Mycoplasmas induce transcription and production of tumor necrosis factor in a monocytic cell line, THP-1, by a protein kinase C-independent pathway.
We demonstrated that mycoplasmas (MP), previously shown to augment the antitumor activity of murine peritoneal macrophages, also induce cytotoxic activity in a human monocytic cell line, THP-1. THP-1 cells were induced to produce cytotoxic activity by MP in a time- and dose-dependent manner. By using neutralization by antibody against tumor necrosis factor (TNF), the cytotoxic activity was shown to be due to TNF released from the MP-stimulated cells. Studies with inhibitors of second-messenger pathways and Northern RNA blot analysis indicated that a Ca2(+)-dependent, but not protein kinase C-dependent, biochemical pathway is involved in MP-induced TNF production by THP-1 cells and that MP induce TNF production in the cells at the level of transcription. MP, unlike other bacteria, lack cell walls and lipopolysaccharide. The possible involvement of a TNF production mechanism distinct from that triggered by lipopolysaccharide is discussed.
Sugama
K
K
Department of Microbiology, Kurume University School of Medicine, Japan.
Kuwano
K
K
Furukawa
M
M
Himeno
Y
Y
Satoh
T
T
Arai
S
S
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D015870:Gene Expression; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008809:Mice, Inbred C3H; D009174:Mycoplasma / Q000276:immunology; D009500:Neutralization Tests; D011493:Protein Kinase C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D015290:Second Messenger Systems / Q000187:drug effects; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D000907:Antibodies, Bacterial; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D011493:Protein Kinase C