Laboratory Studies of Abnormal Host Defense and Immunoregulatory Diseases

1)研究单核细胞和巨噬细胞宿主抵抗新型细菌病原体贝塞登颗粒杆菌感染的决定因素 我们最近的出版物（Zarember等人，Infection and Immunity，2012）表明，G.来自慢性肉芽肿病（CGD）患者的中性粒细胞的Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesdensis-Bethesd 在2013财年，Jessica Chu（博士后IRTA）完成了一项研究，证明CGD人单核细胞和单核细胞衍生的巨噬细胞无法杀死G。Bethesdensitisnormally和这种生物体可以坚持在CGD巨噬细胞。 这篇论文还证明了IFN γ处理的单核细胞的微生物杀伤与残留中性粒细胞NADPH氧化酶活性之间的正相关性。 这一发现在使用IFN（Actimune）治疗CGD患者中具有潜在的诊断意义。 2)G.白屈菜脂多糖（LPS） 在我们研究贝氏颗粒杆菌与免疫细胞的相互作用期间，我们发现该生物体对人类先天免疫系统具有显著的低刺激性，无论是在NADPH氧化酶的弱激活方面还是在细胞因子分泌的不良刺激方面。我们正在与格鲁吉亚大学复杂碳水化合物研究中心的Yossi Shiloach（NIDDK）和Russell Carlson合作，完成这种生物体的非典型脂多糖（LPS）的纯化和结构表征，并确定它是否作为抗炎抑制性LPS。 3)贝塞登木甲醇脱氢酶 为了开发我们对贝塞登革菌感染的血清学检测（参见ZIA AI 000155 -36），我们从该微生物中纯化了甲醇脱氢酶。 使用离子交换和凝胶过滤，制备了高度富集的酶，并且正在进行生物化学测试以鉴定底物特异性，鉴定抑制剂，并且表明了最初认为的更广泛的底物特异性。在与Peter施泰因巴赫（NIH分子模型中心）的合作下，我们对G.白菊

1) To study the determinants of monocyte and macrophage host defenses against infection by the novel bacterial pathogen, Granulibacter bethesdensis Our recent publication (Zarember et al., Infection and Immunity, 2012) demonstrated that killing of G. bethesdensis by neutrophils from patients with chronic granulomatous disease (CGD) was defective and that this Gram-negative pathogen was remarkably resistant to complement and to cationic antimicrobial peptides. During FY13, Jessica Chu (Postdoctoral IRTA) completed a study demonstrating that CGD human monocytes and monocyte-derived macrophages were unable to kill G. bethesdensis normally and that this organism could persist in CGD macrophages. This paper also demonstrated a positive correlation between microbial killing by IFNgamma-treated monocytes and residual neutrophil NADPH oxidase activity. This finding has potential diagnostic implications in the use of IFN (Actimune) to treat CGD patients. 2) G. bethesdensis Lipopolysaccharide (LPS) During our studies of the interaction of Granulibacter bethesdensis with immune cells, we found that this organism is remarkably hypostimulatory of the human innate immune system, both in terms of weak activation of the NADPH oxidase and poor stimulation of cytokine secretion. We are collaborating with Yossi Shiloach (NIDDK) and Russell Carlson of the University of Georgia Complex Carbohydrate Research Center to complete the purification and structural characterization of the atypical lipopolysaccharide (LPS) of this organism and determine whether it acts as an anti-inflammatory inhibitory LPS. 3) G.bethesdensis Methanol Dehydrogenase In order to develop our serological testing for G.bethesdensis infection (see ZIA AI000155-36), we purified Methanol Dehydrogenase from this organism. Using ion exchange and gel filtration, highly enriched enzyme was prepared and biochemical testing is underway to identify substrate specificity, identify inhibitors, and s indicate a much broader substrate specificity that originally thought. In collaboration with Peter Steinbach (NIH Center for Molecular Modeling), we have modeled the structure of G. bethesdensis MDH.