The Innate Immune Response in Lateolabrax japonicus Induced by Lipopolysaccharide from Glaciecola polaris Strain ARK149 (LMG21854)

Glaciecola polaris strain ARK149, a Gram-negative bacterium from Arctic seas, was used to derive lipopolysaccharide (LPS), and the effect of the LPS inducing some innate immunity parameters was investigated in Japanese sea bass, Lateolabrax japonicus. The results showed that the LPS could enhance the phagocytosis activity, lysozyme activity, and bacteriolytic activity in L. japonicus, significantly (P < 0.05) at 1, 7, 14, 21, 28, and 35 d after LPS-injection. The indexes of three parameters increased to the peak of value at 28th d post LPS-injection. Moreover, RT-PCR analysis suggested that LPS significantly up-regulated the expression of both IL-8 and hepcidin in several tissues. These data suggest that the LPS extracted from Glaciecola polaris strain ARK149 can induce innate immunity in L. japonicus.