scholarly journals Antibodies to Tyvelose Exhibit Multiple Modes of Interference with the Epithelial Niche of Trichinella spiralis

2000 ◽  
Vol 68 (4) ◽  
pp. 1912-1918 ◽  
Author(s):  
Catherine S. McVay ◽  
Peter Bracken ◽  
Lucille F. Gagliardo ◽  
Judith Appleton
Keyword(s):  
Epithelial Cells ◽  
Trichinella Spiralis ◽  
In Vivo Studies ◽  
Parasite Development ◽  
Multiple Modes ◽  
Protective Antibodies ◽  
Sensory Reception ◽  
Vitro Model

ABSTRACT Infection with the parasitic nematode Trichinella spiralis is initiated when the L1 larva invades host intestinal epithelial cells. Monoclonal antibodies specific for glycans on the larval surface and secreted glycoproteins protect the intestine against infection. Protective antibodies recognize tyvelose which caps the target glycan. In this study, we used an in vitro model of invasion to further examine the mechanism(s) by which tyvelose-specific antibodies protect epithelial cells against T. spiralis. Using cell lines that vary in susceptibility to invasion, we confirmed and clarified the results of our in vivo studies by documenting three modes of interference: exclusion of larvae from cells, encumbrance of larvae as they migrated within epithelial monolayers, and inhibition of parasite development. Excluded larvae bear cephalic caps (C. S. McVay et al., Infect. Immun. 66:1941–1945, 1998) of immune complexes that may physically block invasion or may interfere with sensory reception. Monovalent Fab fragments prepared from a tyvelose-specific antibody also excluded larvae from cells, demonstrating that antibody binding can inhibit the parasite in the absence of antigen aggregation and cap formation. In contrast, encumbered larvae caused extensive damage to the monolayer yet were not successful in establishing a niche, as reflected by their failure to molt. These results show that antibodies to tyvelose exhibit multiple modes of inhibitory activity, further implicating tyvelose-bearing glycoproteins as mediators of invasion and niche establishment by T. spiralis.

Evaluation of Annona muricata (Graviola) leaves activity against experimental trichinellosis: in vitro and in vivo studies

2021 ◽  
Vol 95 ◽  
Author(s):  
E.S. El-Wakil ◽  
H.F. Abdelmaksoud ◽  
T.S. AbouShousha ◽  
M.M.I. Ghallab
Keyword(s):  
Culture Media ◽  
Trichinella Spiralis ◽  
Drug Effects ◽  
In Vivo Studies ◽  
Control Group ◽  
Annona Muricata ◽  
Group I ◽  
Small Intestinal

Abstract Our work aimed to evaluate the possible effect of Annona muricata (Graviola) leaf extract on Trichinella spiralis in in vitro and in vivo studies. Trichinella spiralis worms were isolated from infected mice and transferred to three culture media – group I (with no drugs), group II (contained Graviola) and group III (contained albendazole) – then they were examined using the electron microscope. In the in vivo study, mice were divided into five groups: GI (infected untreated), GII (prophylactically treated with Graviola for seven days before infection), GIII (infected and treated with Graviola), GIV (infected and treated with albendazole) and GV (infected and treated with a combination of Graviola plus albendazole in half doses). Drug effects were assessed by adults and larvae load beside the histopathological small intestinal and muscular changes. A significant reduction of adult and larval counts occurred in treated groups in comparison to the control group. Histopathologically, marked improvement in the small intestinal and muscular changes was observed in treated groups. Also, massive destruction of the cultured adults’ cuticle was detected in both drugs. This study revealed that Graviola leaves have potential activity against trichinellosis, especially in combination with albendazole, and could serve as an adjuvant to anti-trichinellosis drug therapy.

scholarly journals Targeting Mucosal Sites by Polymeric Immunoglobulin Receptor-directed Peptides

