STUDIES OF MAC-1 LEUKOCYTE GLYCOPROTEINS IN PERIODONTIT

中性粒细胞/单核细胞趋化功能的紊乱一直是 在K局限性青少年牙周炎（LJP）或全身性 青少年牙周炎（GJP）综合征，但分子致病 这些细胞异常的潜在机制还没有完全 阐明。 最近的研究发现了一种新发现的基因 以复发性软组织感染为特征的病症（包括 严重的青春期前泛发性牙周炎），和严重的缺陷， PMN/单核细胞趋化性和其他粘附依赖性细胞功能 其与“粘合剂”家族的缺乏有因果关系， 糖蛋白（Mac-1 [IC 3b受体]，LFA-1和p150，95）表达于 白细胞表面。 拟议的研究将评估：（1）潜在的 Mac-1糖蛋白表达/功能的内在异常 GJF白细胞的LJP，和（2）微生物的可能的病理作用 Mac-1蛋白质。 粘附依赖性PMN/单核细胞功能 （趋化性、聚集、IC 3b吞噬作用或细胞毒性）将被 在设计为使Mac-1最大化的趋化性条件下评估， p150，95表面表达。 这些研究将涉及定量 使用特异性单克隆抗体评估表面蛋白表达 免疫荧光流式细胞术和125 I 免疫沉淀技术。 因为我们的初步研究表明 LJP中性粒细胞的受激Mac-1表达和过度粘附受损， 将使用另外的技术来定量细胞内的 细胞组分中的Mac-1蛋白（伴刀豆球蛋白A -免疫印迹 技术）或这些分子在EBV转化的细胞中的生物合成 淋巴细胞（35 S蛋氨酸标记）。 抗Mac-1单克隆抗体的应用 将尝试在LJP中识别受影响的患者或杂合子 这可能允许阐明的遗传传播的kinetics， 疾病 “牙周病”的可能继发影响 还将评价微生物对Mac-1糖蛋白表达的影响; 正常PMN/单核细胞将与培养物或超声处理物一起孵育 放线共生放线杆菌（Actinobacillus actinomycetemcomitans）、拟杆菌（Bacteroides）和二氧化碳嗜纤维菌（Capnocytophaga sp.） 在趋化性和其他粘附依赖性功能测定中，和 同时评估的表达、功能或诱导 Mac-1 我们的研究应该通过以下方式扩展以前的实验观察： (1)为受损的趋化性和其他 LJP激酶中的白细胞功能异常，（2）描绘 内在（遗传）和/或继发性病理机制和（3） 提供用于鉴定受影响个体的分子标记，或 LJP或GJP性状的杂合子。

Disturbed PMN/monocyte chemotactic function has been consistently demonstrated in K localized juvenile periodontitis (LJP) or generalized juvenile periodontititis (GJP) syndromes, but molecular pathogenic mechanisms underlying these cellular abnormalities have not been fully elucidated. Recent studies have identified a newly recognized genetic disorder characterized by recurrent soft tissue infections (including severe prepubertal generalized periodontitis), and severe deficits of PMN/monocyte chemotaxis and other adherence-dependent cellular functions which are causally related to a deficiency of a family of "adhesive' glycoproteins (Mac-1 [IC3b receptor], LFA-1, and p150, 95) expressed on leukocyte surfaces. The proposed studies will evaluate: (1) potential intrinsic abnormalities of expression/function of Mac-1 glycoproteins of LJP of GJF leukocytes, and (2) possible pathologic effects of microbial products on Mac-1 proteins. Adherence-dependent PMN/monocyte functions (chemotaxis, aggregation, IC3b phagocytosis or cytotoxicity) will be assessed under chemotactic conditions designed to maximize Mac-1 and p150,95 surface expression. These studies will be related to quantitative assessments of surface protein expression employing specific monoclonal antibodies (MAb) in immunofluorescence flow cytometry and 125I immunoprecipitation techniques. Since our preliminary studies indicate impaired stimulated Mac-1 expression and hyperadherence of LJP PMNs, additional techniques will be used to quantitate intracellular pools of Mac-1 proteins in cellular fractions (conconavalin A - immunoblot technique) or biosynthesis of these molecules in EBV-transformed lymphocytes (35S methionine labeling). Applications of anti-Mac-1 MAbs will attempt to identify affected patients or heterozygotes among LJP kindreds which may allow an elucidation of the genetic transmission of disease. Possible secondary influences of "periodontopathic" microorganisms on Mac-1 glycoprotein expression will also be evaluated; normal PMN/monocytes will be incubated with culture filtrates or sonicates of Actinobacillus actinomycetemcomitans, Bacteroides and Capnocytophaga sp. in chemotaxis and other adherence-dependent functional assays, and concurrently assessed with respect to expression, function or induction of Mac-1. Our studies should extend previous experimental observations by: (1) providing a molecular basis for impaired chemotaxis and other abnormalities of leukocyte function among LJP kindreds, (2) delineating intrinsic (genetic) and/or secondary pathologic mechanisms and (3) providing a molecular marker for identification of affected individuals or heterozygotes for LJP or GJP traits.