scholarly journals Tulane Virus Recognizes the A Type 3 and B Histo-Blood Group Antigens

2014 ◽  
Vol 89 (2) ◽  
pp. 1419-1427 ◽  
Author(s):  
Dongsheng Zhang ◽  
Pengwei Huang ◽  
Lu Zou ◽  
Todd L. Lowary ◽  
Ming Tan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Blood Group ◽  
Culture Method ◽  
Blood Group Antigens ◽  
Content Type ◽  
Tulane Virus ◽  
A Cell ◽  
Type 3

ABSTRACTTulane virus (TV), the prototype of theRecovirusgenus in the calicivirus family, was isolated from the stools of rhesus monkeys and can be cultivatedin vitroin monkey kidney cells. TV is genetically closely related to the genusNorovirusand recognizes the histo-blood group antigens (HBGAs), similarly to human noroviruses (NoVs), making it a valuable surrogate for human NoVs. However, the precise structures of HBGAs recognized by TV remain elusive. In this study, we performed binding and blocking experiments on TV with extended HBGA types and showed that, while TV binds all four types (types 1 to 4) of the B antigens, it recognizes only the A type 3 antigen among four types of A antigens tested. The requirements for HBGAs in TV replication were demonstrated by blocking of TV replication in cell culture using the A type 3/4 and B saliva samples. Similar results were also observed in oligosaccharide-based blocking assays. Importantly, the previously reported, unexplained increase in TV replication by oligosaccharide in cell-based blocking assays has been clarified, which will facilitate the application of TV as a surrogate for human NoVs.IMPORTANCEOur understanding of the role of HBGAs in NoV infection has been significantly advanced in the past decade, but direct evidence for HBGAs as receptors for human NoVs remains lacking due to a lack of a cell culture method. TV recognizes HBGAs and can replicatein vitro, providing a valuable surrogate for human NoVs. However, TV binds to some but not all saliva samples from A-positive individuals, and an unexplained observation of synthetic oligosaccharide blocking of TV binding has been reported. These issues have been resolved in this study.

scholarly journals Regulation by ToxR-Like Proteins Converges onvttRBExpression To Control Type 3 Secretion System-Dependent Caco2-BBE Cytotoxicity in Vibrio cholerae

2016 ◽  
Vol 198 (11) ◽  
pp. 1675-1682 ◽  
Author(s):  
Kelly A. Miller ◽  
Madeline K. Sofia ◽  
Jacob W. A. Weaver ◽  
Christopher H. Seward ◽  
Michelle Dziejman
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Vibrio Cholerae ◽  
Secretion System ◽  
Content Type ◽  
Transcriptional Regulatory ◽  
Type 3 Secretion System ◽  
Type 3

ABSTRACTGenes carried on the type 3 secretion system (T3SS) pathogenicity island ofVibrio choleraenon-O1/non-O139 serogroup strain AM-19226 must be precisely regulated in order for bacteria to cause disease. Previously reported results showed that both T3SS function and the presence of bile are required to cause Caco2-BBE cell cytotoxicity during coculture with strain AM-19226. We therefore investigated additional parameters affectingin vitrocell death, including bacterial load and the role of three transmembrane transcriptional regulatory proteins, VttRA, VttRB, and ToxR. VttRAand VttRBare encoded on the horizontally acquired T3SS genomic island, whereas ToxR is encoded on the ancestral chromosome. While strains carrying deletions in any one of the three transcriptional regulatory genes are unable to cause eukaryotic cell death, the results of complementation studies point to a hierarchy of regulatory control that converges onvttRBexpression. The data suggest both that ToxR and VttRAact upstream of VttRBand that modifying the level of eithervttRAorvttRBexpression can strongly influence T3SS gene expression. We therefore propose a model whereby T3SS activity and, hence,in vitrocytotoxicity are ultimately regulated byvttRBexpression.IMPORTANCEIn contrast to O1 and O139 serogroupV. choleraestrains that cause cholera using two main virulence factors (toxin-coregulated pilus [TCP] and cholera toxin [CT]), O39 serogroup strain AM-19226 uses a type 3 secretion system as its principal virulence mechanism. Although the regulatory network governing TCP and CT expression is well understood, the factors influencing T3SS-associated virulence are not. Using anin vitromammalian cell model to investigate the role of three ToxR-like transmembrane transcriptional activators in causing T3SS-dependent cytotoxicity, we found that expression levels and a hierarchical organization were important for promoting T3SS gene expression. Furthermore, our results suggest that horizontally acquired, ToxR-like proteins act in concert with the ancestral ToxR protein to orchestrate T3SS-mediated pathogenicity.

