Understanding How a Key Immune Protein Works in White Croaker Fish

Greg Howard
30th May, 2024

Understanding How a Key Immune Protein Works in White Croaker Fish

Image Source: Natural Science News, 2024

Key Findings

  • Researchers at Zhejiang Ocean University identified the NaIL-10 gene in the fish species Nibea albiflora, which plays a crucial role in the immune system
  • NaIL-10 is highly expressed in immune-related tissues and increases significantly during infections, indicating its role in the immune response
  • Experiments showed that NaIL-10 inhibits pro-inflammatory cytokines, confirming its anti-inflammatory properties and importance in controlling inflammation
Interleukin-10 (IL-10) is a critical immunosuppressive cytokine that regulates inflammation by inhibiting the production and function of pro-inflammatory cytokines. Recent research conducted by Zhejiang Ocean University has characterized the full-length cDNA of IL-10 from Nibea albiflora, a species of fish, providing new insights into the immunomodulatory mechanisms in teleosts[1]. The study identified the NaIL-10 gene, which consists of 1238 base pairs (bp) and includes a 5'-UTR (untranslated region) of 350 bp, a 3'-UTR of 333 bp, and an open reading frame (ORF) of 555 bp. This gene encodes a protein of 184 amino acids with a signal peptide at the N-terminus. Sequence analysis revealed that NaIL-10 shares the typical motifs and conserved cysteine residues characteristic of the IL-10 family, similar to its teleost counterparts. Real-time PCR analysis showed that NaIL-10 is widely distributed across various healthy tissues, with particularly high expression in immune-related tissues such as the head kidney, spleen, kidney, liver, and gill. This widespread distribution suggests a significant role in the immune system of Nibea albiflora. Notably, the expression of NaIL-10 was significantly up-regulated following infections with Vibrio parahaemolyticus, Vibrio alginolyticus, and Poly I:C, indicating its involvement in the immune response to pathogens. Subcellular localization studies demonstrated that NaIL-10 is primarily found in the cytoplasm, both unevenly and aggregately, with a minor presence on the cell membrane. This distribution pattern suggests that NaIL-10 is secreted into the extracellular space, similar to other IL-10 homologs. Further experiments showed that NaIL-10 co-locates with IL-10Rα on the membrane of HEK293T cells, indicating a potential interaction. This interaction was confirmed through GST pull-down and Co-IP studies, establishing the existence of an IL-10 ligand-receptor system in Nibea albiflora. The anti-inflammatory role of NaIL-10 was further validated by experiments on LPS-stimulated RAW264.7 macrophages. Pre-incubation with recombinant NaIL-10 protein significantly inhibited the expression of pro-inflammatory cytokines, including TNF-α, IL-6, and IL-1β. This finding aligns with previous studies that emphasize the anti-inflammatory properties of IL-10 in various immune cells[2][3][4]. IL-10's role in regulating inflammation and preventing tissue damage is well-documented. It is produced by various immune cells, including monocytes/macrophages and T cell subsets, and acts through a receptor complex composed of IL-10R1 and IL-10R2[3]. In monocytes/macrophages, IL-10 reduces the production of inflammatory mediators and inhibits antigen presentation, while enhancing antigen uptake[3]. This dual role helps maintain a balance between immune response and tissue protection, preventing excessive inflammation and tissue damage[2]. The discovery of the IL-10 ligand-receptor system in Nibea albiflora extends our understanding of IL-10's role in non-mammalian species and highlights its evolutionary conservation. This study provides a foundation for further research into the immunomodulatory mechanisms in teleosts, which could have implications for aquaculture and fish health management. In conclusion, the characterization of NaIL-10 from Nibea albiflora by Zhejiang Ocean University reveals its significant role in regulating the immune response and controlling inflammation in teleosts. This study not only expands our understanding of IL-10's function across different species but also underscores the importance of IL-10 in maintaining immune homeostasis and preventing tissue damage during infections[2][3][4].

BiochemAnimal ScienceMarine Biology

References

Main Study

1) Identification, functional characterization and immune response profiles of interleukin-10 in Nibea albiflora.

Published 27th May, 2024

https://doi.org/10.1016/j.fsi.2024.109654

Related Studies

2) IL-10 function, regulation, and in bacterial keratitis.

https://doi.org/10.1089/jop.2014.0018

4) IL-10-producing lymphocytes in inflammatory disease.

https://doi.org/10.3109/08830185.2012.762361


Related Articles

An unhandled error has occurred. Reload 🗙