scholarly journals In Vitro Cell Invasion of Mycoplasma gallisepticum

2000 ◽  
Vol 68 (7) ◽  
pp. 4238-4244 ◽  
Author(s):  
Florian Winner ◽  
Renate Rosengarten ◽  
Christine Citti
Keyword(s):  
Cell Lines ◽  
Cell Invasion ◽  
Mycoplasma Gallisepticum ◽  
Prototype Strain ◽  
Host Cells ◽  
Mucosal Barrier ◽  
Chronic Infections ◽  
Intracellular Space ◽  
Accurate Localization

ABSTRACT The ability of the widespread avian pathogen Mycoplasma gallisepticum to invade cultured human epithelial cells (HeLa-229) and chicken embryo fibroblasts (CEF) was investigated by using the gentamicin invasion assay and a double immunofluorescence microscopic technique for accurate localization of cell-associated mycoplasmas. The presence of intracellular mycoplasmas in both cell lines was clearly demonstrated, with organisms entering the eukaryotic cells within 20 min. Internalized mycoplasmas have the ability to leave the cell, but also to survive within the intracellular space over a 48-h period. Frequencies of invasion were shown to differ between the two cell lines, but were also considerably dependent on the mycoplasma input population. Of the prototype strain R, a low-passage population in artificial medium, Rlow, was capable of active cell invasion, while a high-passage population, Rhigh, showed adherence to but nearly no uptake into HeLa-229 and CEF. By passaging Rlow and Rhigh multiple times through HeLa-229 cells, the invasion frequency was significantly increased. Taken together, these findings demonstrate that M. gallisepticumhas the capability of entering nonphagocytic host cells that may provide this pathogen with the opportunity for resisting host defenses and selective antibiotic therapy, establishing chronic infections, and passing through the respiratory mucosal barrier to cause systemic infections.

scholarly journals Injection of T3SS effectors not resulting in invasion is the main targeting mechanism ofShigellatoward human lymphocytes

2017 ◽  
Vol 114 (37) ◽  
pp. 9954-9959 ◽  
Author(s):  
Laurie Pinaud ◽  
Fatoumata Samassa ◽  
Ziv Porat ◽  
Mariana L. Ferrari ◽  
Ilia Belotserkovsky ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cell Invasion ◽  
Immune Cells ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Host Cells ◽  
Mucosal Barrier ◽  
Functional Consequences ◽  
B And T Lymphocytes

The enteroinvasive bacteriumShigellais a facultative intracellular bacterium known, in vitro, to invade a large diversity of cells through the delivery of virulence effectors into the cell cytoplasm via a type III secretion system (T3SS). Here, we provide evidence that the injection of T3SS effectors does not necessarily result in cell invasion. Indeed, we demonstrate through optimization of a T3SS injection reporter that effector injection without subsequent cell invasion, termed the injection-only mechanism, is the main strategy used byShigellato target human immune cells. We show that in vitro-activated human peripheral blood B, CD4+T, and CD8+T lymphocytes as well as switched memory B cells are mostly targeted by the injection-only mechanism. B and T lymphocytes residing in the human colonic lamina propria, encountered byShigellaupon its crossing of the mucosal barrier, are also mainly targeted by injection-only. These findings reveal that cells refractory to invasion can still be injected, thus extending the panel of host cells manipulated to the benefit of the pathogen. Future analysis of the functional consequences of the injection-only mechanism toward immune cells will contribute to the understanding of the priming of adaptive immunity, which is known to be altered during the course of naturalShigellainfection.

scholarly journals Mechanism of MicroRNA-375 Promoter Methylation in Promoting Ovarian Cancer Cell Malignancy

2021 ◽  
Vol 20 ◽  
pp. 153303382098011
Author(s):  
Junjun Shu ◽  
Ling Xiao ◽  
Sanhua Yan ◽  
Boqun Fan ◽  
Xia Zou ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Protein Expression ◽  
Cell Lines ◽  
Cell Invasion ◽  
Promoter Methylation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Gene Assay ◽  
Cell Malignancy

