Macrophages and microglia in the nervous system
TL;DR: The possible functions of resident and recruited macrophages in the developing and adult nervous system are reviewed and what contribution these cells might make to repair mechanisms in the central and peripheral nervous systems are examined.
About: This article is published in Trends in Neurosciences.The article was published on 1988-01-01. It has received 745 citations till now. The article focuses on the topics: Microglia & Nervous system.
Citations
More filters
TL;DR: Current studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains, and microglial cells are considered the most susceptible sensors of brain pathology.
Abstract: Microglial cells are the resident macrophages in the central nervous system. These cells of mesodermal/mesenchymal origin migrate into all regions of the central nervous system, disseminate through the brain parenchyma, and acquire a specific ramified morphological phenotype termed "resting microglia." Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways they can communicate with macroglial cells and neurons and with cells of the immune system. Likewise, microglial cells express receptors classically described for brain-specific communication such as neurotransmitter receptors and those first discovered as immune cell-specific such as for cytokines. Microglial cells are considered the most susceptible sensors of brain pathology. Upon any detection of signs for brain lesions or nervous system dysfunction, microglial cells undergo a complex, multistage activation process that converts them into the "activated microglial cell." This cell form has the capacity to release a large number of substances that can act detrimental or beneficial for the surrounding cells. Activated microglial cells can migrate to the site of injury, proliferate, and phagocytose cells and cellular compartments.
2,998 citations
TL;DR: Examination of the distribution of microglia in the normal adult mouse brain using immunocytochemical detection of the macrophage specific plasma membrane glycoprotein F4/80 found no evidence of monocyte-like cells in the adult CNS.
1,810 citations
TL;DR: Results indicated that localisation of Iba1 protein is restricted to microglia both in vitro and in vivo, and that Iba 1 protein plays a role in regulating the function of microglIA, especially in the activated microglial.
1,255 citations
TL;DR: Although early microglial recruitment promotes Aβ clearance and is neuroprotective in AD, as disease progresses, proinflammatory cytokines produced in response to Aβ deposition downregulate genes involved in A β clearance and promote Aβ accumulation, therefore contributing to neurodegeneration.
Abstract: Early microglial accumulation in Alzheimer's disease (AD) delays disease progression by promoting clearance of beta-amyloid (Abeta) before formation of senile plaques. However, persistent Abeta accumulation despite increasing microglial numbers suggests that the ability of microglia to clear Abeta may decrease with age and progression of AD pathology. To determine the effects of aging and Abeta deposition on microglial ability to clear Abeta, we used quantitative PCR to analyze gene expression in freshly isolated adult microglia from 1.5-, 3-, 8-, and 14-month-old transgenic PS1-APP mice, an established mouse model of AD, and from their nontransgenic littermates. We found that microglia from old PS1-APP mice, but not from younger mice, have a twofold to fivefold decrease in expression of the Abeta-binding scavenger receptors scavenger receptor A (SRA), CD36, and RAGE (receptor for advanced-glycosylation endproducts), and the Abeta-degrading enzymes insulysin, neprilysin, and MMP9, compared with their littermate controls. In contrast, PS1-APP microglia had a 2.5-fold increase in the proinflammatory cytokines IL-1beta (interleukin-1beta) and tumor necrosis factor alpha (TNFalpha), suggesting that there is an inverse correlation between cytokine production and Abeta clearance. In support of this possibility, we found that incubation of cultured N9 mouse microglia with TNFalpha decreased the expression of SRA and CD36 and reduced Abeta uptake. Our data indicate that, although early microglial recruitment promotes Abeta clearance and is neuroprotective in AD, as disease progresses, proinflammatory cytokines produced in response to Abeta deposition downregulate genes involved in Abeta clearance and promote Abeta accumulation, therefore contributing to neurodegeneration. Antiinflammatory therapy for AD should take this dichotomous microglial role into consideration.
1,122 citations
Cites background from "Macrophages and microglia in the ne..."
...Microglia, the mononuclear phagocytes of the brain (Perry and Gordon, 1988), accumulate in senile plaques in AD patients and in animal models of AD (McGeer et al., 1987; Perlmutter et al., 1990; Frautschy et al., 1998; Dickson, 1999; Stalder et al., 1999)....
[...]
TL;DR: Activated microglia rather than astrocytes or endothelial cells are the candidates as intrinsic antigen presenting cel of the brain due to their pronounced antigen presenting function in vitro.
