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.

scholarly journals Initial Characterization of the Two ClpP Paralogs ofChlamydia trachomatisSuggests Unique Functionality for Each

2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Nicholas A. Wood ◽  
Krystal Y. Chung ◽  
Amanda M. Blocker ◽  
Nathalia Rodrigues de Almeida ◽  
Martin Conda-Sheridan ◽  
...  
Keyword(s):  
Host Cells ◽  
Developmental Cycle ◽  
Intracellular Bacteria ◽  
Clp Protease ◽  
Content Type ◽  
Sexually Transmitted ◽  
Obligate Intracellular ◽  
Developmental Form ◽  
Obligate Intracellular Bacteria

ABSTRACTMembers ofChlamydiaare obligate intracellular bacteria that differentiate between two distinct functional and morphological forms during their developmental cycle, elementary bodies (EBs) and reticulate bodies (RBs). EBs are nondividing small electron-dense forms that infect host cells. RBs are larger noninfectious replicative forms that develop within a membrane-bound vesicle, termed an inclusion. Given the unique properties of each developmental form of this bacterium, we hypothesized that the Clp protease system plays an integral role in proteomic turnover by degrading specific proteins from one developmental form or the other.Chlamydiaspp. have five uncharacterizedclpgenes,clpX,clpC, twoclpPparalogs, andclpB. In other bacteria, ClpC and ClpX are ATPases that unfold and feed proteins into the ClpP protease to be degraded, and ClpB is a deaggregase. Here, we focused on characterizing the ClpP paralogs. Transcriptional analyses and immunoblotting determined that these genes are expressed midcycle. Bioinformatic analyses of these proteins identified key residues important for activity. Overexpression of inactiveclpPmutants inChlamydiaspp. suggested independent function of each ClpP paralog. To further probe these differences, we determined interactions between the ClpP proteins using bacterial two-hybrid assays and native gel analysis of recombinant proteins. Homotypic interactions of the ClpP proteins, but not heterotypic interactions between the ClpP paralogs, were detected. Interestingly, protease activity of ClpP2, but not ClpP1, was detectedin vitro. This activity was stimulated by antibiotics known to activate ClpP, which also blocked chlamydial growth. Our data suggest the chlamydial ClpP paralogs likely serve distinct and critical roles in this important pathogen.IMPORTANCEChlamydia trachomatisis the leading cause of preventable infectious blindness and of bacterial sexually transmitted infections worldwide. Chlamydiae are developmentally regulated obligate intracellular pathogens that alternate between two functional and morphologic forms, with distinct repertoires of proteins. We hypothesize that protein degradation is a critical aspect to the developmental cycle. A key system involved in protein turnover in bacteria is the Clp protease system. Here, we characterized the two chlamydial ClpP paralogs by examining their expression inChlamydiaspp., their ability to oligomerize, and their proteolytic activity. This work will help understand the evolutionarily diverse Clp proteases in the context of intracellular organisms, which may aid in the study of other clinically relevant intracellular bacteria.

scholarly journals Characterization of a Chlamydia psittaciDNA Binding Protein (EUO) Synthesized during the Early and Middle Phases of the Developmental Cycle

1998 ◽  
Vol 66 (3) ◽  
pp. 1167-1173 ◽  
Author(s):  
Li Zhang ◽  
Annemarie L. Douglas ◽  
Thomas P. Hatch
Keyword(s):  
Promoter Region ◽  
Chlamydia Psittaci ◽  
Host Cells ◽  
Upstream Open Reading Frame ◽  
Developmental Cycle ◽  
Binding Property ◽  
Logarithmic Growth Phase ◽  
Reading Frame

