Chlorate: a reversible inhibitor of proteoglycan sulphation in Chlamydia trachomatis-infected cells

2004 ◽  
Vol 53 (2) ◽  
pp. 93-95 ◽  
Author(s):  
Sanaa Fadel ◽  
Adrian Eley
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Chlamydial Infection ◽  
Heparan Sulphate ◽  
Sodium Chlorate ◽  
Inhibitory Effect ◽  
Host Cells ◽  
Reversible Inhibitor ◽  
Sulphated Glycosaminoglycans ◽  
Necessary And Sufficient

Sulphated glycosaminoglycans, such as heparan sulphate, have been shown to be essential for the infectivity of many organisms. The aims of this study were to verify the role of sulphated glycosaminoglycans in chlamydial infection and to investigate whether they are present on chlamydia or chlamydial host cells. The effect of undersulphation of host cells and chlamydial elementary bodies was examined using sodium chlorate. Also studied was whether any inhibitory effect was reversible. The results strongly suggest that Chlamydia trachomatis does not produce heparan sulphate and that heparan sulphate of the host cell is necessary and sufficient to mediate chlamydial infection. The essential role played by the sulphate constituents of the host-cell glycosaminoglycan in the infectivity of LGV serovars, and to a lesser extent of serovar E, was also confirmed.

scholarly journals The Hypothetical Protein CT813 Is Localized in the Chlamydia trachomatis Inclusion Membrane and Is Immunogenic in Women Urogenitally Infected with C. trachomatis

2006 ◽  
Vol 74 (8) ◽  
pp. 4826-4840 ◽  
Author(s):  
Chaoqun Chen ◽  
Ding Chen ◽  
Jyotika Sharma ◽  
Wen Cheng ◽  
Youmin Zhong ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Fusion Proteins ◽  
Chlamydial Infection ◽  
Natural Infection ◽  
Hypothetical Protein ◽  
Growth Cycle ◽  
Host Cells ◽  
Inclusion Membrane ◽  
Urogenital Infection

ABSTRACT Using antibodies raised with chlamydial fusion proteins, we have localized a protein encoded by hypothetical open reading frame CT813 in the inclusion membrane of Chlamydia trachomatis. The detection of the C. trachomatis inclusion membrane by an anti-CT813 antibody was blocked by the CT813 protein but not unrelated fusion proteins. The CT813 protein was detected as early as 12 h after chlamydial infection and was present in the inclusion membrane during the entire growth cycle. All tested serovars from C. trachomatis but not other chlamydial species expressed the CT813 protein. Exogenously expressed CT813 protein in HeLa cells displayed a cytoskeleton-like structure similar to but not overlapping with host cell intermediate filaments, suggesting that the CT813 protein is able to either polymerize or associate with host cell cytoskeletal structures. Finally, women with C. trachomatis urogenital infection developed high titers of antibodies to the CT813 protein, demonstrating that the CT813 protein is not only expressed but also immunogenic during chlamydial infection in humans. In all, the CT813 protein is an inclusion membrane protein unique to C. trachomatis species and has the potential to interact with host cells and induce host immune responses during natural infection. Thus, the CT813 protein may represent an important candidate for understanding C. trachomatis pathogenesis and developing intervention and prevention strategies for controlling C. trachomatis infection.

scholarly journals Fluorescence-Reported Allelic Exchange Mutagenesis-Mediated Gene Deletion Indicates a Requirement for Chlamydia trachomatis Tarp during In Vivo Infectivity and Reveals a Specific Role for the C Terminus during Cellular Invasion

2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Susmita Ghosh ◽  
Elizabeth A. Ruelke ◽  
Joshua C. Ferrell ◽  
Maria D. Bodero ◽  
Kenneth A. Fields ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Host Cells ◽  
Actin Binding ◽  
Wild Type ◽  
Content Type ◽  
Allelic Exchange ◽  
Binding Domains

ABSTRACT The translocated actin recruiting phosphoprotein (Tarp) is a multidomain type III secreted effector used by Chlamydia trachomatis. In aggregate, existing data suggest a role of this effector in initiating new infections. As new genetic tools began to emerge to study chlamydial genes in vivo, we speculated as to what degree Tarp function contributes to Chlamydia’s ability to parasitize mammalian host cells. To address this question, we generated a complete tarP deletion mutant using the fluorescence-reported allelic exchange mutagenesis (FRAEM) technique and complemented the mutant in trans with wild-type tarP or mutant tarP alleles engineered to harbor in-frame domain deletions. We provide evidence for the significant role of Tarp in C. trachomatis invasion of host cells. Complementation studies indicate that the C-terminal filamentous actin (F-actin)-binding domains are responsible for Tarp-mediated invasion efficiency. Wild-type C. trachomatis entry into HeLa cells resulted in host cell shape changes, whereas the tarP mutant did not. Finally, using a novel cis complementation approach, C. trachomatis lacking tarP demonstrated significant attenuation in a murine genital tract infection model. Together, these data provide definitive genetic evidence for the critical role of the Tarp F-actin-binding domains in host cell invasion and for the Tarp effector as a bona fide C. trachomatis virulence factor.

