Citations 2
Genetic coding variant in complement factor B (CFB) is associated with increased risk for perianal Crohn’s disease and leads to impaired CFB cleavage and phagocytosis
Akhlaghpour, Marzieh, Haritunians, Talin , More, Shyam K., Thomas, Lisa , Stamps, Dalton T., Dube, Shishir, Li, Dalin , Yang, Shaohong, Landers, Carol J., Hamade, Hussein , Murali, Ramachandran , Potdar, Alka A. , Wolf, Andrea J. , Botwin, Gregory J., Khrom, Michelle , Faubion, William A. , Jabrì, Bana , Lira, Sérgio A. , Newberry, Rodney D. , Sandler, Robert S. , Sartor, R. Balfour , Xavier, Ramnik J. , Lazarev, Mark , Rioux, John D. , Silverberg, Mark S. , Zaghiyan, Karen , Fleshner, Phillip , Melmed, Gil , Vasiliauskas, Eric A., Ha, Christina , Rabizadeh, Shervin , Syal, Gaurav , Bonthala, Nirupama , Ziring, David , Targan, Stephan R. , Long, Millie D. , Michelsen, Kathrin S. , Nöthen, Markus M. , Ellinghaus, David , D’Amato, Mauro , Halfvarson, Jonas , Lee, James , Limbergen, Johan Van , Mowat, Craig , Hamade, Hussein , Ananthakrishnan, A N , Lira, Sergio A , Cho, Judy H , Michelsen, Kathrin S , Haritunians, Talin , Ellinghaus, David , D'Amato, Mauro , Nöthen, Markus M , Sandler, Robert S , Melmed, Gil Y , Halfvarson, Jonas , Newberry, Rodney D , Rioux, John D , Mengesha, Emebet , Ananthakrishnan, Ashwin N. , Jabrì, Bana , Brant, Steven R , Duerr, Richard H , Schumm, L. Philip , McGovern, Dermot , Lee, James C.
Gut | April 20, 2023 | Volume: 72 | Issue: 11 | Pages: 2068-2080
Objective Perianal Crohn’s disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in Complement Factor B ( CFB ). Design Immunochip-based meta-analysis on 4056 pCD and 11 088 patients with CD from three independent cohorts was performed. Serological and clinical variables were analysed by regression analyses. Risk allele of rs4151651 was introduced into human CFB plasmid by site-directed mutagenesis. Binding of recombinant G252 or S252 CFB to C3b and its cleavage was determined in cell-free assays. Macrophage phagocytosis in presence of recombinant CFB or serum from CFB risk, or protective CD or healthy subjects was assessed by flow cytometry. Results Perianal complications were associated with colonic involvement, OmpC and ASCA serology, and serology quartile sum score. We identified a genetic association for pCD (rs4151651), a non-synonymous SNP (G252S) in CFB , in all three cohorts. Recombinant S252 CFB had reduced binding to C3b, its cleavage was impaired, and complement-driven phagocytosis and cytokine secretion were reduced compared with G252 CFB. Serine 252 generates a de novo glycosylation site in CFB. Serum from homozygous risk patients displayed significantly decreased macrophage phagocytosis compared with non-risk serum. Conclusion pCD-associated rs4151651 in CFB is a loss-of-function mutation that impairs its cleavage, activation of alternative complement pathway, and pathogen phagocytosis thus implicating the alternative complement pathway and CFB in pCD aetiology.
Immune dysregulation in SHARPIN-deficient mice is dependent on CYLD-mediated cell death
Ang, Rosalind L. , Chan, Mark , Legarda, Diana , Sun, Shao‐Cong , Gillespie, Virginia , Chun, Nicholas , Heeger, Peter S. , Lira, Sérgio A. , Ting, Adrian T. , Sun, Shao-Cong , Chun, Nicholas , Heeger, Peter S , Xiong, Huabao , Ting, Adrian T , Sundberg, John P.
Proceedings of the National Academy of Sciences | December 9, 2021 | Volume: 118 | Issue: 50 | Pages: No page available
Significance The mechanisms underlying inflammatory disorders are poorly understood. In this study, we show that inappropriate cell death may cause uncontrolled inflammation. We found that CYLD, an enzyme that removes K63-linked polyubiquitination, is normally inhibited. But in the cpdm mouse strain that has a loss-of-function in the Sharpin gene, the brake on CYLD is no longer present. When CYLD is no longer inhibited, it turns on death signaling in cells exposed to the cytokine TNF, and the ensuing inappropriate cell death causes skin inflammation and other immune disorders in the cpdm mouse. Removing CYLD from the cpdm mouse prevents cell death and reverses the inflammation. We conclude that excessive CYLD activity leads to inappropriate cell death and inflammation.