In vitrocytokines profile and ultrastructural changes of microglia and macrophages following interaction withLeishmania

Parasitology ◽  
2014 ◽  
Vol 141 (8) ◽  
pp. 1052-1063 ◽  
Author(s):  
PATRICIA KARLA SANTOS RAMOS ◽  
MAYSA DE VASCONCELOS BRITO ◽  
FERNANDO TOBIAS SILVEIRA ◽  
CLÁUDIO GUEDES SALGADO ◽  
WANDERLEY DE SOUZA ◽  
...  
Keyword(s):  
Immune Responses ◽  
Parasite Species ◽  
Morphological Changes ◽  
Expression Patterns ◽  
Ultrastructural Changes ◽  
American Cutaneous Leishmaniasis ◽  
Causative Agents ◽  
Infected Cells ◽  
Robust Response

SUMMARYIn the present study, we assessed morphological changes and cytokine production afterin vitrointeraction with causative agents of American cutaneous leishmaniasis and compared the microglia and macrophage immune responses. Cultures of microglia and macrophages infected with stationary-phase promastigotes ofLeishmania(Viannia)shawi, Leishmania(Viannia)braziliensisorLeishmania(Leishmania)amazonensiswere evaluated 24, 48 and 72 h after interaction. Macrophages only presented the classical phagocytic process while microglia also displayed large cytoplasmic projections similar to the ruffles described in macropinocytosis. In the macrophage cultures, the percentage of infected cells increased over time, in a fashion that was dependent on the parasite species. In contrast, in microglial cells as the culture time progressed, there was a significant reduction in the percentage of infected cells independent of parasite species. Measurements of cytokines in macrophage cultures 48 h after interactions revealed distinct expression patterns for different parasites, whereas in microglial cultures they were similar for allLeishmaniatested species. Taken together, our results suggest that microglia may have a higher phagocytic ability and cytotoxic potential than macrophages for all investigated species. The robust response of microglia against all parasite species may suggest microglia have an important role in the defence against cerebral leishmaniasis.

scholarly journals Yellow Fever Virus Down-Regulates mRNA Expression of SOCS1 in the Initial Phase of Infection in Human Cell Lines

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 802
Author(s):  
Michael B. Yakass ◽  
David Franco ◽  
Osbourne Quaye
Keyword(s):  
Mrna Expression ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Expression Patterns ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Interferon Β ◽  
Infected Cells ◽  
Insight Into

Flaviviruses are constantly evolving diverse immune evasion strategies, and the exploitation of the functions of suppressors of cytokine signalling (SOCS) and protein inhibitors of activated STATs (PIAS) to favour virus replication has been described for Dengue and Japanese encephalitis viruses but not for yellow fever virus (YFV), which is still of global importance despite the existence of an effective vaccine. Some mechanisms that YFV employs to evade host immune defence has been reported, but the expression patterns of SOCS and PIAS in infected cells is yet to be determined. Here, we show that SOCS1 is down-regulated early in YFV-infected HeLa and HEK 293T cells, while SOCS3 and SOCS5 are not significantly altered, and PIAS mRNA expression appears to follow a rise-dip pattern akin to circadian-controlled genes. We also demonstrate that YFV evades interferon-β application to produce comparable viral titres. This report provides initial insight into the in vitro expression dynamics of SOCS and PIAS upon YFV infection and a basis for further investigation into SOCS/PIAS expression and how these modulate the immune response in animal models.

scholarly journals Symbiotic Outcome Modified by the Diversification from 7 to over 700 Nodule-Specific Cysteine-Rich Peptides

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 348 ◽  
Author(s):  
Proyash Roy ◽  
Mingkee Achom ◽  
Helen Wilkinson ◽  
Beatriz Lagunas ◽  
Miriam L. Gifford
Keyword(s):  
Morphological Changes ◽  
Expression Patterns ◽  
Terminal State ◽  
Rapid Expansion ◽  
Bacterial Cells ◽  
Positive Regulators ◽  
Bacterial Cell Cycle ◽  
Species Specific ◽  
Secreted Peptides

