posted on 2022-06-23, 10:31authored byEB Nonnecke, PA Castillo, MEV Johansson, EJ Hollox, B Shen, B Lönnerdal, CL Bevins
Intelectins (intestinal lectins) are highly conserved across chordate evolution and have been implicated in various human diseases, including Crohn's disease (CD). The human genome encodes two intelectin genes, intelectin-1 (ITLN1) and intelectin-2 (ITLN2). Other than its high sequence similarity with ITLN1, little is known about ITLN2. To address this void in knowledge, we report that ITLN2 exhibits discrete, yet notable differences from ITLN1 in primary structure, including a unique amino terminus, as well as changes in amino acid residues associated with the glycan-binding activity of ITLN1. We identified that ITLN2 is a highly abundant Paneth cell-specific product, which localizes to secretory granules, and is expressed as a multimeric protein in the small intestine. In surgical specimens of ileal CD, ITLN2 mRNA levels were reduced approximately five-fold compared to control specimens. The ileal expression of ITLN2 was unaffected by previously reported disease-associated variants in ITLN2 and CD-associated variants in neighboring ITLN1 as well as NOD2 and ATG16L1. ITLN2 mRNA expression was undetectable in control colon tissue; however, in both ulcerative colitis (UC) and colonic CD, metaplastic Paneth cells were found to express ITLN2. Together, the data reported establish the groundwork for understanding ITLN2 function(s) in the intestine, including its possible role in CD.
Funding
National Institutes of Health U01AI125926 (Mucosal Immunology Study Team) and R37AI32738.
History
Citation
Nonnecke, EB, Castillo, PA, Johansson, MEV, et al. Human intelectin-2 (ITLN2) is selectively expressed by secretory Paneth cells. FASEB J. 2022; 36:e22200. doi:10.1096/fj.202101870R
Author affiliation
Department of Genetics and Genome Biology
Version
VoR (Version of Record)
Published in
FASEB Journal
Volume
36
Issue
3
Pagination
e22200
Publisher
Federation of American Society of Experimental Biology (FASEB) [Associate Organisation] Wiley Open Access [Commercial Publisher]