Abstract:
Mycoplasma bovis (M. bovis) is the etiologic agent of high mortality epizootics of chronic respiratory disease in American bison (Bison bison). Despite the severity of the disease, no efficacious commercial vaccines have been licensed for the prevention of M. bovis infection in bison. Elongation factor thermal unstable (EFTu) and Heat Shock Protein 70 (Hsp70, DnaK) are highly conserved, constitutively expressed proteins that have previously been shown to provide protection against M. bovis infection in cattle. To assess the suitability of EFTu and Hsp70 as vaccine antigens in bison, the immune response to and protection conferred by an injectable, adjuvanted subunit vaccine comprised of recombinantly expressed EFTu and Hsp70 was evaluated. Vaccinates developed robust antibody and cellular immune responses against both EFTu and Hsp70 antigens. To assess vaccine efficacy, unvaccinated control and vaccinated bison were experimentally challenged with bovine herpes virus-1 (BHV-1) 4 days prior to intranasal infection with M. bovis. Vaccinated bison displayed reductions in joint infection, lung bacterial loads, and lung lesions compared to unvaccinated controls. Together, these results showed that this subunit vaccine reduced clinical disease and bacterial dissemination from the lungs in M. bovis challenged bison and support the further development of protein subunit vaccines against M. bovis for use in bison.
摘要:
牛支原体(M.bovis)是美国野牛(Bisonbison)慢性呼吸道疾病高死亡率流行病学的病原体。尽管疾病严重,没有有效的商业疫苗被许可用于预防野牛中的牛分枝杆菌感染。延长因子热不稳定(EFTu)和热休克蛋白70(Hsp70,DnaK)是高度保守的,组成型表达的蛋白质,其先前已被证明在牛中提供对抗牛分枝杆菌感染的保护。为了评估EFTu和Hsp70作为野牛疫苗抗原的适用性,对注射剂赋予的免疫反应和保护,评价由重组表达的EFTu和Hsp70组成的佐剂化亚单位疫苗。疫苗针对EFTu和Hsp70抗原产生了强大的抗体和细胞免疫反应。为了评估疫苗的功效,在用牛分枝杆菌鼻内感染之前4天用牛疱疹病毒-1(BHV-1)实验攻击未接种的对照和接种的野牛。接种疫苗的野牛显示关节感染减少,肺细菌负荷,与未接种疫苗的对照组相比,肺部病变。一起,这些结果表明,这种亚单位疫苗减少了牛分枝杆菌攻击野牛的临床疾病和肺部细菌传播,并支持进一步开发用于野牛的针对牛分枝杆菌的蛋白质亚单位疫苗。