C5a, the most potent anaphylatoxin generated during complement activation, has important proinflammatory actions and has also been shown to enhance antigen-specific antibody response in mammals, thereby acting as a molecular adjuvant. In rainbow trout, C5a has been shown to have a chemoattractant ability and its receptor has also been found on potential APCs. In this study, we tested the possible role of trout C5a as a molecular adjuvant. We demonstrated the presence of native C5a in trout serum using the antibody generated by recombinant trout C5a, and then we generated recombinant infectious hematopoietic necrosis virus glycoprotein (G), and a G-C5a fusion protein to test the adjuvant activity of trout C5a. Recombinant G-C5a displayed a potent chemoattractant activity in contrast to G alone, indicating that the C5a portion of the fusion protein was functional. Thereafter, G-C5a, partially emulsified in a small quantity of IFA, was injected into one group of trout, while the other group of trout was inoculated with the same dose of recombinant G. At four to sixteen weeks post-injection, the serum IgM antibody levels of the fish injected with recombinant G-C5a were obviously higher than those injected with G protein alone. Thus, these results suggest, for the first time, that C5a acts as molecular adjuvant in teleost fish by enhancing antibody response to a soluble antigen. (C) 2014 Elsevier Ltd. All rights reserved.
1.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Hubei, Peoples R China 2.Clear Spring Foods Inc, Div Res, Buhl, ID 83316 USA 3.Univ Penn, Sch Vet Med, Dept Pathobiol, Philadelphia, PA 19104 USA 4.Lake Super State Univ, Dept Biol Sci, Sault Ste Marie, MI 49783 USA
Wu, Nan; LaPatra, Scott E.; Li, Jun; Sunyer, J. Oriol; Zhang, Yong-An.Complement C5a acts as molecular adjuvant in fish by enhancing antibody response to soluble antigen,FISH & SHELLFISH IMMUNOLOGY,2014,():