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.
Res Vet Sci. 2013 Oct;95(2):444-50. doi: 10.1016/j.rvsc.2013.03.026. Epub 2013 Apr 28.
Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is responsible for septicemia, meningitis, arthritis and several other serious diseases in various species with adhesive and invasive properties. The absence of suitable vaccine confounds the control of SEZ infection. The highly conserved C5a peptidase was served as an invasin to host epithelial cells and involved in the pathogenicity in other streptococcus species. In the present study, the purified recombinant SEZ C5a peptidase (rSCPZ) could adhere to Hep-2 cells and interfere with the invasion of SEZ into Hep-2 cells confirmed by adherence and invasion assay. Immunization of BALB/c mice with rSCPZ could elicit a significant humoral antibody response and could confer significant protection against challenge with a lethal dose of SEZ. In addition, the hyperimmune sera against rSCPZ could efficiently inhibit bacterial growth in a whole blood assay and confer significant protection against SEZ infection in the experiment of passive immunization. The present study suggests that SCPZ could be useful for development of subunit vaccine against SEZ.
马链球菌兽疫亚种（Streptococcus equi ssp. zooepidemicus，SEZ）具有黏附和侵袭特性，可引起多种动物的败血症、脑膜炎、关节炎和其他严重疾病。由于缺乏合适的疫苗，SEZ 感染的防控变得更加复杂。高度保守的 C5a 肽酶被用作侵袭宿主上皮细胞的侵袭素，并参与其他链球菌种的致病性。在本研究中，纯化的重组 SEZ C5a 肽酶（rSCPZ）可通过黏附和侵袭试验证实其能黏附 Hep-2 细胞并干扰 SEZ 对 Hep-2 细胞的侵袭。用 rSCPZ 免疫 BALB/c 小鼠可诱导显著的体液抗体应答，并可显著保护小鼠免受致死剂量 SEZ 的攻击。此外，针对 rSCPZ 的高免血清可在全血试验中有效抑制细菌生长，并在被动免疫实验中对 SEZ 感染提供显著保护。本研究表明，SCPZ 可用于开发针对 SEZ 的亚单位疫苗。
