Effects of TNF-alpha and IL-1 beta on mucin, lysozyme, IL-6 and IL-8 in passage-2 normal human nasal epithelial cells

Abstract

Little is known about the regulatory effects of cytokines on various nasal secretions in normal human nasal epithelial cells. The aim of this study was to examine whether TNF-alpha, IL-1beta or their combination can increase the secretion of mucin as an indicator of mucous secretion, the secretion of lysozyme as an indicator of serous secretion and the secretion of IL-6 and IL-8 as important cytokines. In addition, we wanted to examine their message levels in normal human nasal epithelium. On day 12 of culture, passage-2 normal human nasal epithelial cells were treated with 10 ng/ml TNF-alpha, 10 ng/ml IL-1beta and combinations of both. Twenty-four hours later, the apical secretions were collected. A mixture of TNF-alpha and IL-1beta synergistically increased secretion of mucin, IL-6 and IL-8, but did not increase secretion of lysozyme. A combination of TNF-alpha and IL-1beta showed a questionable increase of MUC2 mRNA levels. TNF-alpha, IL-1beta and a combination of both all significantly increased MUC8 mRNA levels. Neither TNF-alpha, IL-1beta nor a combination of both increased MUC5AC, MUC5B and lysozyme mRNA levels. IL-1beta alone or a combination of TNF-alpha and IL-1beta comparably increased IL-6 and IL-8 mRNA levels slightly. In conclusion, a mixture of inflammatory mediators can synergistically increase secretion of mucin, IL-6 and IL-8 in human nasal epithelium. Accordingly, nasal secretions may be under the control of an inflammatory mediator network.