Actin machinery of phagocytic cells: Universal target for bacterial attack

2002 ◽  
Vol 57 (6) ◽  
pp. 432-440 ◽  
Author(s):  
Iouri F. Belyi
Keyword(s):  
Phagocytic Cells ◽  
Bacterial Attack

Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method

1982 ◽  
Vol 40 ◽  
pp. 332-333
Author(s):  
V. V. Damiano ◽  
R. P. Daniele ◽  
H. T. Tucker ◽  
J. H. Dauber
Keyword(s):  
Quantitative Analysis ◽  
Alveolar Macrophages ◽  
Bulk Sample ◽  
Silica Particles ◽  
Empirical Method ◽  
Phagocytic Cells ◽  
Calibration Standards ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Scanning Electron

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.

scholarly journals Evaluation of the role of CD47 in sickle cell disease

2021 ◽  
Author(s):  
Basmah Eldakhakhny ◽  
Hadeel Al Sadoun ◽  
Nehal Bin Taleb ◽  
Dunya Ahmed Nori ◽  
Nawal Helmi ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Annexin V ◽  
Cell Disease ◽  
Phagocytic Cells ◽  
Surface Marker Expression ◽  
Inflammatory Phenotype ◽  
Healthy Control ◽  
Cell Surface Marker Expression ◽  
Pro Inflammatory Cytokines

AbstractCD47 is a self-marker expressed on the surface of RBCs and work to prevent the process of phagocytosis. SIRPα is the ligand of CD47 that is expressed on the surface of phagocytic cells, such as macrophages, to control the removal of dead/diseased cells. This study aimed to examine the expression of CD47 on RBCs and SIRPα on PBMC cells in SCD patients and the apoptosis of SCD RBCs. We also measured the levels of pro-inflammatory cytokines in SCD patients and correlated it with the cell surface marker expression of CD47 and SIRPα to determine whether CD47 and/or SIRPα played a role in promoting the pro-inflammatory phenotype in SCD. Whole blood samples were drawn from SCD patients, and healthy control and PBMC were isolated and stained with SIRPα. Change in CD47, apoptosis by annexin V marker, and pro-inflammatory cytokines were measured and correlation among these variants was determined. The expression of CD47 was significantly decreased and the apoptosis was increased in RBCs of SCD patients. A higher level of pro-inflammatory cytokines, IL-6 and IL-1β, was found in SCD patients and IL-1β was found to be inversely correlated with SIRPα expression. Our data showed that CD47 of erythrocytes of SCD samples is reduced and that the apoptosis is increased in those patients. Based on the role of CD47, we suggest that increased apoptosis in SCD would be impacted by the reduced level of CD47. An inverse relationship was found between SIRPα marker on PBMC and the increased production of pro-inflammatory cytokines in SCD.

scholarly journals The novel Dbl homology/BAR domain protein, MsgA, of Talaromyces marneffei regulates yeast morphogenesis during growth inside host cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Harshini Weerasinghe ◽  
Hayley E. Bugeja ◽  
Alex Andrianopoulos
Keyword(s):  
Pathogenic Fungi ◽  
Host Cells ◽  
Microbial Pathogens ◽  
Mammalian Host ◽  
Host Immune System ◽  
Nucleotide Exchange ◽  
Phagocytic Cells ◽  
Macrophage Infection ◽  
Bar Domain ◽  
Talaromyces Marneffei

AbstractMicrobial pathogens have evolved many strategies to evade recognition by the host immune system, including the use of phagocytic cells as a niche within which to proliferate. Dimorphic pathogenic fungi employ an induced morphogenetic transition, switching from multicellular hyphae to unicellular yeast that are more compatible with intracellular growth. A switch to mammalian host body temperature (37 °C) is a key trigger for the dimorphic switch. This study describes a novel gene, msgA, from the dimorphic fungal pathogen Talaromyces marneffei that controls cell morphology in response to host cues rather than temperature. The msgA gene is upregulated during murine macrophage infection, and deletion results in aberrant yeast morphology solely during growth inside macrophages. MsgA contains a Dbl homology domain, and a Bin, Amphiphysin, Rvs (BAR) domain instead of a Plekstrin homology domain typically associated with guanine nucleotide exchange factors (GEFs). The BAR domain is crucial in maintaining yeast morphology and cellular localisation during infection. The data suggests that MsgA does not act as a canonical GEF during macrophage infection and identifies a temperature independent pathway in T. marneffei that controls intracellular yeast morphogenesis.

scholarly journals Asparagine-linked oligosaccharides on formyl peptide chemotactic receptors of human phagocytic cells.