scholarly journals Chlamydia-Infected Cells Continue To Undergo Mitosis and Resist Induction of Apoptosis

2004 ◽  
Vol 72 (1) ◽  
pp. 451-460 ◽  
Author(s):  
Whitney Greene ◽  
Yangming Xiao ◽  
Yanqing Huang ◽  
Grant McClarty ◽  
Guangming Zhong
Keyword(s):  
Dna Synthesis ◽  
Host Cell ◽  
Chlamydial Infection ◽  
Host Cells ◽  
Infected Host ◽  
Apoptosis Induction ◽  
Infected Cells ◽  
Induction Of Apoptosis

ABSTRACT Both anti- and proapoptotic activities have been reported to occur during chlamydial infection. To reconcile the apparent controversy, we compared host cell apoptotic responses to infection with 17 different chlamydial serovars and strains. None of the serovars caused any biologically significant apoptosis in the infected host cells. Host cells in chlamydia-infected cultures can continue to undergo DNA synthesis and mitosis. Chlamydia-infected cells are resistant to apoptosis induction, although the extent of the antiapoptotic ability varied between serovars. These observations have demonstrated that an anti- but not proapoptotic activity is the prevailing event in chlamydia-infected cultures.

scholarly journals Interaction of Chlamydia trachomatis with Mammalian Cells Is Independent of Host Cell Surface Heparan Sulfate Glycosaminoglycans

2006 ◽  
Vol 74 (3) ◽  
pp. 1795-1799 ◽  
Author(s):  
Richard S. Stephens ◽  
Jesse M. Poteralski ◽  
Lynn Olinger
Keyword(s):  
Chlamydia Trachomatis ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Host Cell ◽  
Cell Line ◽  
Mammalian Cells ◽  
Chlamydial Infection ◽  
Functional Role ◽  
A Cell ◽  
Host Cell Surface

ABSTRACT The hypothesis that host cell surface heparan sulfate is required to promote chlamydial infection was tested using a cell line (CHO-18.4) containing a single retroviral insertion and the concomitant loss of heparan sulfate biosynthesis. Tests of chlamydial infectivity of heparan sulfate-deficient CHO-18.4 cells and parental cells, CHO-22, demonstrated that both were equally sensitive to infection by Chlamydia trachomatis serovars L2 and D. These data do not support the hypothesis and demonstrate that host cell surface heparan sulfate does not serve an essential functional role in chlamydial infectivity.

scholarly journals Regulation of heparan sulphate metabolism by adenosine 3′:5′-cyclic monophosphate in hepatocytes in culture

1980 ◽  
Vol 192 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Perumana R. Sudhakaran ◽  
Wolfgang Sinn ◽  
Kurt von Figura
Keyword(s):  
Cyclic Amp ◽  
Heparan Sulphate ◽  
Molecular Size ◽  
Rat Hepatocytes ◽  
Inhibitory Effect ◽  
Dibutyryl Cyclic Amp ◽  
Isolated Rat Hepatocytes ◽  
Intracellular Compartments ◽  
Sulphated Glycosaminoglycans ◽  
Chain Synthesis

Freshly isolated rat hepatocytes maintained as monolayers in a serum-free medium synthesize sulphated glycosaminoglycans, most of which behave as heparan sulphate and are mainly distributed into intracellular compartments. Cyclic AMP, dibutyryl cyclic AMP, glucagon, noradrenaline, prostaglandin E1, and theophylline, all drugs and hormones known to increase intracellular cyclic AMP concentrations, decreased the incorporation of 35SO42− into heparan sulphate of intra-, extra- and peri-cellular pools. The inhibition mediated by dibutyryl cyclic AMP was dose-dependent and observed as early as 2h after exposure to the drug. In the presence of 1mm-dibutyryl cyclic AMP, incorporation of 35SO42− or [14C]glucosamine into heparan sulphate was decreased to 40–50%, suggesting that dibutyryl cyclic AMP interfered with the synthesis of heparan sulphate. This was further supported by pulse–chase experiments, where dibutyryl cyclic AMP had no effect on the degradation of sulphated glycosaminoglycans. Heparan sulphates synthesized and secreted into the extracellular pool in the presence of dibutyryl cyclic AMP were smaller in size, whereas the degree of sulphation and molecular size of the heparan sulphate chains released by β-elimination from these proteoglycans were not different from control values. In the presence of 1mm-cycloheximide, 35SO42− incorporation was decreased to 5%. Addition of p-nitrophenyl β-d-xyloside, an artificial acceptor of glycosaminoglycan chain synthesis, enhanced this incorporation to 18%. Dibutyryl cyclic AMP did not have any inhibitory effect on the synthesis of chains initiated on p-nitrophenyl β-d-xylosides. Incorporation of [3H]serine into heparan sulphate was not affected by dibutyryl cyclic AMP, whereas the degree of substitution of serine residues with heparan sulphate chains was less in heparan sulphate synthesized in the presence of dibutyryl cyclic AMP, suggesting that cyclic AMP exerts its effect on the metabolism of sulphated glycosaminoglycans by affecting the transfer of xylose on to the protein core.

