Gene Regulation Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, 751002, India.
Fish Shellfish Immunol. 2018 Sep;80:563-572. doi: 10.1016/j.fsi.2018.06.041. Epub 2018 Jun 27.
The outer-membrane proteins (OMPs) of Aeromonas hydrophila, an imperative fish pathogen accountable for massive economic losses to aquaculture industry, are found to be immunogenic and considered as potential vaccine candidates. In spite of development in the formulation of vaccine candidates against Aeromonas infection, no commercial preparation has been done so far; in addition, the molecular mechanisms of immunoprotection induced by various vaccine formulations in Indian major carp, Labeo rohita, are little known. The present study was undertaken to evaluate the modulation of immunity and expression of immune-related genes post-rOmpF (recombinant outer-membrane protein of A. hydrophila, a novel vaccine candidate) immunization and protective efficacy after A. hydrophila challenge. The rOmpF-immunized fish showed a variable expression of the immune-related genes, viz. toll-like receptor 22 (TLR), complement component 3 (C3), chemokine (CXCa), tumor necrosis factor-α (TNFα), interleukin 1β (IL-1β), manganese superoxide dismutase (MnSOD) and natural killer enhancing factor (NKEF) in the head kidney tissues, when compared to the control group at different time intervals post-vaccination. A significant increase in serum hemolysin titer, ceruloplasmin level and myeloperoxidase activity was observed on day 140 post immunization. Also, bacterial agglutination titer and antiprotease activity were significantly increased on day 42 post immunization. No significant change was observed in lysozyme activity. Challenge studies with live A. hydrophila on day 140 post-immunization of L. rohita significantly increased the relative percentage survival (∼44%) in the vaccinated group. The results suggest that the rOmpF could be used as a potential vaccine candidate to combat A. hydrophila infection in fish.
嗜水气单胞菌的外膜蛋白（OMPs）是一种重要的鱼类病原体，对水产养殖业造成了巨大的经济损失，这些蛋白被发现具有免疫原性，可作为潜在的疫苗候选物。尽管已经开发出针对嗜水气单胞菌感染的疫苗候选物，但到目前为止还没有商业化的制剂；此外，印度主要鲤鱼，罗非鱼，中各种疫苗制剂诱导的免疫保护的分子机制知之甚少。本研究旨在评估 rOmpF（重组嗜水气单胞菌外膜蛋白，一种新型疫苗候选物）免疫接种后免疫调节和免疫相关基因的表达以及在受到嗜水气单胞菌攻击后的保护效果。rOmpF 免疫的鱼类在头肾组织中表现出免疫相关基因（如 TLR22、C3、CXCa、TNFα、IL-1β、MnSOD 和 NKEF）的可变表达，与对照组相比，在不同的时间间隔内，免疫接种后。在免疫后第 140 天，血清溶血素滴度、铜蓝蛋白水平和髓过氧化物酶活性显著增加。此外，在免疫后第 42 天，细菌凝集滴度和抗蛋白酶活性显著增加。溶菌酶活性没有显著变化。在 rOmpF 免疫罗非鱼后第 140 天进行活体嗜水气单胞菌攻毒试验，疫苗组的相对存活率（约 44%）显著提高。结果表明，rOmpF 可用作鱼类抵抗嗜水气单胞菌感染的潜在疫苗候选物。
