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Published on: September 9, 2014
Negative regulation of human mononuclear phagocyte function
Abstract:
At mucosal surfaces, phagocytes such as macrophages coexist with microbial communities; highly controlled regulation of these interactions is essential for immune homeostasis. Pattern-recognition receptors (PRRs) are critical in recognizing and responding to microbial products, and they are subject to negative regulation through various mechanisms, including downregulation of PRR-activating components or induction of inhibitors. Insights into these regulatory mechanisms have been gained through human genetic disease-association studies, in vivo mouse studies utilizing disease models or targeted gene perturbations, and in vitro and ex vivo human cellular studies examining phagocytic cell functions. Although mouse models provide an important approach to study macrophage regulation, human and mouse macrophages exhibit differences, which must be considered when extrapolating mouse findings to human physiology. This review discusses inhibitory regulation of PRR-induced macrophage functions and the consequences of dysregulation of these functions and highlights mechanisms that have a role in intestinal macrophages and in human macrophage studies.
Insights
This review explores how pattern-recognition receptors (PRRs) on macrophages are inhibited to maintain immune balance at mucosal surfaces. Dysregulation can lead to immune system disorders.
Area of Science:
- Immunology
- Microbiology
- Cell Biology
Background:
- Phagocytes, like macrophages, interact with microbes at mucosal surfaces, requiring tight regulation for immune homeostasis.
- Pattern-recognition receptors (PRRs) detect microbial products but are subject to negative regulatory mechanisms.
- Understanding these regulatory pathways is crucial for immune system balance.
Purpose of the Study:
- To review the inhibitory regulation of pattern-recognition receptor (PRR)-induced macrophage functions.
- To discuss the consequences of dysregulated macrophage functions.
- To highlight mechanisms relevant to intestinal macrophages and human studies.
Main Methods:
- Review of human genetic disease-association studies.
- Analysis of in vivo mouse studies using disease models and gene perturbations.
- Examination of in vitro and ex vivo human cellular studies on phagocytic cell functions.
Main Results:
- Identified various negative regulatory mechanisms for PRR-induced macrophage activation.
- Discussed the importance of inhibitory pathways in maintaining immune homeostasis.
- Highlighted species-specific differences between human and mouse macrophages.
Conclusions:
- Inhibitory regulation of PRR-induced macrophage functions is critical for immune homeostasis.
- Dysregulation of these mechanisms has significant consequences for health.
- Further research considering human macrophage specificities is essential.
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