scholarly journals Trichomonas vaginalis Lipophosphoglycan Mutants Have Reduced Adherence and Cytotoxicity to Human Ectocervical Cells

2005 ◽  
Vol 4 (11) ◽  
pp. 1951-1958 ◽  
Author(s):  
Felix D. Bastida-Corcuera ◽  
Cheryl Y. Okumura ◽  
Angie Colocoussi ◽  
Patricia J. Johnson

ABSTRACT The extracellular human pathogen Trichomonas vaginalis is covered by a dense glycocalyx thought to play a role in host-parasite interactions. The main component of the glycocalyx is lipophosphoglycan (LPG), a polysaccharide anchored in the plasma membrane by inositol phosphoceramide. To study the role of LPG in trichomonads, we produced T. vaginalis LPG mutants by chemical mutagenesis and lectin selection and characterized them using morphological, biochemical, and functional assays. Two independently selected LPG mutants, with growth rates comparable to that of the wild-type (parent) strain, lost the ability to bind the lectins Ricinnus comunis agglutinin I (RCA120) and wheat germ agglutinin, indicating alterations in surface galactose and glucosamine residues. LPG isolated from mutants migrated faster than parent strain LPG on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting the mutants had shorter LPG molecules. Dionex high-performance anion exchange chromatography with pulsed amperometric detection analyses revealed galactosamine, glucosamine, galactose, glucose, mannose/xylose, and rhamnose as the main monosaccharides of T. vaginalis parent strain LPG. LPG from both mutants showed a reduction of galactose and glucosamine, corresponding with the reduced size of their LPG molecules and inability to bind the lectins RCA120 and wheat germ agglutinin. Mutant parasites were defective in attachment to plastic, a characteristic associated with avirulent strains of T. vaginalis. Moreover, the mutants were less adherent and less cytotoxic to human vaginal ectocervical cells in vitro than the parental strain. Finally, while parent strain LPG could inhibit the attachment of parent strain parasites to vaginal cells, LPG from either mutant could not inhibit attachment. These combined results demonstrate that T. vaginalis adherence to host cells is LPG mediated and that an altered LPG leads to reduced adherence and cytotoxicity of this parasite.

2004 ◽  
Vol 72 (3) ◽  
pp. 1284-1290 ◽  
Author(s):  
Kirk J. Lubick ◽  
Donald E. Burgess

ABSTRACT Trichomonas vaginalis produces soluble factors that have been reported to have the ability to damage target cells in vitro, and it has been hypothesized that these factors may play a role in the pathogenesis of human trichomoniasis. A lytic factor (LF) was purified from T. vaginalis, and the molecular characteristics of LF were determined. T. vaginalis extract was subjected to hydrophobic chromatography with a 10 to 60% N-propanol gradient in 0.1 M ammonium acetate, resulting in the elution of LF from the column at 30% N-propanol. Cytotoxicity assays revealed that LF was cytotoxic to WEHI 164 cells and bovine red blood cells, and inactivation of LF by treatment with trypsin suggested that the active component of LF was a protein. Size exclusion chromatography of LF produced two fractions at 144 and 168 kDa, and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of LF under reducing conditions revealed two subunits of 57 and 60 kDa. Results of a fluorescence assay of LF on carboxyfluorescein-labeled liposomes composed of phosphatidylcholine-cholesterol showed that liposomes were hydrolyzed, suggesting that LF had phospholipase activity. Thin-layer chromatography analysis of BODIPY (4,4-difluoro-3a,4adiaza-s-indacene)-labeled phosphatidylcholine treated with LF demonstrated products that migrated identically to the products produced by treatment with phospholipase A2 (PLA2). These results suggest that LF is a PLA2 and may be an important virulence factor of T. vaginalis mediating the destruction of host cells and contributing to tissue damage and inflammation in trichomoniasis.


1978 ◽  
Vol 79 (1) ◽  
pp. 132-137 ◽  
Author(s):  
G Mintz ◽  
L Glaser

After separation of whole proteins of chick neural retina by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS), a number of glycoproteins can be detected by staining the gels with 125I-labeled wheat germ agglutinin (WGA) and other lectins. The glycoprotein patterns show both quantitative and qualitative changes between days 7 and 13 of development. Some of these glycoproteins can be separated by chromatography on columns of insolubilized lectins. These observations suggest that purification of some of these glycoproteins identified by staining with radioactive lectins would yield retinal antigens which may be specific for developmental stage and cell type.