Objective: Ovarian cancer (OC) ranks one of the most prevalent fatal tumors of female genital organs. Aberrant promoter methylation triggers changes of microRNA (miR)-375 in OC. Our study aimed to evaluate the mechanism of methylated miR-375 promoter region in OC cell malignancy and to seek the possible treatment for OC. Methods: miR-375 promoter methylation level in OC tissues and cells was detected. miR-375 expression in OC tissues and cell lines was compared with that in demethylated cells. Role of miR-375 in OC progression was measured. Dual-luciferase reporter gene assay was utilized to verify the targeting relationship between miR-375 and Yes-associated protein 1 (YAP1). Then, Wnt/β-catenin pathway-related protein expression was tested. Moreover, xenograft transplantation was applied to confirm the in vitro experiments. Results: Highly methylated miR-375 was seen in OC tissues and cell lines, while its expression was decreased as the promoter methylation increased. Demethylation in OC cells brought miR-375 back to normal level, with obviously declined cell invasion, migration and viability and improved apoptosis. Additionally, miR-375 targeted YAP1 to regulate the Wnt/β-catenin pathway protein expression. Overexpressed YAP1 reversed the protein expression, promoted cell invasion, migration and viability while reduced cell apoptosis. Overexpressed miR-375 in vivo inhibited OC progression. Conclusion: Our study demonstrated that demethylated miR-375 inhibited OC growth by targeting YAP1 and downregulating the Wnt/β-catenin pathway. This investigation may offer novel insight for OC treatment.

scholarly journals 1,3,4-Thiadiazoles Effectively Inhibit Proliferation of Toxoplasma gondii

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1053
Author(s):  
Lidia Węglińska ◽  
Adrian Bekier ◽  
Katarzyna Dzitko ◽  
Barbara Pacholczyk-Sienicka ◽  
Łukasz Albrecht ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Host Cell ◽  
Cell Invasion ◽  
Direct Action ◽  
Human Fibroblasts ◽  
Imidazole Ring ◽  
Host Cells ◽  
In Vitro Assays ◽  
Host Cell Invasion

Congenital and acquired toxoplasmosis caused by the food- and water-born parasite Toxoplasma gondii (T. gondii) is one of the most prevalent zoonotic infection of global importance. T. gondii is an obligate intracellular parasite with limited capacity for extracellular survival, thus a successful, efficient and robust host cell invasion process is crucial for its survival, proliferation and transmission. In this study, we screened a series of novel 1,3,4-thiadiazole-2-halophenylamines functionalized at the C5 position with the imidazole ring (1b–12b) for their effects on T. gondii host cell invasion and proliferation. To achieve this goal, these compounds were initially subjected to in vitro assays to assess their cytotoxicity on human fibroblasts and then antiparasitic efficacy. Results showed that all of them compare favorably to control drugs sulfadiazine and trimethoprim in terms of T. gondii growth inhibition (IC50) and selectivity toward the parasite, expressed as selectivity index (SI). Subsequently, the most potent of them with meta-fluoro 2b, meta-chloro 5b, meta-bromo 8b, meta-iodo 11b and para-iodo 12b substitution were tested for their efficacy in inhibition of tachyzoites invasion and subsequent proliferation by direct action on established intracellular infection. All the compounds significantly inhibited the parasite invasion and intracellular proliferation via direct action on both tachyzoites and parasitophorous vacuoles formation. The most effective was para-iodo derivative 12b that caused reduction in the percentage of infected host cells by 44% and number of tachyzoites per vacuole by 93% compared to non-treated host cells. Collectively, these studies indicate that 1,3,4-thiadiazoles 1b–12b, especially 12b with IC50 of 4.70 µg/mL and SI of 20.89, could be considered as early hit compounds for future design and synthesis of anti-Toxoplasma agents that effectively and selectively block the invasion and subsequent proliferation of T. gondii into host cells.