ABSTRACT The EUO gene (for early upstream open reading frame) ofChlamydia psittaci was previously found to be transcribed better at 1 than at 24 h postinfection. We found that the EUO gene encodes a minor protein that is expressed within 1 h of infection of host cells with C. psittaci 6BC but that protein quantity peaks during the logarithmic growth phase of reticulate bodies (RBs), declines late in the infection (after 20 h) when RBs reorganize into elementary bodies (EBs), and is absent in infectious EBs. EUO protein lacks homology to known proteins but does contain a putative helix-turn-helix motif. We found that recombinant EUO binds to DNA in vitro with a relatively broad specificity. Using the bp −200 to +67 promoter region of the cysteine-rich envelope protein (crp) operon as a model, we show that EUO protein preferentially binds to AT-rich sequences and protects crpDNA from DNase I from approximately bp −60 to −9. We also found that native EUO protein in extracts of RBs binds to the promoter region of the crp operon, demonstrating that the DNA binding property of EUO protein is not an artifact of recombinant methods. Although EUO protein appears to bind to the crp operon with high affinity in vitro (Kd of about 15 nM), it is not known whether the protein binds the crp DNA in vivo.

scholarly journals Efficacy of Guanabenz Combination Therapy against Chronic Toxoplasmosis across Multiple Mouse Strains

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Jennifer Martynowicz ◽  
J. Stone Doggett ◽  
William J. Sullivan
Keyword(s):  
Limit Of Detection ◽  
Acute Infection ◽  
Antagonistic Effect ◽  
Mouse Strains ◽  
Chronic Infections ◽  
Content Type ◽  
Brain Cyst ◽  
The Brain

ABSTRACT Toxoplasma gondii, an obligate intracellular parasite that can cause life-threatening acute disease, differentiates into a quiescent cyst stage to establish lifelong chronic infections in animal hosts, including humans. This tissue cyst reservoir, which can reactivate into an acute infection, is currently refractory to clinically available therapeutics. Recently, we and others have discovered drugs capable of significantly reducing the brain cyst burden in latently infected mice, but not to undetectable levels. In this study, we examined the use of novel combination therapies possessing multiple mechanisms of action in mouse models of latent toxoplasmosis. Our drug regimens included combinations of pyrimethamine, clindamycin, guanabenz, and endochin-like quinolones (ELQs) and were administered to two different mouse strains in an attempt to eradicate brain tissue cysts. We observed mouse strain-dependent effects with these drug treatments: pyrimethamine-guanabenz showed synergistic efficacy in C57BL/6 mice yet did not improve upon guanabenz monotherapy in BALB/c mice. Contrary to promising in vitro results demonstrating toxicity to bradyzoites, we observed an antagonistic effect between guanabenz and ELQ-334 in vivo. While we were unable to completely eliminate the brain cyst burden, we found that a combination treatment with ELQ-334 and pyrimethamine impressively reduced the brain cyst burden by 95% in C57BL/6 mice, which approached the limit of detection. These analyses highlight the importance of evaluating anti-infective drugs in multiple mouse strains and will help inform further preclinical studies of cocktail therapies designed to treat chronic toxoplasmosis.

scholarly journals Deletion of the Mycobacterium tuberculosis Resuscitation-Promoting Factor Rv1009 Gene Results in Delayed Reactivation from Chronic Tuberculosis

2006 ◽  
Vol 74 (5) ◽  
pp. 2985-2995 ◽  
Author(s):  
JoAnn M. Tufariello ◽  
Kaixia Mi ◽  
Jiayong Xu ◽  
Yukari C. Manabe ◽  
Anup K. Kesavan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Human Population ◽  
Acute Infection ◽  
Dependent Manner ◽  
Survival Times ◽  
Chronic Infections ◽  
Synthase Inhibitor

ABSTRACT Approximately one-third of the human population is latently infected with Mycobacterium tuberculosis, comprising a critical reservoir for disease reactivation. Despite the importance of latency in maintaining M. tuberculosis in the human population, little is known about the mycobacterial factors that regulate persistence and reactivation. Previous in vitro studies have implicated a family of five related M. tuberculosis proteins, called resuscitation promoting factors (Rpfs), in regulating mycobacterial growth. We studied the in vivo role of M. tuberculosis rpf genes in an established mouse model of M. tuberculosis persistence and reactivation. After an aerosol infection with the M. tuberculosis Erdman wild type (Erdman) or single-deletion rpf mutants to establish chronic infections in mice, reactivation was induced by administration of the nitric oxide (NO) synthase inhibitor aminoguanidine. Of the five rpf deletion mutants tested, one (ΔRv1009) exhibited a delayed reactivation phenotype, manifested by delayed postreactivation growth kinetics and prolonged median survival times among infected animals. Immunophenotypic analysis suggested differences in pulmonary B-cell responses between Erdman- and ΔRv1009-infected mice at advanced stages of reactivation. Analysis of rpf gene expression in the lungs of Erdman-infected mice revealed that relative expression of four of the five rpf-like genes was diminished at late times following reactivation, when bacterial numbers had increased substantially, suggesting that rpf gene expression may be regulated in a growth phase-dependent manner. To our knowledge, ΔRv1009 is the first M. tuberculosis mutant to have a specific defect in reactivation without accompanying growth defects in vitro or during acute infection in vivo.

