Immunological properties of a heat schock protein from Actinobacillus actinomycetemcomitans.

伴放线放线杆菌是一种兼性革兰氏阴性杆菌，被认为与人类牙周疾病有关。热休克蛋白是一组具有保守结构的蛋白质，它们是响应温度突然升高或其他环境胁迫而合成的。在热休克蛋白中，64-kDa GroEL样蛋白与自身免疫性疾病如类风湿性关节炎的病因有关。本研究对伴放线放线菌和其他牙周致病菌的GroEL样蛋白进行了生化和免疫学特性的研究，对伴放线菌Y 4全细胞SDS提取物的SDS-聚丙烯酰胺凝胶电泳结果表明，从30 ℃到42 ℃或50 ℃的温度变化导致64-kDa蛋白的相对量显著增加。抗伴放线放线菌64 kDa蛋白的单克隆抗体与伴放线菌血清型a和嗜aphrophilus嗜血杆菌、流感嗜血杆菌的62至64 kDa蛋白发生交叉反应。嗜副沫嗜血杆菌。和大肠杆菌。抗Y 4菌株全细胞的兔抗血清与伴放线放线菌Y 4的64-kDa蛋白强烈反应。Westernblot分析表明，18名健康人血清几乎没有与伴放线放线菌Y 4的64-kDa蛋白反应，而1名健康人血清与64-kDa蛋白反应很弱。两个血清从2个本地化的青少年牙周炎患者强烈反应的64 kDa的蛋白质。此外，19例快速进展性牙周炎患者的6份血清与64 kDa蛋白反应。这些结果表明，放线菌的64-kDa蛋白可能是该生物体的免疫显性抗原。

Actinobacillus actinomycelemcomitans is a facultative gram-negative rod that is considered to be associated with human periodontal diseases. Heat shock proteins are a group of proteins with a conserved structure that are synthesized in response to a sudden increase in temperature or to other environmental stress. Among heat shock proteins, the 64-kDa GroEL-like protein has been implicated in the etiology of autoimmune diseases such as rheumatoid arthritis. In this study, we have examined biochemical and immunological properties of a GroEL-like protein from A.actinomycelemcomitans and other periodontopathogenic bacteria.SDS-polyacrylamide gel electrophoresis of SDS extracts from whole cells of A.actinomycelemcomitans Y4 showed that the shift from 30ﾟC to 42ﾟC or 50ﾟC brought about a significant increase in the relative amount of a 64-kDa protein. Monoclonal antibodies to the 64-kDa protein of A.actinomycelemcomitans cross-reacted with 62 to 64-kDa proteins of A.actinomycelemcomitans serotype a and c.Haemophilus aphrophilus, Haemophilus influenzae. Haemophilus paraphrophilus. and Escherichia coli. Rabbit antisera to whole cells of strain Y4 strongly reacted with the 64-kDa protein of A.actinomycelemcomitans Y4. Western blot analysis showed that alomost no sera from 18 healthy individuals reacted with the 64-kDa protein of A.actinomycelemcomitans Y4.although one serum from one healthy subject did react very weakly with the 64-kDa protein. Both sera from 2 localized juvenile periodontitis patients strongly reacted with the 64-kDa protein. In addition, 6 sera from 19 rapidly progressive periodontitis patients reacted with the 64-kDa protein. These results suggest that the 64-kDa protein of A.actinomycelemcomitans may be an immunodominant antigen of the organism.