scholarly journals pH Alkalinization by Chloroquine Suppresses Pathogenic Burkholderia Type 6 Secretion System 1 and Multinucleated Giant Cells

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Jennifer Chua ◽  
Jeffrey L. Senft ◽  
Stephen J. Lockett ◽  
Paul J. Brett ◽  
Mary N. Burtnick ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Biology ◽  
Antibiotic Use ◽  
Giant Cells ◽  
Secretion System ◽  
Multinucleated Giant Cells ◽  
Content Type ◽  
Acid Ph ◽  
Virulence Protein ◽  
System 1

ABSTRACT Burkholderia mallei and B. pseudomallei cause glanders and melioidosis, respectively, in humans and animals. A hallmark of pathogenesis is the formation of granulomas containing multinucleated giant cells (MNGCs) and cell death. These processes depend on type 6 secretion system 1 (T6SS-1), which is required for virulence in animals. We examined the cell biology of MNGC formation and cell death. We found that chloroquine diphosphate (CLQ), an antimalarial drug, inhibits Burkholderia growth, phagosomal escape, and subsequent MNGC formation. This depends on CLQ's ability to neutralize the acid pH because other alkalinizing compounds similarly inhibit escape and MNGC formation. CLQ inhibits bacterial virulence protein expression because T6SS-1 and some effectors of type 3 secretion system 3 (T3SS-3), which is also required for virulence, are expressed at acid pH. We show that acid pH upregulates the expression of Hcp1 of T6SS-1 and TssM, a protein coregulated with T6SS-1. Finally, we demonstrate that CLQ treatment of Burkholderia-infected Madagascar hissing cockroaches (HCs) increases their survival. This study highlights the multiple mechanisms by which CLQ inhibits growth and virulence and suggests that CLQ be further tested and considered, in conjunction with antibiotic use, for the treatment of diseases caused by Burkholderia.

Villonodular synovitis in the spinal canal

1980 ◽  
Vol 52 (6) ◽  
pp. 846-848 ◽  
Author(s):  
George M. Kleinman ◽  
T. Forcht Dagi ◽  
Charles E. Poletti
Keyword(s):  
Giant Cell Tumor ◽  
Spinal Canal ◽  
Giant Cells ◽  
Cell Tumor ◽  
Villonodular Synovitis ◽  
Rare Occurrence ◽  
Multinucleated Giant Cells ◽  
Content Type ◽  
Synovial Tissues ◽  
Fine Print

✓ Villonodular synovitis is believed to be an inflammatory, proliferative reaction of synovial tissues. The case of a 65-year-old woman with a cervical epidural mass is presented in which histological examination showed that the lesion was villonodular synovitis, an extremely rare occurrence. Because of its cellularity and occasional multinucleated giant cells, villonodular synovitis may be confused with metastatic malignancies or giant-cell tumor of bone.

scholarly journals SseK1 and SseK3 Type III Secretion System Effectors Inhibit NF-κB Signaling and Necroptotic Cell Death in Salmonella-Infected Macrophages

2017 ◽  
Vol 85 (3) ◽  
Author(s):  
Regina A. Günster ◽  
Sophie A. Matthews ◽  
David W. Holden ◽  
Teresa L. M. Thurston
Keyword(s):  
Cell Death ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Host Cells ◽  
Macrophage Infection ◽  
Content Type ◽  
Type Iii ◽  
Tnf Α ◽  
Arginine Residues

ABSTRACT Within host cells such as macrophages, Salmonella enterica translocates virulence (effector) proteins across its vacuolar membrane via the SPI-2 type III secretion system. Previously, it was shown that when expressed ectopically, the effectors SseK1 and SseK3 inhibit tumor necrosis factor alpha (TNF-α)-induced NF-κB activation. In this study, we show that ectopically expressed SseK1, SseK2, and SseK3 suppress TNF-α-induced, but not Toll-like receptor 4- or interleukin-induced, NF-κB activation. Inhibition required a DXD motif in SseK1 and SseK3, which is essential for the transfer of N-acetylglucosamine to arginine residues (arginine-GlcNAcylation). During macrophage infection, SseK1 and SseK3 inhibited NF-κB activity in an additive manner. SseK3-mediated inhibition of NF-κB activation did not require the only known host-binding partner of this effector, the E3-ubiquitin ligase TRIM32. SseK proteins also inhibited TNF-α-induced cell death during macrophage infection. Despite SseK1 and SseK3 inhibiting TNF-α-induced apoptosis upon ectopic expression in HeLa cells, the percentage of infected macrophages undergoing apoptosis was SseK independent. Instead, SseK proteins inhibited necroptotic cell death during macrophage infection. SseK1 and SseK3 caused GlcNAcylation of different proteins in infected macrophages, suggesting that these effectors have distinct substrate specificities. Indeed, SseK1 caused the GlcNAcylation of the death domain-containing proteins FADD and TRADD, whereas SseK3 expression resulted in weak GlcNAcylation of TRADD but not FADD. Additional, as-yet-unidentified substrates are likely to explain the additive phenotype of a Salmonella strain lacking both SseK1 and SseK3.