2002 ◽  
Vol 196 (4) ◽  
pp. 551-555 ◽  
Author(s):  
Kendra D. White ◽  
J. Donald Capra
Keyword(s):  
Epithelial Cells ◽  
Fluorescent Protein ◽  
Secretory Component ◽  
In Vivo Studies ◽  
Polymeric Immunoglobulin Receptor ◽  
Immunoglobulin Receptor ◽  
Potential Binding Site ◽  
Green Fluorescent

Polymeric immunoglobulins provide first line humoral defense at mucosal surfaces to which they are specifically transported by the polymeric immunoglobulin receptor (pIgR) on mucosal and glandular epithelial cells. Previous studies from our laboratory suggested that amino acids 402–410 of the Cα3 domain of dimeric IgA (dIgA) represented a potential binding site for the pIgR. Here by binding human secretory component to overlapping decapeptides of Cα3, we confirm these residues and also uncover an additional site. Furthermore, we show that the Cα3 motif appears to be sufficient to direct transport of green fluorescent protein through the pIgR-specific cellular transcytosis system. An alternative approach identified phage peptides, selected from a library by the in vitro Madin Darby Canine Kidney transcytosis assay, for pIgR-mediated transport through epithelial cells. Some transcytosis-selected peptides map to the same 402–410 pIgR-binding Cα3 site. Further in vivo studies document that at least one of these peptides is transported in a rat model measuring hepatic bile transport. In addition to identifying small peptides that are both bound and transported by the pIgR, this study provides evidence that the pIgR-mediated mucosal secretion system may represent a means of targeting small molecule therapeutics and genes to mucosal epithelial cells.

Hypoxia induces capillary network formation in cultured bovine pulmonary microvessel endothelial cells

1995 ◽  
Vol 268 (5) ◽  
pp. L789-L800 ◽  
Author(s):  
P. G. Phillips ◽  
L. M. Birnby ◽  
A. Narendran
Keyword(s):  
In Vitro Model ◽  
Network Formation ◽  
Collagen Gel ◽  
Coronary Artery Occlusion ◽  
In Vivo Studies ◽  
Hypoxic Exposure ◽  
Vitro Model ◽  
Vessel Networks

The development of new vessels (angiogenesis) is essential to wound healing. The center of a wound space is hypoxic, a condition that has been shown to stimulate angiogenesis in animal models of coronary artery occlusion. Because the mechanisms involved in this complex process are difficult to study in situ, an in vitro model would provide a useful complement to in vivo studies. This laboratory has developed and characterized calf pulmonary microvessel endothelial cell (PMVEC) cultures and an in vitro model system of angiogenesis using collagen three-dimensional gels that permit migration of cells into vessel networks. This system was used to study the direct effect of normoxia (20% O2) or hypoxia (5% O2) on PMVEC ability to undergo angiogenesis in vitro. Major changes leading to formation of capillary-like networks occurred during the first 3 days of hypoxic exposure only and included restructuring of actin filament networks, focal changes in distribution of basic fibroblast growth factor, and orientation and migration of cell tracts into a collagen gel matrix to form vessel networks.

scholarly journals Acute drug transfer and particle release of drug coated balloons within a porcine in-vitro model

2017 ◽  
Vol 3 (2) ◽  
pp. 465-468
Author(s):  
Christoph Brandt-Wunderlich ◽  
Lucas Almstädt ◽  
Sebastian Kaule ◽  
Thomas Reske ◽  
Wolfram Schmidt ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Test Methods ◽  
In Vivo Studies ◽  
In Vitro Test ◽  
Drug Transfer ◽  
Particle Release ◽  
Artery Disease ◽  
Vitro Model

AbstractDrug coated balloons (DCB) are used in the therapy of coronary as well as peripheral artery disease. The success of drug transfer to the vessel wall depends on the excipient used in combination with paclitaxel as antiproliferative drug. Although in-vivo studies show very good results with this technology, there is a lack of in-vitro test methods for characterization of various DCB available on the market. This study describes a method to gain information about the drug transfer and the particle release of three different DCB based on cetylpyridinium salycate (Cetpyrsal), hyaluronic acid and iopromide within a porcine in-vitro model. The Cetpyrsal-based DCB showed promising results with the highest drug transfer while producing the lowest number of particles.