Preclinical and correlative studies of cabozantinib (XL184) in urothelial cancer (UC).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 4543-4543
Author(s):  
Andrea Borghese Apolo ◽  
Young H. Lee ◽  
Fabiola Cecchi ◽  
Piyush K. Agarwal ◽  
Howard L. Parnes ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Invasion ◽  
Urothelial Cancer ◽  
Invasive Disease ◽  
Soft Agar ◽  
Visceral Metastasis ◽  
Anchorage Independent Growth ◽  
Median Serum ◽  
Muscle Invasive

4543 Background: Mounting evidence supports Met as a therapeutic target in urothelial cancer (UC). Activated Met can promote angiogenesis and tumor growth by upregulating VEGF and may play a role in UC pathogenesis. Cabozantinib inhibits VEGFR2 and Met pathways. In this study, we assessed shed Met (sMet) levels in the urine and serum of UC patients (pts) and cabozantinib’s effects on HGF-driven UC cell growth and invasion. Methods: sMet levels in serum and urine samples from 31 pts with UC (23 metastatic, 8 muscle-invasive) were correlated with stage, presence of visceral metastases and urinary source. The effects of cabozantinib on 4 human UC-derived cell lines were studied in vitro. Intact RT4, TCC-SUP, T24M2 and T24M3 cells at 80% confluence were serum deprived 16 h, then left untreated or treated with hepatocyte growth factor (HGF) and/or cabozantinib prior to analysis of Met, phospho- (p)Met, pAkt, Akt, pMAPK and MAPK by immunoassay or immunoblotting. Cabozantinib effects on basal and HGF-induced UC cell invasion, proliferation and soft agar growth were measured. Results: Median serum Met levels were modestly higher in pts with metastatic versus muscle-invasive disease. Urinary Met levels were clearly higher in pts with visceral metastasis (P=0.0111) and in urine from ileal conduits and neobladders compared to normally voided urine, regardless of stage (P=0.0489). Met content in UC cell lines was low in RT4 and higher in T24M2, T24M3 and TCC-SUP. Basal pMet content was universally low, increased significantly by HGF and this was reversed by cabozantinib. HGF-driven increases in pAkt/Akt and pMAPK/MAPK in all 4 cell lines were reversed by cabozantinib, as were HGF-enhanced UC cell invasion, proliferation and anchorage independent growth. Conclusions: Median urinary sMet is significantly higher in pts with visceral metastasis and in specimens from ileal conduits and neobladders relative to normally voided urine. UC cell Met content in culture increased with disease grade; HGF stimulated activation of Met and known effectors, and enhanced invasion, growth rate and anchorage-independent growth; cabozantinib effectively reversed these HGF-driven effects. These data support evaluation of cabozantinib in pts with metastatic UC.

Effect of bovine lactoferrin onChlamydia trachomatisinfection and inflammation

2017 ◽  
Vol 95 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Rosa Sessa ◽  
Marisa Di Pietro ◽  
Simone Filardo ◽  
Alessia Bressan ◽  
Luigi Rosa ◽  
...  
Keyword(s):  
Acute Infection ◽  
Host Cells ◽  
Developmental Cycle ◽  
Bovine Lactoferrin ◽  
Bacterial Disease ◽  
Chronic Infections ◽  
Sexually Transmitted ◽  
Obligate Intracellular Pathogen

Chlamydia trachomatis is an obligate, intracellular pathogen responsible for the most common sexually transmitted bacterial disease worldwide, causing acute and chronic infections. The acute infection is susceptible to antibiotics, whereas the chronic one needs prolonged therapies, thus increasing the risk of developing antibiotic resistance. Novel alternative therapies are needed. The intracellular development of C. trachomatis requires essential nutrients, including iron. Iron-chelating drugs inhibit C. trachomatis developmental cycle. Lactoferrin (Lf), a pleiotropic iron binding glycoprotein, could be a promising candidate against C. trachomatis infection. Similarly to the efficacy against other intracellular pathogens, bovine Lf (bLf) could both interfere with C. trachomatis entry into epithelial cells and exert an anti-inflammatory activity. In vitro and in vivo effects of bLf against C. trachomatis infectious and inflammatory process has been investigated. BLf inhibits C. trachomatis entry into host cells when incubated with cell monolayers before or at the moment of the infection and down-regulates IL-6/IL-8 synthesized by infected cells. Six out of 7 pregnant women asymptomatically infected by C. trachomatis, after 30 days of bLf intravaginal administration, were negative for C. trachomatis and showed a decrease of cervical IL-6 levels. This is the first time that the bLf protective effect against C. trachomatis infection has been demonstrated.

