Fc-Epsilon-RI, the High Affinity IgE-Receptor, Is Robustly Expressed in the Upper Gastrointestinal Tract and Modulated by Mucosal Inflammation

Background: The role of the high affinity IgE receptor, FcεRI, in IgE-mediated immune responses of the gastrointestinal (GI) mucosa is poorly understood. Currently, a detailed characterization of FcεRI expression throughout the human gut is lacking. The aim of this study was to define the expression pattern of FcεRI in the GI tract. Methods/Principal Findings: We compared FcεRI expression in children with gastritis/esophagitis (n = 10), celiac disease (n = 10), inflammatory bowel disease (IBD) (n = 9), and normal mucosa (n = 5). The α–subunit of FcεRI (FcεRIα), detected by immunohistochemistry, was found on cells infiltrating the mucosa of the esophagus, the stomach, and the duodenum, but was rarely detected in more distal sections of the GI tract. Accordingly, quantitative RT-PCR analysis on esophagus, stomach, duodenum, colon, and rectum biopsies revealed that FcεRIα and -β expression levels decreased towards the distal intestine. mRNA transcripts of the common Fc-receptor-γ chain were present in the entire GI mucosa. Double-immunofluorescence staining of esophageal specimens confirmed that FcεRIα was expressed on intraepithelial mast cells and Langerhans cells. The mRNA expression levels of the α, β, and γ subunits of FcεRI did not correlate with total serum IgE but were associated with mucosal inflammation. Conclusion/Significance: Our data define the upper GI tract as the main site for IgE-mediated immune activation via FcεRI. Tissue mRNA levels of FcεRIα are regulated by inflammatory conditions rather than serum IgE, indicating that FcεRI might also play a role in pathologies other than allergy

Bayesian and frequentist analysis of an Austrian genome-wide association study of colorectal cancer and advanced adenomas

Most genome-wide association studies (GWAS) were analyzed using single marker tests in combination with stringent correction procedures for multiple testing. Thus, a substantial proportion of associated single nucleotide polymorphisms (SNPs) remained undetected and may account for missing heritability in complex traits. Model selection procedures present a powerful alternative to identify associated SNPs in high-dimensional settings. In this GWAS including 1060 colorectal cancer cases, 689 cases of advanced colorectal adenomas and 4367 controls we pursued a dual approach to investigate genome-wide associations with disease risk applying both, single marker analysis and model selection based on the modified Bayesian information criterion, mBIC2, implemented in the software package MOSGWA. For different case-control comparisons, we report models including between 1-14 candidate SNPs. A genome-wide significant association of rs17659990 (P=5.43x10(-9), DOCK3, chromosome 3p21.2) with colorectal cancer risk was observed. Furthermore, 56 SNPs known to influence susceptibility to colorectal cancer and advanced adenoma were tested in a hypothesis-driven approach and several of them were found to be relevant in our Austrian cohort. After correction for multiple testing (alpha=8.9x10(-4)), the most significant associations were observed for SNPs rs10505477 (P=6.08x10(-4)) and rs6983267 (P=7.35x10(-4)) of CASC8, rs3802842 (P=8.98x10(-5), COLCA1,2), and rs12953717 (P=4.64x10(-4), SMAD7). All previously unreported SNPs demand replication in additional samples. Reanalysis of existing GWAS datasets using model selection as tool to detect SNPs associated with a complex trait may present a promising resource to identify further genetic risk variants not only for colorectal cancer

IDO1 + Paneth cells promote immune escape of colorectal cancer

Abstract: Tumors have evolved mechanisms to escape anti-tumor immunosurveillance. They limit humoral and cellular immune activities in the stroma and render tumors resistant to immunotherapy. Sensitizing tumor cells to immune attack is an important strategy to revert immunosuppression. However, the underlying mechanisms of immune escape are still poorly understood. Here we discover Indoleamine-2,3-dioxygenase-1 (IDO1)+ Paneth cells in the stem cell niche of intestinal crypts and tumors, which promoted immune escape of colorectal cancer (CRC). Ido1 expression in Paneth cells was strictly Stat1 dependent. Loss of IDO1+ Paneth cells in murine intestinal adenomas with tumor cell-specific Stat1 deletion had profound effects on the intratumoral immune cell composition. Patient samples and TCGA expression data suggested corresponding cells in human colorectal tumors. Thus, our data uncovered an immune escape mechanism of CRC and identify IDO1+ Paneth cells as a target for immunotherapy

