Abstract
ABSTRACTInnate immune activation is essential to mount an effective antiviral response and to prime adaptive immunity. Although a crucial role of CD169+ cells during vesicular stomatitis virus (VSV) infections is increasingly recognized, factors regulating CD169+ cells during viral infections remain unclear. Here, we show that tumor necrosis factor is produced by CD11b+ Ly6C+ Ly6G+ cells following infection with VSV. The absence of TNF or TNF receptor 1 (TNFR1) resulted in reduced numbers of CD169+ cells and in reduced type I interferon (IFN-I) production during VSV infection, with a severe disease outcome. Specifically, TNF triggered RelA translocation into the nuclei of CD169+ cells; this translocation was inhibited when the paracaspase MALT-1 was absent. Consequently, MALT1 deficiency resulted in reduced VSV replication, defective innate immune activation, and development of severe disease. These findings indicate that TNF mediates the maintenance of CD169+ cells and innate and adaptive immune activation during VSV infection.IMPORTANCE Over the last decade, strategically placed CD169+ metallophilic macrophages in the marginal zone of the murine spleen and lymph nodes (LN) have been shown to play a very important role in host defense against viral pathogens. CD169+ macrophages have been shown to activate innate and adaptive immunity via “enforced virus replication,” a controlled amplification of virus particles. However, the factors regulating the CD169+ macrophages remain to be studied. In this paper, we show that after vesicular stomatitis virus infection, phagocytes produce tumor necrosis factor (TNF), which signals via TNFR1, and promote enforced virus replication in CD169+ macrophages. Consequently, lack of TNF or TNFR1 resulted in defective immune activation and VSV clearance.
Highlights
Factors regulating CD169ϩ cells during viral infections remain unclear
We show that after vesicular stomatitis virus infection, phagocytes produce tumor necrosis factor (TNF), which signals via TNF receptor 1 (TNFR1), and promote enforced virus replication in CD169ϩ macrophages
Consistent with reports that neutrophils [38, 39] and CD11bϩ Ly6Cϩ Ly6Gϩ cells [40] are important during early defense against bacterial and viral infections via production of proinflammatory cytokines, such as interleukin 1b (IL-1b), IL-6, TNF, and IFN-I, we found a significant increase of TNFϩ CD11bϩ Ly6Cϩ Ly6Gϩ cells (Fig. 1F)
Summary
Factors regulating CD169ϩ cells during viral infections remain unclear. Here, we show that tumor necrosis factor is produced by CD11bϩ Ly6Cϩ Ly6Gϩ cells following infection with VSV. MALT1 deficiency resulted in reduced VSV replication, defective innate immune activation, and development of severe disease. These findings indicate that TNF mediates the maintenance of CD169ϩ cells and innate and adaptive immune activation during VSV infection. IFN-I triggers strong inhibitory effects on viral replication and is crucial for preventing severe infections with the vesicular stomatitis virus (VSV) model system [1, 15]. TNF Promotes CD169ϩ Macrophage Survival doses of VSV, replication of VSV in CD169ϩ cells in the spleen and lymph node tissue is important for inducing protective immunity and preventing CNS infection [9, 10]. The VSV backbone is used during vaccination to induce protective immunity against viruses such as Ebola virus [25]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
