Neutrophils recruited to immunization sites initiating vaccine-induced antibody responses by locally expressing BAFF

• Published in: iScience 2022-06, Vol.25 (6), p.104453-104453, Article 104453
• Main Authors: Wang, Yangyang, Qu, Kuo, Lu, Wenting, Zhao, Peiyan, Wang, Zhe, Cui, Cuiyun, Liu, Ye, Yang, Ming, Yu, Yongli, Wang, Liying
• Format: Article
• Language: English
• Subjects: Components of the immune system; Immune response; Immunology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2022.104453

Neutrophils played a key role in the innate immune responses. Less is known about whether and how the neutrophils recruited in the immunization sites affecting the vaccine-induced antibody responses. In the process of evaluating the efficacy of an oil-in-water emulsion-formulated vaccine in mice, we found that neutrophils were rapidly and massively recruited to immunization sites but were barely detected in the draining lymph nodes. Interestingly, B cell-activating factor (BAFF) was abundantly expressed in the recruiting neutrophils at a very early stage. The initial neutrophil-derived BAFF firstly brought about the B cell responses in the local part, then subsequently in lymphoid organs. Activated B cells produced more BAFF through TLR9-IRF5 signaling pathway, thereby amplifying the vaccine-induced antibody responses. Suppressing BAFF in the neutrophils could weaken the B cell activation and reduce the antibody production. The data indicate that vaccines endow neutrophils with the potential to orchestrate antibody responses at immunization sites. [Display omitted] •Neutrophils at immunization sites influencing subsequent immune responses•Neutrophil-driven BAFF at immunization sites assisting B cell responses to vaccines•Activated B cells produce more BAFF through TLR9-IRF5 signaling pathway•BAFF-producing neutrophils orchestrate antibody responses at immunization sites Components of the immune system; Immune response; Immunology