Abstract：
Coxsackievirus B3 (CVB3) triggers viral myocarditis, with no effective vaccine yet. This fecal-oral transmitted pathogen has prompted interest in mucosal immunization strategies to impede CVB3 spread. We developed a new attenuated vaccine strain, named CVB3(mu). The potential of CVB3(mu) to stimulate mucosal immune protection remains to be elucidated. This study evaluates the attenuation characteristics of CVB3(mu) via a rapid evolution cellular model and RNA sequencing. Its temperature sensitivity and safety were evaluated through in vitro and in vivo experiments. The mucosal immunity protection of CVB3(mu) was assessed via intranasal immunization in Balb/c mice. The results indicate that CVB3(mu) exhibits temperature sensitivity and forms smaller plaques. It sustains fewer genetic mutations and still possesses certain attenuated traits up to the 25th passage, in comparison to CVB3(WT). Intranasal immunization elicited a significant serum neutralizing antibodies, and a substantial sIgA response in nasal washes. In vivo trials revealed CVB3(mu) protection in adult mice and passive protection in suckling mice against lethal CVB3(WT) challenges. In conclusion, CVB3(mu), a live attenuated intranasal vaccine, provides protection involving humoral and mucosal immunity, making it a promising candidate to control CVB3 spread and infection.
摘要：
柯萨奇病毒B3（CVB3）引发病毒性心肌炎，还没有有效的疫苗。这种粪便-口腔传播的病原体引起了人们对粘膜免疫策略的兴趣，以阻止CVB3传播。我们开发了一种新的减毒疫苗株，命名为CVB3(mu)。CVB3(mu)刺激粘膜免疫保护的潜力仍有待阐明。本研究通过快速进化细胞模型和RNA测序评估了CVB3（mu）的衰减特征。通过体外和体内实验评估其温度敏感性和安全性。通过鼻内免疫在Balb/c小鼠中评估CVB3(mu)的粘膜免疫保护。结果表明，CVB3（mu）表现出温度敏感性，并形成较小的斑块。它维持较少的基因突变，并且直到第25代仍具有某些减弱的性状，与CVB3（WT）相比。鼻内免疫引发显著的血清中和抗体，和在鼻洗液中大量的sIgA反应。体内试验揭示了成年小鼠中的CVB3（mu）保护和乳鼠中针对致死性CVB3（WT）挑战的被动保护。总之,CVB3（亩），鼻内减毒活疫苗，提供涉及体液和粘膜免疫的保护，使其成为控制CVB3传播和感染的有希望的候选者。
