IL-21 Enhances the Immune Protection Induced by the Vibrio Vulnificus Hemolysin A Protein

Abstract We previously reported that the Vibrio vulnificus hemolysin A (VvhA) protein elicited good immune protection and could effectively control V. vulnificus infection in mice. However, its molecular mechanism remains unknown. In this study, we found that IL-21 enhances immune protection by inducing a Tfh-cell and germinal center (GC) B-cell response. We used RNA-seq and identified 10 upregulated and 30 downregulated genes that were involved in IL-21-upregulated protection. We also performed Gene Ontology (GO) analysis and pathway analysis of these differentially expressed genes. Our findings indicate that IL-21 can enhance the immune protection effect of VvhA protein and may serve as a novel strategy for enhancing the immune protection effect of protein vaccines.