Biology of the Immune Response

研究人员检查了正常人和与癌症高发相关的先天性和获得性免疫缺陷状态患者的人体免疫反应。我们目前的研究集中在Wiskott-Aldrich综合征(WAS)、X连锁高IgM综合征、选择性IgA缺乏症、共同变量免疫缺陷(CVID)和X连锁无丙种球蛋白血症和孤立性生长激素缺乏症(XLA/GHD)患者。我们继续研究Wiskott-Aldrich综合征蛋白(WASP)的功能。我们已经确定了WASP基因自发遗传逆转的患者，这些研究为基因校正细胞的选择性优势提供了证据。这一观察结果提出了针对Wiskott-Aldrich综合征的基因纠正治疗策略的可能性。事实上，使用这样的策略，我们已经纠正了AS患者原始T细胞结构和功能的异常表型。对造血干细胞的进一步研究也在计划之中。我们还表明，通过流式细胞术可以很容易地完成对骨髓移植后AS患者中WASP表达的细胞嵌合体的评估。这一方法的使用将有助于深入了解干细胞纠正AS的必要因素，从而为WAS提供更有科学依据的骨髓治疗策略。最近完成了两项I期临床试验：1)重组CD40配体治疗X连锁高IgM综合征患者，2)BLyS治疗选择性IgA缺乏症。目前正在计划对这两种疾病进行第二阶段临床试验。研究表明，CVID和选择性IgA缺乏症的遗传基础。我们认为这些疾病本质上是等位基因，是免疫球蛋白类开关重组“泄漏”失败的结果。为了对异常基因表达有可能的了解，我们正在使用基因芯片分析刺激的CVID和正常B细胞的差异基因表达。我们已经确定了CVID和选择性IgA缺乏症的候选基因。在已经分析的100个患者样本中，这种基因发生了大约30%的突变。我们目前手头还有300个病人样本供分析。对候选基因的了解揭示了一条功能途径，值得进行更多的研究，目前正在计划中。X连锁无丙种球蛋白血症和孤立性生长激素缺乏症(XLA/GHD)与更常见的X连锁无丙种球蛋白血症(XLA)或由Bruton酪氨酸激酶(BTK)突变引起的Bruton病有许多相似之处。我们已经证明XLA/GHD不同于XLA，因为以前的患者在BTK表达方面没有异常，包括正常的催化活性。我们已经证明，XLA/GHD患者有一种名为E74样因子4(ELF4)的基因突变，或髓系精灵1样因子(MEF1)基因ID：56501。该基因在5例男性患者中均发生突变，3例女性携带者均为杂合子，在检测的600多条正常X染色体中未发现该突变。目前的研究集中在这种基因突变的功能后果上。

Studies were performed to examine the human immune response in normal individuals and in patients with congenital and acquired immunodeficiency states associated with a high frequency of cancer. We have focused our current studies on patients with the Wiskott-Aldrich syndrome (WAS), X-linked hyper-IgM syndrome, selective IgA deficiency, Common Variable Immune Deficiency (CVID) and X-linked agammaglobulinemia and isolated growth hormone deficiency (XLA/GHD). We continue to study the function of the Wiskott-Aldrich Syndrome Protein (WASP). We have identified patients with spontaneous genetic reversions in the WASP gene and these studies have provided evidence for a selective advantage of gene corrected cells. This observation raises the possibility of a gene correction therapeutic strategy for the Wiskott-Aldrich syndrome. In fact, using such a strategy we have corrected the abnormal structural and functional phenotype of primary T-cells from WAS patients. Further studies on hemotopoetic stem cells are planned. We have also shown that the evaluation of cellular chimerism with regard to WASP expression in WAS patients after bone marrow transplantation can be easily accomplished by flow cytometry. Use of this approach should provide insight into the necessary elements for stem cell correction of the WAS lead to more scientifically-grounded bone marrow treatment strategies for the WAS.Two Phase I clinical trials have recently been completed: 1) recombinant CD40 ligand treatment of patients with X-linked hyper IgM syndrome and 2) BLyS treatment of selective IgA deficiency. Phase II clinical trials are currently being planned for both diseases. Studies have suggested a genetic basis for CVID and selective IgA deficiency. We view these diseases as allelic in nature and the result from a "leaky" failure of immunoglobulin class-switch recombination. To gain possible insight into aberrant gene expression, we are using cDNA microarrays to analyze differential gene expression in stimulated CVID and normal B-cells. We have identified a candidate gene for CVID and selective IgA deficiency. This gene is mutated in approximately 30% of the 100 patient samples already analyzed. We currently have in hand another 300 patient samples for analysis. Knowledge of the candidate gene reveals a pathway of function which is deserving of additional investigations which are currently being planned. X-linked agammaglobulinemia and isolated growth hormone deficiency (XLA/GHD) shares many features with the more common X-linked agammaglobulinemia (XLA) or Bruton's disease caused by mutations in Bruton's tyrosine kinase (Btk). We have shown XLA/GHD to be distinct from XLA since the former patients have no abnormalities in Btk expression including normal catalytic activity. We have shown that patients with XLA/GHD have mutations in a gene called E74-like factor 4(ELF4), or myeloid elf-1-like factor(MEF)-GeneID: 56501. This gene is mutated in all 5 affected male patients, all 3 female disease carriers are heterozygous for the mutation and the mutation was not observed in over 600 normal X-chromosomes examined. Current studies are focusing on the functional consequences of this gene mutation