Search results for "Macrophage"
showing 10 items of 781 documents
Posttranslational modifications by ADAM10 shape myeloid antigen-presenting cell homeostasis in the splenic marginal zone
2021
The spleen contains phenotypically and functionally distinct conventional dendritic cell (cDC) subpopulations, termed cDC1 and cDC2, which each can be divided into several smaller and less well-characterized subsets. Despite advances in understanding the complexity of cDC ontogeny by transcriptional programming, the significance of posttranslational modifications in controlling tissue-specific cDC subset immunobiology remains elusive. Here, we identified the cell-surface–expressed A-disintegrin-and-metalloproteinase 10 (ADAM10) as an essential regulator of cDC1 and cDC2 homeostasis in the splenic marginal zone (MZ). Mice with a CD11c-specific deletion of ADAM10 (ADAM10(ΔCD11c)) exhibited a …
Correlation between expression of cyclooxygenase-2 and the presence of inflammatory cells in human primary hepatocellular carcinoma: Possible role in…
2005
im: To investigate the association of cyclooxygenase-2 (COX-2) expression with angiogenesis and the number and type of inflammatory cells (macrophages/Kupffer cells; mast cells) within primary hepatocellular carcinoma (HCC) tissues and adjacent non-tumorous (NT) tissues. Methods: Immunohistochemistry for COX-2, CD34, CD68 and mast cell tryptase (MCT) was performed on 14 well-characterized series of liver-cirrhosis-associated HCC patients. COX-2 expression and the number of inflammatory cells in tumor lesions and surrounding liver tissues of each specimen were compared. Moreover, COX-2, CD34 staining and the number of inflammatory cells in areas with different histological degrees within eac…
Oncogene transformation can induce tolerogenicity in murine macrophages after down-regulation of immunogenicity without altering major histocompatibi…
1993
In vitro studies on cell lines may allow analyses of the mechanisms of immunogenicity and tolerogenicity in cells. We used a model of oncogenic transformation of an established murine macrophage cell line and report here that one v-mos-transformed clone expressing unaltered high amounts of MHC class I and II antigens does not induce proliferation of unprimed T cells in primary mixed lymphocyte reactions, in sharp contrast to its non-transformed parental cells. Interestingly, this clone induces specific unresponsiveness, as revealed by the lack of responsiveness of MHC-specific T cells when subsequently exposed to the pertinent MHC alloantigens in immunogenic form but unaltered MHC-third par…
Circulating CSF-1 Promotes Monocyte and Macrophage Phenotypes that Enhance Lupus Nephritis
2009
Macrophages mediate kidney disease and are prominent in a mouse model (MRL- Fas lpr ) of lupus nephritis. Colony stimulating factor-1 (CSF-1) is the primary growth factor for macrophages, and CSF-1 deficiency protects MRL- Fas lpr mice from kidney disease and systemic illness. Whether this renoprotection derives from a reduction of macrophages and whether systemic CSF-1, as opposed to intrarenal CSF-1, promotes macrophage-dependent lupus nephritis remain unclear. Here, we found that increasing systemic CSF-1 hastened the onset of lupus nephritis in MRL- Fas lpr mice. Using mutant MRL- Fas lpr strains that express high, moderate, or no systemic CSF-1, we detected a much higher tempo of kidne…
Human CD8+ T-cells Recognizing Peptides from Mycobacterium tuberculosis (Mtb) Presented by HLA-E Have an Unorthodox Th2-like, Multifunctional, Mtb In…
2015
Mycobacterial antigens are not exclusively presented to T-cells by classical HLA-class Ia and HLA-class II molecules, but also through alternative antigen presentation molecules such as CD1a/b/c, MR1 and HLA-E. We recently described mycobacterial peptides that are presented in HLA-E and recognized by CD8+ T-cells. Using T-cell cloning, phenotyping, microbiological, functional and RNA-expression analyses, we report here that these T-cells can exert cytolytic or suppressive functions, inhibit mycobacterial growth, yet express GATA3, produce Th2 cytokines (IL-4,-5,-10,-13) and activate B-cells via IL-4. In TB patients, Mtb specific cells were detectable by peptide-HLA-E tetramers, and IL-4 and…
