title: IL-6-transfected tumor cells modulate the status of CD8(+) and CD4(+) T cells to control tumor growth.
abstract: IL-6 is a proinflammatory cytokine secreted by tumor cells and immune cells to affect the development of cancer. This study demonstrates the effects of tumor-derived IL-6 on the malignancy of tumor cells and tumor immunity. The tumor cell line, EG7, was transfected with a mammalian expression vector encoding the full length of murine IL-6 to mimic IL-6-secreting tumor cells. Two IL-6 transfectants with low and high IL-6 production were compared in vitro and in vivo. While the in vitro proliferation rates of both transfectants and the parental line were similar, high expression of IL-6 induced a significant reduction in tumor growth in vivo. Concomitantly, there was an increase in IFN-gamma positive tumor-infiltrating lymphocytes and a decrease in the suppressive CD4(+)CD25(+)FoxP3(+) population. These results demonstrate the direct effects of tumor-derived IL-6 on cancer development and the induction of tumor immunity.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chia-Ling
authors.initials: CL
authors.lastname: Hsieh
authors.forename: Shih-Jen
authors.initials: SJ
authors.lastname: Liu
authors.forename: Chia-Rui
authors.initials: CR
authors.lastname: Shen
authors.forename: Mei-Yu
authors.initials: MY
authors.lastname: Chen
authors.forename: Shu-Ching
authors.initials: SC
authors.lastname: Hsu
authors.forename: Jy-Ping
authors.initials: JP
authors.lastname: Tsai
authors.forename: Yi-Shiuan
authors.initials: YS
authors.lastname: Li
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Yang
authors.forename: Pele
authors.initials: P
authors.lastname: Chong
authors.forename: Hsin-Wei
authors.initials: HW
authors.lastname: Chen
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D045744:Cell Line, Tumor; D007111:Immunity, Cellular / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology*; D051379:Mice; D016513:Mice, SCID; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000628:therapy; D014162:Transfection
chemical_list: D015850:Interleukin-6; D007371:Interferon-gamma