Role of WASP and N-WASP in B cell maturation, homing and function

Wiskott-Aldrich综合征(Was)是一种严重的免疫缺陷，由WASP突变引起， 属于控制从头肌动蛋白成核的蛋白质家族。目前尚不清楚是否存在体液缺陷 在AS患者和WASP-/-小鼠中观察到的免疫反应反映了WASP对B细胞的内在作用 分化和功能，以及N-WASP在这些过程中是否起到补偿作用。 我们将检验WASP和/或N-WASP缺乏表达影响B淋巴细胞的假设 以细胞固有的方式成熟、归巢和发挥功能。 为此，我们将在体内研究WASP+和WASP-细胞之间的竞争模型，并 老鼠。我们还将开发条件敲除模型，其中WASP和/或N-WASP的表达是 B淋巴细胞消融。具体来说，我们会： 1)通过体内分析，分析WASP在B细胞发育成熟中的作用 无论是在老鼠身上还是在人类身上都存在竞争模型。 将分析携带者WASP+和WASP-细胞中记忆性和幼稚B细胞的比例 XLT。我们还将分析WASP在生发中心反应和随后的体细胞高突变中的作用 在WASP+/-小鼠和在B细胞中N-WASP表达缺失的WASP+/-小鼠中进行免疫。 2)检验B细胞特异性缺乏WASP和/或N-WASP影响B细胞成熟的假设， 在体内的归巢和功能。 为此，我们将建立B细胞WASP缺乏症的条件模型。我们将测试 B细胞特异性缺失小鼠外周血中B细胞的分布、归巢及免疫应答 WASP和/或N-WASP。我们将分析WASP B细胞特异性缺陷小鼠对 侵袭性肺炎链球菌感染，并探讨IgM记忆B细胞数量可能存在的缺陷 WASP基因突变患者。 3)验证B细胞特异性缺失WASP和/或N-WASP在体外影响B细胞功能的假设。 为此，我们将在体外研究B细胞的趋化、激活和类转换重组。 B细胞特异性缺乏WASP和/或N-WASP的小鼠。 我们预计，这个项目的结果将使我们能够更好地了解WAS的生物学，并将 这对于开发包括基因疗法在内的内脏疾病的新治疗形式具有重要意义。

The Wiskott-Aldrich syndrome (WAS) is a severe immune deficiency, caused by mutations of WASP, that belongs to a family of proteins that control de novo actin nucleation. It is unclear whether defects in humoral immunity observed in patients with WAS and in WASP-/- mice reflect a B-cell intrinsic role of WASP for B cell differentiation, and function, and whether N-WASP may play a compensatory role in these processes. We will test the hypothesis that lack of expression of WASP and/or N-WASP affects B lymphocyte maturation, homing and function in a cell-intrinsic fashion. To this purpose, we will study in vivo competition models between WASP+ and WASP- cells in humans and mice. We will also develop conditional knock-out models in which expression of WASP and/or N-WASP is ablated in B lymphocytes. Specifically, we will: 1) analyze the role of WASP in B cell development and maturation, through the analysis of in vivo competition models both in mice and in humans. The proportion of memory and naive B cells will be analyzed among WASP+ and WASP- cells in carriers of XLT. We will also analyze the role of WASP in germinal center reaction and somatic hypermutation following immunization in WASP+/- mice and in WASP+/- mice in which expression of N-WASP is deleted in B cells. 2) test the hypothesis that the B-cell specific lack of WASP and/or N-WASP affects B cell maturation, homing and function in vivo. To this purpose, we will develop a conditional model of WASP deficiency in B cells. We will test the peripheral distribution and homing of B cells, and response to immunization in mice with B-cell specific lack of WASP and/or N-WASP. We will analyze susceptibility of mice with B-cell-specific deficiency of WASP to invasive S. pneumoniae infection, and explore possible defects in the number of IgM memory B cells in patients with WASP gene mutations. 3) test the hypothesis that the B-cell specific lack of WASP and/or N-WASP affects B cell function in vitro. To this purpose, chemotaxis, activation and class-switch recombination will be studied in vitro in B cells from mice with B-cell specific lack of WASP and/or N-WASP. We anticipate that the results of .this project will allow a better understanding of the biology of WAS, and will be important for development of novel forms of treatment of WAS, including gene therapy.