Search results for "macrophage"
showing 10 items of 781 documents
Time course of mycobacterial infection of dendritic cells in the lungs of intranasally infected mice
2004
Summary Setting : Dendritic cells (DC) could regulate between the protective and pathogenic immune responses following tuberculous infection. In this paper we investigated if their early infection in the lungs represents a plausible alternative to cross-priming with mycobacterial antigens acquired from infected macrophages. Objective : To determine the extent and time course of infection of lung DCs following intranasal inoculation of BALB/c mice with green fluorescent protein (GFP) tagged Bacillus Calmette-Guerin (BCG). Results : A fraction of GFP-BCG infected lung cells were classified as monocytic DCs with the CD11c + IA + 33D1 + CD8a − phenotype. These cells represented 5–18% of the tot…
About the role of TLR2 and TLR4 in cytokine secretion by murine macrophages in response to Candida albicans.
2006
Dear Editor, In a recent issue of FEMS Immunology and Medical Microbiology , Blasi (2005) studied the biological role of Toll-like receptor (TLR)2 and TLR4 in the effector and secretory responses of murine macrophages to the fungal species Candida albicans . In their article, the authors conclude that the secretory response to C. albicans appears to be TLR4- but not TLR2-dependent. In our opinion this statement is misleading as the results reported do not support this conclusion and, therefore, we wish to comment on this issue. There is evidence indicating that TLR2 is the main receptor involved in triggering cytokine production by murine macrophages in response to C. albicans . Phospholipo…
Visceral leishmaniasis, hypertriglyceridemia and secondary hemophagocytic lymphohistiocytosis
2016
cytokines, an upregulation of adhesion molecules and MHC I and II molecules on mono/macrophages, and an expansion of inflammatory monocytes. This exaggerated inflammatory response is responsible for necrosis and organ failure and results in uncontrolled proliferation and phagocytic activity of histiocytes [2]. Hypertriglyceridemia (fasting, greater than or equal to 265 mg/100 ml) is one of the current diagnostic criteria for HLH [2]. Several studies link hypertriglyceridemia to inhibition of lipoprotein lipase (LPL) by tumor necrosis factor-α (TNF-α), and TNF-α is a powerful autocrine and paracrine regulator of adipose tissue [3]. Indeed, many different sources of intense and prolonged T-ly…
Mannose-Decorated Multicomponent Supramolecular Polymers Trigger Effective Uptake into Antigen-Presenting Cells
2018
A modular route to prepare functional self-assembling dendritic peptide amphiphiles decorated with mannosides, to effectively target antigen-presenting cells, such as macrophages, is reported. The monomeric building blocks were equipped with tetra(ethylene glycol)s (TEGs) or labeled with a Cy3 fluorescent probe. Experiments on the uptake of the multifunctional supramolecular particles into murine macrophages (Mφs) were monitored by confocal microscopy and fluorescence-activated cell sorting. Mannose-decorated supramolecular polymers trigger a significantly higher cellular uptake and distribution, relative to TEG carrying bare polymers. No cytotoxicity or negative impact on cytokine producti…
In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania b…
2014
The in vitro leishmanicidal activity and cytotoxicity of pyrazole-containing macrocyclic polyamines 1-4 was assayed on Leishmania infantum and Leishmania braziliensis species. Compounds 1-4 were more active and less toxic than glucantime and both infection rates and ultrastructural alterations confirmed that 1 and 2 were highly leishmanicidal and induced extensive parasite cell damage. Modifications in the excretion products of parasites treated with 1-3 were also consistent with substantial cytoplasm alterations. Compound 2 was highlighted as a potent inhibitor of Fe-SOD in both species, whereas its effect on human CuZn-SOD was poor. Molecular modelling suggested that 2 could deactivate Fe…
Macrophage inflammatory protein-1.
2003
Macrophage inflammatory protein (MIP)-1alpha was identified 15 years ago as the first of now four members of the MIP-1 CC chemokine subfamily. These proteins termed CCL3 (MIP-1alpha), CCL4 (MIP-1beta), CCL9/10 (MIP-1delta), and CCL15 (MIP-1gamma) according to the revised nomenclature for chemokines are produced by many cells, particularly macrophages, dendritic cells, and lymphocytes. MIP-1 proteins, which act via G-protein-coupled cell surface receptors (CCR1, 3, 5), e.g. expressed by lymphocytes and monocytes/macrophages (MPhi), are best known for their chemotactic and proinflammatory effects but can also promote homoeostasis. The encouraging results of preclinical studies in murine model…
The monocyte-macrophage system is affected in lysosomal storage diseases: an immunoelectron microscopic study
1997
Studying peripheral blood mononuclear cells (PBMCs) has become an important diagnostic tool in lysosomal storage diseases. Previous studies revealed that B and subclasses of T lymphocytes participate in the storage process, whereas the role of circulating monocytes was not clear. In this study, the involvement of CD14+ monocytes in lysosomal diseases was investigated. Blood samples from six patients with different lysosomal storage disorders were studied, including one with late--infantile and three with juvenile neuronal ceroid--lipofuscinoses, and two with mucopolysaccharidosis type VI. CD14+ cells were separated immunomagnetically from PBMCs and studied by light and electron microscopy. …
Multiple sclerosis patients show an increased spontaneous activity of their peripheral blood monocytes as measured by chemiluminescence
1983
I has been reported that myelin basic protein (BP) reacts extremely sensitively to peroxide, which is formed when monocytes/macrophages are stimulated to produce a "respiratory burst" (RB). We measured the RB activity by means of chemiluminescence in peripheral blood monocytes/macrophages (MO) of 17 MS patients, 5 patients with a viral infection of the CNS, and 14 control persons. The median of the spontaneous RB activity of MS patients compared with the median of our control group showed a highly significant increase (P = 0.0002). All MS patients examined possessed a clearly increased MO activity. The highest values, however, were found in MS patients in a bout (means = 315%, means = 296%)…
Signalling through TLR2/MyD88 induces differentiation of murine bone marrow stem and progenitor cells to functional phagocytes in response to Candida…
2009
Summary We have previously demonstrated that inactivated yeasts and hyphae of Candida albicans induce in vitro the proliferation of murine haematopoietic stem and progenitor cells (HSPCs, sorted as LKS cells: Lin - c-Kit + Sca-1 + ) as well as their differentia- tion to lineage-positive cells, through a MyD88- dependent pathway. In this work, we have found that this process is mainly mediated by TLR2, and that expanding cells express myeloid and not lym- phoid markers. Incubation of long-term repopulat- ing HSCs (Lin - CD105 + and Sca-1 + ) with C. albicans yeasts resulted in their proliferation and up regu- lation of the common myeloid progenitors (CMPs) markers, CD34 and FcgRII/III, by a …
Detection of a TLR2 agonist by hematopoietic stem and progenitor cells impacts the function of the macrophages they produce
2013
Several groups have shown that detection of microbial components by TLRs on hematopoietic stem and progenitor cells (HSPCs) instructs myeloid cell generation, raising interest in the possibility of targeting TLRs on HSPCs to boost myelopoiesis. However, although "TLR-derived" cells exhibit myeloid cell characteristics (phagocytosis, cytokine production, antigen presentation), it is not clear whether they are functionally equivalent to macrophages derived in the absence of TLR activation. Our in vitro and in vivo studies show that macrophages derived from mouse and human HSPC subsets (including stem cells) exposed to a TLR2 agonist prior to or during macrophage differentiation produce lower …