Legume-rhizobium symbiosis represents one of the most successfully co-evolved mutualisms. Within nodules, the bacterial cells undergo distinct metabolic and morphological changes and differentiate into nitrogen-fixing bacteroids. Legumes in the inverted repeat lacking clade (IRLC) employ an array of defensin-like small secreted peptides (SSPs), known as nodule-specific cysteine-rich (NCR) peptides, to regulate bacteroid differentiation and activity. While most NCRs exhibit bactericidal effects in vitro, studies confirm that inside nodules they target the bacterial cell cycle and other cellular pathways to control and extend rhizobial differentiation into an irreversible (or terminal) state where the host gains control over bacteroids. While NCRs are well established as positive regulators of effective symbiosis, more recent findings also suggest that NCRs affect partner compatibility. The extent of bacterial differentiation has been linked to species-specific size and complexity of the NCR gene family that varies even among closely related species, suggesting a more recent origin of NCRs followed by rapid expansion in certain species. NCRs have diversified functionally, as well as in their expression patterns and responsiveness, likely driving further functional specialisation. In this review, we evaluate the functions of NCR peptides and their role as a driving force underlying the outcome of rhizobial symbiosis, where the plant is able to determine the outcome of rhizobial interaction in a temporal and spatial manner.

scholarly journals Biphasic Modulation of Apoptotic Pathways in Cryptosporidium parvum-Infected Human Intestinal Epithelial Cells

2008 ◽  
Vol 77 (2) ◽  
pp. 837-849 ◽  
Author(s):  
Jin Liu ◽  
Mingqi Deng ◽  
Cheryl A. Lancto ◽  
Mitchell S. Abrahamsen ◽  
Mark S. Rutherford ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Expression Patterns ◽  
Nuclear Condensation ◽  
Successful Infection ◽  
Cell Gene Expression ◽  
Infected Cells ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
The Impact

ABSTRACT The impact of Cryptosporidium parvum infection on host cell gene expression was investigated by microarray analysis with an in vitro model using human ileocecal HCT-8 adenocarcinoma cells. We found changes in 333 (2.6%) transcripts at at least two of the five (6, 12, 24, 48, and 72 h) postinfection time points. Fifty-one of the regulated genes were associated with apoptosis and were grouped into five clusters based on their expression patterns. Early in infection (6 and 12 h), genes with antiapoptotic roles were upregulated and genes with apoptotic roles were downregulated. Later in infection (24, 48, and 72 h), proapoptotic genes were induced and antiapoptotic genes were downregulated, suggesting a biphasic regulation of apoptosis: antiapoptotic state early and moderately proapoptotic state late in infection. This transcriptional profile matched the actual occurrence of apoptosis in the infected cultures. Apoptosis was first detected at 12 h postinfection and increased to a plateau at 24 h, when 20% of infected cells showed nuclear condensation. In contrast, experimental silencing of Bcl-2 induced apoptosis in 50% of infected cells at 12 h postinfection. This resulted in a decrease in the infection rate and a reduction in the accumulation of meront-containing cells. To test the significance of the moderately proapoptotic state late in the infection, we inhibited apoptosis using pancaspase inhibitor Z-VAD-FMK. This treatment also affected the progression of C. parvum infection, as reinfection, normally seen late (24 h to 48 h), did not occur and accumulation of mature meronts was impaired. Control of host apoptosis is complex and crucial to the life of C. parvum. Apoptosis control has at least two components, early inhibition and late moderate promotion. For a successful infection, both aspects appear to be required.

scholarly journals Pet secretion, internalization and induction of cell death during infection of epithelial cells by enteroaggregative Escherichia coli

