An unexpected role for hypoxic response: oxygenation and inflammation.
The eradication of invading microorganisms depends initially on innate immunity mechanisms that preexist in all individuals and act within minutes of infection. Pathogen spread is often countered by an inflammatory response that recruits more effector molecules and cells of the innate immune system from local blood vessels, while inducing clotting farther downstream so that pathogens cannot spread throughout the blood. If a microorganism crosses an epithelial barrier and begins to replicate in the tissues of the host, it is, in some cases, immediately recognized by the mononuclear phagocytes, or macrophages, that reside in tissues. Macrophages mature continuously from circulating monocytes that leave the circulation to migrate into tissues throughout the body. The second major family of phagocytes, the neutrophils or polymorphonuclear leukocytes (PMNs) are short-lived cells that are abundant cells in the blood but are not present in healthy tissues. Both phagocytic cell types play a key role in innate immunity because they can recognize, ingest and destroy many pathogens without the aid of an adaptive immune response. This infiltration of neutrophils and later macrophages to the site of bacterial infection is tightly linked with the need of these immune defense cells to respond to the tissue microenvironment.
Peyssonaux
Carole
C
Division of Biological Sciences, University of California, San Diego, San Diego, California 92093-0366, USA.
Johnson
Randall S
RS
D000818:Animals; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D001424:Bacterial Infections / Q000276:immunology; D015687:Cell Hypoxia / Q000502:physiology*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D005947:Glucose / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007113:Immunity, Innate / Q000276:immunology / Q000502:physiology; D007249:Inflammation / Q000276:immunology*; D008247:Lysosomes / Q000378:metabolism; D008264:Macrophages / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D017382:Reactive Oxygen Species / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D051794:Von Hippel-Lindau Tumor Suppressor Protein
C497396:ARNT protein, human; D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017382:Reactive Oxygen Species; D018336:Receptors, Aryl Hydrocarbon; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D042461:Vascular Endothelial Growth Factor A; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; C497446:VHL protein, human; D005947:Glucose