scholarly journals Liver myofibroblasts regulate the phenotype and function of monocytes through soluble factors in cirrhosis

2012 ◽  
Vol 5 (1) ◽  
pp. 143-149 ◽  
Author(s):  
MIN ZHANG ◽  
FENG-LAN WANG ◽  
JIAN-YUN ZHU ◽  
YU-BAO ZHENG ◽  
QI-YI ZHAO ◽  
...  
Keyword(s):  
Soluble Factors ◽  
Liver Myofibroblasts ◽  
And Function

Cytokine-activated NK cells inhibit PMN apoptosis and preserve their functional capacity

Blood ◽  
2010 ◽  
Vol 116 (8) ◽  
pp. 1308-1316 ◽  
Author(s):  
Nupur Bhatnagar ◽  
Henoch S. Hong ◽  
Jayendra K. Krishnaswamy ◽  
Arash Haghikia ◽  
Georg M. Behrens ◽  
...  
Keyword(s):  
Nk Cells ◽  
Functional Capacity ◽  
Nk Cell ◽  
Expression Patterns ◽  
Critical Role ◽  
Cell Contact ◽  
Polymorphonuclear Cells ◽  
Soluble Factors ◽  
And Function

Abstract Natural killer (NK) cells and polymorphonuclear cells (PMNs) play a critical role in the first line of defense against microorganisms. Upon host infection, PMNs phagocytose invading pathogens with subsequent killing by oxidative or nonoxidative mechanisms. NK cells are known to have immunoregulatory effects on T cells, B cells, dendritic cells (DCs), and monocytes through secretion of various soluble products and cell-cell contact. However, their impact on PMN survival and function is not well known. We found that soluble factors derived from cytokine-activated NK cells delay PMN apoptosis and preserve their ability to perform phagocytosis and produce reactive oxygen species (ROS). The expression patterns of CD11b and CD62L on PMNs differed according to the cytokine combination used for NK-cell stimulation. Irrespective of the NK-cell treatment, however, PMN survival was prolonged with sustained functional capacity. We found that interferon γ, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor α produced by NK cells upon stimulation with cytokines played a crucial role in NK cell–mediated effects on PMNs. Our study demonstrates that soluble factors derived from cytokine-activated NK cells send survival signals to PMNs, which would promote their accumulation and function at the site of inflammation in vivo.

scholarly journals DC Maturation and Function are Not Altered by Melanoma-Derived Immunosuppressive Soluble Factors

2012 ◽  
Vol 176 (1) ◽  
pp. 301-308 ◽  
Author(s):  
Joel M. Baumgartner ◽  
Kimberly R. Jordan ◽  
Ling-Jia Hu ◽  
Cara C. Wilson ◽  
Anirban Banerjee ◽  
...  
Keyword(s):  
Soluble Factors ◽  
And Function ◽  
Dc Maturation

Human Mesenchymal Stem Cells Exert Immunosuppressive Capacities by Induction of Regulatory T Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2414-2414
Author(s):  
Kirsten Canté-Barrett ◽  
Jessica M.E. van den Oever ◽  
Willem E. Fibbe
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Fold Increase ◽  
T Cell Proliferation ◽  
Soluble Factors ◽  
Cell Divisions ◽  
And Function ◽  
Cells Cultured