1,122 citations
References
More filters
Book•
01 Jan 1967
TL;DR: This document describes the development and application of various methods for immunologic studies using monoclonal antibodies, a type of antibody, and some of the methods used in these studies are currently in use.
Abstract: Monoclonal antibodies Applications: monoclonal antibodies Applications: immunological methods Additional clinical applications of immunological methods General methods for immunologic studies.
3,279 citations
2,654 citations
TL;DR: The identity of an important cell type that supports replication of the AIDS retrovirus in brain tissue was determined in two affected individuals and these cells were mononucleated and multinucleated macrophages that actively synthesized viral RNA and produced progeny virions in the brains of the patients.
Abstract: One of the common neurological complications in patients with the acquired immune deficiency syndrome (AIDS) is a subacute encephalopathy with progressive dementia. By using the techniques of cocultivation for virus isolation, in situ hybridization, immunocytochemistry, and transmission electron microscopy, the identity of an important cell type that supports replication of the AIDS retrovirus in brain tissue was determined in two affected individuals. These cells were mononucleated and multinucleated macrophages that actively synthesized viral RNA and produced progeny virions in the brains of the patients. Infected brain macrophages may serve as a reservoir for virus and as a vehicle for viral dissemination in the infected host.
1,675 citations
TL;DR: Immunoprecipitation experiments demonstrated that the antigen F4/80 is part of a component of Mr 160000 which is synthesized by the MΦ and, at least in part, exposed on the cell surface.
Abstract: A hybridoma clone which secretes a macrophage (MΦ)-specific monoclonal antibody, F4/80, was produced by fusing spleen cells from a rat hyperimmunized with cultured thioglycollate-induced mouse peritoneal MΦ with a mouse myeloma, NS1. Binding of antibody to primary cells and cell lines was detected by radioimmune indirect binding assay, autoradiography or fluorescence-activated cell sorter analysis. F4/80 binds to mouse MΦ from the peritoneal cavity or other sources, blood monocytes, MΦ derived from bone marrow precursors in culture and MΦ-like cell lines, but not to other cells, including polymorphonuclear leukocytes, lymphocytes or fibroblasts. F4/80 does not bind to MΦ via Fc receptors, is not cytotoxic and is of the rat IgG2b subclass. Since F4/80 binds to all MΦ defined by adherence, morphology and immune phagocytosis, it provides a new marker to define the MΦ in the mouse. Large differences in expression of antigen F4/80 were found, depending on intraperitoneal stimulation, time in culture and stage of maturation. Immunoprecipitation experiments demonstrated that the antigen F4/80 is part of a component of Mr 160000 which is synthesized by the MΦ and, at least in part, exposed on the cell surface.
1,558 citations
TL;DR: The AIDS dementia complex is established as a distinct clinical and pathological entity and, together with accumulating virological evidence, suggests that it is caused by direct LAV/HTLV‐III brain infection.
Abstract: In order to define the histopathological substrate of the dementia that frequently complicates the acquired immune deficiency syndrome (AIDS), we analyzed the neuropathological findings in 70 autopsied adult AIDS patients, 46 of whom had suffered clinically overt dementia. Less than 10% of the brains were histologically normal. Abnormalities were found predominantly in the white matter and in subcortical structures, with relative sparing of the cortex. Their frequency and severity generally correlated well with the degree and duration of clinical dementia. Most commonly noted was diffuse pallor in the white matter, which in the pathologically milder cases was accompanied by scanty perivascular infiltrates of lymphocytes and brown-pigmented macrophages, and in the most advanced cases by clusters of foamy macrophages and multinucleated cells associated with multifocal rarefaction of the white matter. However, in nearly one third of the demented cases the histopathological findings were remarkably bland in relation to the severity of clinical dysfunction. In addition, similar mild changes were noted in over one half of the nondemented patients, consistent with subclinical involvement. Vacuolar myelopathy was found in 23 patients and was generally more common and severe in patients with advanced brain pathology. Evidence of cytomegalovirus (CMV) infection was noted in nearly one quarter of the brains and was associated with a relative abundance of microglial nodules, but correlated neither with the major subcortical neuropathology nor with the clinical dementia, indicating that CMV infection likely represented a second, superimposed process. This study establishes the AIDS dementia complex as a distinct clinical and pathological entity and, together with accumulating virological evidence, suggests that it is caused by direct LAV/HTLV-III brain infection.
1,252 citations