title: Changes of T cells and cytokines TGF-β1 and IL-10 in mice during liver metastasis of colon carcinoma: implications for liver anti-tumor immunity.
abstract: BACKGROUND
  The local and systemic regulation of the immune system may play important roles in the process of liver metastasis of colorectal carcinoma. The aim of this study was to establish a reproducible experimental liver metastasis model, to identify changes in T cells and cytokines TGF-β1 and IL-10, and to explore a possible mechanism of liver metastasis of colon carcinoma.
  
  
  METHODS
  We used a colon carcinoma liver metastasis model, in which different numbers of CT-26 murine colon carcinoma cells (1 × 10(3), 5 × 10(3), 1 × 10(4), 5 × 10(4), and 1 × 10(5)) were injected into the spleen. The liver and spleen tissues were examined for T cell markers using flow cytometry. Liver tissues were analyzed for IL-10 and transforming growth factor beta 1 (TGF-β1) expression using immunohistochemistry.
  
  
  RESULTS
  Spleen injection of colon carcinoma cells is a reproducible animal model for liver metastases, which resulted in quantity-dependent metastatic growth. We provided a snapshot of the hepatic immune microenvironment in the mouse liver metastasis model. Injection of A large number of tumor cells (5 × 10(4) and 1 × 10 (5) ) decreased anti-tumor cell counts, such as CD4(+) and CD8(+) T cells, and increased immune-suppressive cell counts (CD4(+)CD25(+) Treg cells). In addition, the expression levels of immunosuppressive cytokines IL-10 and TGF-β1 were also increased with the number of tumor cells.
  
  
  CONCLUSIONS
  Changes in the systemic and local immunological environment contribute to immunological escape mechanisms during liver metastasis of colon carcinoma, and therapies aiming at immune microenvironment may prove a useful strategy in the treatment of metastatic disease in the future.
authors.affiliation: Department of Hepatobiliary Surgery, The Sixth Affiliated Hospital of Sun Yat-Sen University, 26 Yuancunerheng Road, Guangzhou 510655, PR China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Huang
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zou
authors.forename: Lei
authors.initials: L
authors.lastname: Lian
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Wu
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: He
authors.forename: Xiaowen
authors.initials: X
authors.lastname: He
authors.forename: Xianrui
authors.initials: X
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Ping
authors.initials: P
authors.lastname: Lan
mesh_terms: D000818:Animals; D003110:Colonic Neoplasms / Q000276:immunology* / Q000473:pathology*; D005260:Female; D007109:Immunity; D016753:Interleukin-10 / Q000276:immunology*; D008099:Liver / Q000276:immunology*; D008113:Liver Neoplasms / Q000276:immunology* / Q000556:secondary*; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology*; D053773:Transforming Growth Factor beta1 / Q000276:immunology*
chemical_list: D053773:Transforming Growth Factor beta1; D016753:Interleukin-10