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 Type III Secretion System-Dependent Translocation of Ectopically Expressed Yop Effectors into Macrophages by Intracellular Yersinia pseudotuberculosis

2011 ◽  
Vol 79 (11) ◽  
pp. 4322-4331 ◽  
Author(s):  
Yue Zhang ◽  
Galina Romanov ◽  
James B. Bliska
Keyword(s):  
Cell Death ◽  
Type Iii Secretion ◽  
Yersinia Pseudotuberculosis ◽  
Bacterial Pathogen ◽  
Type Iii Secretion System ◽  
Inducible Promoter ◽  
Secretion System ◽  
Host Cells ◽  
Content Type ◽  
Type Iii

ABSTRACTYersinia pseudotuberculosisis a Gram-negative bacterial pathogen. Virulence inY. pseudotuberculosisrequires the plasmid-encoded Ysc type III secretion system (T3SS), which functions to translocate a set of effectors called Yops into infected host cells. The effectors function to antagonize phagocytosis (e.g., YopH) or to induce apoptosis (YopJ) in macrophages infected withY. pseudotuberculosis. Additionally, when antiphagocytosis is incomplete andY. pseudotuberculosisis internalized by macrophages, the bacterium can survive in phagosomes. Previous studies have shown that delivery of effectors into host cells occurs efficiently whenYersiniais extracellular. However, it is not clear whether the T3SS can be utilized by intracellularY. pseudotuberculosisto translocate Yops. This possibility was investigated here usingY. pseudotuberculosisstrains that express YopJ or YopH under the control of an inducible promoter. Bone marrow-derived murine macrophages were infected with these strains under conditions that prevented the survival of extracellular bacteria. Effector translocation was detected by measuring apoptosis or the activities of Yop-β-lactamase fusion proteins. Results showed that macrophages underwent apoptosis when YopJ expression was induced prior to phagocytosis, confirming that delivery of this effector prior to or during uptake is sufficient to cause cell death. However, macrophages also underwent apoptosis when YopJ was ectopically expressed after phagocytosis; furthermore, expression of the translocator YopB from intracellular bacteria also resulted in increased cell death. Analysis by microscopy showed that translocation of ectopically expressed YopH- or YopJ-β-lactamase fusions could be correlated with the presence of viableY. pseudotuberculosisin macrophages. Collectively, our results suggest that the Ysc T3SS ofY. pseudotuberculosiscan function within macrophage phagosomes to translocate Yops into the host cytosol.

scholarly journals The cytotoxic type 3 secretion system 1 ofVibriorewires host gene expression to subvert cell death and activate cell survival pathways

2017 ◽  
Vol 10 (479) ◽  
pp. eaal4501 ◽  
Author(s):  
Nicole J. De Nisco ◽  
Mohammed Kanchwala ◽  
Peng Li ◽  
Jessie Fernandez ◽  
Chao Xing ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Cell Survival ◽  
Secretion System ◽  
Host Gene Expression ◽  
Survival Pathways ◽  
Type 3 Secretion System ◽  
Activate Cell ◽  
System 1 ◽  
Type 3

Type III secretion system 1 of Vibrio parahaemolyticus induces oncosis in both epithelial and monocytic cell lines

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 837-851 ◽  
Author(s):  
Xiaohui Zhou ◽  
Michael E. Konkel ◽  
Douglas R. Call
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Type Iii Secretion ◽  
Vibrio Parahaemolyticus ◽  
Active Form ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Monocytic Cell ◽  
Type Iii ◽  
System 1

The Vibrio parahaemolyticus type III secretion system 1 (T3SS1) induces cytotoxicity in mammalian epithelial cells. We characterized the cell death phenotype in both epithelial (HeLa) and monocytic (U937) cell lines following infection with V. parahaemolyticus. Using a combination of the wild-type strain and gene knockouts, we confirmed that V. parahaemolyticus strain NY-4 was able to induce cell death in both cell lines via a T3SS1-dependent mechanism. Bacterial contact, but not internalization, was required for T3SS1-induced cytotoxicity. The mechanism of cell death involves formation of a pore structure on the surface of infected HeLa and U937 cells, as demonstrated by cellular swelling, uptake of cell membrane-impermeable dye and protection of cytotoxicity by osmoprotectant (PEG3350). Western blot analysis showed that poly ADP ribose polymerase (PARP) was not cleaved and remained in its full-length active form. This result was evident for seven different V. parahaemolyticus strains. V. parahaemolyticus-induced cytotoxicity was not inhibited by addition of the pan-caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (Z-VAD-FMK) or the caspase-1 inhibitor N-acetyl-tyrosyl-valyl-alanyl-aspartyl-aldehyde (Ac-YVAD-CHO); thus, caspases were not involved in T3SS1-induced cytotoxicity. DNA fragmentation was not evident following infection and autophagic vacuoles were not observed after monodansylcadaverine staining. We conclude that T3SS1 of V. parahaemolyticus strain NY-4 induces a host cell death primarily via oncosis rather than apoptosis, pyroptosis or autophagy.

