Identification and Characterization of Lipopolysaccharide Induced TNFα Factor from Blunt Snout Bream, Megalobrama amblycephala

Abstract

Lipopolysaccharide induced TNFα factor (LITAF) is an important transcription factor responsible for regulation of tumor necrosis factor α. In this study, a novel litaf gene (designated as Malitaf) was identified and characterized from blunt snout bream, Megalobrama amblycephala. The full-length cDNA of Malitaf was of 956 bp, encoding a polypeptide of 161 amino acids with high similarity to other known LITAFs. A phylogenetic tree also showed that Malitaf significantly clustered with those of other teleost, indicating that Malitaf was a new member of fish LITAF family. The putative maLITAF protein possessed a highly conserved LITAF domain with two CXXC motifs. The mRNA transcripts of Malitaf were detected in all examined tissues of healthy M. amblycephala, including kidney, head kidney, muscle, liver, spleen, gill, and heart, and with the highest expression in immune organs: spleen and head kidney. The expression level of Malitaf in spleen was rapidly up-regulated and peaked (1.29-fold, p < 0.05) at 2 h after lipopolysaccharide (LPS) stimulation. Followed the stimulation of Malitaf, Matnfα transcriptional level was also transiently induced to a high level (51.74-fold, p < 0.001) at 4 h after LPS stimulation. Taken together, we have identified a putative fish LITAF ortholog, which was a constitutive and inducible immune response gene involved in M. amblycephala innate immunity during the course of a pathogenic infection.

Natural Resistance Associated Macrophage Protein Is Involved in Immune Response of Blunt Snout Bream, Megalobrama amblycephala

“…However, during 12 h to 24 h after LPS stimulation, the extreme decrease of maNramp mRNA transcript might block the excess generation of cytokines [ 50 ], so that the innate immune response to invasive and harmful bacteria could be optimally controlled, which was observed in litaf gene of M . amblycephala [ 4 ].…”

“…It is naturally distributed in the affiliated lakes of Yangtze River, such as Liangzi, Poyang, and Yuni Lakes [ 3 ]. Owing to some characteristics such as herbivorous habit, faster growth rate, and delicate flesh quality, it has been widely cultured in China during the last decades [ 4 ]. In 2016, the total output of blunt snout bream in China has reached over 796,000,000 kg [ 5 ].…”