CHOLERA--PATHOGENESIS AND IMMUNOLOGY

本研究的目的是帮助了解 霍乱是一种由弧菌引起的流行性肠道疾病， cholesterol 01，在有机体和分子水平上， 期望这些信息将导致理性的发展， 和有效的免疫预防手段。 因为霍乱是 越来越多的妇科疾病是由 在结构、功能和免疫学上 与霍乱肠毒素有关，观察结果与以下方面有关： 数十亿病例和数百万死亡的更大的全球性问题 每年都有大量的儿童死于疟疾，尤其是第三世界的儿童。 霍乱肠毒素（CT）于1959年被发现， 1969年的部分特征。 在随后的时期，期望， 与白喉和破伤风一样，类毒素疫苗可以预防这种疾病。 尽管早期的实验令人鼓舞， 意见。 现在人们知道，这种疾病，霍乱，是一种有效的 一种免疫过程，在此过程中，人类宿主与一种聚生体接触 霍乱弧菌在体内生长的产物 小肠 除了肠毒素，还包括定植 因子，如毒素协同调节的皮利（TCP）、其他表面成分 包括脂多糖（LPS）和外膜蛋白、HA/蛋白酶 和其他可溶性因子，细胞相关的甘露糖敏感的 E1 Tor生物型的血凝素、鞭毛和可能的其他血凝素 因素 这种疾病在人体内引起的牢固免疫力还没有 被非活体制剂复制，胃肠外给药或 口服给药，或通过活的减毒突变体，口服给药， 尽管已经获得了一定程度的保护--即使在没有 毒素抗原 毒素抗原本身的研究结果 更加令人失望 这一建议解决了一些原因， 对于以前的失败的类毒素疫苗，它解决了发展， 一种新型霍乱疫苗，由一种无毒的脱脂脂LPS结合物组成 和霍乱毒素;此外，它将继续处理其他 可能导致野生型的毒力和免疫原性的因素， 型霍乱弧菌。 该技术包括合成， 序列连续重叠肽的分析 CT的免疫显性B亚基蛋白和位点- 特异性诱变以产生产生CT的霍乱弧菌菌株 其无毒但表达全毒素的主要表位。 这 CT还将与LPS寡糖交联以形成缀合物 能刺激抗菌和抗毒免疫的疫苗。 我们 将进一步检查和定义HA/蛋白酶和甘露糖的作用- 霍乱弧菌附着和/或脱离中的敏感血凝素 并检查相位变化在胆总管静脉混浊中的意义 殖民地

The goals of this research are to contribute to the understanding of the pathogenesis of cholera, an epidemic diarrheal disease caused by Vibrio cholerae 01, at both the organismal and the molecular levels, with the expectation that this information will lead to the development of rational and effective means of immunoprophylaxis. As cholera is the prototype of an expanding number of diarrheal diseases which are mediated by enterotoxins which are structurally, functionally and immunologically related to the cholera enterotoxin(s), the observations are pertinent to the larger global problem of the billions of cases and millions of deaths annually from diarrheal diseases especially in children in the Third World. Cholera enterotoxin (CT) was discovered in 1959 and it was purified and partially characterized in 1969. In the ensuing period, expectations that, as with diptheria and tetanus, a toxoid vaccine would prevent the disease have not been fulfilled despite early encouraging experimental observations. It is now known that the disease, cholera, is an effective immunizing process in which the human host is presented with a consortium of products elaborated by the cholera vibrios growing in vivo in/on the small bowel. In addition to the enterotoxin, these include colonization factors, such as toxin-coregulated pili (TCP), other surface components including lipopolysaccharide (LPS) and outer membrane proteins, HA/protease and other soluble factors, the cell-associated mannose-sensitive hemagglutinin of the E1 Tor biotype, the flagellum and, possibly, other factors. The solid immunity evoked in people by the disease has not yet been duplicated by non-living preparations, administered parenterally or perorally, or by living attenuated mutants, administered perorally, although some degree of protection has been attained -- even in the absence of toxin antigen. Results of studies with toxin antigen by itself have been even more disappointing. This proposal addresses some of the reasons for previous failures of toxoid vaccines; it addresses the development of a new cholera vaccine to consist of a non-toxic conjugate of de-lipidated LPS and cholera toxin; and, in addition, it will continue to address other factors which may contribute to the virulence and immunogenicity of wild- type cholera vibrios in vivo. The technology includes the synthesis and analysis of sequential continuous overlapping peptides comprising the immunologically dominant B-subunit protein of CT and the use of site- specific mutagenesis to create a V. cholerae strain which produces a CT which is not toxic but expresses the major epitopes of the holotoxin. This CT will also be cross-linked to LPS oligosaccharide to form a conjugate vaccine which will stimulate both antibacterial and antitoxic immunity. We will further examine and define the role of HA/protease and the mannose- sensitive hemagglutinin in attachment and/or detachment of cholera vibrios and examine the significance of phase variation in opacity of V. cholerae colonies.