Anti-Interleukin-17 monoclonal antibody, clone UD22-29I20

BACKGROUND & AIMS: Altered gut microbiota is implicated in development of colorectal cancer (CRC). Some intestinal bacteria have been reported to potentiate intestinal carcinogenesis by producing genotoxins, altering the immune response and intestinal microenvironment, and activating oncogenic signaling pathways. We investigated whether stool from patients with CRC could directly induce colorectal carcinogenesis in mice. METHODS: We obtained stored stool samples from participants in a metagenome study performed in Hong Kong. Conventional (male C57BL/6) mice were given azoxy-methane to induce colon neoplasia after receiving a course of antibiotics in drinking water. Mice were gavaged twice weekly with stool from 5 patients with CRC or 5 healthy individuals (controls) for 5 weeks. Germ-free C57BL/6 mice were gavaged once with stool from 5 patients with CRC or 5 controls. We collected intestinal tissues from mice and performed histology, immunohistochemistry, expression microarray, quantitative polymerase chain reaction, immunoblot, and flow cytometry analyses. We performed 16S ribosomal RNA gene sequencing analysis of feces from mice. RESULTS: Significantly higher proportions of conventional mice fed with stool from individuals with CRC than control stool developed high-grade dysplasia (P < .05) and macroscopic polyps (P < .01). We observed a higher proportion of proliferating (Ki-67-positive) cells in colons of germ-free mice fed with stool from patients with CRC vs those fed with stool from controls (P < .05). Feces from germ-free and conventional mice fed with stool from patients with CRC vs controls contained different microbial compositions, with lower richness in mice fed with stool from patients with CRC. Intestines collected from conventional and germ-free mice fed with stool from patients with CRC had increased expression of cytokines that modulate inflammation, including C-X-C motif chemokine receptor 1, C-X-C motif chemokine receptor 2, interleukin 17A (IL17A), IL22, and IL23A. Intestines from conventional and germ-free mice fed with stool from patients with CRC contained higher proportions of T-helper 1 (Th1) cells (2.25% vs 0.44%) and Th17 cells (2.08% vs 0.31%) (P < .05 for each) than mice fed with stool from controls. Real-time polymerase chain reaction arrays revealed up-regulation of genes involved in cell proliferation, stemness, apoptosis, angiogenesis, invasiveness, and metastasis in mice fed with stool from patients with CRC. CONCLUSIONS: We fed stool samples from patients with CRC and heathy individuals to germ-free mice and conventional mice with azoxymethane. We found stool from patients with CRC to increase the numbers of polyps, levels of intestinal dysplasia and proliferation, markers of inflammation, and proportions of Th1 and Th17 cells in colon, compared with stool from individuals without CRC. This study provides evidence that the fecal microbiota from patients with CRC can promote tumorigenesis in germ-free mice and mice given a carcinogen.

Background & Aims: The microenvironment regulates hepatoma stem cell behavior. However, the contributions of lymphatic endothelial cells to the hepatoma stem cell niche remain largely unknown; we aimed to analyze this contribution and elucidate the mechanisms behind it. Methods: Associations between lymphatic endothelial cells and CD133(+) hepatoma stem cells were analyzed by immunofluorescence and adhesion assays; with the effects of their association on IL-17A expression examined using western blot, quantitative reverse transcription PCR and luciferase reporter assay. The effects of IL-17A on the self-renewal and tumorigenesis of hepatoma stem cells were examined using sphere and tumor formation assays. The role of IL-17A in immune escape by hepatoma stem cells was examined using flow cytometry. The expression of IL-17A in hepatoma tissues was examined using immunohistochemistry. Results: CD133(+) hepatoma stem cells preferentially interact with lymphatic endothelial cells. The interaction between the mannose receptor and high-mannose type N-glycans mediates the interaction between CD133(+) hepatoma stem cells and lymphatic endothelial cells. This interaction activates cytokine IL17A expression in lymphatic endothelial cells. IL-17A promotes the self-renewal of hepatoma stem cells. It also promotes their immune escape, partly through upregulation of PD-Ll. Conclusion: Interactions between lymphatic endothelial cells and hepatoma stem cells promote the self-renewal and immune escape of hepatoma stem cells, by activating IL-17A signaling. Thus, inhibiting IL-17A signaling may be a promising approach for hepatoma treatment. Lay summary: The microenvironment is crucial for the self-renewal and development of hepatoma stem cells, which lead to the development of liver cancer. Lymphatic endothelial cells are an important component of this niche microenvironment, helping hepatoma stem cells to self-renew and escape immune attack, by upregulating IL-17A signaling. Thus, targeting IL-17A signaling is a potential strategy for the treatment of hepatoma. (C) 2019 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.