State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, North Third Road, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China.
Vaccine. 2013 Feb 27;31(10):1400-5. doi: 10.1016/j.vaccine.2012.12.079. Epub 2013 Jan 7.
Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is an important pathogen associated with opportunistic infections of a wide range of species, including horses, pigs and humans. The absence of suitable vaccine confounds the control of SEZ infection. Cell surface protein (CSP) has been identified as an immunogenic protein in the previous study but its protective efficacy is not clear. In the present study, the purified recombinant CSP could elicit a significant humoral antibody response and could confer significant protection against challenge with lethal dose of SEZ in mice model. CSP could adhere to the HEp-2 cells confirmed by flow cytometry and inhibit adherence of SEZ to HEp-2 cells in an adherence inhibition assay. In addition, real-time PCR demonstrated that CSP was induced in vivo following infection of mice with SEZ. Our findings suggest that CSP may play a potential role in the pathogenesis of SEZ and could be a target for the development of a novel subunit vaccine against SEZ infection.
马链球菌兽疫亚种（Streptococcus equi ssp. zooepidemicus，SEZ）是一种重要的病原体，与多种物种的机会性感染有关，包括马、猪和人类。缺乏合适的疫苗使得 SEZ 感染的控制变得复杂。在之前的研究中，细胞表面蛋白（CSP）已被鉴定为一种免疫原性蛋白，但它的保护效果尚不清楚。在本研究中，纯化的重组 CSP 可引起显著的体液抗体反应，并可显著保护小鼠免受致死剂量 SEZ 的攻击。流式细胞术证实 CSP 可黏附于 HEp-2 细胞，并在黏附抑制试验中抑制 SEZ 与 HEp-2 细胞的黏附。此外，实时 PCR 表明 CSP 在 SEZ 感染小鼠后可在体内诱导。我们的研究结果表明，CSP 可能在 SEZ 的发病机制中起重要作用，可能成为开发针对 SEZ 感染的新型亚单位疫苗的靶标。
