Functional characterization of obscure puffer ToNK-lysin: A novel immunomodulator possessing anti-bacterial and anti-inﬂammatory properties

Yaxing Yang; Xiaorui Song; Nan Cui; Tianying Lei; Ying Huang; Yan Shi; Yadong Hu; Xinghu Zhou; Zhe Zhao

doi:10.1016/j.fsi.2023.109080

Functional characterization of obscure puffer ToNK-lysin: A novel immunomodulator possessing anti-bacterial and anti-inﬂammatory properties

Fish Shellfish Immunol. 2023 Nov:142:109080. doi: 10.1016/j.fsi.2023.109080. Epub 2023 Sep 23.

Authors

Yaxing Yang¹, Xiaorui Song¹, Nan Cui¹, Tianying Lei¹, Ying Huang¹, Yan Shi¹, Yadong Hu², Xinghu Zhou², Zhe Zhao³

Affiliations

¹ Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization, Hohai University, Nanjing 210024, China; Department of Marine Biology, College of Oceanography, Hohai University, Nanjing 210024, China.
² Jiangsu Innovation Center of Marine Bioresource, Jiangsu Coast Development Group Co., Ltd, Nanjing, 210019, China.
³ Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization, Hohai University, Nanjing 210024, China; Department of Marine Biology, College of Oceanography, Hohai University, Nanjing 210024, China. Electronic address: zhezhao@hhu.edu.cn.

PMID: 37748586
DOI: 10.1016/j.fsi.2023.109080

Abstract

NK-lysins are one of the most abundant antimicrobial peptides produced by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs), and identified as a new class of intrinsically disordered proteins, playing critical roles in the cell-mediated cytotoxicity response, as well as immunomodulatory and antimicrobial activities upon a significant range of pathogens. In the present study, an NK-lysin was identiﬁed from Obscure puffer Takifugu obscurus (ToNK-lysin). The open reading frame of ToNK-lysin sequence spans 423 bp, encoding a peptide with 140 amino acids which shares a moderate residue identity (18%-60%) with NK-lysin of mammals and other teleost species. Phylogenetic analysis revealed that ToNK-lysin was most closely related to NK-lysins from the Pleuronectiformes (Bastard halibut Paralichthys olivaceus and Pacific halibut Hippoglossus stenolepis). Comprehensive computational analysis revealed that ToNK-lysin have substantial level of intrinsic disorder, which might be contribute to its multifunction. The transcripts of the ToNK-lysin were detected in multiple examined tissues and most abundant in gills. After bacterial and Poly I:C challenge, the transcriptional levels of ToNK-lysin were significantly up-regulated in the head kidney, liver and spleen at different time points. The recombinant ToNK-lysin showed significant antibacterial activity against Vibrio harveyi and Escherichia coli, and the ToNK-lysin treatment not only reduced the bacterial loads in liver and head kidney, but also alleviated the pathogen-mediated upregulation of immune-related genes. In addition, the co-incubation with rToNK-lysin protein remarkably degraded bacterial genomic DNA, suggesting the potential mechanism of ToNK-lysin against microbes. These results suggest that ToNK-lysin possess antibacterial and immunoregulatory function both in vivo and in vitro, which may allow it a potential applicability to the aquaculture industry.

Keywords: Antibacterial activity; Bacterial loads; Intrinsic disorder; NK-Lysin; Obscuru puffer (Takifugu obscurus).

MeSH terms

Adjuvants, Immunologic
Amino Acid Sequence
Animals
Anti-Bacterial Agents* / pharmacology
Immunologic Factors / pharmacology
Mammals / metabolism
Phylogeny
Proteolipids / genetics
Tetraodontiformes*

Substances

Anti-Bacterial Agents
Adjuvants, Immunologic
Immunologic Factors
Proteolipids