Identification of single nucleotide polymorphisms in the TNFRSF17 gene and their association with gastrointestinal disorders
MOLECULES AND CELLS
Authors: Chae, Soo-Cheon; Yu, Ji-In; Oh, Gyung-Jae; Choi, Chang-Soo; Choi, Suck-Chei; Yang, Yun-Sik; Yun, Ki-Jung
Abstract
TNFRSF17 is preferentially expressed in mature B lymphocytes, and may be important for the development of B cells. TNFRSF17 is selected as a candidate susceptibility gene to IBD pathogenesis by our cDNA microarray analysis, and we showed the specific expression of TNFRSF17 in resting and activated CD19(+) cells obtained from human blood. We identified four SNPs (g-1729G > A, g.2295T > C, g.2445G > A and g.2493G > A) and one variation site (g.894delT) in the TNFRSF17 gene using direct sequencing analysis. In addition, the association of the genotype and allelic frequencies of these SNPs was studied in healthy controls and in patients with ulcerative colitis (UC) or irritable bowel syndrome (IBS). Although, the genotype and allelic frequencies of these SNPs, in the UC and IBS patients, were not significantly different from those in the healthy controls, the distribution of the AAG, GGA, AGG and AAA haplotypes, of the SNPs (g.-1729G > A, g.2445G > A and g.2493G > A) associated with the TNFRSF17 gene, in the UC patients, were notably different from those of the healthy controls (P = 0.002, 0.002, 4.7E-4 and 3.3E-6, respectively). Moreover, the frequencies of the AAG, AGG, GAG and GAA haplotypes were significantly different in the IBS patients compared to the healthy controls (P = 4.2E-5, 4.4E-17, 1.8E-22 and 1.6E-10, respectively). These results suggest that the haplotypes of the TNFRSF17 polymorphisms might be associated with UC and IBS susceptibility.
The Plasma Cell Signature in Autoimmune Disease
ARTHRITIS & RHEUMATOLOGY
Authors: Streicher, Katie; Morehouse, Christopher A.; Groves, Christopher J.; Rajan, Bhargavi; Pilataxi, Fernanda; Lehmann, Kim P.; Brohawn, Philip Z.; Higgs, Brandon W.; McKeever, Kathleen; Greenberg, Steven A.; Fiorentino, David; Richman, Laura K.; Jallal, Bahija; Herbst, Ronald; Yao, Yihong; Ranade, Koustubh
Abstract
Objective. Production of pathogenic autoantibodies by self-reactive plasma cells (PCs) is a hallmark of autoimmune diseases. We undertook this study to investigate the prevalence of PCs and their relationship to known pathogenic pathways to increase our understanding of the role of PCs in disease progression and treatment response. Methods. We developed a sensitive gene expression-based method to overcome the challenges of measuring PCs using flow cytometry. Whole-genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA1, IGJ, IGKC, IGKV4-1, and TNFRSF17, expressed predominantly in PCs. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy, for evaluating the relationship between PCs and other autoimmune disease-related genes, and for estimating PC levels in affected blood and tissue from patients with multiple autoimmune diseases. Results. The PC signature was highly sensitive and capable of detecting a change in as few as 360 PCs. The PC signature was reduced more than 90% in scleroderma patients following anti-CD19 treatment, and this reduction was highly correlated (r = 0.80) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed that 30-35% of lupus and rheumatoid arthritis patients had increased levels of PCs. Conclusion. This newly developed PC signature provides a robust and accurate method of measuring PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases who may benefit from PC-depleting therapy.