scholarly journals Host cell amplification of nutritional stress contributes to persistence in Chlamydia trachomatis

2021 ◽  
Author(s):  
Nick D. Pokorzynski ◽  
REY CARABEO
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
De Novo ◽  
Host Cells ◽  
Guanine Nucleotide ◽  
Nucleotide Synthesis ◽  
Rate Limiting Step ◽  
Metabolic Consequence ◽  
Rate Limiting ◽  
Insight Into

Persistence, a viable, but non-replicating state has been implicated in diseases caused by Chlamydia trachomatis. Multiple nutritional stressors produce a superficially similar "persistent" state, yet no systematic comparison has been made to determine their likeness. We employed host-pathogen dual RNA-sequencing under both iron- and tryptophan-starved conditions to gain insight into chlamydial persistence and identify contributions by the host cell. Analysis of the transcriptome of iron- or tryptophan-starved Chlamydia revealed a common "core" component and a stress-specific "accessory" subset. Despite the overall transcriptomic differences of host cells starved for either iron or tryptophan, both stressors induced persistence. A common metabolic consequence of the stressors was a reduction in intracellular GTP levels. Mizoribine inhibition of IMDPH1, which catalyzes the rate-limiting step in de novo guanine nucleotide synthesis reproduced to a similar extent GTP depletion, and inhibited chlamydial growth as expected for a pathogen that is auxotrophic for GTP. Thus, the reduction of guanine nucleotide synthesis manifests amplification of either iron or tryptophan starvation contributing to persistence. These findings illustrate that a nutritionally stressed host cell remains effective in arresting growth of Chlamydia by targeting metabolic pathways required by the pathogen.

scholarly journals Long-Term Episomal Maintenance of Bovine Papillomavirus Type 1 Plasmids Is Determined by Attachment to Host Chromosomes, Which Is Mediated by the Viral E2 Protein and Its Binding Sites

1999 ◽  
Vol 73 (5) ◽  
pp. 4404-4412 ◽  
Author(s):  
Ivar Ilves ◽  
Sirje Kivi ◽  
Mart Ustav
Keyword(s):  
Host Cell ◽  
Binding Sites ◽  
Regulatory Region ◽  
Host Cells ◽  
Bovine Papillomavirus ◽  
E2 Protein ◽  
Multiple Binding Sites ◽  
Stable Maintenance ◽  
Necessary And Sufficient

ABSTRACT Papillomavirus genomes are stably maintained as extrachromosomal nuclear plasmids in dividing host cells. To address the mechanisms responsible for stable maintenance of virus, we examined nuclear compartmentalization of plasmids containing the full-length upstream regulatory region (URR) from the bovine papillomavirus type 1 (BPV1) genome. We found that these plasmids are tightly associated with the nuclear chromatin both in the stable cell lines that maintain episomal copies of the plasmids and in transiently transfected cells expressing the viral E1 and E2 proteins. Further analysis of viral factors revealed that the E2 protein in trans and its multiple binding sites in cis are both necessary and sufficient for the chromatin attachment of the plasmids. On the other hand, the BPV1 URR-dependent plasmid replication and chromatin attachment processes are clearly independent of each other. The ability of the plasmids to stably maintain episomes correlates clearly with their chromatin association function. These data suggest that viral E2 protein-mediated attachment of BPV1 genomes to the host cell chromatin could provide a mechanism for the coupling of viral genome multiplication and partitioning to the host cell cycle during viral latent infection.

scholarly journals Rottlerin Inhibits Chlamydial Intracellular Growth and Blocks Chlamydial Acquisition of Sphingolipids from Host Cells

2007 ◽  
Vol 74 (4) ◽  
pp. 1243-1249 ◽  
Author(s):  
Pooja Shivshankar ◽  
Lei Lei ◽  
Jie Wang ◽  
Guangming Zhong
Keyword(s):  
Host Cell ◽  
Chlamydial Infection ◽  
Host Factors ◽  
Host Cells ◽  
Potential Mechanism ◽  
Infection Cycle ◽  
Intracellular Growth ◽  
Minimal Inhibition Concentration ◽  
Middle Stage ◽  
Inhibition Concentration

