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Scandinavian Journal of Immunology May 2023This paper presents the role of macrophage efferocytosis, the process of elimination of apoptotic bodies-elements formed during vascular atherosclerosis. The mechanisms... (Review)
Review
This paper presents the role of macrophage efferocytosis, the process of elimination of apoptotic bodies-elements formed during vascular atherosclerosis. The mechanisms of macrophage efferocytosis are presented, introducing the specific signals of this process, that is, 'find me', 'eat me' and 'don't eat me'. The role of the process of efferocytosis in the formation of vascular atherosclerosis is also presented, including the factors and mechanisms that determine it, as well as the factors that determine the maintenance of homeostasis in the vessels, including the formation of vascular atherosclerosis.
Topics: Humans; Apoptosis; Phagocytosis; Macrophages; Atherosclerosis
PubMed: 36583598
DOI: 10.1111/sji.13251 -
American Journal of Respiratory Cell... Aug 2022
Topics: Macrophages; Macrophages, Alveolar; Phagocytosis; Respiratory System; Smoking
PubMed: 35580150
DOI: 10.1165/rcmb.2022-0160ED -
Current Neuropharmacology 2021Autophagy and phagocytosis are two important endogenous lysosomal dependent clearing systems in the organism. In some neurological disorders, excessive autophagy or... (Review)
Review
Autophagy and phagocytosis are two important endogenous lysosomal dependent clearing systems in the organism. In some neurological disorders, excessive autophagy or dysfunctional phagocytosis has been shown to contribute to brain injury. Recent studies have revealed that there are underlying interactions between these two processes. However, different studies show inconsistent results for the contribution of autophagy to the phagocytic process in diverse phagocytes and relatively little is known about the link between them especially in the brain. It is critical to understand the role that autophagy plays in phagocytic process in order to promote the clearance of endogenous and exogenous detrimental materials. In this review, we highlight the studies focusing on phagocytosis and autophagy occurring in the brain and summarizing the possible regulatory roles of autophagy in the process of phagocytosis. Balancing the roles of autophagy and phagocytosis may be a promising therapeutic strategy for the treatment of some neurological diseases in the future.
Topics: Autophagy; Brain; Humans; Lysosomes; Nervous System Diseases; Phagocytosis
PubMed: 33827410
DOI: 10.2174/1570159X19666210407150632 -
Immunology Letters Feb 2023The phagocytosis and clearance of dying cells by macrophages, a process termed efferocytosis, is essential for both maintaining homeostasis and promoting tissue repair... (Review)
Review
The phagocytosis and clearance of dying cells by macrophages, a process termed efferocytosis, is essential for both maintaining homeostasis and promoting tissue repair after infection or sterile injury. If not removed in a timely manner, uncleared cells can undergo secondary necrosis, and necrotic cells lose membrane integrity, release toxic intracellular components, and potentially induce inflammation or autoimmune diseases. Efferocytosis also initiates the repair process by producing a wide range of pro-reparative factors. Accumulating evidence has revealed that macrophage efferocytosis defects are involved in the development and progression of a variety of inflammatory and autoimmune diseases. The underlying mechanisms of efferocytosis impairment are complex, disease-dependent, and incompletely understood. In this review, we will first summarize the current knowledge about the normal signaling and metabolic processes of macrophage efferocytosis and its importance in maintaining tissue homeostasis and repair. We then will focus on analyzing the molecular and cellular mechanisms underlying efferocytotic abnormality (impairment) in disease or injury conditions. Next, we will discuss the potential molecular targets for enhanced efferocytosis in animal models of disease. To provide a balanced view, we will also discuss some deleterious effects of efferocytosis.
Topics: Animals; Apoptosis; Phagocytosis; Macrophages; Inflammation; Signal Transduction
PubMed: 36740099
DOI: 10.1016/j.imlet.2023.02.001 -
The Yale Journal of Biology and Medicine Dec 2019Cell death can occur through numerous regulated mechanisms, from apoptosis to necrosis, entosis, and others. Each has a distinct mode of regulation and effect on tissue... (Review)
Review
Cell death can occur through numerous regulated mechanisms, from apoptosis to necrosis, entosis, and others. Each has a distinct mode of regulation and effect on tissue homeostasis. While the elimination of individual cells is typically considered the relevant physiologic endpoint of cell death, in some cases the remnants left behind by death can also function to support tissue homeostasis. Here we discuss specific functions of the end products of cell death, and how "after-death" functions may contribute to the roles of programmed cell death in physiology.
Topics: Animals; Apoptosis; Entosis; Humans; Models, Biological; Phagocytosis
PubMed: 31866783
DOI: No ID Found -
Nature Nanotechnology Dec 2022Solid tumours display a limited response to immunotherapies. By contrast, haematological malignancies exhibit significantly higher response rates to immunotherapies as...
Solid tumours display a limited response to immunotherapies. By contrast, haematological malignancies exhibit significantly higher response rates to immunotherapies as compared with solid tumours. Among several microenvironmental and biological disparities, the differential expression of unique immune regulatory molecules contributes significantly to the interaction of blood cancer cells with immune cells. The self-ligand receptor of the signalling lymphocytic activation molecule family member 7 (SLAMF7), a molecule that is critical in promoting the body's innate immune cells to detect and engulf cancer cells, is expressed nearly exclusively on the cell surface of haematologic tumours, but not on solid ones. Here we show that a bispecific nanobioconjugate that enables the decoration of SLAMF7 on the surface of solid tumours induces robust phagocytosis and activates the phagocyte cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway, sensitizing the tumours to immune checkpoint blockade. Our findings support an immunological conversion strategy that uses nano-adjuvants to improve the effectiveness of immunotherapies for solid tumours.