scholarly journals Genetic Diversity and Histo-Blood Group Antigen Interactions of Rhesus Enteric Caliciviruses

2010 ◽  
Vol 84 (17) ◽  
pp. 8617-8625 ◽  
Author(s):  
Tibor Farkas ◽  
Robert W. Cross ◽  
Edwin Hargitt ◽  
Nicholas W. Lerche ◽  
Ardythe L. Morrow ◽  
...  
Keyword(s):  
Blood Group ◽  
Neutralizing Antibodies ◽  
Blood Group Antigens ◽  
Primate Research ◽  
Serum Samples ◽  
Genetic Types ◽  
High Prevalence ◽  
Tulane Virus

ABSTRACT Recently, we reported the discovery and characterization of Tulane virus (TV), a novel rhesus calicivirus (CV) (T. Farkas, K. Sestak, C. Wei, and X. Jiang, J. Virol. 82:5408-5416, 2008). TV grows well in tissue culture, and it represents a new genus within Caliciviridae, with the proposed name of Recovirus. We also reported a high prevalence of CV antibodies in macaques of the Tulane National Primate Research Center (TNPRC) colony, including anti-norovirus (NoV), anti-sapovirus (SaV), and anti-TV (T. Farkas, J. Dufour, X. Jiang, and K. Sestak, J. Gen. Virol. 91:734-738, 2010). To broaden our knowledge about CV infections in captive nonhuman primates (NHP), 500 rhesus macaque stool samples collected from breeding colony TNPRC macaques were tested for CVs. Fifty-seven (11%) samples contained recovirus isolates. In addition, one NoV was detected. Phylogenetic analysis classified the recovirus isolates into two genogroups and at least four genetic types. The rhesus NoV isolate was closely related to GII human NoVs. TV-neutralizing antibodies were detected in 88% of serum samples obtained from primate caretakers. Binding and plaque reduction assays revealed the involvement of type A and B histo-blood group antigens (HBGA) in TV infection. Taken together, these findings indicate the zoonotic potential of primate CVs. The discovery of a genetically diverse and prevalent group of primate CVs and remarkable similarities between rhesus enteric CVs and human NoVs opens new possibilities for research involving in vitro and in vivo models of human NoV gastroenteritis.

scholarly journals Role of Klebsiella pneumoniae Type 1 and Type 3 Fimbriae in Colonizing Silicone Tubes Implanted into the Bladders of Mice as a Model of Catheter-Associated Urinary Tract Infections

2013 ◽  
Vol 81 (8) ◽  
pp. 3009-3017 ◽  
Author(s):  
Caitlin N. Murphy ◽  
Martin S. Mortensen ◽  
Karen A. Krogfelt ◽  
Steven Clegg
Keyword(s):  
Urinary Tract ◽  
Klebsiella Pneumoniae ◽  
Urinary Tract Infections ◽  
Wild Type ◽  
Content Type ◽  
Tract Infections ◽  
Type 3

ABSTRACTCatheter-associated urinary tract infections are biofilm-mediated infections that cause a significant economic and health burden in nosocomial environments. Using a newly developed murine model of this type of infection, we investigated the role of fimbriae in implant-associated urinary tract infections by the Gram-negative bacteriumKlebsiella pneumoniae, which is a proficient biofilm former and a commonly isolated nosocomial pathogen. Studies have shown that type 1 and type 3 fimbriae are involved in attachment and biofilm formationin vitro, and these fimbrial types are suspected to be important virulence factors during infection. To test this hypothesis, the virulence of fimbrial mutants was assessed in independent challenges in which mouse bladders were inoculated with the wild type or a fimbrial mutant and in coinfection studies in which the wild type and fimbrial mutants were inoculated together to assess the results of a direct competition in the urinary tract. Using these experiments, we were able to show that both fimbrial types serve to enhance colonization and persistence. Additionally, a double mutant had an additive colonization defect under some conditions, indicating that both fimbrial types have unique roles in the attachment and persistence in the bladder and on the implant itself. All of these mutants were outcompeted by the wild type in coinfection experiments. Using these methods, we are able to show that type 1 and type 3 fimbriae are important colonization factors in the murine urinary tract when an implanted silicone tube is present.

