Influence Of Nonstructural Proteins Of Respiratory Syncytial Virus On T Subsets Differentiation

Objectives:Human respiratory syncytial virus (RSV), a major cause of severe respiratory diseases, constitutes an important risk factor for the development of subsequent asthma. The present study was designed to screen the interacting proteins of two nonstructural(NS1and NS2)proteins and test abnormal signal transduction of bronchial epithelial in searching for mechanism of the subsets drift of CD4+T lymphocytes.Methods:Constructing lentiviral vectors of NS1or NS2to infect bronchial epithelial cells, immune coprecipitation and mass spectrometry technologies were used to screen and identify their interacted proteins; Western blotting technology was used to identify the ubiquitination modification of interacting proteins; bisulfite sequencing was used to detect the methylation of Notch1gene. Co-culturing bronchial epithelial cells and CD4+T lymphocytes, flow cytometry was used to detect the subsets differentiation of CD4+T lymphocyte, ELISA assay was used to detect the secretions of cytokine IFN-gamma, IL-4and IL-17in the supernatant.Results:(1) NS1can interact with histone H2BD with its elongin C binding region;(2) NS1can induce monoubiquitination of histone H2BD interaction;(3) NS1can induce the demethylation of Notch1gene;(4) NS1had no effects on bronchial epithelial cell-driven subsets differentiation of T lymphocyte, while NS2inhibited the differentiation of Th17, which can be reversed by inhibitors of ubiquitination.(5) Viral non-structural proteins had no effects on the secretions of cytokines in co-cultured supernatant. Conclusion:NS1interacted with H2BD specifically and induced H2BD monoubiquitination and subsequent activation of downstream Notch1. NS2inhibited Th17’s differentiation, which was related with degradation activity of ubiquitination.