The VSL#3 probiotic formula induces mucin gene expression and secretion in colonic epithelial cells

2007 ◽  
Vol 292 (1) ◽  
pp. G315-G322 ◽  
Author(s):  
C. Caballero-Franco ◽  
K. Keller ◽  
C. De Simone ◽  
K. Chadee
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
In Vivo Studies ◽  
Lactobacillus Species ◽  
Mucin Secretion ◽  
Colonic Epithelial Cells ◽  
Dnase Treatment

Several studies have stressed the importance of the microbiota in the maintenance of the gastrointestinal epithelium. Administration of probiotic bacteria, supplements composed of microbiota constituents, was previously shown to diminish symptoms in patients suffering from inflammatory bowel diseases. This raises the possibility that probiotics may play an active role in enhancing the intestinal barrier at the mucosal surface. In this study, we investigated whether the clinically tested VSL#3 probiotic formula and/or its secreted components can augment the protective mucus layer in vivo and in vitro. For in vivo studies, Wistar rats were orally administered the probiotic mixture VSL#3 on a daily basis for seven days. After treatment, basal luminal mucin content increased by 60%. In addition, we exposed isolated rat colonic loops to the VSL#3 probiotic formula, which significantly stimulated colonic mucin (MUC) secretion and MUC2 gene expression; however, MUC1 and MUC3 gene expression were only slightly elevated. The effect of the VSL#3 mucin secretagogue was also tested in vitro by use of LS 174T colonic epithelial cells. In contrast to the animal studies, cultured cells incubated with VSL#3 bacteria did not exhibit increased mucin secretion. However, the bacterial secreted products contained in the conditioned media stimulated a remarkable mucin secretion effect. Among the three bacterial groups ( Lactobacilli, Bifidobacteria, and Streptococci) contained in VSL#3, the Lactobacillus species were the strongest potentiator of mucin secretion in vitro. A preliminary characterization of the putative mucin secretagogue suggested that it was a heat-resistant soluble compound, which is not sensitive to protease and DNase treatment. These findings contribute to a better understanding of the complex and beneficial interaction between colonic epithelial cells and intestinal bacteria.

scholarly journals RNAi-mediated silencing of Trichinella spiralis serpin-type serine protease inhibitors results in a reduction in larval infectivity

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Nana Yi ◽  
Pengcheng Yu ◽  
Lijia Wu ◽  
Zhaokun Liu ◽  
Jingzhe Guan ◽  
...  
Keyword(s):  
Survival Rate ◽  
Epithelial Cells ◽  
Serine Protease ◽  
Protease Inhibitors ◽  
Intestinal Epithelial Cells ◽  
Trichinella Spiralis ◽  
Intestinal Epithelial ◽  
Serine Protease Inhibitors

AbstractTrichinella spiralis serpin-type serine protease inhibitors (TsSPIs) are expressed in adult worms (AW), newborn larvae (NBL) and muscle larvae (ML) of T. spiralis, with the ML stage demonstrating the highest expression level. This study aims to determine TsSPI functions in larval viability and invasion of intestinal epithelial cells in vitro, as well as their development, survival, and fecundity in vivo via RNAi. TsSPI-specific siRNAs and dsRNA were transfected into ML by incubation. The silencing effect of TsSPI transcription and expression was determined using qPCR and western blot, respectively. After incubation in 60 ng/μL dsRNA–TsSPI for 3 days, larval TsSPI mRNA and protein expression levels were reduced by 68.7% and 68.4% (P < 0.05), respectively. dsRNA-mediated silencing of TsSPI significantly impacted larval invasion into intestinal epithelial cells in vitro but did not affect the survival rate of larvae. After challenge with dsRNA–TsSPI-treated ML, mice exhibited a 56.0% reduction in intestinal AW burden and 56.9% reduction in ML burden (P < 0.05), but NBL production of female AW remained the same (P > 0.05). Our results revealed that RNAi-mediated silencing of TsSPI expression in T. spiralis significantly reduced larval infectivity and survival in the host but had no effect on the survival rate and fecundity. Furthermore, TsSPIs have no effect on the growth and reproduction of parasites but may be directly involved in regulating the interaction of T. spiralis and the host. Therefore, TsSPIs are crucial in the process of T. spiralis larval invasion and parasite survival in the host.

