BIOLOGICAL EFFECTS OF PERTUSSIS TOXIN B-OLIGOMER

百日咳是发展中国家儿童发病率的主要原因。 由于对百日咳疫苗反应性的担忧， 在发达国家的许多地区，发病率有所增加。百日咳 百日咳杆菌毒素(PT)是百日咳杆菌的主要毒力因子。 各种效应，包括淋巴细胞增多，对组胺的敏化，以及 促进胰岛素分泌。有趣的是，B或结合成分 将其活性部分递送到靶细胞的PT(B-寡聚体)具有 其本身的生物学效应，即钙动员随后 淋巴细胞增殖和血小板聚集。这些行动，即 都不依赖于G-的ADP-核糖化。 PT具有已知的大部分作用的蛋白质。收购 更多的信息是重要的，因为许多无细胞百日咳疫苗 含有可消除全毒素活性的PT，但含有B-齐聚物 效果存在或增强。在这项提案中，不同的准备工作 将评估B-寡聚体和全毒素在诱导B-低聚体和全毒素中的效力。 寡聚体效应(淋巴细胞增殖和血小板活化)。这个 将探索涉及的第二个信使系统，并展示其他 细胞类型将根据对B-寡聚体的反应而定。B-受体 将确定齐聚物的作用并确定B-的结构要求 将用含有毒素的低聚物来研究其影响 特定位置的突变。最后，B-齐聚物之间的关系 钙的动员和随后靶细胞的中毒 将研究ADP-核糖基化。生成的数据将提供 B-齐聚物作为研究工具的前景及其指导作用 作为无细胞百日咳疫苗的抗原。

Pertussis is a major cause of childhood morbidity in the developing world and as a result of concerns about pertussis vaccine reactogenicity, has increased in incidence in many areas of the developed world. Pertussis toxin (PT), a major virulence factor of Bordetella pertussis, elicits a variety of effects including lymphocytosis, sensitization to histamine, and enhancement of insulin secretion. Intriguingly, the B or binding component of PT (B-oligomer), which delivers its active portion to target cells, has biological effects of its own, namely calcium mobilization followed by lymphocyte proliferation and platelet aggregation. These actions, which are poorly understood, are independent of the ADP-ribosylation of G- proteins by which PT has the majority of its known effects. Acquisition of more information is important because many acellular pertussis vaccines contain PT in which holotoxin activities are eliminated, but B-oligomer effects are present or enhanced. In this proposal, different preparations of B-oligomer and holotoxin will be evaluated for potency in eliciting B- oligomer effects (lymphocyte proliferation and platelet activation). The second messenger systems involved will be explored and a screen of other cell types will be made for responses to B-oligomer. The receptor for B- oligomer action will be identified and the structural requirements for B- oligomer to elicit its effects will be studied with toxins containing mutations at specific sites. Finally, the relationship between B-oligomer mobilization of calcium and the subsequent intoxication of a target cell by ADP-ribosylation will be investigated. The resultant data will provide a perspective on using B-oligomer as a research tool and will guide its use as an antigen in acellular pertussis vaccine.