ACTIVATION OF MACROPHAGES BY LACTOFERRIN - SECRETION OF TNF-ALPHA, IL-8 AND NO

When macrophages were cultured with lactoferrin, cytokines such as tum or 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 ma ximum secretion of IL-8 was observed at 6 h of incubation. The concent ration of IL-8 in the culture medium remained almost constant between 24-72 h. In contrast, no siginificant effect on NO secretion was obser ved at 6 h, but a significant effect was observed at 24 h and secretio n gradually increased between 24-72 h. The effects of lactoferrin on t he secretion of TNF-alpha, IL-8 and NO were dose-dependent and lactofe rrin had a significant effect on secretion at concentrations greater t han 10 mg/ml. The use of reverse transcription-polymerase chain reacti on (RT-PCR) showed that the results obtained were consistant with the cytokine secretion results. It is concluded that lactoferrin activates macrophages which result in the secretion of TNF-alpha IL-8 and NO.