Glycomic analysis of antibody indicates distinctive glycosylation profile in patients with autoimmune cholangitis.
抗体的 Glycomic 分析表明自身免疫性胆管炎患者具有独特的糖基化谱。
- 作者列表："Zhou X","Kailemia MJ","Sun Y","Shuai Z","Yang GX","Dhaliwal S","Cristoferi L","Leung PSC","Invernizzi P","Bowlus CL","Lebrilla CB","Ansari AA","Ridgway WM","Zhang W","Gershwin ME
:Glycosylation of antibodies, particularly in the Fc domain, critically modulate the ability of antibodies to bind to FcRs, maintaining immune quiescence to achieve a finely orchestrated immune response. The removal of sialic acid and galactose residues dramatically alters the physiological function of IgGs, and alterations of Ig glycosylation have been associated with several autoimmune disorders. However, Ig glycosylation has not been extensively studied in autoimmune cholangitis. We applied triple quadruple mass spectroscopy with subsequent multiple reaction monitoring to elucidate the profile, composition and linkage of sugar residues of antibody glycans in patients with primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and healthy controls (HC). Agalactosylated, HexNAc terminated IgG1 glycoforms were enriched in both PBC and PSC. Levels of IgM glycans at site N439 and fucosylated glycans in J chain, were significantly decreased in PBC compared to PSC and HC. PSC patients had decreased bisecting glycoforms and increased biantennary glycoforms on IgA compared to PBC. Importantly, our data demonstrate the association of distinct branching and composition patterns of Ig glycoforms with disease severity and liver cirrhosis, which highlight the importance of glycan biology as a potential mechanism and/or a disease specific signal of inflammation.
: 抗体的糖基化，特别是在 Fc 结构域，关键地调节抗体与 FcRs 结合的能力，维持免疫静止以实现精细编排的免疫应答。唾液酸和半乳糖残基的去除显著改变了 IgGs 的生理功能，Ig 糖基化的改变与几种自身免疫性疾病相关。然而，Ig 糖基化在自身免疫性胆管炎中尚未被广泛研究。我们应用三重四联质谱和随后的多反应监测来阐明原发性胆汁性胆管炎 (PBC) 患者抗体聚糖的特征、组成和糖残基的连接,原发性硬化性胆管炎 (PSC) 和健康对照 (HC)。Agalactic 化，HexNAc 终止的 IgG1 糖型在 PBC 和 PSC 中均富集。与 PSC 和 HC 相比，PBC 中 N439 位点的 IgM 聚糖和 J 链的岩藻糖基化聚糖水平显著降低。与 PBC 相比，PSC 患者 IgA 上的二分糖型减少，双触角糖型增加。重要的是，我们的数据证明了 Ig 糖型的不同分支和组成模式与疾病严重程度和肝硬化的相关性,这突出了聚糖生物学作为炎症的潜在机制和/或疾病特异性信号的重要性。
METHODS:BACKGROUND & AIMS:Lifetime risk of biliary tract cancer (BTC) in primary sclerosing cholangitis (PSC) exceeds 20% and BTC is currently the leading cause of death in PSC patients. To open new avenues for management, we aimed to delineate novel and clinically relevant genomic and pathological features of a large panel of PSC-associated BTC (PSC-BTC). APPROACH & RESULTS:We analysed formalin fixed, paraffin embedded tumor tissue from 186 PSC-BTC patients from 11 centers in eight countries with all anatomical locations included. We performed tumor DNA sequencing at 42 clinically relevant genetic loci to detect mutations, translocations and copy number variations, along with histomorphological and immunohistochemical characterization. Irrespective of the anatomical localization, PSC-BTC exhibited a uniform molecular and histological characteristic similar to extrahepatic cholangiocarcinoma. We detected a high frequency of genomic alterations typical of extrahepatic cholangiocarcinoma, e.g. TP53 (35.5%), KRAS (28.0%), CDKN2A (14.5%), and SMAD4 (11.3%), as well as potentially druggable mutations (e.g. HER2/ERBB2). We found a high frequency of non-typical/non-ductal histomorphological subtypes (55.2%) and of the usually rare BTC precursor lesion, intraductal papillary neoplasia (18.3%) CONCLUSION: Genomic alterations in PSC-BTC include a significant number of putative actionable therapeutic targets. Notably, PSC-BTC show a distinct extrahepatic morpho-molecular phenotype, independent of the anatomical location of the tumor. These findings advance our understanding of PSC-associated cholangiocarcinogenesis and provide strong incentives for clinical trials to test genome-based personalized treatment strategies in PSC-BTC.
