Comparison of the roles of house dust mite allergens, ovalbumin and lipopolysaccharides in the sensitization of mice to establish a model of severe neutrophilic asthma

Abstract

Neutrophilic asthma (NA) is associated with a severe disease course and poor response to corticosteroids. The present study aimed to compare the effects of various concentrations of house dust mite (HDM) allergens, ovalbumin (OVA), the major egg allergen, and lipopolysaccharide (LPS) in combination on the onset of severe NA. Female C57BL/6 mice were grouped according to a random number table and intranasally sensitized with HDM/LPS/OVA extracts on days 0, 1 and 2 of the study. In group 1, mice received 50 µg HDM + 50 µg OVA + 15 µg LPS, mice in group 2 received 50 µg HDM + 100 µg OVA + 15 µg LPS, mice in group 3 received 100 µg HDM + 50 µg OVA + 15 µg LPS and those in group 4 received 100 µg HDM + 100 µg OVA + 15 µg LPS, while mice in the control group received saline only. The mice were then challenged by OVA solution with atomized excitation on days 14, 15, 18, 19 and 20 for 30 min each. Ethology, airway hyperresponsiveness (AHR), immune cell distributions in bronchoalveolar lavage fluid (BALF), and specific cytokines interleukin 17A (IL-17A) and IL-4 in serum were assessed. Histological examination of inflammation by hematoxylin and eosin staining and immunohistochemical assessment of neutrophils (NEU), eosinophils (EOS), IL-17A and IL-4 were also performed. Compared with the control group, the HDM/OVA/LPS-sensitized groups 1–4 had markedly increased BALF cells, serum interleukin IL-17A and IL-4, inflammatory cell infiltration, EOS as well as IL-17A and IL-4 by immunohistochemical staining (all P<0.05). Among the four HDM/OVA/LPS-sensitized groups, mice of group 4 had higher AHR, a significantly higher total cell number, NEU and EOS in BALF as well as significantly higher NEU and NEU/EOS ratios according to immunohistochemical staining when compared to groups 1–3 (P<0.05 for all). In conclusion, sensitization with 100 µg HDM + 100 µg OVA + 15 µg LPS successfully established a severe asthma model with a predominantly neutrophilic inflammatory phenotype.

MBD2 regulates differentiation and function of Th17 cells in neutrophils- dominant asthma via HIF-1α

“…In murine asthma models, LPS or HDM administration via the airways increased Th17 cell response and the production of IL-17 [ 15 ]. In a previous study, we showed that 100 μg HDM + 100 μg OVA + 15 μg LPS was successful for establishing a neutrophils-dominant asthma [ 26 ].…”

“…This shows that neutrophilic asthma mice primarily exhibited Th17 cell differentiation, and the recruitment of neutrophils, thus promoting the development of asthma. And the data in detail was published by our team [ 26 ].MBD2, a DNA methylation regulation element, can regulate T cell differentiation [ 27 , 28 ]. Although little is known about epigenetic regulation in neutrophils-dominant asthma, in our study we report that MBD2 expression in splenic CD4 + T cells and lungs from neutrophils-dominant asthma mice was significantly higher compared to conventional asthma mice and the control group.…”

Yupingfeng San Inhibits NLRP3 Inflammasome to Attenuate the Inflammatory Response in Asthma Mice

“…The ethology of the mice was evaluated by observation of the following parameters: Fur luster, touching of nose and scratching of ears, irritability, sneezing, rapid breathing and incontinence ( Jia et al, 2017 ).…”

Comparative analysis of the role of mast cells in murine asthma models using Kit‐sufficient mast cell‐deficient animals

“…Despite accumulating evidence of their role in human asthma, the function of MCs in mouse models of allergic airway inflammation is still a matter of controversy, with several contradicting results. A source of variation in the published literature derives from the route/regimen of immunization and the choice of allergen, [41][42][43][44] but the main difficulty in reaching conclusive results stems from the use of Kit mutant mice. These animals lack MCs but show several additional alterations compared to wild-type mice that complicate interpretation of results.…”