ABSTRACT We report that rottlerin, a plant-derived compound known to inhibit various mammalian kinases, profoundly inhibited chlamydial growth in cell culture with a minimal inhibition concentration of 1 μM. The inhibition was effective even when rottlerin was added as late as the middle stage of chlamydial infection cycle, against multiple Chlamydia species, and in different host cell lines. Pretreatment of host cells with rottlerin prior to infection also blocked chlamydial growth, suggesting that rottlerin targets host factors. Moreover, rottlerin did not alter the chlamydial infection rate and did not directly target chlamydial protein synthesis and secretion. The rottlerin-mediated inhibition of chlamydial replication and inclusion expansion correlated well with the rottlerin-induced blockade of host cell sphingolipid trafficking from the Golgi apparatus into chlamydial inclusions. These studies not only allowed us to identify a novel antimicrobial activity for rottlerin but also allowed us to uncover a potential mechanism for rottlerin inhibition of chlamydial growth.

scholarly journals A Novel Cleavage Pattern of Complement C5 Induced by Chlamydia trachomatis Infection via the Chlamydial Protease CPAF

2022 ◽  
Vol 11 ◽  
Author(s):  
Liang Peng ◽  
Jingping Gao ◽  
Zihao Hu ◽  
Hongbo Zhang ◽  
Lingli Tang ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Serine Protease ◽  
Chlamydial Infection ◽  
Inhibitory Effect ◽  
Cleavage Pattern ◽  
Potential Therapeutic Target ◽  
Chlamydia Trachomatis Infection ◽  
Sexually Transmitted ◽  
Strong Inhibitory Effect ◽  
Nafamostat Mesylate

Urogenital Chlamydia trachomatis infection is one of the most common bacterial sexually transmitted diseases globally. Untreated C. trachomatis infections can ascend to the upper genital tract and establish a series of severe complications. Previous studies using C3−/− and C5−/− mice models demonstrated that C3-independent activation of C5 occurred during C. trachomatis infection. However, the mechanism of how chlamydial infection activates C5 in the absence of C3 has yet to be elucidated. To delineate interactions between C5 and chlamydial infection, cleavage products in a co-incubation system containing purified human C5 and C. trachomatis-HeLa229 cell lysates were analyzed, and a novel cleavage pattern of C5 activation induced by C. trachomatis infection was identified. C5 was cleaved efficiently at the previously unidentified site K970, but was cleaved poorly at site R751. C5b was modified to C5bCt, which later formed C5bCt-9, which had enhanced lytic ability compared with C5b-9. The chlamydial serine protease CPAF contributed to C3-independent C5 activation during C. trachomatis infection. Nafamostat mesylate, a serine protease inhibitor with a good safety profile, had a strong inhibitory effect on C5 activation induced by chlamydial infection. These discoveries reveal the mechanism of C3-independent C5 activation induced by chlamydial infection, and furthermore provide a potential therapeutic target and drug for preventing tubal fibrosis caused by chlamydial infection.

scholarly journals Differential glycosaminoglycan binding of Chlamydia trachomatis OmcB protein from serovars E and LGV

2008 ◽  
Vol 57 (9) ◽  
pp. 1058-1061 ◽  
Author(s):  
Sanaa Fadel ◽  
Adrian Eley
Keyword(s):  
Escherichia Coli ◽  
Chlamydia Trachomatis ◽  
Heparan Sulphate ◽  
Significant Inhibition ◽  
Host Cells ◽  
Wild Type ◽  
E Coli ◽  
Dependent Mechanism

We recently showed that OmcB protein from Chlamydia trachomatis serovar LGV1 functions as an adhesin. In this study, we produced Escherichia coli expressing OmcB from serovar E and compared this OmcB to OmcB from serovar LGV1. Infectivity inhibition assays carried out with serovars LGV1 and E of C. trachomatis in the presence of recombinant OmcB showed considerable (∼60 %) inhibition of infectivity. In the presence of heparan sulphate, there was significant inhibition (68 %) of adherence of E. coli expressing OmcB from serovar LGV1 only. In a further experiment, recombinant OmcB from serovar LGV1 showed minimal binding to glycosaminoglycan (GAG)-deficient cells, whilst to the same cells, recombinant OmcB from serovar E showed binding equal to that to the wild-type cells. Our experiments strongly suggest that OmcB from serovar E, in contrast to that from serovar LGV1, is not binding to host cells through a GAG-dependent mechanism.

Sign in / Sign up

Export Citation Format

Share Document