Effect of Treg Cells on CD4+Th Immune Responses During Acute FIV Infection

急性 FIV 感染期间 Treg 细胞对 CD4 Th 免疫反应的影响

• 批准号: 7860415
• 负责人: ANGELA M MEXAS
• 金额: $ 12.66万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7860415
• 关键词: AIDS/HIV problem; Acute; Antibodies; Antigens; Biological Assay; Biopsy; Blood; CD4 Positive T Lymphocytes; CD80 gene; CD8B1 gene; CTLA4 gene; Cell Count; Cell Proliferation; Cell Separation; Cell physiology; Cell surface; Cells; Chronic; Coculture Techniques; Color; Cytokine Suppression; Data; Enzyme-Linked Immunosorbent Assay; Family Felidae; Feline Immunodeficiency Virus; Felis catus; Flow Cytometry; Future; Gagging; HIV; HIV Infections; Helper-Inducer T-Lymphocyte; IL2RA gene; Immune System Diseases; Immune response; Immune system; Immunosuppression; Immunosuppressive Agents; In Vitro; Infection; Interleukin-2; Measures; Mediator of activation protein; Messenger RNA; Modeling; PTPRC gene; Peripheral Blood Mononuclear Cell; Phase; Phenotype; Plasma; Play; Population; Production; Property; Regulatory T-Lymphocyte; Research Personnel; Resistance; Reverse Transcriptase Polymerase Chain Reaction; Role; SELL gene; Sorting - Cell Movement; Speed; Staging; Staining method; Stains; Surface; T-Lymphocyte; T-Lymphocyte Subsets; TGFB1 gene; Testing; Therapeutic; Thymidine; Time; Viral; Viremia; Virus; Virus Diseases; anergy; cytokine; design; enzyme linked immunospot assay; in vivo; lymph nodes; research study; response; time interval

DESCRIPTION (provided by applicant): Evidence suggests that HIV persistence may result from its ability to irreversibly damage the acquired immune system shortly after infection is established. CD4+CD25+ T regulatory (Treg) cells with T cell immunosuppressive properties are possible mediators of this early T cell immune dysfunction. CD4+CD25+ Treg cells harbor a productive virus infection in HIV infected people and FIV infected cats, and are activated for potent immunosuppressor function in vivo. While CD4+CD25+ Treg cells have been shown to play a role in regulating CD4+ and CD8+ immune responses against HIV and FIV antigens in vitro, it is not known at what time following infection these cells become infected and activated or what effect they might have on the early protective T cell immune response. To determine the role of Treg cells in the immunopathogenesis of HIV infection we propose to utilize the FIV model to test our hypothesis that CD4+CD25+ Treg cells become infected and activated during the acute stage of FIV infection leading to the immunosuppression of CD4+ T helper (Th) cell anti-FIV responses. Cats will be experimentally infected with the NCSU-1 isolate of FIV and blood and lymph node biopsies will be collected at 1 week intervals following inoculation. Real-Time PCR and anti-FIV-gag intracellular staining will be used to determine the time of infection, number of copies of the virus and absolute numbers of CD4+CD25+ and CD4+CD25- infected T cells. These data will be correlated with plasma viremia levels as detected by RT-PCR. Flow cytometry and cell sorting will assess the expression of phenotypic activation markers (CD80, CD86 and CTLA4) and markers for regulatory function (FoxP3, TGF?1) in infected and non-infected CD4+CD25+ and CD4+CD25- T cell subsets at different time points during the acute phase of infection. In addition, experiments will be designed to assess changes in the suppressive function of CD4+CD25+ Treg cells on target CD4+ Th cell immune responses, such as IL-2 and IFN-y production and cell proliferation. In vitro infection of CD4+CD25- and CD4+CD25+ T cell populations will be used to corroborate the results obtained from in vivo studies. HIV is currently estimated to infect more than 37 million people worldwide. FIV is a well established model of HIV/AIDS. The results of these experiments will have implications in future therapeutic strategies against HIV and FIV, and contribute to our current understanding of Treg cell function.

描述（由申请人提供）：证据表明，艾滋病毒持久性可能是由于其在建立感染后不久不可逆转地损害所获得的免疫系统的能力而导致的。具有T细胞免疫抑制特性的CD4+ CD25+ T调节（Treg）细胞是这种早期T细胞免疫功能障碍的介体。 CD4+ CD25+ Treg细胞具有艾滋病毒感染的人和FIV感染猫的生产性病毒感染，并在体内激活有效的免疫抑制剂功能。尽管已显示CD4+ CD25+ Treg细胞在体外对针对HIV和FIV抗原的CD4+和CD8+免疫反应中发挥作用，但在感染后，这些细胞在什么时候被感染和激活或它们可能对早期保护性T细胞免疫反应产生什么作用。为了确定Treg细胞在HIV感染的免疫发病发生中的作用，我们建议利用FIV模型来测试我们的假设，即在FIV感染的急性阶段CD4+ CD25+ Treg细胞在FIV感染的急性阶段被感染和激活，从而导致CD4+ T Helper（TH）细胞抗FIV反应的免疫抑制。猫将通过FIV的NCSU-1分离株进行实验感染，接种后，将以1周的间隔收集血液和淋巴结活检。实时PCR和抗FIV-GAG细胞内染色将用于确定感染时间，病毒的拷贝数以及CD4+CD25+和CD4+CD4+CD25-感染的T细胞的绝对数量。这些数据将与RT-PCR检测到的血浆病毒血症水平相关。流式细胞术和细胞分类将评估表型激活标记（CD80，CD86和CTLA4）的表达，并在感染和未感染的CD4+CD25+和未感染的CD4+CD25- T细胞子集中，在感染和未感染的CD4+CD25+和未感染的CD4+CD25+和未感染的CD4+CD25- T细胞子集中，在急性阶段感染的时间点上，在受感染的CD4+CD25+和CD4+CD25- T细胞子集中的表达。此外，将设计实验来评估靶标CD4+ TH细胞免疫反应（例如IL-2和IFN-Y产生和细胞增殖）对CD4+ CD25+ Treg细胞抑制功能的变化。 CD4+CD25和CD4+CD25+T细胞种群的体外感染将用于证实从体内研究获得的结果。目前估计艾滋病毒在全球感染超过3700万人。 FIV是艾滋病毒/艾滋病的良好模型。这些实验的结果将对未来针对HIV和FIV的治疗策略产生影响，并有助于我们当前对Treg细胞功能的理解。