Mechanisms of Impaired HIV-associated B cell and Pneumococcal Vaccine responses

产品说明：HIV相关的B细胞缺陷与继发性感染、自身免疫性疾病和B细胞淋巴瘤的发病率增加有关。感染率高，如肺炎球菌性肺炎和菌血症，以及艾滋病毒感染者对预防性疫苗的反应差，甚至对抗逆转录病毒疗法的反应差，可能与B细胞产生足够数量、质量和功能的抗体以控制这些病原体的能力受损有关。有效抗体的开发需要抗原结合高变区的突变以增强与病原体的结合，以及保守恒定区的变化（从IgM转变为IgG或伊加）以增强对生物体的杀伤。这两种作用都是由淋巴组织中诱导位点（生发中心（GC））的B细胞中的关键分子--活化诱导的胞苷脱氨酶（AID）控制的。HIV感染可对生殖中心的结构和功能以及B细胞本身产生显著的有害影响。结果是产生低浓度的抗体，并且具有有限的保护活性。 我们建议通过多参数流式细胞术表征B细胞表型、AID的表达、调节和功能来研究HIV感染患者和对照成人中的B细胞异常，以支持B细胞对体外模型刺激的响应以及对肺炎球菌疫苗的体内攻击。我们利用临床，细胞和分子的方法来了解B细胞缺陷在艾滋病毒感染和疫苗的背景下，评估潜在的保护所提供的抗体，他们引发以及在他们的作用作为控制和有针对性的探针的综合免疫功能。

DESCRIPTION: HIV-associated B cell defects are associated with an increased incidence of secondary infections, autoimmune disease and B cell lymphomas. High rates of infection, such as pneumococcal pneumonia and bacteremia, and poor responses to preventive vaccines among persons with HIV infection, even with antiretroviral therapy, may be related to an impaired ability of B cells to generate antibodies of sufficient quantity, quality and function to control these pathogens. The development of effective antibodies requires mutations in the antigen-binding hypervariable region to enhance binding to pathogens as well as changes in the conserved constant regions (switch from IgM to IgG or IgA) to enhance killing of organisms. Both of these effects are controlled by a pivotal molecule, activation-induced cytidine deaminase (AID), in B cells in inductive sites in lymphoid tissue, the germinal centers (GC). HIV infection can have dramatic detrimental effects on the architecture and function of germinal centers as well as on B cells themselves. The consequence is the production of antibodies in low concentrations and with limited protective activity. We propose to study B cell abnormalities in patients with HIV infection and control adults by characterizing B cell phenotype by multiparameter flow cytometry, expression, regulation and function of AID to support B cells in response to model stimuli in vitro as well as with in vivo challenge with pneumococcal vaccines. We utilize clinical, cellular and molecular approaches to understanding B cell defects during HIV infections and vaccines in the context of evaluating the potential protection afforded by the antibodies they elicit as well as in their role as controlled and targeted probes of integrated immune function.