scholarly journals p47 GTPases Regulate Toxoplasma gondii Survival in Activated Macrophages

2005 ◽  
Vol 73 (6) ◽  
pp. 3278-3286 ◽  
Author(s):  
Barbara A. Butcher ◽  
Robert I. Greene ◽  
Stanley C. Henry ◽  
Kimberly L. Annecharico ◽  
J. Brice Weinberg ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Acute Infection ◽  
Host Cells ◽  
Intracellular Growth ◽  
Latex Beads ◽  
Cellular Factors ◽  
Ifn Γ ◽  
Normal Inhibition

ABSTRACT The cytokine gamma interferon (IFN-γ) is critical for resistance to Toxoplasma gondii. IFN-γ strongly activates macrophages and nonphagocytic host cells to limit intracellular growth of T. gondii; however, the cellular factors that are required for this effect are largely unknown. We have shown previously that IGTP and LRG-47, members of the IFN-γ-regulated family of p47 GTPases, are required for resistance to acute T. gondii infections in vivo. In contrast, IRG-47, another member of this family, is not required. In the present work, we addressed whether these GTPases are required for IFN-γ-induced suppression of T. gondii growth in macrophages in vitro. Bone marrow macrophages that lacked IGTP or LRG-47 displayed greatly attenuated IFN-γ-induced inhibition of T. gondii growth, while macrophages that lacked IRG-47 displayed normal inhibition. Thus, the ability of the p47 GTPases to limit acute infection in vivo correlated with their ability to suppress intracellular growth in macrophages in vitro. Using confocal microscopy and sucrose density fractionation, we demonstrated that IGTP largely colocalizes with endoplasmic reticulum markers, while LRG-47 was mainly restricted to the Golgi. Although both IGTP and LRG-47 localized to vacuoles containing latex beads, neither protein localized to vacuoles containing live T. gondii. These results suggest that IGTP and LRG-47 are able to regulate host resistance to acute T. gondii infections through their ability to inhibit parasite growth within the macrophage.

scholarly journals Pharmacological iron-chelation as an assisted nutritional immunity strategy against Piscirickettsia salmonis infection

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Mario Caruffo ◽  
Dinka Mandakovic ◽  
Madelaine Mejías ◽  
Ignacio Chávez-Báez ◽  
Pablo Salgado ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Iron Chelation ◽  
Iron Chelator ◽  
Host Cells ◽  
Bacterial Disease ◽  
Protective Capacity ◽  
Intracellular Iron ◽  
Piscirickettsia Salmonis

Abstract Salmonid Rickettsial Septicaemia (SRS), caused by Piscirickettsia salmonis, is a severe bacterial disease in the Chilean salmon farming industry. Vaccines and antibiotics are the current strategies to fight SRS; however, the high frequency of new epizootic events confirms the need to develop new strategies to combat this disease. An innovative opportunity is perturbing the host pathways used by the microorganisms to replicate inside host cells through host-directed antimicrobial drugs (HDAD). Iron is a critical nutrient for P. salmonis infection; hence, the use of iron-chelators becomes an excellent alternative to be used as HDAD. The aim of this work was to use the iron chelator Deferiprone (DFP) as HDAD to treat SRS. Here, we describe the protective effect of the iron chelator DFP over P. salmonis infections at non-antibiotic concentrations, in bacterial challenges both in vitro and in vivo. At the cellular level, our results indicate that DFP reduced the intracellular iron content by 33.1% and P. salmonis relative load during bacterial infections by 78%. These findings were recapitulated in fish, where DFP reduced the mortality of rainbow trout challenged with P. salmonis in 34.9% compared to the non-treated group. This is the first report of the protective capacity of an iron chelator against infection in fish, becoming a potential effective host-directed therapy for SRS and other animals against ferrophilic pathogens.

