The immunological mechanisms of in ovo vaccination

在OVO中，接种疫苗是鸡孵化后接种疫苗的一种替代方法。这是一种安全、动物和用户友好的方法，可以每小时接种约60,000个鸡蛋。这项技术已经开发得很好，可以使用病毒载体接种病毒疾病，推广细菌和寄生虫疫苗技术的努力正在进行中。尽管在卵子疫苗接种中可以成功，但新生儿的不成熟免疫系统显示出功能缺陷，限制了这项技术的成功率。目前家禽业使用的体内疫苗是活体复制病毒。为了推广和改进这项技术应用于灭活疫苗或佐剂亚单位疫苗，了解早期生命免疫本体论以及影响粘膜表面抗原摄取和诱导免疫反应的细胞和分子机制是至关重要的。我们将调查鸟类新生儿的免疫环境是否像以前在哺乳动物中所显示的那样，随着Th1型反应的抑制而两极分化为Th2型免疫。先天免疫还表现出抗原提呈细胞的功能缺陷；Toll样受体的表达和信号传递经历了与不同功能反应相关的成熟变化。因此，该项目将检验这一假设，即通过适当的刺激可以克服新生儿先天和获得性免疫系统固有的调节限制。已经提出了多种方法，包括提高训练有素的先天免疫，改变先天受体激动剂和新的年龄特异性佐剂系统。彻底了解免疫本体论以及可能影响新生儿免疫反应诱导的细胞和分子因素将是该项目的一部分。

In ovo vaccination is an alternative approach to post-hatch vaccination of chickens. It is a safe, animal and user-friendly method that enables vaccination ~60,000 eggs per hour. The technology has been well developed for vaccination against viral diseases using viral vectors and efforts to extend the technology for bacterial and parasitic vaccines are in progress. Although in ovo vaccination can be successful, the immature immune system of a neonate shows functional deficiencies that limit the success rate of this technology. The in ovo vaccines currently used in the poultry industry are live replicating viruses. To extend and improve this technology for application of inactivated vaccines or adjuvanted subunit vaccines, it is of utmost importance that we understand early life immune ontology and the cellular and molecular mechanisms that affect antigen uptake at mucosal surfaces and induction of immune responses. We will investigate if the avian neonatal immunological milieu is polarised towards Th2-type immunity with dampening of Th1-type responses as previously shown in mammals. Innate immunity also shows functional deficiency in antigen-presenting cells; expression and signalling of Toll-like receptors undergo maturational changes associated with distinct functional responses. Therefore, this project will test the hypothesis that the inherent regulatory constraints of the neonate innate and adaptive immune system can be surmounted by appropriate stimulation. A variety of approaches have been proposed including improved trained innate immunity, altered innate receptor agonists and novel age-specific adjuvantation systems. Gaining a thorough understanding of the immune ontology and cellular and molecular factors that can influence the induction of immune responses in neonates will part of this project.