Automated cell counting of astrocytes on patterned substrates containing aliphatic and charged properties

1995 ◽  
Vol 53 ◽  
pp. 974-975
Author(s):  
W. Shain ◽  
H. Ancin ◽  
H.C. Craighead ◽  
M. Isaacson ◽  
L. Kam ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Attachment ◽  
Culture Method ◽  
Cell Counting ◽  
Data Sets ◽  
Nuclear Staining ◽  
Double Positive ◽  
A Cell ◽  
Wafer Test ◽  
Cell Densities

Neural protheses have potential to restore nervous system functions lost by trauma or disease. Nanofabrication extends this approach to implants for stimulating and recording from single or small groups of neurons in the spinal cord and brain; however, tissue compatibility is a major limitation to their practical application. We are using a cell culture method for quantitatively measuring cell attachment to surfaces designed for nanofabricated neural prostheses.Silicon wafer test surfaces composed of 50-μm bars separated by aliphatic regions were fabricated using methods similar to a procedure described by Kleinfeld et al. Test surfaces contained either a single or double positive charge/residue. Cyanine dyes (diIC18(3)) stained the background and cell membranes (Fig 1); however, identification of individual cells at higher densities was difficult (Fig 2). Nuclear staining with acriflavine allowed discrimination of individual cells and permitted automated counting of nuclei using 3-D data sets from the confocal microscope (Fig 3). For cell attachment assays, LRM5 5 astroglial cells and astrocytes in primary cell culture were plated at increasing cell densities on test substrates, incubated for 24 hr, fixed, stained, mounted on coverslips, and imaged with a 10x objective.

scholarly journals The role of sialic acid in the expression of human MN blood group antigens.

1979 ◽  
Vol 254 (6) ◽  
pp. 2112-2119 ◽  
Author(s):  
J.E. Sadler ◽  
J.C. Paulson ◽  
R.L. Hill
Keyword(s):  
Sialic Acid ◽  
Blood Group ◽  
Blood Group Antigens ◽  
Mn Blood Group

A New In Vitro Model for Predicting the Toxicity of Cosmetic Products

1992 ◽  
Vol 20 (1) ◽  
pp. 138-143
Author(s):  
Maria Carrara ◽  
Lorenzo Cima ◽  
Roberto Cerini ◽  
Maurizio Dalle Carbonare
Keyword(s):  
Cell Culture ◽  
Cultured Cells ◽  
Neutral Red ◽  
Total Protein Content ◽  
Cosmetic Products ◽  
Cell Culture Insert ◽  
A Cell ◽  
Vitro Model ◽  
Cosmetic Emulsions

A method has been developed whereby cosmetic products which are not soluble in water or in alcohol can be brought into contact with cell cultures by being placed in a cell culture insert, which is then placed in the cell culture well. Preliminary experiments were carried out with L929 cells, and cytotoxicity was evaluated by measuring neutral red uptake and the total protein content of treated cultured cells. Encouraging results were obtained in comparisons of three cosmetic emulsions and of one emulsion containing a range of concentrations of two preservatives, Kathon CG and Bronopol.

scholarly journals Self-Assembling Polypeptide Hydrogels as a Platform to Recapitulate the Tumor Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3286
Author(s):  
Dariusz Lachowski ◽  
Carlos Matellan ◽  
Ernesto Cortes ◽  
Alberto Saiani ◽  
Aline F. Miller ◽  
...  
Keyword(s):  
Cell Culture ◽  
Tumor Microenvironment ◽  
Cancer Cell ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Pancreatic Cancer Cell Line ◽  
Cancer Cell Line ◽  
Culture Systems ◽  
A Cell

