Gan Z.,Guangdong Ocean University |
Gan Z.,Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals |
Gan Z.,Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Insititutes |
Wang B.,Guangdong Ocean University |
And 19 more authors.
Fish and Shellfish Immunology | Year: 2015
CD59, the major inhibitor of membrane attack complex, plays a crucial role in regulation of complement activation. In this paper, a CD59 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD59) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for complement-inhibitory activity were detected in the deduced amino acid sequence of On-CD59. In healthy Nile tilapia, the On-CD59 transcripts could be detected in all the examined tissues, with the most abundant expression in the brain. When immunized with inactivated S. agalactiae, there was a clear time-dependent expression pattern of On-CD59 in the skin, brain, head kidney, thymus and spleen, with quite different kinetic expressions. The assays for the complement-inhibitory activity suggested that recombinant On-CD59 protein had a species-selective inhibition of complement. Moreover, our works showed that recombinant On-CD59 protein may possess both binding activities to PGN and LTA and inhibiting activity of S.agalactiae. These findings indicated that On-CD59 may play important roles in the immune response to S.agalactiae in Nile tilapia. © 2015 Elsevier Ltd.