PMN LEUKOCYTE MOTILITY/ADHESIVE PROPERTIES IN NEONATES

蛋白质卡路里营养不良的新生儿和婴儿处于高水平 由损伤引起的系统性感染的发展风险 吞噬细胞的组织动员。这些调查将 评估可能导致中性粒细胞受损的致病机制 和/或在这些和其他高危人群中动员单核细胞。 这些研究的主要重点将包括功能性的测定。 细胞黏附和迁移特性之间的关系， 这些模型中病理细胞黏附特性的表征， 以及细胞骨架蛋白可能的病理影响的决定因素 关于细胞移位和其他依赖于黏附的细胞功能。这个 “粘附性”在新生儿中性粒细胞运动障碍中的病理作用 表面糖蛋白(GP138)将用荧光法进行研究 活化细胞分选、I125免疫沉淀(放射自显影)和 Na3HB4标记技术和封堵实验 抗OKM-1、LFA-1和GP138的亚基单抗。功能和 GP138与Triton X不溶性细胞骨架的结构关系 “蛋白质”和趋化因子受体将被评估，并且 GP138的“上调”特性及表达调控 将在新生儿、成人和GP138的比较评估中进行研究 中性粒细胞缺乏。受损者病理分泌决定因素的研究 新生儿中性粒细胞运动/黏附功能异常 脱颗粒(乳铁蛋白放射免疫分析)，膜“加成”(透射电子显微镜形态计量学) 和/或细胞表面电荷的改变(细胞电泳法)，以及 分泌物的特征将在数量上和暂时相关 对GP138或FMLP受体“上调”。致病机制 新生儿白细胞造成的微管组装受损的原因将是 免疫沉淀微管蛋白的免疫化学特性研究 (双向凝胶电泳法)和定量评估 新生儿白细胞中的钙调蛋白。进一步刻画 健康和感染新生儿的趋化作用异常和 蛋白质卡路里营养不良的婴儿将使用 补体C3a和C5a的放射免疫测定、血清功能评估 趋化因子(聚集计量学和形状变化分析)。这个 趋化作用增强与卵巢癌临床发生的关系 新生儿全身感染时的中性粒细胞减少或肺功能障碍 将会被确定。最后，改良静脉注射的效果。 给健康新生儿注射免疫球蛋白 B群链球菌趋化作用和吞噬细胞作用的研究 将对体外试验进行评估。这些调查应该会提供新的 关于体外异常的临床相关性的信息 吞噬细胞的生物学功能，确定临床危险因素 和其他高危儿科宿主，并为 对这些患者炎性功能障碍的预防性或治疗性方法 临床模型。

Human neonates and infants with protein calorie malnutrition are at high risk for the development of systemic infections resulting from impaired tissue mobilization of phagocytic cells. These investigations will evaluate pathogenic mechanisms that may account for impaired PMN leukocyte and/or monocyte mobilization in these and other high risk populations. Major emphases of these studies will include determinations of functional relationships between cellular adherence and migratory properties, characterization of pathologic cell adhesive properties in these models, and determinants of possible pathologic influences of cytoskeletal proteins on cell translocation and other adherence dependent cell functions. The pathologic contributions to impaired neonatal PMN motility of "adhesive" surface glycoproteins (GP138) will be studied employing fluorescence activated cell sorting, I125 immunoprecipitation (autoradiography) and Na3HB4 labelling techniques and blocking experiments employing specific subunit monoclonal antibodies to OKM-1, LFA-1, and GP138. Functional and structural relationships of GP138 to Triton X Insoluble cytoskeletal "proteins", and chemotactic factor receptors will be evaluated, and the characteristics of "up regulation" and modulation of expression of GP138 will be studied in comparative assessments in neonatal, adult, and GP138 deficient PMNs. Studies of pathologic secretory determinants of impaired motility/adherence of neonatal PMNs including abnormalities of degranulation (lactoferrin RIA), membrane "addition" (TEM morphometry) and/or alterations of cell surface charge (cell electrophoresis), and characteristics of secretion will be quantitatively and temporarily related to GP138 or FMLP receptor "up regulation". Pathogenic mechanisms accounting for impaired microtubule assembly by neonatal leukocytes will be studied by immunochemical characterization of immunoprecipitated tubulin (two dimensional gel electrophoresis) and quantitative assessments of calmodulin in neonatal leukocytes. A further characterization of abnormalities of chemotaxigenesis in healthy and infected neonates and infants with protein calorie malnutrition will be performed employing radioimmunoassays for C3a and C5a, functional assessments of serum chemotactic factors (aggregometry and shape change assays.) The relationship of elevated chemotaxigenesis to the clinical occurence of neutropenia or pulmonary dysfunction in neonates with systemic infection will be determined. Finally, the effects of modified intravenous immunoglobulin administered to healthy neonates with respect to chemotaxigenesis by and opsonophagocytosis for Group B streptococci in vitro will be evaluated. These investigations should provide new information concerning the clinical relevance of in vitro abnormalities of biologic functions of phagocytes, identify clinical risk factors in these and other high risk pediatric hosts, and provide a rationale for preventative or therapeutic approaches to inflammatory dysfunction in these clinical models.