1976 ◽  
Vol 71 (2) ◽  
pp. 606-623 ◽  
Author(s):  
A Lernmark ◽  
A Nathans ◽  
D F Steiner

Methods have been developed for the isolation on a semi-micro scale of a plasma membrane-enriched fraction from rat islets of Langerhans. An important feature of these experiments is the use of 125I-labeled wheat germ agglutinin as a specific probe for plasma membrane-containing fractions. The partly purified plasma membrane fraction had a density in sucrose of about 1.10 and was enriched in the activities of 5'-nucleotidase, alkaline phosphatase, sodium-potassium, and magnesium-dependent ATPase and adenylate cyclase. It contained only very low levels of acid phosphatase, cytochrome c oxidase, insulin, and RNA. Further purification was hampered by the relatively small amounts of fresh plasma membrane material that could be obtained from 16-24 rats in each experiment. When islets were prelabeled with radioactive fucose, the plasma membrane-enriched fraction contained radioactivity at a four- to fivefold higher specific acivity than the whole islet homogenate. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis of plasma membrane-enriched fractions pooled from several experiments revealed a distinctive pattern of protein bands as compared with other less pure fractions. With respect to rapidity, apparent specificity, and easy reversibility of the labeling of the plasma membrane fraction, 125I-wheat germ agglutinin provides a highly useful tool for the detection of microgram quantities of plasma membrane components which should be applicable to many other systems as well.


1990 ◽  
Vol 68 (4) ◽  
pp. 699-704 ◽  
Author(s):  
Yuzuru Kubohara ◽  
Koji Okamoto

A new stalk-specific wheat germ agglutinin (WGA) binding protein, wst34, has been identified in Dictyostelium discoideum and purified by the use of preparative sodium dodecyl sulfate - polyacrylamide gel electrophoresis and a WGA-affinity column. In normal development, wst34 appears during culmination and is maintained in stalk cells. It has a molecular mass of 34 kilodaltons and a pI value of 5.5–6.5. A polyclonal antiserum raised against stalk cell proteins of Dictyostelium mucoroides recognizes wst34 in western blots of D. discoideum proteins.Key words: Dictyostelium discoideum, Dictyostelium mucoroides, wheat germ agglutinin.


1982 ◽  
Vol 58 (1) ◽  
pp. 23-33
Author(s):  
R.L. Shoeman ◽  
H.G. Schweiger

Modification of existing two-dimensional techniques enables isoelectric focusing and sodium dodecyl sulphate polyacrylamide gel electrophoresis of complex mixtures of proteins to be completed within 8 h. The method was optimized to separate the protein components of a wheat germ cell-free translation system, providing a statistically proven resolution better than 0. 03 of a pH unit for the isoelectric point and 1000 for Mr. Fourteen of the more than 300 proteins separated were characterized with respect to Mr and isoelectric point relative to standard proteins under the same conditions. Stained wheat germ proteins thus serve as internal standards for analysis of in vitro translation products.


1999 ◽  
Vol 65 (3) ◽  
pp. 1348-1351 ◽  
Author(s):  
Renato Tarsi ◽  
Carla Pruzzo

ABSTRACT The role of surface proteins in Vibrio choleraeattachment to chitin particles in vitro was studied. Treatment ofV. cholerae O1 ATCC 14034 and ATCC 14035 with pronase E reduced the attachment of bacteria to chitin particles by 57 to 77%. A statistically significant reduction was also observed when the attachment to chitin was evaluated in the presence of homologous Sarkosyl-insoluble membrane proteins (MPs) (67 to 84%),N-acetylglucosamine (GlcNAc) (62%), the sugar that makes up chitin, and wheat germ agglutinin (40 to 56%), a lectin that binds GlcNAc. The soluble oligomersN,N′-diacetylchitobiose orN,N′,N"-triacetylchitotriose caused an inhibition of 14 to 23%. Sarkosyl-insoluble MPs able to bind chitin particles were isolated and visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; two of these peptides (molecular sizes, 36 and 53 kDa) specifically bind GlcNAc.


