Search results for "Macrophage"

Morphological changes in adherent cells induced by Clostridium difficile toxins.

1991

Correlation of renal tubular epithelial cell-derived interleukin-18 up-regulation with disease activity in MRL-Faslpr mice with autoimmune lupus neph…

2002

Objective MRL-Faslpr mice spontaneously develop an autoimmune disease that mimics systemic lupus erythematosus in humans. Infiltrating T cells expressing interferon-γ (IFNγ) are responsible for the autoimmune kidney destruction in MRL-Faslpr mice, and interleukin-18 (IL-18) released by mononuclear phagocytes stimulates T cells to produce the IFNγ. Since MRL-Faslpr T cells are characterized by an overexpression of the IL-18 receptor accessory chain, we sought to determine the impact of IL-18 on the progression of lupus nephritis in MRL-Faslpr mice. Methods IL-18 expression in sera and kidney tissues from MRL-Faslpr mice was determined by enzyme-linked immunosorbent assay (ELISA), reverse tra…

Cytokine-mediated regulation of monocyte/macrophage cytotoxicity in human immunodeficiency virus-1 infection.

1992

Monocyte/macrophage-mediated tumor cytotoxicity was studied in patients infected with human immunodeficiency virus-1 (HIV-1) at various stages [Center for disease control (CDC) classification] of the disease. using the P-815 tumor cell line as target cells, the results demonstrated reduced monocyte/macrophage cytotoxicity early in HIV-1-related disease (CDCIII, P0.01). This cellular dysfunction sustained during the progression of the disease. Evidence could be presented that neither exogenous application of macrophage-stimulating cytokines (e.g. interferons) nor their endogenous induction in vitro restored monocyte/macrophage cytotoxicity. However, enhanced tumor necrosis factor (TNF)-alpha…

Influence of aging on murine neutrophil and macrophage function against Candida albicans.

2008

Previous work by our group showed that aged C57BL/6 mice develop an altered innate and adaptive immune response to Candida albicans and are more susceptible to systemic primary candidiasis. In this work, we used young (2-3 months old) and aged (18-20 months old) C57BL/6 mice to study in vitro the influence of aging on (1) the fungicidal activity of neutrophils and macrophages, (2) the production of cytokines by resident peritoneal macrophages in response to C. albicans, and (3) cell surface Toll-like receptor (TLR) 2 expression on resident peritoneal macrophages. Our results indicate that murine phagocytes have a fungicidal activity well preserved with aging. In vitro production of proinfla…

Modulation of accessory cell function of immortalized bone marrow-derived macrophages by granulocyte/macrophage colony-stimulating factor.

1993

To generate cloned macrophage populations with sensitivity towards granulocyte/macrophage colony-stimulating factor (GM-CSF), bone marrow-derived macrophages (BMM phi) were immortalized by transformation with SV40. A panel of transformed clones was established. The majority of clones represented independently derived transformants, as evidenced by restriction fragment length polymorphism using genomic DNA digested with EcoRI and TaqI and the 5.2 kb SV40 DNA for hybridization analysis. The cells belong to the macrophage lineage according to several criteria, e.g. the presence of nonspecific esterase, their phagocytic capacity and their morphology. Many clones were potent antigen-presenting c…

Recent Advances on the Innate Immune Response to Coxiella burnetii.

2021

Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding…

Dectin-1 mediatesin vitrophagocytosis ofCandida albicansyeast cells by retinal microglia: Figure 1

2011

We have investigated the expression of TLR2 and Dectin-1 in retinal microglia and their involvement in Candida albicans phagocytosis using a cytometric approach. The expression of both receptors has been demonstrated in CD11b+ retinal cells. Phagocytosis of pHrodo-labelled C. albicans yeasts by microglial CD11b+ cells of C57BL/6 mice was inhibited both by the Dectin-1 antagonist laminarin and anti-Dectin-1 antibodies, whereas phagocytosis of yeasts by retinal microglia of TLR2 KO mice was unaffected. These data indicate that phagocytosis of C. albicans yeasts by retinal microglia is mediated by Dectin-1, whereas TLR2 does not play a significant role in this process.

ESAT-6 Peptide Recognition by Bovine CD8 + Lymphocytes of Naturally Infected Cows in Herds from Southern Italy

2006

ABSTRACT The aim of this study was to define epitopes of Mycobacterium bovis from ESAT-6 (early secretory antigen of 6 kDa) recognized by CD8 + T lymphocytes from cows naturally infected with Mycobacterium bovis . We found that bovine CD8 + T cells recognized 10 out of 11 ESAT-6 peptides tested.

Role of murine macrophages and complement in experimental campylobacter infection

1988

Summary. The roles of macrophages and the complement system as potential host defence mechanisms in mice against campylobacter infection were studied in vivo, by depleting the murine serum-complement or the phagocytic cells. Macrophage-depletion was performed by intraperitoneal (i.p.) injection of silica dust, Liquoid or dextran sulphate. During 5 days after infection, such mice showed a significant increase in mortality, compared with controls. In contrast, mice that were previously decomplemented by i.p. injection of Cobra Venom Factor showed no significant increase in mortality. The results with combined macrophage depletion and decomplementation did not differ from those with macrophage…

LAAE-14, a new anti-inflammatory drug, increases the survival ofCandida albicans-inoculated mice

2003

LAAE-14, a lipidic acid-amido ether derivative, has been recently described as a new anti-inflammatory drug. We have studied the effect of treatment with this compound on the susceptibility of mice to in vivo experimental Candida albicans infection. ICR mice orally treated with LAAE-14 (25 mg kg(-1)) and experimentally intravenously infected showed a significantly increased survival as compared to control mice. In vitro, the compound did not inhibit the growth of C. albicans yeast cells or the yeast-to-hyphal transition. The in vitro production of prostaglandin E2 by peritoneal macrophages in response to the yeasts and hyphae of C. albicans was significantly decreased upon treatment with LA…