Microbiology ◽  
2009 ◽  
Vol 155 (9) ◽  
pp. 2895-2906 ◽  
Author(s):  
Miguel Betancourt-Sanchez ◽  
Fernando Navarro-Garcia
Keyword(s):  
Escherichia Coli ◽  
Cell Death ◽  
Epithelial Cells ◽  
Morphological Changes ◽  
Eukaryotic Cell ◽  
Transcriptional Level ◽  
Cell Detachment ◽  
Wild Type ◽  
Infected Cells

In an in vitro model using HEp-2 cells treated with purified plasmid-encoded toxin (Pet), we have identified morphological changes characterized by cell rounding and detachment after toxin internalization; these changes progress to cell death. However, these effects have not yet been shown to occur during the infection of epithelial cells by enteroaggregative Escherichia coli (EAEC). Here, we show that the secretion of Pet by EAEC is regulated at the transcriptional level, since secretion was inhibited in eukaryotic cell culture medium, although Pet was efficiently secreted in the same medium supplemented with tryptone. Inefficient secretion of Pet by EAEC in DMEM prevented cell detachment, whereas efficient Pet secretion in DMEM/tryptone increased cell detachment in a HEp-2 cell adherence assay. Interestingly, Pet toxin was efficiently delivered to epithelial cells, since it was internalized into epithelial cells infected with EAEC at similar concentrations to those obtained by using 37 μg ml−1 purified Pet protein. Additionally, Pet was not internalized when the epithelial cells were infected with a pet clone, HB101(pCEFN1), unlike the wild-type strain, which has a high adherence capability. There is a correlation between Pet secretion by EAEC, the internalization of Pet into epithelial cells, cell detachment and cell death in EAEC-infected cells. The ratio between live and dead cells decreased in cells treated with wild-type EAEC in comparison with cells treated with an isogenic mutant in the pet gene, whereas the effects were restored by complementing the mutant with the pet gene. All these data indicate that Pet is an important virulence factor in the pathogenesis of EAEC infection.

scholarly journals Pseudomonas aeruginosa ExoT Acts In Vivo as a GTPase-Activating Protein for RhoA, Rac1, and Cdc42

2002 ◽  
Vol 70 (4) ◽  
pp. 2198-2205 ◽  
Author(s):  
B. I. Kazmierczak ◽  
J. N. Engel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cells ◽  
Morphological Changes ◽  
Stress Fiber ◽  
Secreted Proteins ◽  
In Vitro Activity ◽  
Gtpase Activating Protein ◽  
Infected Cells

ABSTRACT The Pseudomonas aeruginosa protein ExoT is a bacterial GTPase-activating protein (GAP) that has in vitro activity toward Rho, Rac, and Cdc42 GTPases. Expression of ExoT both inhibits the internalization of strain PA103 by macrophages and epithelial cells and is associated with morphological changes (cell rounding and detachment) of infected cells. We find that expression of ExoT leads to the loss of GTP-bound RhoA, Rac1, and Cdc42 in transfected HeLa cells, demonstrating that ExoT has GAP activity in vivo toward all three GTPases. GAP activity is absolutely dependent on the presence of arginine at position 149 but is not affected by whether ExoT is expressed in the absence or presence of other P. aeruginosa type III secreted proteins. We also demonstrate that expression of ExoT in epithelial cells is sufficient to cause stress fiber disassembly by means of ExoT's GAP activity toward RhoA.

scholarly journals Ultrastructural changes and cyclic AMP in frog oxyntic cells.

