A Frameshift in CSF2RB Predominant Among Ashkenazi Jews Increases Risk for Crohn%26apos;s Disease and Reduces Monocyte Signaling via GM-CSF

作者:Chuang Ling Shiang; Villaverde Nicole; Hui Ken Y; Mortha Arthur; Rahman Adeeb; Levine Adam P; Haritunians Talin; Ng Sok Meng Evelyn; Zhang Wei; Hsu Nai Yun; Facey Jody Ann; Luong Tramy; Fernandez Hernandez Heriberto; Li Dalin; Rivas Manuel; Schiff Elena R; Gusev Alexander; Schumm L Phillip; Bowen Beatrice M; Sharma Yashoda; Ning Kaida; Remark Romain; Gnjatic Sacha; Legnani Peter; George James; Sands Bruce E; Stempak Joanne M; Datta Lisa W; Lipka Seth
来源:Gastroenterology, 2016, 151(4): 710-+.
DOI:10.1053/j.gastro.2016.06.045

摘要

BACKGROUND & AIMS: Crohn's disease (CD) has the highest prevalence in Ashkenazi Jewish populations. We sought to identify rare, CD-associated frameshift variants of high functional and statistical effects. METHODS: We performed exome sequencing and array-based genotype analyses of 1477 Ashkenazi Jewish individuals with CD and 2614 Ashkenazi Jewish individuals without CD (controls). To validate our findings, we performed genotype analyses of an additional 1515 CD cases and 7052 controls for frameshift mutations in the colony-stimulating factor 2-receptor b common subunit gene (CSF2RB). Intestinal tissues and blood samples were collected from patients with CD; lamina propria leukocytes were isolated and expression of CSF2RB and granulocyte-macrophage colony-stimulating factor-responsive cells were defined by adenomatous polyposis coli (APC) time-of-flight mass cytometry (CyTOF analysis). Variants of CSF2RB were transfected into HEK293 cells and the expression and functions of gene products were compared. RESULTS: In the discovery cohort, we associated CD with a frameshift mutation in CSF2RB (P = 8.52 x 10(-4)); the finding was validated in the replication cohort (combined P = 3.42 x 10(-6)). Incubation of intestinal lamina propria leukocytes with granulocyte-macrophage colony-stimulating factor resulted in high levels of phosphorylation of signal transducer and activator of transcription (STAT5) and lesser increases in phosphorylation of extracellular signal-regulated kinase and AK straining transforming (AKT). Cells co-transfected with full-length and mutant forms of CSF2RB had reduced pSTAT5 after stimulation with granulocyte-macrophage colony-stimulating factor, compared with cells transfected with control CSF2RB, indicating a dominant-negative effect of the mutant gene. Monocytes from patients with CD who were heterozygous for the frameshift mutation (6% of CD cases analyzed) had reduced responses to granulocyte-macrophage colony-stimulating factor and markedly decreased activity of aldehyde dehydrogenase; activity of this enzyme has been associated with immune tolerance. CONCLUSIONS: In a genetic analysis of Ashkenazi Jewish individuals, we associated CD with a frameshift mutation in CSF2RB. Intestinal monocytes from carriers of this mutation had reduced responses to granulocyte-macrophage colony-stimulating factor, providing an additional mechanism for alterations to the innate immune response in individuals with CD.