Dissection of protective responses to heterologous Campylobacter vaccines

空肠弯曲杆菌是细菌性食源性人畜共患病的最大病因。弯曲杆菌大量定植的家禽与人类疾病之间存在密切联系。通过接种疫苗减少鸡体内弯曲杆菌的能力将大大减少人类感染。最近有研究表明，一种沙门氏菌疫苗向鸡的免疫系统提供一种特定的弯曲杆菌蛋白（CjaA），可以防止弯曲杆菌的定植。CjaA是一种氨基酸转运体，我们已经确定了其他几种类似的转运体作为疫苗的候选体。我们已经证明当弯曲杆菌在鸡的肠子里时它们就会被表达出来。我们将在沙门氏菌表达这些其他转运蛋白的地方制造疫苗，并测试它们的保护作用。CjaA疫苗起作用的原因尚不清楚。用于向鸡疫苗中呈递CjaA的沙门氏菌株仍然具有一定的毒力特征，这可能会推动免疫的发展。我们将研究不同毒力的沙门氏菌疫苗株在发展针对CjaA的免疫反应中的作用。了解沙门氏菌毒力特性在疫苗功能中的作用将有助于制定更好的控制弯曲杆菌的策略。与BB/D00019X/1接头

Campylobacter jejuni is the largest cause of bacterial food borne zoonoses. There is a strong link between poultry, which are colonised to a high level by Campylobacter, and human disease. The ability to reduce Campylobacter in chickens by vaccination would greatly reduce human infection. Recently it has been shown that a Salmonella vaccine which presents a specific Campylobacter protein (CjaA), to the chicken immune system can protect against Campylobacter colonisation. CjaA is a transporter of amino-acids and we have identified several other similar transporters as candidates for vaccines. We have shown these are expressed when Campylobacter is in the intestines of the chicken. We will create vaccines where Salmonella expresses these other transport proteins and test them for protection. The reason why the CjaA vaccine works is not clear. The Salmonella strain that is used to present CjaA to the chicken vaccine still possesses some virulence traits which may drive the development of immunity. We will investigate the role of Salmonella vaccine strains which vary in their virulence, in the development of the immune response against CjaA. The understanding of the role of the Salmonella virulence properties in function of the vaccine will allow the development of improved strategies for control of Campylobacter. Joint with BB/D00019X/1