scholarly journals Once-versus thrice-daily netilmicin combined with amoxicillin, penicillin, or vancomycin against Enterococcus faecalis in a pharmacodynamic in vitro model.

1996 ◽  
Vol 40 (10) ◽  
pp. 2258-2261 ◽  
Author(s):  
S Schwank ◽  
J Blaser
Keyword(s):  
Enterococcus Faecalis ◽  
Half Life ◽  
In Vitro Model ◽  
Bacterial Biofilm ◽  
In Vivo Studies ◽  
Bacterial Killing ◽  
Once Daily ◽  
Vitro Model

Several in vitro and in vivo studies as well as clinical trials have demonstrated that once-daily aminoglycoside regimens are as effective as or more effective than multiple daily dosings. However, the most favorable aminoglycoside dosing regimen for treating enterococcal endocarditis remains controversial. The same total dose of netilmicin was administered as once-daily (24-micrograms/ml peaks) and thrice-daily (8 micrograms/ml) regimens in a pharmacodynamic in vitro model simulating exposure of Enterococcus faecalis to human serum kinetics. Netilmicin was administered in combination with continuous infusions of amoxicillin, vancomycin, or penicillin against a bacterial biofilm adhering to glass beads. No significant differences in bacterial killing were found after 24 or 48 h between the once- and thrice-daily regimens. Additional experiments considering animal kinetics (half-life of netilmicin, 20 min) instead of human kinetics (half-life, 2.5 h) in the pharmacodynamic model also revealed similar results. The addition of netilmicin synergistically increased the activity of vancomycin (P < 0.05). In contrast, amoxicillin alone was as effective as the combination with netilmicin. Thus, it could not be established in this model that once-daily dosing of aminoglycosides is contraindicated for treating infections caused by E. faecalis.

An in vitro model of ischemia/reperfusion-induced microvascular injury

1990 ◽  
Vol 259 (1) ◽  
pp. G134-G139 ◽  
Author(s):  
W. Inauen ◽  
D. N. Granger ◽  
C. J. Meininger ◽  
M. E. Schelling ◽  
H. J. Granger ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
In Vitro Model ◽  
Cell Injury ◽  
Ischemia Reperfusion ◽  
In Vivo Studies ◽  
Cell Detachment ◽  
51Cr Release ◽  
Vitro Model

The major objective of this study was to develop an in vitro model of ischemia/reperfusion (I/R)-induced microvascular injury. Cultured venular endothelial cells were grown to confluency, labeled with 51Cr, and exposed to different durations of anoxia (0.5, 1, 2, 3, and 4 h). 51Cr release and cell detachment (indexes of cell injury) were determined at different times after reoxygenation (1, 2, 4, 6, 8, and 18 h). Because in vivo studies have implicated neutrophils in I/R injury, in some experiments human neutrophils were added to the endothelial cells upon reoxygenation. Periods of anoxia greater than or equal to 2 h resulted in 70-80% 51Cr release and 80-95% cell detachment upon reoxygenation. Under these conditions (near maximal injury), the addition of neutrophils produced negligible effects. Periods of anoxia less than or equal to 1 h resulted in 30-40% 51Cr release and 50-60% cell detachment. Under these conditions (moderate cell injury), addition of neutrophils enhanced endothelial cell injury. Using a 30-min period of anoxia, we also assessed the effects of superoxide dismutase (SOD; 300 U/ml) and allopurinol (20 microM) on anoxia/reoxygenation (A/R)-induced injury in the presence or absence of neutrophils. In the absence of neutrophils, SOD or allopurinol did not protect against A/R-induced injury. However, in the presence of neutrophils, both SOD and allopurinol attenuated the increases in 51Cr release. The results derived using this in vitro model of I/R injury are largely consistent with published in vivo studies. Thus this in vitro model may provide further insights regarding the mechanisms involved in I/R injury.