The tumor microenvironment plays a critical role in modulating cancer cell migration, metabolism, and malignancy, thus, highlighting the need to develop in vitro culture systems that can recapitulate its abnormal properties. While a variety of stiffness-tunable biomaterials, reviewed here, have been developed to mimic the rigidity of the tumor extracellular matrix, culture systems that can recapitulate the broader extracellular context of the tumor microenvironment (including pH and temperature) remain comparably unexplored, partially due to the difficulty in independently tuning these parameters. Here, we investigate a self-assembled polypeptide network hydrogel as a cell culture platform and demonstrate that the culture parameters, including the substrate stiffness, extracellular pH and temperature, can be independently controlled. We then use this biomaterial as a cell culture substrate to assess the effect of stiffness, pH and temperature on Suit2 cells, a pancreatic cancer cell line, and demonstrate that these microenvironmental factors can regulate two critical transcription factors in cancer: yes-associated protein 1 (YAP) and hypoxia inducible factor (HIF-1A).

scholarly journals PapRIV, a BV-2 microglial cell activating quorum sensing peptide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yorick Janssens ◽  
Nathan Debunne ◽  
Anton De Spiegeleer ◽  
Evelien Wynendaele ◽  
Marta Planas ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Model ◽  
Dependent Manner ◽  
Communication Signals ◽  
Gram Positive Bacteria ◽  
A Cell ◽  
Gastro Intestinal Tract

AbstractQuorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.

Modulation of vascular tone in renal microcirculation by erythrocytes: role of EDRF

1993 ◽  
Vol 264 (1) ◽  
pp. H190-H195 ◽  
Author(s):  
J. D. Imig ◽  
D. Gebremedhin ◽  
D. R. Harder ◽  
R. J. Roman
Keyword(s):  
Vascular Tone ◽  
Physiological Salt Solution ◽  
Nitric Oxide Synthase Inhibitor ◽  
Renal Microcirculation ◽  
Vasoconstrictor Response ◽  
A Cell ◽  
Afferent Arterioles ◽  
Synthase Inhibitor

The effect of erythrocytes (red blood cells, RBC) on vascular tone in the renal microcirculation was examined using the juxtamedullary nephron microvascular preparation perfused in vitro with a physiological salt solution containing 5% albumin. The basal diameters of the arcuate, interlobular, proximal, and distal afferent arterioles averaged 444 +/- 24, 74 +/- 3, 29 +/- 1, and 19 +/- 1 micron, respectively, when perfused with a cell-free solution at a pressure of 80 mmHg. The diameters of the arcuate and interlobular arteries increased by 14 +/- 4 and 13 +/- 4%, respectively, whereas the diameter of the proximal and distal portions of the afferent arterioles decreased by 7 +/- 2% when perfusion pressure was elevated from 80 to 160 mmHg. The addition of RBC to the perfusate reduced the basal diameters of interlobular and afferent arterioles by 11 +/- 4 and 15 +/- 3%, respectively. The maximal vasoconstrictor response was seen after the addition of only 1% RBC to the perfusate. Removal of platelets did not block the vasoconstrictor response to addition of RBC to the perfusate. The role of endothelium-derived relaxing factor (EDRF) in the vasoconstrictor response to RBC was studied by addition of nitric oxide synthase inhibitor, N omega-nitro-L-arginine (L-NNA, 100 microM) to the perfusate. L-NNA reduced the basal diameters of interlobular and afferent arterioles by 7 +/- 3 and 9 +/- 3%, respectively, and abolished the vasoconstrictor response to RBC. L-NNA had no effect on the pressure-diameter relationships of the preglomerular vasculature when added to perfusates already containing RBC.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae

2015 ◽  
Vol 60 (3) ◽  
pp. 1226-1233 ◽  
Author(s):  
Petros Ioannou ◽  
Aggeliki Andrianaki ◽  
Tonia Akoumianaki ◽  
Irene Kyrmizi ◽  
Nathaniel Albert ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cell Culture ◽  
Antifungal Agents ◽  
Fold Increase ◽  
Culture Conditions ◽  
The Other ◽  
Related Factors ◽  
Content Type

The modestin vitroactivity of echinocandins againstAspergillusimplies that host-related factors augment the action of these antifungal agentsin vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against variousAspergillusspecies under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P= 0. 0005). Importantly, the enhanced activity of caspofungin againstAspergillusspp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinatingAspergillushyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin withAspergillushyphae (P< 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery toAspergillushyphae.

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