THE ROLE OF SURFACE MOLECULES IN THE METABOLISM AND ECOLOGY OF ORAL BACTERIA

表面分子在口腔细菌代谢和生态中的作用

• 批准号: 3940004
• 负责人: J LONDON
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 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/3940004
• 关键词: Actinomyces; Actinomycetales infection; Streptococcus infection; Streptococcus sanguis; antibacterial antibody; antibody formation; cell adhesion; hybrid cells; membrane activity; microorganism metabolism; monoclonal antibody; oral bacteria; pilus

Monoclonal antibodies (MAbs) were prepared against the B. loescheii adhesins responsible for this organism's coaggregation with Streptococcus sanguis 34 and Actinomyces israelii PK14 by screening hybridoma supernatants specifically for coaggregation- blocking activity. Ten hybridomas were selected for preparation of ascites fluid in mice. Of these, 4 specifically blocked the B. loescheii - S. sanguis coaggregation and 2 inhibited the B. loescheii - A. israelii interaction. MAb or Fab' fragments inhibited these coaggregations at low levels suggesting that the antibodies were specific for regions near or at the binding sties of the respective adhesins. These MAbs were used to confirm that the adhesins consisted of a 75kD (S. sanguis specific adhesin) and 45kD (A. israelii specific adhesin) subunits, respectively, using radiolabeled adhesin-containing preparations. In the native form, the S. sanguis adhesin is a pentamer with a M.W. of 380kD. Using radiolabeled MAbs in direct binding assays, it was determined that each B. loescheii cell carries a maximum of approximately 300 S. sanguis specific adhesins and 600 A. israelii specific adhesins on its surface. The MAbs, were used also to localize the respective adhesins on the surface of the cells. Both types of adhesins were shown to be associated with the distal portion of the organisms fimbriae. The adhesions were arranged randomly in small to large clusters which extended away from the fimbriae. Preliminary studies with the radiolabeled adhesions suggest that the two types of adhesions are closely associated with one another on the surface of the cell. Employing the same strategy described above, MAbs specific for the afimbriate 250kD adhesin of Capnocytophaga gingivalis, which mediates its coaggregation with A. israelii PK16, are currently being prepared. Concurrently, the carbohydrate receptor of S. sanguis 34 which mediates coaggregation with Capnocytophaga ochracea is being purified and characterized.

制备了抗B。 Loescheii粘附素对这种生物的共聚起作用 用血链球菌34和以色列放线菌PK14 筛选杂交瘤细胞上清液以进行共聚集- 阻挡活动。选择了10株杂交瘤进行制备。 对小鼠腹水的影响。其中，有4家专门屏蔽了B。 Loescheii-S.sanguis共聚集和2抑制B. Loescheii-A.israelii相互作用。单抗或Fab片段 在低水平抑制这些共聚体，表明 抗体是针对靠近或位于结合区的区域的。 各自的粘附素。这些单抗被用来证实 粘附素由75kD(血链球菌特异性粘附素)和 45kD(以色列沙门氏菌特异性粘附素)亚基，使用 含有粘附素的放射性标记制剂。在原生形式中， 血吸虫粘附素是一种五聚体，相对分子质量为380kD。vbl.使用 在直接结合分析中，确定了放射性标记的单抗 每个B.loescheii细胞最多携带大约300S。 血吸虫特异性粘附素和600以色列血吸虫特异性粘附素 它的表面。单抗，也被用来定位各自的 细胞表面的粘附素。这两种粘附素都是 被证明与生物体的远端部分有关 菌毛。粘连按从小到大随机排列 从菌毛向外延伸的簇状物。初步 对放射性标记粘连的研究表明，这两种类型的粘连 的粘连是紧密联系在一起的 细胞的表面。 采用与上述相同的策略，单抗专用于 牙周炎微孢子虫250kD粘附素 介导其与以色列链球藻PK16的共聚集，目前 正在做准备。同时，苏云金杆菌的碳水化合物受体。 介导与吞噬细胞共聚集的Sanguis 34 赭科植物正在进行提纯和鉴定。