METHODS:BACKGROUND:The impact of inflammatory bowel disease (IBD) activity on long-term outcomes after liver transplantation (LT) for primary sclerosing cholangitis (PSC) is unknown. We examined the impact of post-LT IBD activity on clinically significant outcomes. METHODS:One hundred twelve patients undergoing LT for PSC from 2 centers were studied for a median of 7 years. Patients were divided into 3 groups according to their IBD activity after LT: no IBD, mild IBD, and moderate to severe IBD. Patients were classified as having moderate to severe IBD if they met at least 1 of 3 criteria: (i) Mayo 2 or 3 colitis or Simple Endoscopic Score-Crohn's Disease ≥7 on endoscopy; (ii) acute flare of IBD necessitating steroid rescue therapy; or (iii) post-LT colectomy for medically refractory IBD. RESULTS:Moderate to severe IBD at any time post-transplant was associated with a higher risk of Clostridium difficile infection (27% vs 8% mild IBD vs 8% no IBD; P = 0.02), colorectal cancer/high-grade dysplasia (21% vs 3% both groups; P = 0.004), post-LT colectomy (33% vs 3% vs 0%) and rPSC (64% vs 18% vs 20%; P < 0.001). Multivariate analysis revealed that moderate to severe IBD increased the risk of both rPSC (relative risk [RR], 8.80; 95% confidence interval [CI], 2.81-27.59; P < 0.001) and colorectal cancer/high-grade dysplasia (RR, 10.45; 95% CI, 3.55-22.74; P < 0.001). CONCLUSIONS:Moderate to severe IBD at any time post-LT is associated with a higher risk of rPSC and colorectal neoplasia compared with mild IBD and no IBD. Patients with no IBD and mild IBD have similar post-LT outcomes. Future prospective studies are needed to determine if more intensive treatment of moderate to severe IBD improves long-term outcomes in patients undergoing LT for PSC.
METHODS::T cells from patients with primary sclerosing cholangitis (PSC) show a prominent IL-17 response upon stimulation with bacteria or fungi, yet the reasons for this dominant TH17 response in PSC are not clear. Here, we analyzed the potential role of monocytes in microbial recognition and in skewing the T cell response towards Th17. Monocytes and T cells from blood and livers of PSC patients and controls were analyzed ex vivo and in vitro using trans-well experiments with cholangiocytes. Cytokine production was measured using flow cytometry, ELISA, RNA in situ hybridization and quantitative real time PCR. Genetic polymorphisms were obtained from Immunochip analysis. Following ex vivo stimulation with PMA/Ionomycin, PSC patients showed significantly increased numbers of IL-17A-producing peripheral blood CD4+ T cells compared to PBC patients and healthy controls, indicating increased Th17 differentiation in vivo. Upon stimulation with microbes, monocytes from PSC patients produced significantly more IL-1β and IL-6, cytokines known to drive Th17 cell differentiation. Moreover, microbe-activated monocytes induced the secretion of Th17 and monocyte-recruiting chemokines CCL-20 and CCL-2 in human primary cholangiocytes. In livers of patients with PSC cirrhosis, CD14hi CD16int and CD14lo CD16hi monocytes/macrophages were increased compared to alcoholic cirrhosis and monocytes were found to be located around bile ducts. Conclusion: PSC patients show increased Th17 differentiation already in vivo. Microbe-stimulated monocytes drive Th17 differentiation in vitro and induce cholangiocytes to produce chemokines mediating recruitment of Th17 cells and more monocytes into portal tracts. Taken together, these results point to a pathogenic role of monocytes in patients with PSC.