IFN‐γ protects from apoptotic neutrophil‐mediated tissue injury during acute Listeria monocytogenes infection. Issue 9 (25th July 2018)

• Record Type: Journal Article
• Authors: Wang, Guan; Lin, Ang; Han, Qiuju; Zhao, Huajun; Tian, Zhigang; Zhang, Jian
• Is Part Of: European journal of immunology. Volume 48:Issue 9(2018)
• Page Start: 1470
• Page End: 1480
• Publication Date: 2018-07-25
• Subjects: IFN‐γ -- Listeria monocytogenes -- Macrophages -- Neutrophils -- Tissue injury; Immunology -- Periodicals; 616.079
• DOI: 10.1002/eji.201847491
• Languages: English
• ISSNs: 0014-2980

Abstract

Abstract: Listeria monocytogenes (LM) is a foodborne Gram‐positive intracellular pathogen that can cause listeriosis in humans and animals. Although phagocytes are known to be involved in the response to this infection, the role of neutrophils is not entirely clear. Here, we have demonstrated that soon after LM infection, a large number of IFN‐γ‐producing neutrophils quickly accumulated in the spleen, blood, and peritoneal cavity. Both in vivo and in vitro experiments demonstrated that neutrophils were an important source of IFN‐γ. IFN‐γ played a critical protective role against acute LM infection, as demonstrated by the poor survival of Ifng −/− mice. Moreover, IFN‐γ promoted bacterial clearance by the neutrophils, thereby inhibiting LM‐induced neutrophil apoptosis and spleen damage. In addition to this, IFN‐γ could effectively drive macrophage‐mediated phagocytosis of apoptotic neutrophils, which was accompanied with TGF‐β secretion and was involved in protection against tissue injury. Importantly, by phagocytizing apoptotic neutrophils, macrophages obtained myeloperoxidase, an important bactericidal molecule only produced by neutrophils, which further promoted the antibacterial activity of macrophages. These findings demonstrate that neutrophils are an important source of IFN‐γ at the early stage of LM infection, which is characterized by both LM elimination and tissue‐protective effects. Abstract : Neutrophils are an important source of IFN‐γ in acute LM infection. IFN‐γ promotes bacterial clearance by neutrophils, and alleviates tissue injury by inhibiting LM‐induced neutrophil apoptosis, promoting macrophage‐mediated phagocytosis of apoptotic neutrophils and TGF‐β secretion. The antibacterial activity of macrophages is enhanced by MPO obtained from apoptotic neutrophils. .