scholarly journals Pseudomonas aeruginosa Forms Biofilms in Acute Infection Independent of Cell-to-Cell Signaling

2007 ◽  
Vol 75 (8) ◽  
pp. 3715-3721 ◽  
Author(s):  
J. Andy Schaber ◽  
W. Jeffrey Triffo ◽  
Sang Jin Suh ◽  
Jeffrey W. Oliver ◽  
Mary Catherine Hastert ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Colonization ◽  
Acute Infection ◽  
Opportunistic Pathogen ◽  
Confocal Scanning Laser Microscopy ◽  
Chronic Infections ◽  
Signaling Mechanism ◽  
Confocal Scanning Laser

ABSTRACT Biofilms are bacterial communities residing within a polysaccharide matrix that are associated with persistence and antibiotic resistance in chronic infections. We show that the opportunistic pathogen Pseudomonas aeruginosa forms biofilms within 8 h of infection in thermally injured mice, demonstrating that biofilms contribute to bacterial colonization in acute infections as well. Using light, electron, and confocal scanning laser microscopy, P. aeruginosa biofilms were visualized within burned tissue surrounding blood vessels and adipose cells. Although quorum sensing (QS), a bacterial signaling mechanism, coordinates differentiation of biofilms in vitro, wild-type and QS-deficient P. aeruginosa strains formed similar biofilms in vivo. Our findings demonstrate that P. aeruginosa forms biofilms on specific host tissues independently of QS.

scholarly journals Glycosylation-dependent galectin–receptor interactions promoteChlamydia trachomatisinfection

2018 ◽  
Vol 115 (26) ◽  
pp. E6000-E6009 ◽  
Author(s):  
Agustin L. Lujan ◽  
Diego O. Croci ◽  
Julián A. Gambarte Tudela ◽  
Antonella D. Losinno ◽  
Alejandro J. Cagnoni ◽  
...  
Keyword(s):  
Host Cell ◽  
Host Cells ◽  
Bacterial Invasion ◽  
Tubal Infertility ◽  
Sexually Transmitted ◽  
Multiple Strategies ◽  
Host Cell Interactions ◽  
Infected Cells ◽  
Obligate Intracellular Pathogen

Chlamydia trachomatis(Ct) constitutes the most prevalent sexually transmitted bacterium worldwide. Chlamydial infections can lead to severe clinical sequelae including pelvic inflammatory disease, ectopic pregnancy, and tubal infertility. As an obligate intracellular pathogen,Cthas evolved multiple strategies to promote adhesion and invasion of host cells, including those involving both bacterial and host glycans. Here, we show that galectin-1 (Gal1), an endogenous lectin widely expressed in female and male genital tracts, promotesCtinfection. Through glycosylation-dependent mechanisms involving recognition of bacterial glycoproteins andN-glycosylated host cell receptors, Gal1 enhancedCtattachment to cervical epithelial cells. Exposure to Gal1, mainly in its dimeric form, facilitated bacterial entry and increased the number of infected cells by favoringCt–CtandCt–host cell interactions. These effects were substantiated in vivo in mice lacking Gal1 or complex β1–6-branchedN-glycans. Thus, disrupting Gal1–N-glycan interactions may limit the severity of chlamydial infection by inhibiting bacterial invasion of host cells.

scholarly journals CPAF selectively degrades chlamydial T cell antigens for inhibiting antigen presentation

2017 ◽  
Vol 11 (11) ◽  
pp. 868-875
Author(s):  
Yuyang Zhang ◽  
Guangming Zhong ◽  
Huihua Cai ◽  
Siping Chen ◽  
Donghua Sun ◽  
...  
Keyword(s):  
T Cell ◽  
Antigen Presentation ◽  
Bacterial Disease ◽  
Vitro Assay ◽  
Sexually Transmitted ◽  
Cell Antigen ◽  
T Cell Antigens ◽  
In The Wild

