About this Research Topic
Neutrophils are abundant leukocytes that play a critical role in microbial surveillance and killing, thereby providing protection from the constant threat of foreign microorganisms, and for the most part keeping us in good health. Numerous studies focused on neutrophil migration, activation, production of NADPH oxidase-derived oxidants, and mobilization of granule proteins in response to microbes have established the basic mechanisms involved in microbe killing. However, the role of neutrophils in innate immunity and host defense has been revolutionized recently by discoveries revealing neutrophil immunomodulatory capacity.
This capacity manifests via direct interactions with other leukocytes, including T-cells, B-cells, NK cells, macrophages and dendritic cells, as well as neutrophil synthesis and secretion of cytokines, all of which are influenced further through modulation of neutrophil lifespan and cell death during infection. At the same time, it has also been established that neutrophils are not a homogenous cell population and can exhibit significant phenotypic and functional plasticity in different tissue microenvironments, as indicated by studies of human patients and animal models of infectious and inflammatory diseases. Microbial pathogens are also very resourceful and have evolved sophisticated and multifaceted strategies to avoid, inhibit, or resist this diverse antimicrobial artillery and evade elimination by neutrophils. Consequently, manipulation of neutrophil function by pathogens can sustain infection and may also induce substantial host tissue damage. A detailed understanding of the interactions between neutrophils and pathogenic microbes is therefore essential for the development of new therapeutic strategies to combat infectious diseases.
This Research Topic will include several review articles that reprise the different roles and functions of neutrophils in the immune response as a prelude to articles that focus on neutrophil interactions with pathogens. Phagocytosis and mechanisms of priming and microbe killing will be reviewed, as will current understanding of neutrophil phenotypic plasticity and immunomodulatory functions, with a focus on neutrophil phenotypic changes during inflammation, and interactions of these cells with other key leukocytes during the immune response. In addition, review articles, primary research, or commentaries focused on the interactions and crosstalk between neutrophils and microbial pathogens are of significant interest. Studies of the cellular and molecular mechanisms used by microbial pathogens to perturb neutrophil phenotype, function and lifespan are encouraged. In vivo studies of neutrophil-pathogen interactions in human patients or animal models, pathogen evasion strategies and mechanisms, and translational studies that highlight the role of neutrophils in acute and chronic infectious diseases and inflammation are also welcomed.
Keywords: Neutrophils, bacteria, pathogenesis, infectious diseases, inflammation, cell death, innate immunity, cytokines, phenotypic plasticity