Abstract It is widely accepted that Mesenchymal Stem Cells (MSCs) exhibit immunosuppressive capacities in vitro and in vivo. In an effort to understand the mechanism of suppression, co-cultures of MSCs with several types of immune cells have been studied. MSCs inhibit B- and T cell proliferation and inhibit the generation, maturation and function of dendritic cells. In the present study, we evaluated the effect of MSCs on the expansion and function of regulatory T cells (T regs). Human bone-marrow derived MSCs were cultured and expanded in low-glucose DMEM containing 10% FCS and frozen until used in experiments. Freshly isolated, MACS selected human CD4+CD25+ T regs were cultured in IMDM, supplemented with 10% pooled human serum and 300 units/ml IL-2, in the presence or absence of irradiated MSCs (60 Gy) (ratio MSCs: T regs = 1:5). Results are derived from 3 to 15 independent experiments. In the presence of IL-2 and MSCs, the percentage of FOXP3+ CD4+CD25+ T cells increased from 26.8% ±2.2 (no MSCs) to 42.3% ±2.4 (with MSCs) over a period of 5 days, representing a 1.6 (±0.1)-fold induction. Moreover, a distinct CD4+CD25+ population with high FOXP3 expression appeared after 5 days of culture in the presence of MSCs (23.3% ±2.5 in the presence of MSCs versus 7.2% ±1.0 in the absence of MSCs). This CD4+CD25+FOXP3hi population was not observed after co-culturing MSCs and CD4+CD25− T cells (1.7% ±0.6). To show that the MSC-induced T regs were functionally suppressive, freshly isolated CFSE-labeled CD4+ T cells were stimulated with PHA (0.8 μg/ml). After 3 days, about 40% of the T cells had undergone one or more cell divisions as measured by CFSE dilution. Addition of MSC-induced T regs (in a 1:1 ratio) resulted in a 50% reduction of the proliferation of CFSE-labeled T cells (down to 15–20% of cells undergoing one or more cell divisions). Control CD4+CD25+ T cells cultured in the absence of MSCs did not suppress T cell proliferation. These results indicate that MSC-induced CD4+CD25+ FOXP3hi cells exert regulatory function. To study whether the induction of T regs by MSCs was dependent on cell-cell contact, co-culture experiments were performed in transwells where MSCs were physically separated from T cells. CD4+CD25+ T cells co-cultured with MSCs in transwells showed a 1.4 (±0.1)-fold increase in the percentage of FOXP3hi cells, in comparison with T cells cultured in the absence of MSCs. Similarly, direct co-cultures of MSCs and T cells resulted in a 1.8 (±0.2)-fold increase in the percentage of FOXP3hi T regs. In addition, medium derived from co-cultures of MSCs and CD4+CD25+ T cells and added to freshly isolated CD4+CD25+ T cells resulted in a 2.6 (±0.6) fold increase in the percentage of CD4+CD25+FOXP3hi T regs, implicating that FOXP3hi induction by MSCs was mediated by soluble factors. Since T Cell Receptor-stimulated naïve T cells (as well as natural T regs, generated in the thymus) require both IL-2 and TGF-β to become induced T regs, we analyzed the involvement of TGF-β. Addition of the pharmacological inhibitor of the TGF-β receptor (SB431542) only marginally reduced FOXP3 induction in the presence of MSCs, suggesting that MSC-mediated expression of high FOXP3 levels requires alternate or additional cytokines. In conclusion, we show that MSCs promote the induction of CD4+CD25+ T cells that express high levels of FOXP3 and these MSC-induced T regs suppress proliferation of PHA-stimulated CD4+ T cells. These effects are mediated by soluble factors produced during the co-culture of MSCs and T cells. The cytokines involved are presently unknown, but likely do not involve TGF-β.

scholarly journals Shaping of Monocyte-Derived Dendritic Cell Development and Function by Environmental Factors in Rheumatoid Arthritis

2021 ◽  
Vol 22 (24) ◽  
pp. 13670
Author(s):  
Frédéric Coutant
Keyword(s):  
Rheumatoid Arthritis ◽  
Environmental Factors ◽  
Osteoclast Differentiation ◽  
Cell Populations ◽  
Molecular Signaling ◽  
Soluble Factors ◽  
Monocyte Differentiation ◽  
Synovial Tissues ◽  
And Function

Dendritic cells (DC) are heterogeneous cell populations essential for both inducing immunity and maintaining immune tolerance. Chronic inflammatory contexts, such as found in rheumatoid arthritis (RA), severely affect the distribution and the function of DC, contributing to defective tolerance and fueling inflammation. In RA, the synovial fluid of patients is enriched by a subset of DC that derive from monocytes (Mo-DC), which promote deleterious Th17 responses. The characterization of environmental factors in the joint that impact on the development and the fate of human Mo-DC is therefore of great importance in RA. When monocytes leave the blood and infiltrate inflamed synovial tissues, the process of differentiation into Mo-DC can be influenced by interactions with soluble factors such as cytokines, local acidosis and dysregulated synoviocytes. Other molecular factors, such as the citrullination process, can also enhance osteoclast differentiation from Mo-DC, favoring bone damages in RA. Conversely, biotherapies used to control inflammation in RA, modulate also the process of monocyte differentiation into DC. The identification of the environmental mediators that control the differentiation of Mo-DC, as well as the underlying molecular signaling pathways, could constitute a major breakthrough for the development of new therapies in RA.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

The Effect of Oxidized Cholesterol on the Aorta of Rabbits- Scanning Electron Microscopic Observations

1982 ◽  
Vol 40 ◽  
pp. 340-341
Author(s):  
S. K. Pena ◽  
C. B. Taylor ◽  
J. Hill ◽  
J. Safarik
Keyword(s):  
Cholesterol Biosynthesis ◽  
Cholesterol Content ◽  
Arterial Injury ◽  
Electron Microscopic ◽  
Aortic Smooth Muscle ◽  
Oxidized Cholesterol ◽  
Initial Event ◽  
Membrane Structure And Function ◽  
Scanning Electron Microscopic ◽  
And Function

Introduction: Oxidized cholesterol derivatives have been demonstrated in various cell cultures to be very potent inhibitors of 3-hvdroxy-3- methylglutaryl Coenzyme A reductase which is a principle regulator of cholesterol biosynthesis in the cell. The cholesterol content in the cells exposed to oxidized cholesterol was found to be markedly decreased. In aortic smooth muscle cells, the potency of this effect was closely related to the cytotoxicity of each derivative. Furthermore, due to the similarity of their molecular structure to that of cholesterol, these oxidized cholesterol derivatives might insert themselves into the cell membrane, alter membrane structure and function and eventually cause cell death. Arterial injury has been shown to be the initial event of atherosclerosis.