1978 ◽  
Vol 76 (1) ◽  
pp. 31-42 ◽  
Author(s):  
K S Carlisle ◽  
C S Chew ◽  
S J Hersey
Keyword(s):  
Cyclic Amp ◽  
Acid Secretion ◽  
Surface Area ◽  
Acid Production ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Ultrastructural Changes ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor

In vitro frog gastric mucosa was employed as a model for a combined physiological, biochemical, and ultrastructural study of the morphological changes which accompany the onset of acid secretion by the oxyntic cell. The histamine H2-receptor antagonist metiamide was used to provide a reproducible control state. Stimulation of acid production by theophylline resulted in a 10-fold increase in plasma membrane surface area and a distinct change in the conformation of mitochondrial cristae. Studies using the acid secretion inhibitors, thiocyanate and anoxia, demonstrated that neither acid production per se nor oxidative metabolism is essential for the theophylline-dependent changes in surface area. Increases in tissue cyclic AMP levels were observed under the conditions producing morphological changes. It is postulated that surface area changes induced by theophylline are controlled by cellular cyclic AMP levels.

scholarly journals Characterization of Mice Deficient in the Src Family Nonreceptor Tyrosine Kinase Frk/rak

2002 ◽  
Vol 22 (14) ◽  
pp. 5235-5247 ◽  
Author(s):  
Subhashini Chandrasekharan ◽  
Ting Hu Qiu ◽  
Nawal Alkharouf ◽  
Kelly Brantley ◽  
James B. Mitchell ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Expression Patterns ◽  
Developmental Expression ◽  
Epithelial Tissue ◽  
Intestinal Damage ◽  
Specific Expression ◽  
Nonreceptor Tyrosine Kinase ◽  
Euthyroid Sick Syndrome ◽  
Epithelial Tissues

ABSTRACT Frk/rak belongs to a novel family of Src kinases with epithelial tissue-specific expression. Although developmental expression patterns and functional overexpression in vitro have associated these kinases with growth suppression and differentiation, their physiological functions remain largely unknown. We therefore generated mice carrying a null mutation in iyk, the mouse homolog of Frk/rak. We report here that frk/rak−/− mice are viable, show similar growth rates to wild-type animals, and are fertile. Furthermore, a 2-year study of health and survival did not identify differences in the incidence and spectrum of spontaneous tumors or provide evidence of hyperplasias in frk/rak−/− epithelial tissues. Histological analysis of organs failed to reveal any morphological changes in epithelial tissues that normally express high levels of Frk/rak. Ultrastructural analysis of intestinal enterocytes did not identify defects in brush border morphology or structural polarization, demonstrating that Frk/rak is dispensable for intestinal cytodifferentiation. Additionally, frk/rak-null mice do not display altered sensitivity to intestinal damage induced by ionizing radiation. cDNA microarray analysis revealed an increase in c-src expression and identified subtle changes in the expression of genes regulated by thyroid hormones. Significant decreases in the circulating levels of T3 but not T4 hormone are consistent with this observation and reminiscent of euthyroid sick syndrome, a stress-associated clinical condition.

scholarly journals Evidences for lipid involvement in SARS-CoV-2 cytopathogenesis

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Roberta Nardacci ◽  
Francesca Colavita ◽  
Concetta Castilletti ◽  
Daniele Lapa ◽  
Giulia Matusali ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Vero Cells ◽  
Blood Cholesterol ◽  
Ultrastructural Changes ◽  
Type Ii ◽  
Cytopathic Effects ◽  
Type Ii Pneumocytes ◽  
Infected Cells ◽  
Accumulation Of Lipids

AbstractThe pathogenesis of SARS-CoV-2 remains to be completely understood, and detailed SARS-CoV-2 cellular cytopathic effects requires definition. We performed a comparative ultrastructural study of SARS-CoV-1 and SARS-CoV-2 infection in Vero E6 cells and in lungs from deceased COVID-19 patients. SARS-CoV-2 induces rapid death associated with profound ultrastructural changes in Vero cells. Type II pneumocytes in lung tissue showed prominent altered features with numerous vacuoles and swollen mitochondria with presence of abundant lipid droplets. The accumulation of lipids was the most striking finding we observed in SARS-CoV-2 infected cells, both in vitro and in the lungs of patients, suggesting that lipids can be involved in SARS-CoV-2 pathogenesis. Considering that in most cases, COVID-19 patients show alteration of blood cholesterol and lipoprotein homeostasis, our findings highlight a peculiar important topic that can suggest new approaches for pharmacological treatment to contrast the pathogenicity of SARS-CoV-2.