1985 ◽  
Vol 260 (4) ◽  
pp. 2509-2514
Author(s):  
H L Malech ◽  
J P Gardner ◽  
D F Heiman ◽  
S A Rosenzweig
Keyword(s):  
Phagocytic Cells ◽  
Formyl Peptide

scholarly journals 981 DEPRESSED OXIDATIVE METABOLISM IN INFLUENZA VIRUS INFECTED PHAGOCYTIC CELLS

1981 ◽  
Vol 15 ◽  
pp. 606-606
Author(s):  
J S Abramson ◽  
E I Mills ◽  
G S Giebink ◽  
P G Quie
Keyword(s):  
Influenza Virus ◽  
Oxidative Metabolism ◽  
Phagocytic Cells

scholarly journals Induction of Mouse Melioidosis with Meningitis by CD11b+ Phagocytic Cells Harboring Intracellular B. pseudomallei as a Trojan Horse

2013 ◽  
Vol 7 (8) ◽  
pp. e2363 ◽  
Author(s):  
Pei-Ju Liu ◽  
Yao-Shen Chen ◽  
Hsi-Hsu Lin ◽  
Wei-Feng Ni ◽  
Tsung-Han Hsieh ◽  
...  
Keyword(s):  
Trojan Horse ◽  
Phagocytic Cells

The in vitro effect of kynurenic acid on the rainbow trout (Oncorhynchus mykiss) leukocyte and splenocyte activity

2014 ◽  
Vol 17 (3) ◽  
pp. 453-458 ◽  
Author(s):  
J. Małaczewska ◽  
A. K. Siwicki ◽  
R. Wójcik ◽  
W. a. Turski ◽  
E. Kaczorek
Keyword(s):  
Rainbow Trout ◽  
Immune Cells ◽  
Kynurenic Acid ◽  
Kynurenine Pathway ◽  
Phagocytic Cells ◽  
Mitogenic Response ◽  
Tryptophan Degradation ◽  
Selective Ligand ◽  
Vitro Effect

Abstract Kynurenic acid (KYNA), an endogenous neuroprotectant formed along the kynurenine pathway of tryptophan degradation, is a selective ligand of the GPR35 receptor, which can be found on the surface of various populations of human immune cells. In infections and inflammations, KYNA produces an anti-inflammatory effect through this receptor, by depressing the synthesis of reactive oxygen species and pro-inflammatory cytokines. However, it is still unrecognized whether receptors for kynurenic acid are also localized on immune cells of poikilothermic animals, or whether KYNA is able to affect these cells. The objective of this study has been to determine the effect of different concentrations of kynurenic acid (12.5 μM to 10 mM) on the viability and mitogenic response of lymphocytes and on the activity of phagocytic cells isolated from blood and the spleen of rainbow trout. The results imply low toxicity of kynurenic acid towards fish immune cells, and the proliferative effect observed at the two lowest concentrations of KYNA (12.5 μM and 25 μM) seems indicative of endogenous kynurenic acid being capable of activating fish lymphocytes. Non-toxic, micromole concentrations of KYNA, however, had no influence on the mitogenic response of lymphocytes nor on the activity of phagocytes in rainbow trout under in vitro conditions. There is some likelihood that such an effect could be observed at lower, nanomole concentrations of KYNA.

scholarly journals Lymphocytes are detrimental during the early innate immune response against Listeria monocytogenes

2006 ◽  
Vol 203 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Javier A. Carrero ◽  
Boris Calderon ◽  
Emil R. Unanue
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Innate Immune Response ◽  
Early Stage ◽  
Bacterial Pathogen ◽  
Interleukin 10 ◽  
Innate Immune ◽  
Type I ◽  
Phagocytic Cells ◽  
Immunodeficient Mice

Mice deficient in lymphocytes are more resistant than normal mice to Listeria monocytogenes infection during the early innate immune response. This paradox remains unresolved: lymphocytes are required for sterilizing immunity, but their presence during the early stage of the infection is not an asset and may even be detrimental. We found that lymphocyte-deficient mice, which showed limited apoptosis in infected organs, were resistant during the first four days of infection but became susceptible when engrafted with lymphocytes. Engraftment with lymphocytes from type I interferon receptor–deficient (IFN-αβR−/−) mice, which had reduced apoptosis, did not confer increased susceptibility to infection, even when the phagocytes were IFN-αβR+/+. The attenuation of innate immunity was due, in part, to the production of the antiinflammatory cytokine interleukin 10 by phagocytic cells after the apoptotic phase of the infection. Thus, immunodeficient mice were more resistant relative to normal mice because the latter went through a stage of lymphocyte apoptosis that was detrimental to the innate immune response. This is an example of a bacterial pathogen creating a cascade of events that leads to a permissive infective niche early during infection.

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