Pentraxin 3 promotes airway inflammation in experimental asthma.

BACKGROUND: Pentraxin 3 (PTX3) regulates multiple aspects of innate immunity and tissue inflammation. Recently, it has been reported that PTX3 deficiency enhances interleukin (IL)-17A-dominant pulmonary inflammation in an ovalbumin (OVA)-induced mouse asthma model. However, whether PTX3 treatment would provide protection against allergic airway inflammation has not been clearly elucidated. The goal of this study was to further investigate the effect of recombinant PTX3 administration on the phenotype of asthma. METHODS: C57BL/6 J mice were sensitized and challenged with OVA to induce eosinophilic asthma model, as well as sensitized with OVA plus LPS and challenged with OVA to induce neutrophilic asthma model. We evaluated effect of recombinant PTX3 on asthma phenotype through both asthma models. The bronchoalveolar lavage fluid (BALF) inflammatory cells and cytokines, airway hyperresponsiveness, and pathological alterations of the lung tissues were assessed. RESULTS: In both eosinophilic and neutrophilic asthma models, PTX3 treatment provoked airway hyperresponsiveness, concomitant with increased inflammatory cytokines IL-4, IL-17, eotaxin, and transforming growth factor (TGF)-ß1 and aggravated airway accumulation of inflammatory cells, especially eosinophils and neutrophils. In histological analysis of the lung tissue, administration of PTX3 promoted inflammatory cells infiltration, mucus production, and collagen deposition. In addition, PTX3 also significantly enhanced STAT3 phosphorylation in lung tissue. CONCLUSION: Our results show that exogenous PTX3 can exacerbate multiple asthmatic features by promoting both eosinophils and neutrophils lung infiltration and provide new evidence to better understand the complex role of PTX3 in allergic airway inflammation.