Topics: Humans; Membrane Proteins; Immunotherapy; Neoplasms; Phagocytosis
PubMed: 36357792
DOI: 10.1038/s41565-022-01245-7 -
Frontiers in Cellular and Infection... 2020Monocytes and their derivatives, including macrophages and dendritic cells, play diverse roles in the response to fungal pathogens. Sensing of fungi by monocytes... (Review)
Review
Monocytes and their derivatives, including macrophages and dendritic cells, play diverse roles in the response to fungal pathogens. Sensing of fungi by monocytes triggers signaling pathways that mediate direct effects like phagocytosis and cytokine production. Monocytes can also present fungal antigens to elicit adaptive immune responses. These monocyte-mediated pathways may be either beneficial or harmful to the host. In some instances, fungi have developed mechanisms to evade the consequences of monocyte activation and subvert these cells to promote disease. Thus, monocytes are critically involved in mediating the outcomes of these often highly fatal infections. This review will highlight the roles of monocytes in the immune response to some of the major fungi that cause invasive human disease, including , and , and discuss potential strategies to manipulate monocyte responses in order to enhance anti-fungal immunity in susceptible hosts.
Topics: Antigens, Fungal; Fungi; Humans; Macrophages; Monocytes; Phagocytosis
PubMed: 32117808
DOI: 10.3389/fcimb.2020.00034 -
Cell and Tissue Research Sep 2019The uptake of macromolecules and larger energy-rich particles into the cell is known as phagocytosis. Phagocytosed material is enzymatically degraded in membrane-bound... (Review)
Review
The uptake of macromolecules and larger energy-rich particles into the cell is known as phagocytosis. Phagocytosed material is enzymatically degraded in membrane-bound vesicles of the endosome/lysosome system (intracellular digestion). Whereas most, if not all, cells of the animal body are equipped with the molecular apparatus for phagocytosis and intracellular digestion, a few cell types are specialized for a highly efficient mode of phagocytosis. These are the ("professional") macrophages, motile cells that seek out and eliminate pathogenic invaders or damaged cells. Macrophages form the backbone of the innate immune system. Developmentally, they derive from specialized compartments within the embryonic mesoderm and early vasculature as part of the process of hematopoiesis. Intensive research has revealed in detail molecular and cellular mechanisms of phagocytosis and intracellular digestion in macrophages. In contrast, little is known about a second type of cell that is "professionally" involved in phagocytosis, namely the "enteric phagocyte." Next to secretory (zymogenic) cells, enteric phagocytes form one of the two major cell types of the intestine of most invertebrate animals. Unlike vertebrates, these invertebrates only partially digest food material in the intestinal lumen. The resulting food particles are absorbed by phagocytosis or pinocytosis and digested intracellularly. In this review, we provide a brief overview of the enteric phagocytes described electron microscopically for diverse invertebrate clades, to then to compare these cells with the "canonical" phagocyte ultrastructure established for macrophages. In addition, we will review observations and speculations associated with the hypothesis that macrophages are evolutionarily derived from enteric phagocytes. This idea was already proposed in the late nineteenth century by Elias Metschnikoff who pioneered the research of phagocytosis for both macrophages and enteric phagocytes. We presume that modern approaches to better understand phagocytosis will be helped by considering the deep evolutionary relationship between the two cell types.
Topics: Animals; Biological Evolution; Macrophages; Phagocytosis
PubMed: 31485720
DOI: 10.1007/s00441-019-03096-6 -
Current Opinion in Immunology Oct 2019Neutrophils are a crucial first line of defense against infection, migrating rapidly into tissues where they deploy granule components and toxic oxidants for efficient... (Review)
Review
Neutrophils are a crucial first line of defense against infection, migrating rapidly into tissues where they deploy granule components and toxic oxidants for efficient phagocytosis and microbe killing. Subsequent apoptosis and clearance of dying neutrophils are essential for control of infection and resolution of the inflammatory response. A subset of microbial pathogens survive exposure to neutrophils by manipulating phagocytosis, phagosome-granule fusion, oxidant production, and lifespan. Elucidating how they accomplish this unusual feat provides new insights into normal neutrophil function. In this review, we highlight recent discoveries about the ways in which neutrophils use cell-intrinsic mechanisms to control infection, and how these defenses are subverted by pathogens.
Topics: Animals; Biomarkers; Host-Pathogen Interactions; Humans; Immunity, Innate; Neutrophils; Oxidation-Reduction; Oxidative Stress; Phagocytosis; Phagosomes; Reactive Oxygen Species
PubMed: 31302568
DOI: 10.1016/j.coi.2019.05.004 -
Frontiers in Immunology 2023As the first responders, neutrophils lead the innate immune response to infectious pathogens and inflammation inducing agents. The well-established pathogen neutralizing... (Review)
Review
As the first responders, neutrophils lead the innate immune response to infectious pathogens and inflammation inducing agents. The well-established pathogen neutralizing strategies employed by neutrophils are phagocytosis, the action of microbicide granules, the production of ROS, and the secretion of neutrophil extracellular traps (NETs). Only recently, the ability of neutrophils to sense and respond to pathogen-associated molecular patterns is being appreciated. This review brings together the current information about the intracellular recognition of DNA by neutrophils and proposes models of signal amplification in immune response. Finally, the clinical relevance of DNA sensing by neutrophils in infectious and non-infectious diseases including malignancy are also discussed.
Topics: Neutrophils; Immunity, Innate; Extracellular Traps; Phagocytosis; DNA
PubMed: 37483598
DOI: 10.3389/fimmu.2023.1208137