CD4+ T cells mediate respiratory syncytial virus (RSV)-induced airway inflammation through secreting Th2 cytokines

Abstract

Objective To investigate the role of CD4+ T cells in airway inflammation induced by respiratory syncytial virus (RSV) infection. Methods Animal models of acute RSV infection were established. Lung tissues were stained with hematoxylin and eosin (HE) to observe histopathological changes. Total number of CD4+ T cells and the number of CD4+ T cells secreting Th1/Th2 cytokines (IFN-γ, IL-4, IL-5 and IL-13) in spleen were detected by flow cytometry. Adoptive transfer of CD4+ T cells was performed to identify the role of CD4+ T cells in RSV-induced airway inflammation. Results RSV infection increased the total number of splenic CD4+ T cells, particularly Th2-type CD4+ T cells. The absolute numbers of IL-4/IL-5/IL-13-secreting CD4+ T cells were increased significantly after RSV infection. Furthermore, adoptive transfer of CD4+ T cells into BALB/c mice not only promoted the infiltration of mononuclear cells in lung, but also enhanced the secretion of Th2 cytokines during RSV infection. Conclusion CD4+ T cells are involved in RSV-induced airway inflammation through secreting Th2 cytokines. Key words: Respiratory syncytial virus; CD4+ T cell; Airway inflammation