference

通过宿主细胞 RNA 干扰抑制粘膜 HIV-1 传播

• 批准号: 8195248
• 负责人: ALEXANDRA L HOWELL
• 金额: --
• 依托单位: WHITE RIVER JUNCTION VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8195248
• 关键词: Adult; Affect; Animal Model; Antibodies; Antigen Presentation; Antigen-Presenting Cells; Antigens; Antiretroviral resistance; Area; B-Lymphocytes; Binding; Biological Models; Blood Cells; C Type Lectin Receptors; C-Type Lectins; CCR5 gene; CD4 Antigens; CD4 Positive T Lymphocytes; CXCR4 Receptors; CXCR4 gene; Cell Count; Cells; Centers for Disease Control and Prevention (U.S.); Chemokine (C-C Motif) Receptor 5; Child; Coitus; Control Groups; Dendritic Cells; Deposition; Development; Disease; Dose; Endocytosis; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Foundations; Gastrointestinal tract structure; Genetic Transcription; Genital system; Goals; HIV; HIV Receptors; HIV-1; Health; Healthcare; Healthcare Systems; Human; Human Characteristics; Immune; Immune response; Immune system; Immunologic Deficiency Syndromes; Incidence; Individual; Infection; Invaded; Investigation; Kinetics; Lead; Lectin; Leukocytes; Life; Lymphocyte; Lymphoid Cell; Measurement; Measures; Mediating; Military Personnel; Modeling; Monitor; Mucosal Immune Responses; Mucous Membrane; Mus; Myeloid Cells; Nucleic Acids; Pathogenesis; Pathology; Peptides; Peripheral; Persons; Pharmaceutical Preparations; Plasma; Play; Population; Process; Proteins; RNA; RNA Interference; Reagent; Reporting; Retroviridae; Reverse Transcription; Role; Route; Scientist; Site; Stem cells; Surface; Synapses; T-Cell Receptor; T-Lymphocyte; Technology; Testing; Tetanus Toxoid; Therapeutic; Time; Tissues; Toxic effect; Transfection; Vaccines; Veterans; Viral; Viral Load result; Viral Proteins; Virus; base; chemokine receptor; cytokine; design; functional disability; gastrointestinal; human stem cells; immunodeficient mouse model; in vivo; intercellular cell adhesion molecule; lymph nodes; macrophage; microbicide; mucosal site; nanoparticle; novel strategies; novel therapeutic intervention; particle; pathogen; prevent; receptor; receptor binding; receptor expression; reconstitution; rectal; reproductive; response; trafficking; transmission process; uptake

6. Project Abstract The mucosal immune system plays a central role in preventing the transmission of HIV-1 by a combination of rapid, non-specific responses mediated by innate immune cells, as well as by the induction of specific responses mediated by acquired immune cells. Macrophages and dendritic cells (DC) in mucosal tissues express receptors that are triggered by viral proteins and nucleic acids, leading to the secretion of anti-viral factors that destroy the invading pathogen. These professional antigen presenting cells (APC) also endocytose HIV-1 and present viral peptides to responding T cells in association with HLA class I and class II proteins. However, APC also express CD4, CCR5, and CXCR4 receptors and can become productively infected with HIV-1. In addition, DC can capture HIV-1 via viral binding to C type lectins including DC-SIGN (DC-specific ICAM-grabbing non-integrin). Cell-to-cell contact between an HIV-infected macrophage or DC and a T cell during antigen presentation can lead to infection of T cells by HIV-1, either by the secretion of newly- synthesized virus across the viral synapse that forms between these cells ("cis" infection), or by the transfer of unmodified HIV-1 from the DC to the T cell ("trans" infection). T cells that are either directly infected with HIV- 1, or become infected after interaction with infected APC, then migrate to adjacent lymph nodes, leading to the transmission of HIV-1 from mucosal sites to the periphery. The overall goal of these studies is to determine the extent to which mucosal HIV-1 transmission can be inhibited by blocking expression of CCR5 and DC-SIGN on mucosal macrophages, DC and T cells. Our hypothesis is that preventing HIV-1 binding to macrophages, DC and T cells would dramatically reduce infection of these cells, and also the subsequent APC- mediated infection of responding T cells. We propose to use RNA interference (RNAi) with short-interfering RNA (siRNA) to silence expression of CCR5 and DC-SIGN on mucosal leukocytes from the female reproductive and gastrointestinal tracts using an immunodeficient mouse model that is reconstituted with human progenitor cells and expresses all major human immune cell populations. Our specific aims will determine the extent to which silencing CCR5 and DC-SIGN within mucosal tissues of humanized NOD/SCID/BLT mice leads to the inhibition of HIV-1 infection after intravaginal or intrarectal challenge with HIV-1 (specific aim 1). These studies will include defining optimal doses and routes of administration of siRNA, and also determining whether siRNA can inhibit both cell-free as well as cell associated HIV-1 infection. In addition, we will determine whether inhibition of HIV-1 infection across mucosal tissues correlates with the degree of receptor silencing, as additional anti-viral mechanisms may occur as a function of siRNA exposure. In subsequent studies, we will define the anti-viral mechanisms that contribute to the inhibition of HIV-1 infection by determining the extent to which silencing expression of CCR5 and DC-SIGN on leukocytes in mucosal tissues of NOD/SCID/BLT mice enhances immune responses to HIV-1 and to a model antigen, tetanus toxoid (specific aim 2). Studies in this aim will quantify acquired immune responses to HIV-1 and to tetanus toxoid in siRNA-treated mice by measuring humoral and cellular immune responses. Our overall goal is to develop novel approaches to inhibit the transmission of HIV-1 from mucosal sites to the periphery. Silencing cellular receptors important for HIV-1 infection could augment other therapeutic approaches designed to reduce mucosal HIV-1 transmission, including vaccines and microbicides.

6. 项目摘要