The human epithelium represents the interface between the body and the environment. The epithelial cell-derived cytokine milieu has been discussed as a “master switch” in the development of allergic disease. Prebiotics, probiotics or active microbial structures are assumed to not only influence host microbial homeostasis but also directly affect epithelial and immune cells.
The aim of this study was to isolate and culture primary nasal epithelial cells (HNECs) from well characterized non-atopic and atopic donors and to subsequently characterize their innate immune receptor repertoire, physical and immunological barrier function and response.
Secondly, it should be tested if short-chain galacto- and long chain fructo-oligosaccharides (scGOS/lcFOS) and lactic acid bacteria (LAB) or lactocepin have a direct effect on epithelial cell physical and immunological barrier function and response.
A method to isolate and culture HNECs from clinically and immunologically well characterized patients was established and cells derived from atopic or non-atopic donors were compared with respect to their barrier integrity, expression of toll-like receptors (TLRs), inflammasome components as well as immune responses in steady state and after stimulation. Moreover, human primary KCs and HNECs from non-atopic or atopic (eczema) donors were stimulated in different cell culture systems and treated with lactocepin or a specific mixture of non-digestible scGOS/lcFOS and lactic acid bacteria.
HNECs showed all characteristics of epithelial cells.Unstimulated HNECs expressed TLR1-6 and 9 while TLR-9 protein expression was lower in cells of atopic donors than in cells of non-atopic donors. Chemokine responses after stimulation were similar between HNECs of atopic and non-atopic donors. However, secretion of IL-18 and IL-33 was elevated under steady state and after stimulation in HNECs of AR donors as compared to controls. Similarly, activation of the inflammasome resulted in higher IL-1ß levels in HNECs of atopics.
scGOS/lcFOS, both alone, or in combination with LABs decreased the IFN-?- and TNF-a-induced secretion of pro-inflammatory CXCL-10 and CCL-5 while this effect was only reproducible for CCL-5 in atopic (eczema) donor derived cells. Stimulation with the bacterial endopeptidase lactocepin, significantly decreased the IFN-?- and TNF-a-induced secretion of CXCL-10 and CCL-5 in HNECs and KCs, irrespective of the donor atopy status. CCL-2 levels were only decreased in KCs from non-atopic donors. The combination of scGOS/lcFOS and LAB induced a temporary significant rise in TER in ALI cultures derived from non-atopic donors.
Results of this study indicate differences in expression levels of innate immune components and responses in cells derived from atopic donors when compared to non-atopic donors. Thus, different expression patterns of innate immune components may be predisposing factors skewing the development of immune function away from tolerance towards allergy susceptibility. Direct immune-modulatory properties of prebiotics and probiotics were observed but affected by atopy status.
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The human epithelium represents the interface between the body and the environment. The epithelial cell-derived cytokine milieu has been discussed as a “master switch” in the development of allergic disease. Prebiotics, probiotics or active microbial structures are assumed to not only influence host microbial homeostasis but also directly affect epithelial and immune cells.
The aim of this study was to isolate and culture primary nasal epithelial cells (HNECs) from well characterized non-ato...
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