Inhibition of cell invasion by indomethacin on glioma cell lines: in vitro study

2005 ◽  
Vol 72 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Maode Wang ◽  
Daizo Yoshida ◽  
Shouxun Liu ◽  
Akira Teramoto
Keyword(s):  
Cell Lines ◽  
Cell Invasion ◽  
Glioma Cell ◽  
In Vitro Study ◽  
Vitro Study ◽  
Glioma Cell Lines

scholarly journals Attachment and invasion ofToxoplasma gondiiandNeospora caninumto epithelial and fibroblast cell linesin vitro

Parasitology ◽  
2005 ◽  
Vol 131 (5) ◽  
pp. 583-590 ◽  
Author(s):  
YING LEI ◽  
M. DAVEY ◽  
J. T. ELLIS
Keyword(s):  
Cell Lines ◽  
Neospora Caninum ◽  
Fibroblast Cell ◽  
Cell Types ◽  
Vero Cells ◽  
Host Cells ◽  
Trypsin Treatment ◽  
Epithelial Cell Lines ◽  
Pre Treatment

Attachment and invasion ofToxoplasma gondiiandNeospora caninumto a cat and a dog fibroblast cell line and 2 epithelial cell lines (a cat kidney and Vero) were comparedin vitrousing fluorescence antibody methodology. In addition, trypsin treatment of tachyzoites was used to determine whether protein molecules were essential to the process of invasion. The results show that bothT. gondiiandN. caninuminvaded all 4 cell lines, and that pre-treatment ofT. gondiitachyzoites with trypsin caused an increase in the ability of the parasite to invade these host cells. FurthermoreT. gondii, in comparison toN. caninum, invaded all 4 cell lines at greater levels. The results here support the conclusion that bothT. gondiiandN. caninumhave the ability to invade a variety of cell types including both dog and cat cells, and questions the utility of Vero cells as an appropriate host cell forin vitrostudies on the biology of these taxa.

scholarly journals Eimeria tenella Eimeria-specific protein that interacts with apical membrane antigen 1 (EtAMA1) is involved in host cell invasion

2020 ◽  
Author(s):  
Cong Li ◽  
Qiping Zhao ◽  
Shunhai Zhu ◽  
Qingjie Wang ◽  
Haixia Wang ◽  
...  
Keyword(s):  
Cell Invasion ◽  
Apical Membrane ◽  
Specific Protein ◽  
Host Cells ◽  
Host Cell Invasion ◽  
Secreted Protein ◽  
Interacting Proteins ◽  
Apical Membrane Antigen 1

Abstract Background: Avian coccidiosis is a widespread, economically significant disease of poultry, caused by several species of the protozoan parasite Eimeria. Among these species, E. tenella causes hemorrhagic pathologies and high mortality. These parasites have complex and diverse lifestyles that require the invasion of their host cells. This is mediated by various proteins secreted from apical secretory organelles. Apical membrane antigen 1 (AMA1), which is released from micronemes and is conserved across all apicomplexans, plays a central role in the host cell invasion. In a previous study, some putative EtAMA1-interacting proteins of E. tenella were screened. In this study, we characterized one putative EtAMA1-interacting protein, E. tenella Eimeria -specific protein (EtEsp).Methods: Bimolecular fluorescence complementation (BiFC) and glutathione S-transferase (GST) fusion protein pull-down (GST pull-down) were used to confirm the interaction between EtAMA1 and EtEsp in vivo and in vitro. The expression of EtEsp was analyzed in different developmental stages of E. tenella with quantitative PCR and western blotting. The secretion of EtEsp protein was tested with staurosporine when sporozoites were incubated in complete medium at 41 °C.The localization of EtEsp was analyzed with an immunofluorescence assay. An in vitro invasion inhibition assay was conducted to assess the ability of antibodies against EtEsp to inhibit cell invasion by E. tenella sporozoites.Results: The interaction between EtAMA1 and EtEsp was confirmed with BiFC in vivo and by GST pull-down in vitro. Our results show that EtEsp is differentially expressed during distinct phases of the parasite life cycle. An immunofluorescence analysis showed that the EtEsp protein is mainly distributed on the parasite surface, and that the expression of this protein increases during the development of the parasite in the host cells. Using staurosporine, we showed that EtEsp is a secreted protein, but not from micronemes. In inhibition tests, a polyclonal anti-rEtEsp antibody attenuated the capacity of E. tenella to invade host cells in vitro. Conclusion: In this study, we show that EtEsp interacts with EtAMA1 and that the protein is secreted protein, but not from micronemes. The protein participates in the sporozoite invasion of host cells and maybe involved in the growth of the parasite in the host. These data have implications for the use of EtAMA1 or EtAMA1-interacting proteins as targets in intervention strategies against avian coccidiosis.