1991 ◽  
Vol 69 (4) ◽  
pp. 282-290 ◽  
Author(s):  
Darren D. Browning ◽  
Danton H. O'Day

To determine which glycoproteins may be critical to sexual development in Dictyostelium discoideum, cell samples from different developmental stages were separated by sodium dodecyl sulfate – polyacrylamide gel electrophoresis and blotted to nitrocellulose. Concanavalin A (ConA) and wheat germ agglutinin (WGA) binding proteins were visualized on the blots using an immunochemical procedure employing peroxidase–antiperoxidase. ConA labelled at least 28 proteins, but only one band showed calcium-dependent changes in its expression. WGA bound at least 30 proteins and changes in several bands were observed that did not occur in calcium-deficient controls. Two WGA-binding glycoproteins which migrated at 200 and 166 kilodaltons (kDa), respectively, showed developmental changes associated with the time of cell fusion. One WGA-binding and one ConA-binding glycoprotein migrating at 130 and 126 kDa, respectively, appeared later during sexual development, in association with the phase of zygote differentiation. Several WGA- and ConA-binding glycoproteins decreased during sexual development, but were not affected by the absence of calcium ions. Tunicamycin (1 μg/mL) inhibited cell fusion when added to sexual cultures prior to the appearance of the 166-kDa glycoprotein gp166. The effects of this inhibitor on development support the importance of glycoproteins to cell fusion during sexual development in D. discoideum.Key words: Dictyostelium, cell fusion, glycoprotein, tunicamycin, concanavalin A, wheat germ agglutinin, calcium.


1978 ◽  
Vol 175 (3) ◽  
pp. 841-852 ◽  
Author(s):  
R D Andersen ◽  
U Weser

Poly(A)+ (polyadenylated) mRNA coding for metallothioneins was purified 13-fold from rat liver polyribosomes and was identified by its ability to direct the biosynthesis of these proteins in a wheat-germ cell-free system. The carboxymethylated products of the protein-synthesizing system in vitro were analysed with sodium dodecyl sulphate/20% polyacrylamide-gel electrophoresis. The labelled compounds [3H]serine and [35S]cysteine were incorporated at high specific radioactivity into proteins that co-migrated with authentic metallothioneins. No [3H]leucine incorporation was found, in agreement with the amino acid composition of the metallothioneins. Metallothionein mRNA had a sedimentation coefficient of 9 S and carried a maximum of four ribosomes. At 5 h after a subcutaneous injection of ZnCl2 or CdCl2 (10 mumol/kg body wt.), the amount of this mRNA increased approx. 2- and 4-fold respectively, on the basis of translation in vitro. The increase in metallothionein mRNA (defined by translation in the wheat-germ system) was transient and, after CdCl2 treatment, fell back to control values by 17 h. Metallothioneins constituted a maximum of 0.8% of the total protein products synthesized in the wheat-germ system by total mRNA isolated from rat liver after CdCl2 treatment.


2021 ◽  
Vol 12 ◽  
pp. 204173142098752
Author(s):  
Nadiah S Sulaiman ◽  
Andrew R Bond ◽  
Vito D Bruno ◽  
John Joseph ◽  
Jason L Johnson ◽  
...  

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.


1982 ◽  
Vol 2 (4) ◽  
pp. 412-425 ◽  
Author(s):  
S I Reed ◽  
J Ferguson ◽  
J C Groppe

The CDC28 gene was subcloned from a plasmid containing a 6.5-kilobase-pair segment of Saccharomyces cerevisiae DNA YRp7(CDC28-3) by partial digestion with Sau3A and insertion of the resulting fragments into the BamHI sites of YRp7 and pRC1. Recombinant plasmids were obtained containing inserts of 4.4 and 3.1 kilobase pairs which were capable of complementing a cdc28(ts) mutation. R-loop analysis indicated that each yeast insert contained two RNA coding regions of about 0.8 and 1.0 kilobase pairs, respectively. In vitro mutagenesis experiments suggested that the smaller coding region corresponded to the CDC28 gene. When cellular polyadenylic acid-containing RNA, separated by agarose gel electrophoresis after denaturation with glyoxal and transferred to nitrocellulose membrane, was reacted with labeled DNA from the smaller coding region, and RNA species of about 1 kilobase in length was detected. Presumably, the discrepancy in size between the R-loop and electrophoretic determinations is due to a segment of polyadenylic acid which is excluded from the R-loops. By using hybridization of the histone H2B mRNAs to an appropriate probe as a previously determined standards, it was possible to estimate the number of CDC28 mRNA copies per haploid cell as between 6 and 12 molecules. Hybrid release translation performed on the CDC29 mRNA directed the synthesis of a polypeptide of 27,000 daltons, as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. This polypeptide was not synthesized when mRNA prepared from a cdc28 nonsense mutant was translated in a parallel fashion. However, if the RNA from a cell containing the CDC28 gene on a plasmid maintained at a high copy number was translated, the amount of in vitro product was amplified fivefold.


Sign in / Sign up

Export Citation Format

Share Document