Zhang Ze, Yu Angen, Lan Jiangfeng, Zhang Hua, Hu Minqiang, Cheng Jiewei, Zhao Lijuan, Lin Li, Wei Shun
Department of Aquatic Animal Medicine, Research Center for Marine Biology, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, China; School of Life Sciences, Beijing Normal University, Beijing, 100875, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Changping, 102206, Beijing, China.
Department of Aquatic Animal Medicine, Research Center for Marine Biology, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
Fish Shellfish Immunol. 2017 Apr;63:255-260. doi: 10.1016/j.fsi.2017.02.019. Epub 2017 Feb 20.
Streptococcosis due to the bacterium Streptococcus agalactiae (S. agalactiae) has resulted in enormous economic losses in aquaculture worldwide, especially in the tilapia culture industry. Previously, there were limited vaccines that could be employed against streptococcosis in tilapia. This study aimed to develop a vaccine candidate using the glyceraldehyde-phosphate dehydrogenase protein (GapA) of S. agalactiae encoded by the gapA gene. Tilapia were intraperitoneally injected with PBS, PBS + Freund's adjuvant, PBS + Montanide's adjuvant, GapA + Freund's adjuvant, GapA + Montanide's adjuvant, killed S. agalactiae whole cells (WC)+Freund's adjuvant, or killed S. agalactiae whole cells (WC)+ Montanide's adjuvant. They were then challenged with S. agalactiae, and the relative percentage survival (RPS) was monitored 14 days after the challenge. The highest RPSs were observed in the WC groups, with 76.7% in WC + Freund's adjuvant and 74.4% in WC + Montanide's adjuvant groups; these were followed by the GapA groups, with 63.3% in GapA + Freund's adjuvant and 45.6% in GapA + Montanide's adjuvant groups. The RPS of the PBS group was 0%, and those of PBS + Freund's adjuvant and PBS + Montanide's adjuvant groups were 6.7% and 3.3%, respectively. Additionally, the IgM antibody responses elicited in GapA groups and WC groups were significantly higher than those in PBS groups. Furthermore, the expressions of cytokine (IL-1β and TNF-α) mRNAs in the GapA groups and WC groups were significantly higher than those in the PBS groups. Taken together, these results reveal that the GapA protein is a promising vaccine candidate that could be used to prevent streptococcosis in tilapia.
由无乳链球菌（S. agalactiae）引起的链球菌病已在全球水产养殖业中造成巨大经济损失，尤其是在罗非鱼养殖业。以前，可用于预防罗非鱼链球菌病的疫苗有限。本研究旨在利用gapA基因编码的无乳链球菌甘油醛-3-磷酸脱氢酶蛋白（GapA）开发一种候选疫苗。给罗非鱼腹腔注射磷酸盐缓冲液（PBS）、PBS + 弗氏佐剂、PBS + 蒙旦尼佐剂、GapA + 弗氏佐剂、GapA + 蒙旦尼佐剂、灭活的无乳链球菌全菌（WC）+ 弗氏佐剂或灭活的无乳链球菌全菌（WC）+ 蒙旦尼佐剂。然后用无乳链球菌对它们进行攻毒，并在攻毒后14天监测相对存活率（RPS）。在WC组中观察到最高的RPS，WC + 弗氏佐剂组为76.7%，WC + 蒙旦尼佐剂组为74.4%；其次是GapA组，GapA + 弗氏佐剂组为63.3%，GapA + 蒙旦尼佐剂组为45.6%。PBS组的RPS为0%，PBS + 弗氏佐剂组和PBS + 蒙旦尼佐剂组的RPS分别为6.7%和3.3%。此外，GapA组和WC组引发的IgM抗体反应明显高于PBS组。此外，GapA组和WC组中细胞因子（IL-1β和TNF-α）mRNA的表达明显高于PBS组。综上所述，这些结果表明GapA蛋白是一种有前景的候选疫苗，可用于预防罗非鱼的链球菌病。