scholarly journals Microneme Rhomboid Protease TgROM1 Is Required for Efficient Intracellular Growth of Toxoplasma gondii

2008 ◽  
Vol 7 (4) ◽  
pp. 664-674 ◽  
Author(s):  
Fabien Brossier ◽  
G. Lucas Starnes ◽  
Wandy L. Beatty ◽  
L. David Sibley
Keyword(s):  
Toxoplasma Gondii ◽  
Cell Invasion ◽  
Secretory Pathway ◽  
Transmembrane Domain ◽  
Critical Role ◽  
Host Cells ◽  
Wild Type ◽  
Intracellular Growth ◽  
Adhesive Proteins

ABSTRACT Rhomboids are serine proteases that cleave their substrates within the transmembrane domain. Toxoplasma gondii contains six rhomboids that are expressed in different life cycle stages and localized to different cellular compartments. Toxoplasma rhomboid protein 1 (TgROM1) has previously been shown to be active in vitro, and the orthologue in Plasmodium falciparum processes the essential microneme protein AMA1 in a heterologous system. We investigated the role of TgROM1 to determine its role during in vitro growth of T. gondii. TgROM1 was localized in the secretory pathway of the parasite, including the Golgi apparatus and micronemes, which contain adhesive proteins involved in invasion of host cells. However, unlike other micronemal proteins, TgROM1 was not released onto the parasite surface during cell invasion, suggesting it does not play a critical role in cell invasion. Suppression of TgROM1 using the tetracycline-regulatable system revealed that ROM1-deficient parasites were outcompeted by wild-type T. gondii. ROM1-deficient parasites showed only modest decrease in invasion but replicated more slowly than wild-type cells. Collectively, these results indicate that ROM1 is required for efficient intracellular growth by T. gondii.

scholarly journals Cytadherence-Deficient Mutants of Mycoplasma gallisepticum Generated by Transposon Mutagenesis

2003 ◽  
Vol 71 (7) ◽  
pp. 3812-3820 ◽  
Author(s):  
Sigalit Mudahi-Orenstein ◽  
Sharon Levisohn ◽  
Steven J. Geary ◽  
David Yogev
Keyword(s):  
Fibroblast Cell ◽  
Mycoplasma Gallisepticum ◽  
Transposon Mutagenesis ◽  
Model Systems ◽  
Host Cells ◽  
Original Strain ◽  
Human Lung Fibroblast ◽  
Transposon Insertion

ABSTRACT Cytadherence-related molecules of Mycoplasma gallisepticum strain R-low were identified by Tn4001 transposon mutagenesis with the hemadsorption (HA) assay as an indicator for cytadherence. Three Gmr HA-negative (HA−) colonies displaying a stable HA− phenotype through several successive generations in which gentamicin selection was maintained were isolated from four independent transformation experiments and characterized. Southern blot analysis showed that the transposon was inserted as a single copy within the genome of each of the HA− mutants, suggesting that the transposon insertion was directly responsible for their inability to attach to erythrocytes. Sequence analysis of the transposon insertion sites revealed that in two mutants, the transposon was inserted at two distinct sites within the gapA structural gene. In the third mutant, the insertion was mapped within the crmA gene, which is located immediately downstream of the gapA gene as part of the same operon. In vitro attachment experiments with the MRC-5 human lung fibroblast cell line showed that the cytadherence capabilities of the HA− mutants were less than 25% those of original strain R. Experimental infection of chickens, the natural host of M. gallisepticum, with each of the three mutants demonstrated significantly impaired colonization and host responses. These data demonstrate conclusively the role of both GapA and CrmA proteins in the adherence of M. gallisepticum to host cells in model systems and in vivo colonization. Furthermore, these results underscore the relevance of in vitro cytadherence model systems for studying the pathogenesis of natural infections in chickens.

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