RESUMO
Objective:To study the expression of Toll like receptor 3 (TLR3) in human adenocarcinoma of the lung cells induced by respiratory syncytial virus (RSV) and its significance in the diagnosis of pneumonia in children.Methods:A549 cells were divided into RSV infection group [added 1 μg/ml Lipopolysaccharide (TLR3 agonist) transfected RSV virus after 150 μl intervention], Lipopolysaccharide stimulation group (added 1 μg/ml Lipopolysaccharide 150 μl intervention) and normal control group (normal culture). The mRNA expressions of tumor necrosis factor-α, interleukin 8, TLR3 protein and TLR3 in A549 Cells of different groups were compared. We prospectively selected 80 children with RSV infectious pneumonia admitted to Baoding Second Central Hospital from August 2019 to October 2021 as the RSV pneumonia group, and sixty children with common pneumonia were taken as the common pneumonia group, and 60 healthy children in our hospital were taken as the control group. The mRNA expression of serum TLR3 in different groups was compared, and the diagnostic efficacy of serum TLR3 in RSV pneumonia was evaluated by receiver operating characteristic.Results:There was a statistically significant difference in the expression of TLR3 protein among different groups of A549 cells ( P<0.001). The expression differences of TLR3 mRNA in different groups of A549 cells at different time points were statistically significant(all P<0.001). There was significant difference in the expression of tumor necrosis factor-α and interleukin 8 of A549 cells at different time points in different groups (all P<0.05). There was a statistically significant difference in the expression of serum TLR3 mRNA among the three groups of subjects ( F=155.237, P<0.001). The critical value for TLR3 gene diagnosis was 66.87, with corresponding sensitivity of 73.75%, specificity of 70.83%, and the area under curve (AUC) of 0.803(95% CI: 0.753-0.855). Conclusions:Respiratory syncytial virus induces human lung cancer cells and promotes disease progression through TLR3 expression; Serum TLR3 can be used for the diagnosis of RSV pneumonia.