Profiles of immune infiltration in seasonal allergic rhinitis and related genes and pathways

•Up-regulated of CD8+ T cell and down-regulated of neutrophils in the whole blood of SAR patients.•CD4+ T cell genes and associated cytokines significantly differed in allergen-treated SAR patients compared to healthy and diluent-treated SAR patients.•T cell receptor signaling pathways and Th1/Th2 cell differentiation may be involved in the mechanism of SAR development.•Heightened CD4+ T cell activation in the nasal mucosa region of SAR patients after allergen challenge.