IL-6-transfected tumor cells modulate the status of CD8(+) and CD4(+) T cells to control tumor growth.
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.
Hsieh
Chia-Ling
CL
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
Liu
Shih-Jen
SJ
Shen
Chia-Rui
CR
Chen
Mei-Yu
MY
Hsu
Shu-Ching
SC
Tsai
Jy-Ping
JP
Li
Yi-Shiuan
YS
Yang
Ching-Jen
CJ
Chong
Pele
P
Chen
Hsin-Wei
HW
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
D015850:Interleukin-6; D007371:Interferon-gamma