IDO1 + Paneth cells promote immune escape of colorectal cancer

Abstract: Tumors have evolved mechanisms to escape anti-tumor immunosurveillance. They limit humoral and cellular immune activities in the stroma and render tumors resistant to immunotherapy. Sensitizing tumor cells to immune attack is an important strategy to revert immunosuppression. However, the underlying mechanisms of immune escape are still poorly understood. Here we discover Indoleamine-2,3-dioxygenase-1 (IDO1)+ Paneth cells in the stem cell niche of intestinal crypts and tumors, which promoted immune escape of colorectal cancer (CRC). Ido1 expression in Paneth cells was strictly Stat1 dependent. Loss of IDO1+ Paneth cells in murine intestinal adenomas with tumor cell-specific Stat1 deletion had profound effects on the intratumoral immune cell composition. Patient samples and TCGA expression data suggested corresponding cells in human colorectal tumors. Thus, our data uncovered an immune escape mechanism of CRC and identify IDO1+ Paneth cells as a target for immunotherapy

The number of human hepatocytes needed for optimum engraftment was determined by the level of human albumin secretion in the cells.

<p>Plots represent the mean human albumin concentration and interquartile ranges of human albumin levels (ug/mL) in the serum <i>of </i><i>MUP-uPA-SCID/Bg</i> mice transplanted with different numbers of human hepatocytes (n=25, 310 ug/mL <u>+</u>45, n=31, 1.75 mg/mL <u>+</u>365, n=20, 1.8 mg/mL <u>+</u>339).</p

Long-term viral propagation of HCV genotype 1a in <i>MUP-uPA/SCID/Bg</i> chimeric mice.

<p>Several engrafted and HCV inoculated chimeric mice were monitored for 60 days post-inoculation for HCV replication and compared to mice that were not inoculated with HCV. Plasma from HCV-infected Chimpanzee was used as a positive control for HCV RNA copies in qRT-PCR assays.</p

<i>MUP-uPA/SCID/Bg</i> mice sensitivity to HBV.

<p>Titration of hepatitis B virus in mice infected with various virus dilutions of HBV-infected chimpanzee plasma and assayed by q-PCR (n= 3-5).</p

Perioperative Chemotherapy Including Bevacizumab in Potentially Curable Metastatic Colorectal Cancer: Long-Term Follow-Up of the ASSO-LM1 Trial

In 2007, the ASSO-LM1 trial, a multicenter prospective study, was initiated to investigate the resectability (R0) rate following preoperative combination therapy with XELOX and bevacizumab in patients with potentially resectable colorectal liver metastases. Six cycles of systemic therapy were administered preoperatively, although the sixth cycle did not include bevacizumab, resulting in 5 weeks between the last bevacizumab dose and surgery. Treatment with bevacizumab plus XELOX was restarted for another six cycles postoperatively. In total, 43 patients were enrolled in the ASSO-LM1 trial. Eight patients were ineligible for resection due to protocol violation and progression in two patients. The resectability of operated patients was 97% with 34 R0 resections and one R1 resection. Postoperative morbidity occurred in 22% of patients, of which three operative revisions were related to the primary tumor resection. Efficacy results for response in 38 eligible patients confirmed an ORR of 66%, 31% SD and 3% PD according to RECIST. Preoperative grade 3/4 adverse events were 17% diarrhea, 5% HFS and 5% thromboembolic events. Overall survival significantly differed depending upon the fulfillment of adjuvant treatment in curative resected patients (59.1 mo vs. 30.8 mo). In conclusion, the ASSO-LM1 trial is a hypothesis-generating study confirming the prognostic benefits of perioperative therapy with XELOX and bevacizumab in patients with metastatic colorectal cancer confined to the liver