J Cancer 2017; 8(13):2424-2435. doi:10.7150/jca.19639
Loss of Tff1 Promotes Pro-Inflammatory Phenotype with Increase in the Levels of RORγt+ T Lymphocytes and Il-17 in Mouse Gastric Neoplasia
1. Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN 37232;
2. Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232;
3. Divison of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232;
4. Division of Urology, Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115;
5. Division of Gastroenterology, Hepatology, & Nutrition, Vanderbilt University Medical Center, Nashville, TN 37232;
6. Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt 35516.
* equal contribution
Soutto M, Saleh M, Arredouani MS, Piazuelo B, Belkhiri A, El-Rifai W. Loss of Tff1 Promotes Pro-Inflammatory Phenotype with Increase in the Levels of RORγt+ T Lymphocytes and Il-17 in Mouse Gastric Neoplasia. J Cancer 2017; 8(13):2424-2435. doi:10.7150/jca.19639. Available from http://www.jcancer.org/v08p2424.htm
Background: TFF1 deficiency induces a mucosal pro-inflammatory phenotype that contributes to gastric tumorigenesis in mouse and human. Methods: We utilized the Tff1-KO mouse model to assess the impact of TFF1 loss on immune cells infiltration in the stomach. We used single cell suspension, flow cytometry, immunohistochemistry, and quantitative PCR (qPCR) assays. Results: The Tff1-KO gastric mucosa demonstrated high chronic inflammatory scores (score: 3-4) at age 2 months, which exacerbated at age 8 months (score: 4-6). We next used single-cell suspensions for flow cytometry analysis of total leukocytes (CD45+ cells), total T lymphocytes (CD45+CD3+cells), T cell subsets (CD4+, CD8+, and CD3+CD4-CD8-cells), and monocytes/macrophages (CD45+F4/80+cells). The results demonstrated an age-dependent (2 → 8 month age) significant increase of leukocytes (p<0.05), T cells (p<0.05), and monocytes/macrophages (p<0.001) in the gastric mucosa of the Tff1-KO mice, as compared to Tff1-WT. A similar increase was observed in blood samples (p<0.05). Using ionomycin to activate CD4+ splenocytes, the results indicated that Tff1-KO CD4+ splenocytes secreted higher levels of IL-17A (p<0.05 at 2 and p<0.001 at 8 months) and IL-17F (p<0.05 at 2 and 8 months) than Tff1-WT splenocytes. Conversely, Tff1-KO CD8+-cells secreted less IL-17F, but comparable levels of IL-17A. In addition, we detected a significant upregulation of Il-17 mRNA expression in gastric tissues in the Tff1-KO, as compared to Tff1-WT (p<0.001). Conclusions: The results identify TFF1 loss as a major pro-inflammatory step that modulates the tumor microenvironment and immune cell infiltration in the stomach. Furthermore, the data suggest that the increase of IL-17A and IL-17F in Th17 cells, derived from CD4+ T cells, reflects the chronic inflammation in gastric mucosa, whereas the absence of change of IL-17A and decrease of IL-17F in CD8+Tc17 cells suggest loss of cytotoxic function of CD8+Tc17 cells during gastric tumorigenesis of the Tff1-KO mice.
Keywords: TFF1, Immune cells, CD8, lymphocytes, Il-17, gastric cancer.