口蹄疫病毒与塞内卡病毒灭活抗原免疫小鼠脾脏的转录组学差异分析

Transcriptomic differences between the spleens of mice immunized with inactivated antigens of foot-and-mouth disease virus and Senecavirus A

摘要:

本研究旨在探究C57BL/6小鼠免疫口蹄疫病毒(foot and mouth disease virus, FMDV)与塞内卡病毒(Senecavirus A, SVA) 2种病原的免疫应答差异，为解析获得性免疫调控机制提供理论基础。将灭活纯化的FMDV与SVA抗原分别免疫C57BL/6小鼠，设置PBS免疫对照组；利用流式细胞术分析免疫14、28 d后各组小鼠脾淋巴细胞中Th1与Th2细胞的比例，并进行小鼠脾脏转录组测序和分析；通过体外抗原刺激鼠巨噬细胞验证筛选差异表达基因。结果显示，小鼠免疫14 d后，FMDV与SVA抗原免疫组诱导Th1/Th2型免疫应答水平无显著差异，免疫28 d后，SVA抗原免疫组诱导Th1型与Th2型免疫应答水平均高于FMDV抗原免疫组；转录组测序获得2种抗原免疫后2组共有差异基因Rsad2和Tspan8等，可能参与FMDV和SVA抗原激活Th1/Th2型免疫应答反应的过程；FMDV与SVA抗原体外刺激巨噬细胞分泌IL-12、IL-33，差异基因Tspan8、Rsad2的表达趋势与转录组测序结果一致，Rsad2的表达受I型干扰素(IFNα、IFNβ)的调控。本研究获得了2种小鼠脾脏中抗原免疫应答相关的差异基因，为进一步研究FMDV和SVA免疫应答机制奠定基础。

Abstract:

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.