PM2.5 Promotes Helper T Cell 9 Differentiation And Participates In The Pathogenesis Of Allergic Rhinitis

Objective:The composition of air pollutants is very complex,and it is very different in different regions,different pollution sources and different meteorological conditions.As the main component of air pollutants,PM2.5 is closely related to the severity of respiratory symptoms.A large number of previous studies have confirmed that PM2.5 aggravates the symptoms of rhinitis in patients with allergic rhinitis by aggravating the oxidative stress of nasal mucosa.The pathogenesis of allergic rhinitis is complex,and a variety of inflammatory factors are involved.Helper T cell 9,as a newly discovered inflammatory cell involved in the pathogenesis of allergic rhinitis,participates in nasal mucosal inflammatory response by secreting IL-9.The increase of IL-9 level will aggravate the inflammatory symptoms of allergic rhinitis.It is found that PM2.5 aggravates asthma symptoms by affecting the differentiation of Th9 cells in peripheral blood,and the upper and lower respiratory tract is the same disease,suggesting that PM2.5 may aggravate allergic rhinitis by promoting the differentiation of Th9 cells.This study intends to study whether PM2.5 participates in and aggravates the occurrence of AR by promoting the differentiation of Th9 cells,and to explore the specific mechanism of PM2.5 inducing and aggravating the attack of AR.The purpose of this study is to provide experimental evidence for revealing the relationship between air pollution and the onset of AR.Methods:C57BL/6 mice sensitized by ovalbumin were used to induce allergic rhinitis.According to whether they were exposed to PM2.5 or not,they were divided into four experimental groups: AR group,AR+ anti-IL-9 antibody group,PM2.5 exposure AR group and PM2.5 exposure AR+ anti-IL-9 antibody group.The control group was treated with normal saline.The peripheral serum of mice was collected and the expression of IL-4,IL-5 and IL-9 in peripheral blood of mice was detected by enzyme-linked immunosorbent assay(ELISA).Results:The expression of IL-4,IL-5 and IL-9 protein in PM2.5 exposure group was higher than that in AR group,and the expression of IL-5 protein in anti-IL-9 antibody group was significantly lower than that in AR group and PM2.5 group(P < 0.05).Conclusion:PM2.5 can aggravate the inflammatory reaction of nasal mucosa in AR mice.PM25 exposure can increase the differentiation of Th9 in peripheral blood and the levels of IL-4,IL-5 and IL-9 in peripheral serum of AR mice.After treatment with anti-IL-9 antibody,the symptoms of rhinitis in mice exposed to PM2.5 were improved,and the levels of IL-4,IL-5 and IL-9 in peripheral serum of mice were decreased.