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Human intelectin‐2 (ITLN2) is selectively expressed by secretory Paneth cells
Author(s) -
necke Eric B.,
Castillo Patricia A.,
Johansson Malin E. V.,
Hollox Edward J.,
Shen Bo,
Lönnerdal Bo,
Bevins Charles L.
Publication year - 2022
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.202101870r
Subject(s) - paneth cell , biology , messenger rna , gene , ulcerative colitis , microbiology and biotechnology , small intestine , disease , biochemistry , medicine , pathology
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.