The aim of this study was to compare the immune responses of C57BL/6 mice immunized with two pathogens, foot-and-mouth disease virus (FMDV) and Senecavirus A (SVA), and to provide clues for revealing the regulatory mechanisms of acquired immunity. Inactivated and purified FMDV and SVA antigens were used to immunize C57BL/6 mice respectively, and the mice immunized with PBS were taken as the control. The percentages of Th1 and Th2 cells in the spleen lymphocytes of mice in each group were analyzed by flow cytometry at 14 and 28 days after immunization. RNA-Seq was performed for the spleen. Mouse macrophages were stimulated with the antigens in vitro to examine the expression of the differentially expressed genes (DEGs) screened out. The results showed that 14 days after immunization, there was no significant difference in the magnitude of the Th1/Th2 immune response elicited by the FMDV and SVA antigens. After 28 days, the magnitudes of the Th1 and Th2 immune responses elicited by the SVA antigen were higher than those elicited by the FMDV antigen. RNA-Seq revealed two common DEGs, Rsad2 and Tspan8, between the two immunization groups, which indicated that the two genes may be involved in the activation of the Th1/Th2 immune responses by FMDV and SVA antigens. FMDV and SVA antigens stimulated macrophages to secrete interleukin (IL)-12 and IL-33 in vitro, and the expression of Tspan8 and Rsad2 was consistent with the RNA-Seq results. The expression of Rsad2 was regulated by type I interferons (IFNα, IFNβ). In this study, we obtained the DEGs involved in the immune responses to the two antigens in mouse spleen, which provides a molecular basis for investigating the immune response mechanisms induced by FMDV and SVA.
Keywords: RNA-seq; Senecavirus A (SVA); Th1/Th2 immune response; foot-and-mouth disease virus (FMDV); spleen.