Activation of macrophages by lactoferrin: secretion of TNF-alpha, IL-8 and NO.
When macrophages were cultured with lactoferrin, cytokines such as tumor necrosis factor (TNF-alpha), interleukin 8 (IL-8) and nitric oxide (NO) were secreted. Secretion of TNF-alpha peaked at 6 h of incubation in the presence of lactoferrin and then declined. About 80% of the maximum secretion of IL-8 was observed at 6 h of incubation. The concentration of IL-8 in the culture medium remained almost constant between 24-72 h. In contrast, no significant effect on NO secretion was observed at 6 h, but a significant effect was observed at 24 h and secretion gradually increased between 24-72 h. The effects of lactoferrin on the secretion of TNF-alpha, IL-8 and NO were dose-dependent and lactoferrin had a significant effect on secretion of at concentrations greater than 10 mg/ml. The use of reverse transcription-polymerase chain reaction (RT-PCR) showed that the results obtained were consistent with the cytokine secretion results. It is concluded that lactoferrin activates macrophages which result in the secretion of TNF-alpha, IL-8 and NO.
Sorimachi
K
K
Department of Microbiology, Dokkyo University School of Medicine, Tochigi, Japan.
Akimoto
K
K
Hattori
Y
Y
Ieiri
T
T
Niwa
A
A
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016209:Interleukin-8 / Q000378:metabolism*; D007700:Kinetics; D007781:Lactoferrin / Q000494:pharmacology*; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D016209:Interleukin-8; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D007781:Lactoferrin