Common carp intelectin 3 (cITLN3) plays a role in the innate immune response

Linyi Bai; Guanliu Yu; Yujie Liu; Muhammad Aizaz; Guiwen Yang; Lei Chen

doi:10.1016/j.fsi.2023.109057

Common carp intelectin 3 (cITLN3) plays a role in the innate immune response

Fish Shellfish Immunol. 2023 Oct:141:109057. doi: 10.1016/j.fsi.2023.109057. Epub 2023 Sep 7.

Authors

Linyi Bai¹, Guanliu Yu², Yujie Liu², Muhammad Aizaz², Guiwen Yang², Lei Chen³

Affiliations

¹ Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, 250000, PR China; School of Life Sciences, Zhengzhou University, Zhengzhou, PR China.
² Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, 250000, PR China.
³ Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, 250000, PR China. Electronic address: chenlei@sdnu.edu.cn.

PMID: 37673388
DOI: 10.1016/j.fsi.2023.109057

Abstract

Intelectin is a lectin with the capacity to recognize and bind to carbohydrates. In this study, we successfully cloned cITLN3 from common carp, which consists of a signal peptide domain, a FReD domain, and an intelectin domain. The expression levels of cITLN3 were detected in various organs of common carp, including the liver, head kidney, spleen, foregut, midgut, and hindgut, with the highest expression observed in the liver. Following infection with Staphylococcus aureus (S. aureus) or Aeromonas hydrophila (A. hydrophila), the expression level of cITLN3 was significantly upregulated in all organs of common carp. Subsequently, we expressed and purified the recombinant cITLN3 protein using an E. coli expression system. The cITLN3 could aggregate both gram-positive and gram-negative bacteria in the presence of Ca²⁺, with a stronger affinity for gram-positive bacteria. Moreover, our study demonstrated that cITLN3 displayed a higher binding affinity towards PGN compared to LPS. Furthermore, we observed that cITLN3 had the potential to inhibit bacterial proliferation in common carp and safeguard intestinal integrity during bacterial stimulation. And the results also indicated that cITLN3 might played a role in the Toll-like receptors (TLRs) signaling pathway activation.