scholarly journals A Role for Caspases in Lens Fiber Differentiation

1998 ◽  
Vol 140 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Yasuki Ishizaki ◽  
Michael D. Jacobson ◽  
Martin C. Raff
Keyword(s):  
Epithelial Cells ◽  
Cysteine Proteases ◽  
Lens Epithelial Cells ◽  
Lens Fiber ◽  
Caspase Family ◽  
Vitro Model ◽  
Normal Differentiation ◽  
Enzymatic Machinery

There is increasing evidence that programmed cell death (PCD) depends on a novel family of intracellular cysteine proteases, called caspases, that includes the Ced-3 protease in the nematode Caenorhabditis elegans and the interleukin-1β–converting enzyme (ICE)-like proteases in mammals. Some developing cells, including lens epithelial cells, erythroblasts, and keratinocytes, lose their nucleus and other organelles when they terminally differentiate, but it is not known whether the enzymatic machinery of PCD is involved in any of these normal differentiation events. We show here that at least one CPP32 (caspase-3)-like member of the caspase family becomes activated when rodent lens epithelial cells terminally differentiate into anucleate lens fibers in vivo, and that a peptide inhibitor of these proteases blocks the denucleation process in an in vitro model of lens fiber differentiation. These findings suggest that at least part of the machinery of PCD is involved in lens fiber differentiation.

scholarly journals Immunohistochemical profile of HIF-1α, VEGF-A, VEGFR2 and MMP9 proteins in tegumentary leishmaniasis

2012 ◽  
Vol 87 (5) ◽  
pp. 709-713 ◽  
Author(s):  
Carlos Alberto de Carvalho Fraga ◽  
Marcos Vinicius Macedo de Oliveira ◽  
Lucas Rodrigues Alves ◽  
Agostinho Gonçalves Viana ◽  
Adriana Alkmin de Sousa ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Skin Lesions ◽  
Activation Mechanism ◽  
In Vivo Studies ◽  
Protein Levels ◽  
Tegumentary Leishmaniasis ◽  
Protein Expressions

BACKGROUND: Leishmaniasis is one of the most important infectious diseases worldwide. Our study can provide more knowledge about angiogenic and hypoxic events in leishmaniasis. We attempted to verify whether the HIF-1 α protein expression may be associated to VEGF-A, VEGFR2 and MMP9 in leishmanial lesions. OBJECTIVES: Besides understanding the pathway, we performed the correlation of VEGF-A, VEGFR2 and MMP9 proteins. METHODS: In this study, we gathered 54 paraffin blocks taken from skin lesions in patients from northern Minas Gerais, Brazil, with confirmed diagnosis of tegumentary leishmaniasis. Immunohistochemistry was used to evaluate the expression of the proteins. The expression of HIF-1α was categorized into two groups according to the median: HIF-1 α lower and HIF-1 α higher. RESULTS: We observed increase of VEGFR2 and MMP9 protein expressions in HIF-1 α higher group of epithelial cells. Spearman analyses in epithelial cells showed correlation between VEGF-A and MMP9, VEGFR2 and MMP9 protein expression. CONCLUSIONS: HIF-1 α higher group showed increase of VEGFR2 and MMP9 proteins. In epithelial cells, VEGF-A was correlated to MMP9 protein. Furthermore, considering leukocyte cells, VEGFR2 was negatively correlated to MMP9 protein levels. This pathway possibly prepares the cells for a higher activity in a hypoxic or an angiogenic microenvironment. Other in vitro and in vivo studies may clarify the activation mechanism and the response from the proteins HIF-1 α, VEGFR2 and MMP-9 in tegumentary leishmaniasis.

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