BIOLOGICAL EFFECTS OF PERTUSSIS TOXIN B-OLIGOMER

百日咳是发展中国家儿童发病的主要原因 由于对百日咳疫苗反应原性的担忧， 在发达国家的许多地区发病率都有所上升。 百日咳 毒素（PT）是百日咳杆菌的主要毒力因子， 多种效应，包括淋巴细胞增多、组胺致敏和 增强胰岛素分泌。 有趣的是，B或结合成分 PT（B-寡聚体），将其活性部分递送至靶细胞， 其自身的生物效应，即钙动员， 淋巴细胞增殖和血小板聚集。 这些行动 目前尚不清楚，独立于G- 蛋白质，PT具有其大部分已知的作用。 收购 更多的信息是重要的，因为许多无细胞百日咳疫苗 含有其中全毒素活性被消除的PT，但B-寡聚体 效果是存在的或增强的。 在这份提案中， 将评估B-寡聚体和全毒素在诱导B- 寡聚体效应（淋巴细胞增殖和血小板活化）。 的 第二信使系统涉及将探讨和其他屏幕 细胞类型将用于对B-寡聚体的应答。 B-受体 将确定低聚物的作用，并确定B- 寡聚体，以引起其影响将研究与毒素， 特定位点的突变。 最后，B-寡聚体与 钙的动员和随后的靶细胞中毒， 将研究ADP-核糖基化。 结果数据将提供一个 使用B-寡聚物作为研究工具的观点，并将指导其使用 作为无细胞百日咳疫苗中的抗原。

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.