scholarly journals Polarly Localized EccE1 Is Required for ESX-1 Function and Stabilization of ESX-1 Membrane Proteins in Mycobacterium tuberculosis

2019 ◽  
Vol 202 (5) ◽  
Author(s):  
Paloma Soler-Arnedo ◽  
Claudia Sala ◽  
Ming Zhang ◽  
Stewart T. Cole ◽  
Jérémie Piton
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Membrane Proteins ◽  
Cell Biology ◽  
Ex Vivo ◽  
Eukaryotic Cell ◽  
Secretion System ◽  
Effector Proteins ◽  
Intracellular Bacterium ◽  
Stable Complex ◽  
Content Type

ABSTRACT Mycobacterium tuberculosis is a slow-growing intracellular bacterium with the ability to induce host cell death and persist indefinitely in the human body. This pathogen uses the specialized ESX-1 secretion system to secrete virulence factors and potent immunogenic effectors required for disease progression. ESX-1 is a multisubunit apparatus with a membrane complex that is predicted to form a channel in the cytoplasmic membrane. In M. tuberculosis this complex is composed of five membrane proteins: EccB1, EccCa1, EccCb1, EccD1, and EccE1. In this study, we have characterized the membrane component EccE1 and found that deletion of eccE1 lowers the levels of EccB1, EccCa1, and EccD1, thereby abolishing ESX-1 secretion and attenuating M. tuberculosis ex vivo. Surprisingly, secretion of EspB was not affected by loss of EccE1. Furthermore, EccE1 was found to be a membrane- and cell wall-associated protein that needs the presence of other ESX-1 components to assemble into a stable complex at the poles of M. tuberculosis. Overall, this investigation provides new insights into the role of EccE1 and its localization in M. tuberculosis. IMPORTANCE Tuberculosis (TB), the world’s leading cause of death of humans from an infectious disease, is caused by the intracellular bacterium Mycobacterium tuberculosis. The development of successful strategies to control TB requires better understanding of the complex interactions between the pathogen and the human host. We investigated the contribution of EccE1, a membrane protein, to the function of the ESX-1 secretion system, the major virulence determinant of M. tuberculosis. By combining genetic analysis of selected mutants with eukaryotic cell biology and proteomics, we demonstrate that EccE1 is critical for ESX-1 function, secretion of effector proteins, and pathogenesis. Our research improves knowledge of the molecular basis of M. tuberculosis virulence and enhances our understanding of pathogenesis.

scholarly journals A New ESX-1 Substrate inMycobacterium marinumThat Is Required for Hemolysis but Not Host Cell Lysis

2019 ◽  
Vol 201 (14) ◽  
Author(s):  
Rachel E. Bosserman ◽  
Kathleen R. Nicholson ◽  
Matthew M. Champion ◽  
Patricia A. Champion
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Host Response ◽  
Secretion System ◽  
Mycobacterial Species ◽  
Macrophage Infection ◽  
Content Type ◽  
Family Protein ◽  
Species Specific ◽  
System 1 ◽  
Insight Into

ABSTRACTThe ESX-1 (ESAT-6 system 1) secretion system plays a conserved role in the virulence of diverse mycobacterial pathogens, including the human pathogenMycobacterium tuberculosisandM. marinum, an environmental mycobacterial species. The ESX-1 system promotes the secretion of protein virulence factors to the extracytoplasmic environment. The secretion of these proteins triggers the host response by lysing the phagosome during macrophage infection. Using proteomic analyses of theM. marinumsecretome in the presence and absence of a functional ESX-1 system, we and others have hypothesized that MMAR_2894, a PE family protein, is a potential ESX-1 substrate inM. marinum. We used genetic and quantitative proteomic approaches to determine if MMAR_2894 is secreted by the ESX-1 system, and we defined the requirement ofMMAR_2894for ESX-1-mediated secretion and virulence. We show that MMAR_2894 is secreted by the ESX-1 system inM. marinumand is itself required for the optimal secretion of the known ESX-1 substrates inM. marinum. Moreover, we found that MMAR_2894 was differentially required for hemolysis and cytolysis of macrophages, two lytic activities ascribed to theM. marinumESX-1 system.IMPORTANCEBothMycobacterium tuberculosis, the cause of human tuberculosis (TB), andMycobacterium marinum, a pathogen of ectotherms, use the ESX-1 secretion system to cause disease. There are many established similarities between the ESX-1 systems inM. tuberculosisand inM. marinum. Yet the two bacteria infect different hosts, hinting at species-specific functions of the ESX-1 system. Our findings demonstrate that MMAR_2894 is a PE protein secreted by the ESX-1 system ofM. marinum. We show that MMAR_2894 is required for the optimal secretion of mycobacterial proteins required for disease. Because theMMAR_2894gene is not conserved inM. tuberculosis, our findings demonstrate that MMAR_2894 may contribute to a species-specific function of the ESX-1 system inM. marinum, providing new insight into how theM. marinumandM. tuberculosissystems differ.

