The JAK inhibitor, Tofacitinib, Corrects the Overexpression of CEACAM6 and Limits Susceptibility to AIEC Caused by Reduced Activity of the IBD Associated Gene, PTPN2

• Published in: medRxiv : the preprint server for health sciences
• Main Authors: Chatterjee, Pritha, Canale, Vinicius, King, Stephanie J, Shawki, Ali, Lei, Hillmin, Haddad, Michael, Gries, Casey M, McGovern, Dermot P B, Borneman, James, McCole, Declan F
• Format: Journal Article
• Language: English
• Published: United States 28.09.2024
• DOI: 10.1101/2024.09.26.24314341

A cohort of patients with inflammatory bowel disease (IBD) exhibit expansion of the gut pathobiont, adherent-invasive (AIEC). Loss of activity of the IBD susceptibility gene, protein tyrosine phosphatase type 2 ( ), results in dysbiosis of the gut microbiota both in human subjects and mice. Further, constitutive knock-out ( -KO) mice display expansion of AIEC compared to wildtype littermates. CEACAM6, a host cell surface glycoprotein, is exploited by AIEC to attach to and enter intestinal epithelial cells (IECs). Here, we investigate the role of IEC-specific in restricting AIEC invasion. Biopsies from IBD patients heterozygous (CT) or homozygous (CC) for the SNP (single nucleotide polymorphism) were processed for immunohistochemistry. HT-29 intestinal epithelial cells (IEC) were transfected with control shRNA ( -CTL), or a shRNA targeted towards ( -KD). The SNP was inserted ( -KI), or a complete knock-out of ( - KO) was generated, with CRISPR-Cas9 gene editing of Caco-2BBe IEC lines. Adherence and invasion assays were performed with either the human IBD AIEC isolate, LF82, or a novel fluorescent-tagged mouse adherent-invasive ( AIEC ) at multiplicity of infection (MOI) of 10. IL-6 and the pan-JAK inhibitor tofacitinib were administered to interrogate JAK-STAT signaling. Protein expression was determined by western blotting and densitometry. CEACAM6 expression was elevated (colon and ileum) in IBD patients carrying the SNP (CT, CC) compared to wildtype (TT) IBD patients. HT-29 and Caco-2BBe cell lines deficient in expressed significantly higher levels of CEACAM6. Further, -KI and -KO cell lines also displayed greater adherence and invasion by AIEC LF82 and higher AIEC invasion. CEACAM6 expression was further elevated after administration of IL-6 in -deficient cell lines compared to untreated controls. Silencing of STAT1 and 3 partially reduced CEACAM6 protein expression. Tofacitinib significantly reduced the elevated CEACAM6 protein expression and the higher AIEC adherence and invasion in -KI and PTPN2-KO cell lines compared to DMSO controls. Our findings highlight a crucial role for in restricting pathobiont entry into host cells. Our study also describes a role for the FDA-approved drug, tofacitinib (Xeljanz) in correcting the JAK-STAT- mediated over-expression of CEACAM6, used by pathobionts as an entry portal into host cells. These findings suggest a role for JAK-inhibitors in mitigating AIEC colonization in IBD-susceptible hosts.