scholarly journals METABOLIC AND ULTRASTRUCTURAL CHANGES INDUCED IN ADIPOSE TISSUE BY INSULIN

1960 ◽  
Vol 8 (1) ◽  
pp. 83-101 ◽  
Author(s):  
Russell J. Barrnett ◽  
Eric G. Ball
Keyword(s):  
Adipose Tissue ◽  
Plasma Membrane ◽  
Plasma Membranes ◽  
Morphological Changes ◽  
Ultrastructural Changes ◽  
Cytoplasmic Matrix ◽  
Smooth Membrane ◽  
Metabolic Action ◽  
Rat Adipose Tissue

The addition in vitro of insulin to rat adipose tissue (epididymal) produces marked metabolic changes which may be followed by measurement of the net gas exchange of the tissue. Using this method to monitor the metabolic action of insulin, concomitant observations with the electron microscope on the tissue have been made. These reveal that pronounced morphological changes are induced by insulin. The plasma membranes of the adipose cells become invaginated at many sites to form minute finger-like indentations. Numerous tiny, membrane-bounded vesicles are also present and arranged in relationship to the plasma membrane in such a way as to suggest that their formation occurred when a recessed fold was pinched off. Deeper in the cytoplasm, especially in specimens that had been incubated a longer time, numerous large, smooth, membrane-limited vesicles are seen. Finally, in these incubated specimens the cytoplasmic matrix has lost much of its granular nature, small lipid droplets are frequently found in the cytoplasm and suggestive changes have occurred in mitochondria. In control specimens, incubated without insulin for identical periods of time, indentations and vesicles in the plasma membrane are sparse at best and no vesicles or membrane-bound spaces appear deeper in the cytoplasm. The metabolic and morphologic changes induced by insulin seem to be interdependent events. Both changes appear to be initiated rapidly and concomitantly in the tissue. Both processes are initiated by insulin at concentrations considered to be physiological, 0.004 µg. (100 µunits) per ml. Insulin treated with alkali fails to initiate either process. It is concluded that insulin initiates pinocytosis in rat adipose tissue and the possible significance of this process in the mode of action of insulin is discussed.

scholarly journals In Vitro Antifungal Activity of Hexahydropyrimidine Derivatives against the Causative Agents of Dermatomycosis

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Francislene J. Martins ◽  
César A. Caneschi ◽  
Mônica P. Senra ◽  
Gustavo S. G. Carvalho ◽  
Adilson D. da Silva ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Morphological Changes ◽  
Trichophyton Mentagrophytes ◽  
Microsporum Canis ◽  
Microsporum Gypseum ◽  
Scanning Electron Micrographs ◽  
Epidermophyton Floccosum ◽  
Synthetic Drugs ◽  
Causative Agents

Nitrogenated heterocyclic compounds are present in both natural and synthetic drugs, and hexahydropyrimidine derivatives may prove to be efficient in treating dermatomycosis causing fungi. This study evaluated the antifungal activity of four hexahydropyrimidine derivatives against the dermatomycosis causing fungi. These derivatives were synthesized, characterized, and assessed in terms of their activity against Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Fusarium oxysporum, and Epidermophyton floccosum between concentrations 7.8 and 1,000 μg mL−1. Scanning electron micrographs were assessed for the active derivatives and reference drugs, and these micrographs revealed that new agents cause morphological changes in fungi. The derivatives HHP1, HHP3, and HHP4 revealed poor activity against the four fungal strains (MICs range 500–1000 μg mL−1). Compound HHP3 was found to be the best potential antifungal agent among those tested and was the most effective among all the active derivatives that caused morphological changes in the susceptible strains.

Sign in / Sign up

Export Citation Format

Share Document