scholarly journals Salmonella entericaEffectors SifA, SpvB, SseF, SseJ, and SteA Contribute to Type III Secretion System 1-Independent Inflammation in a Streptomycin-Pretreated Mouse Model of Colitis

2019 ◽  
Vol 87 (9) ◽  
Author(s):  
Shigeki Matsuda ◽  
Takeshi Haneda ◽  
Hiyori Saito ◽  
Tsuyoshi Miki ◽  
Nobuhiko Okada
Keyword(s):  
Mouse Model ◽  
Type Iii Secretion ◽  
Intestinal Inflammation ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Time Range ◽  
Content Type ◽  
Type Iii ◽  
System 1 ◽  
Inflammatory Changes

ABSTRACTSalmonella entericaserovar Typhimurium (S.Typhimurium) induces inflammatory changes in the ceca of streptomycin-pretreated mice. In this mouse model of colitis, the type III secretion system 1 (T3SS-1) has been shown to induce rapid inflammatory change in the cecum at early points, 10 to 24 h after infection. Five proteins, SipA, SopA, SopB, SopD, and SopE2, have been identified as effectors involved in eliciting intestinal inflammation within this time range. In contrast, a T3SS-1-deficient strain was shown to exhibit inflammatory changes in the cecum at 72 to 120 h postinfection. However, the effectors eliciting T3SS-1-independent inflammation remain to be clarified. In this study, we focused on two T3SS-2 phenotypes, macrophage proliferation and cytotoxicity, to identify the T3SS-2 effectors involved in T3SS-1-independent inflammation. We identified a mutant strain that could not induce cytotoxicity in a macrophage-like cell line and that reduced intestinal inflammation in streptomycin-pretreated mice. We also identified five T3SS-2 effectors, SifA, SpvB, SseF, SseJ, and SteA, associated with T3SS-1-independent macrophage cytotoxicity. We then constructed a strain lacking T3SS-1 and all the five T3SS-2 effectors, termed T1S5. TheS.Typhimurium T1S5 strain significantly reduced cytotoxicity in macrophages in the same manner as a mutantinvA spiBstrain (T1T2). Finally, the T1S5 strain elicited no inflammatory changes in the ceca of streptomycin-pretreated mice. We conclude that these five T3SS-2 effectors contribute to T3SS-1-independent inflammation.

Morphological assessment of the development of multinucleated giant cells in glioma by using mitosis-specific phosphorylated antibodies

2003 ◽  
Vol 98 (4) ◽  
pp. 854-859 ◽  
Author(s):  
Kenkou Maeda ◽  
Masaaki Mizuno ◽  
Toshihiko Wakabayashi ◽  
Syuntarou Takasu ◽  
Tetsurou Nagasaka ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Giant Cells ◽  
Laser Scanning Confocal Microscopy ◽  
Multinucleated Giant Cells ◽  
Content Type ◽  
Scanning Confocal Microscopy ◽  
Drug Treatments ◽  
Fine Print

Object. The nature and origin of multinucleated giant cells in glioma have not been made clear. To investigate the phosphorylation of intermediate filaments, the authors studied multinucleated giant cells in vitro and in vivo by using mitosis-specific phosphorylated antibodies. Methods. Cultured human glioma cells were immunostained with monoclonal antibodies (mAbs) 4A4, KT13, and TM71, which recognized the phosphorylation of vimentin at Ser55, glial fibrillary acidic protein at Ser13, and vimentin at Ser71, respectively. Subsequently, the nature of multinucleated giant cells was investigated using laser scanning confocal microscopy. In addition, paraffin-embedded tissue sections obtained in three patients with giant cell glioblastoma were also investigated. Multinucleated giant cells were immunoreacted with the mAb 4A4 and not with KT13 and TM71 in vitro and in vivo. In addition, the authors obtained these results in multinucleated giant cells under natural conditions, without drug treatments. Conclusions. Findings in this investigation indicated that multinucleated giant cells are those remaining in mitosis between metaphase and telophase, undergoing neither fusion nor degeneration.

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