Introduction: Chlamydia trachomatis is the leading cause of sexually transmitted bacterial disease, which may cause significant threats, such as pelvic inflammatory disease and tubal factor infertility, to women if untreated. The pathological mechanisms of chlamydia-induced disease remain largely unknown, but it has been proposed that CPAF, a chlamydia-secreted serine protease, may play major roles in aiding chlamydial infection and contribute to chlamydia pathogenesis during in vivo infection. According to previous results, CPAF targets host immunity by degrading antimicrobial peptides and neutralizing complement activity; however, whether CPAF is involved in chlamydial antigen presentation has never been reported. Methodology: Antigen presentation assay was used to monitor the effects of CPAF on OT1-, OT2-, and chlamydia T cell antigen-mediated antigen presentation. In vitro cell-free degradation assay was used to detect CPAF processing of chlamydia T cell antigens. Results: We found that CPAF preferably inhibits OT2- but not OT1-mediated antigen presentation. CPAF inhibits OT2 antigen presentation by direct proteolytic cleavage in the wild type CPAF, but not enzymatic mutants. Importantly, several previously identified chlamydial T cell antigens were selectively degraded by CPAF when co-incubated in vitro. In addition, specific inhibition T cell antigen presentation by CPAF was correlated with T cell antigen cleavage by CPAF in vitro assay. Conclusions: Our experiments demonstrated that CPAF selectively and specifically degrades chlamydial T cell antigens, which chlamydia may utilize as a novel mechanism for evading host immune responses to promote chlamydia survival.

scholarly journals Initial Characterization of the Two ClpP Paralogs ofChlamydia trachomatisSuggests Unique Functionality for Each

2018 ◽  
Author(s):  
Nicholas A. Wood ◽  
Krystal Chung ◽  
Amanda Blocker ◽  
Nathalia Rodrigues de Almeida ◽  
Martin Conda-Sheridan ◽  
...  
Keyword(s):  
Host Cells ◽  
Developmental Cycle ◽  
Clp Protease ◽  
Developmentally Regulated ◽  
Sexually Transmitted ◽  
Obligate Intracellular ◽  
Clp Proteases ◽  
Integral Role ◽  
Developmental Form

AbstractChlamydiais an obligate intracellular bacterium that differentiates between two distinct functional and morphological forms during its developmental cycle: elementary bodies (EBs) and reticulate bodies (RBs). EBs are non-dividing, small electron dense forms that infect host cells. RBs are larger, non-infectious replicative forms that develop within a membrane-bound vesicle, termed an inclusion. Given the unique properties of each developmental form of this bacterium, we hypothesized that the Clp protease system plays an integral role in proteomic turnover by degrading specific proteins from one developmental form or the other.Chlamydiahas five uncharacterizedclpgenes:clpX,clpC, twoclpPparalogs, andclpB. In other bacteria, ClpC and ClpX are ATPases that unfold and feed proteins into the ClpP protease to be degraded, and ClpB is a deaggregase. Here, we focused on characterizing the ClpP paralogs. Transcriptional analyses and immunoblotting determined these genes are expressed mid-cycle. Bioinformatic analyses of these proteins identified key residues important for activity. Over-expression of inactiveclpPmutants inChlamydiasuggested independent function of each ClpP paralog. To further probe these differences, we determined interactions between the ClpP proteins using bacterial two-hybrid assays and native gel analysis of recombinant proteins. Homotypic interactions of the ClpP proteins, but not heterotypic interactions between the ClpP paralogs, were detected. Interestingly, ClpP2, but not ClpP1, protease activity was detectedin vitro. This activity was stimulated by antibiotics known to activate ClpP, which also blocked chlamydial growth. Our data suggest the chlamydial ClpP paralogs likely serve distinct and critical roles in this important pathogen.ImportanceChlamydia trachomatisis the leading cause of preventable infectious blindness and of bacterial sexually transmitted infections worldwide. Chlamydiae are developmentally regulated, obligate intracellular pathogens that alternate between two functional and morphologic forms with distinct repertoires of proteins. We hypothesize that protein degradation is a critical aspect to the developmental cycle. A key system involved in protein turnover in bacteria is the Clp protease system. Here, we characterized the two chlamydial ClpP paralogs by examining their expression inChlamydia, their ability to oligomerize, and their proteolytic activity. This work will help understand the evolutionarily diverse Clp proteases in the context of intracellular organisms, which may aid in the study of other clinically relevant intracellular bacteria.

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