STUDIES OF PRIMARY IMMUNODEFICIENCY DISEASES

原发性免疫缺陷疾病的研究

• 批准号: 3746594
• 负责人: W STROBER
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3746594
• 关键词: B lymphocyte; T lymphocyte; antibody formation; cytokine; gene rearrangement; gene therapy; human genetic material tag; human subject; hypogammaglobulinemia; immunodeficiency; immunoglobulin genes; immunopathology; lymphocyte proliferation; polymerase chain reaction; tissue /cell culture; transfection

Studies in our laboratory have focused on defining the nature of the B cell and T cell defects in Common Variable Immunodeficiency (CVI), a heterogeneous group of primary acquired human immunodeficiency states characterized by hypogammaglobulinemia and impaired functional antibody responses, at the cellular level, and identifying molecular mechanisms responsible for these defects. Studies of purified B cells of patients with CVI show that although the cells have a normal capacity to proliferate, they manifest differentiation defects at multiple levels. Compared with controls, circulating CVI B cell populations contain reduced numbers of sIgG+ and sIgA+ cells with a commensurate increase in sIgM+ B cells, suggesting an in vivo defect in isotype switch. In addition, CVI B cells manifest Ig secretion defects on stimulation. These Ig secretion defects are not overcome by addition of a variety of cytokines. In further studies we show that despite the above abnormalities, CVI B cells are induced to express normal or near-normal levels of C mu, C gamma, and C alpha mRNA after 7 days of stimulation with anti-CD40 and IL-10. That this C-H mRNA expression represents a recovery of CVI B cell differentiation is supported by studies of Ig secretion in which CVI B cells that are first stimulated for 7 days with anti-CD40 and IL-10 and then restimulated in coculture with activated normal allogeneic T cells and IL-10, secrete substantial levels of IgM and IgG and increased amounts of IgA. Overall, therefore, CVI B cell function can be significantly improved by maintenance in culture. These data suggest the abnormalities of B cell differentiation in CVI are reversible and that the defect is a form of B cell anergy. Commensurate with this hypothesis, we have done further experiments whose preliminary results, in fact, indicate that there is a defect in the ability of CVI B cells to act as antigen presenting cells. A second project focuses on X-linked agammaglobulinemia (XLA), another major humoral immunodeficiency syndrome. In affected individuals, B cell development is arrested at the pre-B cell stage with absence of mature B cells, resulting from mutations in a gene termed btk whose product normally exhibits tyrosine kinase. In collaboration with others, we have begun working toward gene therapy of XLA. presently, we have developed a retroviral construct with the btk gene and confirmed its successful transfection into NIH 3T3 fibroblast cells by polymerase chain reaction (PCR).

我们实验室的研究集中在定义B的性质上 常见变异型免疫缺陷（CVI）中的细胞和T细胞缺陷， 原发性获得性人类免疫缺陷状态异质组 以低丙种球蛋白血症和功能性抗体受损为特征 反应，在细胞水平上，并确定分子机制 对这些缺陷负责。 患者B细胞的纯化研究 与CVI显示，虽然细胞有正常的能力， 当它们增殖时，它们在多个水平上表现出分化缺陷。 与对照组相比，循环CVI B细胞群含有减少的 sIgG+和sIgA+细胞数量以及sIgM+ B相应增加 细胞，表明同种型转换存在体内缺陷。 此外，CVI B细胞在刺激时表现出IG分泌缺陷。 这些IG的分泌 通过加入多种细胞因子不能克服这些缺陷。 在 进一步的研究表明，尽管有上述异常，CVI B细胞 被诱导表达正常或接近正常水平的C μ、C γ， 用抗CD 40和IL-10刺激7天后的C α mRNA。的 这种C-H mRNA表达代表CVI B细胞的恢复 IG分泌的研究支持了这种分化，其中CVI B 首先用抗CD 40和IL-10刺激7天的细胞， 然后与活化的正常同种异体T细胞共培养再刺激 和IL-10，分泌大量的IgM和IgG， 的伊加。 因此，总的来说，CVI B细胞功能可显著降低 在文化中得到改善。 这些数据表明 B细胞分化的缺陷是可逆的， B细胞无反应性的形式。 与这个假设相对应，我们已经做了 进一步的实验，其初步结果，事实上，表明， CVI B细胞作为抗原的能力存在缺陷 递呈细胞。 第二个项目关注X连锁无丙种球蛋白血症 (XLA)另一种主要的体液免疫缺陷综合征。 在受影响 在某些个体中，B细胞发育被阻滞在前B细胞阶段， 缺乏成熟的B细胞，由称为btk的基因突变引起 其产物通常显示酪氨酸激酶。 协同 其他人，我们已经开始对XLA基因治疗的工作。 目前，我们 已经开发了一种带有btk基因的逆转录病毒结构，并证实其 聚合酶链成功转染NIH 3 T3成纤维细胞 反应（PCR）。