GM-CSF Programs Hematopoietic Stem and Progenitor Cells During Candida albicans Vaccination for Protection Against Reinfection
2021
More mechanistic studies are needed to reveal the hidden details of in vivo-induced trained immunity. Here, using a Candida albicans live vaccine mouse model we show that vaccination protects mice against a secondary infection and increases the number of bone marrow, and especially, splenic trained monocytes. Moreover, vaccination expands and reprograms hematopoietic stem and progenitor cells (HSPCs) early during infection and mobilize them transiently to the spleen to produce trained macrophages. Trained HSPCs are not only primed for myeloid cell production but also reprogramed to produce a greater amount of proinflammatory cytokines in response to a second challenge. Additionally, their a…
Gene toxicity studies on titanium dioxide and zinc oxide nanomaterials used for UV-protection in cosmetic formulations
2010
Titanium dioxide and zinc oxide nanomaterials, used as UV protecting agents in sunscreens, were investigated for their potential genotoxicity in in vitro and in vivo test systems. Since standard OECD test methods are designed for soluble materials and genotoxicity testing for nanomaterials is still under revision, a battery of standard tests was used, covering different endpoints. Additionally, a procedure to disperse the nanomaterials in the test media and careful characterization of the dispersed test item was added to the testing methods. No genotoxicity was observed in vitro (Ames' Salmonella gene mutation test and V79 micronucleus chromosome mutation test) or in vivo (mouse bone marrow…
MyD88 is dispensable for resistance toParacoccidioides brasiliensisin a murine model of blood-borne disseminated infection
2008
We have studied the role of MyD88, an adaptor protein of Toll-like receptors (TLRs), in murine defenses against Paracoccidioides brasiliensis in a model of blood-borne disseminated infection. Wild-type (WT) and MyD88-deficient mice infected intravenously with P. brasiliensis yeast cells showed an equivalent fungal burden, as well as similar levels of proinflammatory IL-1beta, IL-6, IL-12p70, tumor necrosis factor (TNF)-alpha and MIP-2, T-helper type 1 (Th1) (IFN-gamma) and Th2 cytokines (IL-4) in tissue homogenates. In vitro production of TNF-alpha, IFN-gamma and IL-12p70, by antigen-stimulated splenocytes from infected animals, was also similar in both types of mice; this production of Th1…
Blockade of MIF-CD74 Signalling on Macrophages and Dendritic Cells Restores the Antitumour Immune Response Against Metastatic Melanoma.
2018
Mounting an effective immune response against cancer requires the activation of innate and adaptive immune cells. Metastatic melanoma is the most aggressive form of skin cancer. While immunotherapies have shown a remarkable success in melanoma treatment, patients develop resistance by mechanisms that include the establishment of an immune suppressive tumor microenvironment. Thus, understanding how metastatic melanoma cells suppress the immune system is vital to develop effective immunotherapies against this disease. In this study, we find that macrophages (MOs) and dendritic cells (DCs) are suppressed in metastatic melanoma and that the Ig-CDR-based peptide C36L1 is able to restore MOs and …
Early Cellular Reactions in Mechanically Stimulated Gingival Connective Tissue
2001
Aim: The aim of this study was to describe early cellular reactions occuring in mechnically stimulated gingival connective tissue. Material and Method: Elastic bands were inserted between the maxillary first and second molars of male rats aged 8 weeks, which were pulse-labeled with 3H-thymidine and subsequently killed in groups together with labeled control animals after periods of 1–168 hours. Autoradiographs were prepared from plastic mesiodistal sections and parameters of cell proliferation determined in gingival connective tissue sampling areas coronal to the interdental bone crest and in the central zone of the body of the papilla between the second and third molars. The incidence of m…