Lactoferrin Administration Into The Nostril Prevents And Treats Murine Allergic Rhinitis And Its Mechanisms

Objectives:To investigate the expression levels of lactoferrin mRNA and protein in nasal cavity in controls and allergic rhinitis mice and its relationship with allergic rhinitis. To investigate the local effect of intranasal administration recombinant human (rh) LF and its underlying mechanisms on AR in BALB/c mice.Methods:BALB/c mice were used to establish allergic rhinitis which was induced by ovalbumin. The infiltration of eosinophils, goblet cells, and mast cells in nasal mucosa was examined by hematoxylin&eosin, periodic acid-Schiff, mast cell staining, respectively. The expression levels of T-subsets related transcription factors and cytokines and lactoferrin mRNA and protein in the nasal mucosa were detected using real time RT-PCR and enzyme-linked immunosorbent assay among controls and allergic rhinitis, respectively. The method of Spearman was used to analyzed the relationship between lactoferrin expression and the number of eosinophils.Results:We found that the number of eosinophils, goblet cells, and mast cells, as well as mRNA and protein expression of type2helper T (Th2), Th17, and regulatory T (Treg) cells in the nasal cavity, were significantly up-regulated in AR mice compared with the controls (P<0.01), Conversely, administration of rhLF prior to or after intranasal ovalbumin challenge markedly down-regulated these same parameters (P<0.01). Thl-specific mRNA and protein expression in the nasal cavity of the controls was not different from that in AR mice, but expression significantly increased with rhLF treatment (P<0.01). The mRNA and protein expression of endogenous LF in the nasal cavity was significantly down-regulated in AR mice compared with the controls (P<0.01). However, after rhLF treatment, endogenous LF mRNA and protein expression was significantly upregulated (P<0.01). There was a negative correlation between the number of inflammatory cells and lactoferrin expression levels (r=-0.920, P<0.01). There was a negative correlation between the number of eosinophils and lactoferrin expression levels (r=-0.920, P<0.01) Conclusions:The expression levels of lactoferrin mRNA and protein were obviously decreased in mice of allergic rhinitis, it indicates that lactoferrin may be involved in the pathogenesis of allergic rhinitis. Exogenous rhLF inhibited allergic inflammation in AR mice, most likely by promoting the endogenous LF expression and skewing T cells to a Thl but not a Th2and Th17phenotype in the nasal mucosa. Our findings suggest that rhLF treatment may be a novel therapeutic approach for prevention and treatment AR.