Ultrastructure of developing visual cortical synapses in the cat superior colliculus

1991 ◽  
Vol 49 ◽  
pp. 156-157
Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce
Keyword(s):  
Superior Colliculus ◽  
Phosphate Buffer ◽  
Receptive Fields ◽  
Visual Cortical Area ◽  
Cortical Synapses ◽  
Visual Cortical ◽  
And Function ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Cat Superior Colliculus

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.

Structural modifications of intercellular junctions.

1978 ◽  
Vol 36 (2) ◽  
pp. 330-331
Author(s):  
J. Metz ◽  
M. Merlo ◽  
W. G. Forssmann
Keyword(s):  
Gap Junctions ◽  
Intercellular Junctions ◽  
Cell Isolation ◽  
Extrahepatic Cholestasis ◽  
Structural Modifications ◽  
Pancreatic Duct Ligation ◽  
Pancreatic Cells ◽  
Duct Ligation ◽  
Thin Sectioning ◽  
And Function

Structure and function of intercellular junctions were studied under the electronmicroscope using conventional thin sectioning and freeze-etch replicas. Alterations of tight and gap junctions were analyzed 1. of exocrine pancreatic cells under cell isolation conditions and pancreatic duct ligation and 2. of hepatocytes during extrahepatic cholestasis.During the different steps of cell isolation of exocrine pancreatic cells, gradual changes of tight and gap junctions were observed. Tight junctions, which formed belt-like structures around the apex of control acinar cells in situ, subsequently diminished, became interrupted and were concentrated into macular areas (Fig. 1). Aggregations of membrane associated particles, which looked similar to gap junctions, were intermixed within tight junctional areas (Fig. 1). These structures continously disappeared in the last stages of the isolation procedure. The intercellular junctions were finally separated without destroying the integrity of the cell membrane, which was confirmed with porcion yellow, lanthanum chloride and horse radish peroxidase.

Structural similarity of ribosomes from E. coli and A. salina

1978 ◽  
Vol 36 (2) ◽  
pp. 242-243
Author(s):  
M. Boublik ◽  
R.M. Wydro ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Ribosomal Proteins ◽  
Direct Evidence ◽  
Structural Similarity ◽  
Carbon Support ◽  
Artemia Salina ◽  
Uranyl Acetate ◽  
Biological Assays ◽  
E Coli ◽  
And Function ◽  
Fine Carbon

Ribosomes are ribonucleoprotein particles necessary for processing the genetic information of mRNA into proteins. Analogy in composition and function of ribosomes from diverse species, established by biochemical and biological assays, implies their structural similarity. Direct evidence obtained by electron microscopy seems to be of increasing relevance in understanding the structure of ribosomes and the mechanism of their role in protein synthesis.The extent of the structural homology between prokaryotic and eukaryotic ribosomes has been studied on ribosomes of Escherichia coli (E.c.) and Artemia salina (A.s.). Despite the established differences in size and in the amount and proportion of ribosomal proteins and RNAs both types of ribosomes show an overall similarity. The monosomes (stained with 0.5% aqueous uranyl acetate and deposited on a fine carbon support) appear in the electron micrographs as round particles with a diameter of approximately 225Å for the 70S E.c. (Fig. 1) and 260Å for the 80S A.s. monosome (Fig. 2).

The Scanning Electron Microscopic Observation of the Vestibular Sensory Epithelia

1969 ◽  
Vol 27 ◽  
pp. 40-41
Author(s):  
D.J. Lim ◽  
W.C. Lane
Keyword(s):  
Semicircular Canals ◽  
Electron Microscopic Observation ◽  
Gravitational Acceleration ◽  
Electron Microscopic ◽  
Sensory Epithelia ◽  
Scanning Electron Microscopic ◽  
Vestibular Sensory Epithelia ◽  
And Function ◽  
Sand Piles ◽  
Active Investigation

The morphology and function of the vestibular sensory organs has been extensively studied during the last decade with the advent of electron microscopy and electrophysiology. The opening of the space age also accelerated active investigation in this area, since this organ is responsible for the sensation of balance and of linear, angular and gravitational acceleration.The vestibular sense organs are formed by the saccule, utricle and three ampullae of the semicircular canals. The maculae (sacculi and utriculi) have otolithic membranes on the top of the sensory epithelia. The otolithic membrane is formed by a layer of thick gelatin and sand-piles of calcium carbonate crystals (Fig.l).

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