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Edgren, Tomas
Publications (10 of 11) Show all publications
Costa, T., Francis, M. K., Farag, S., Edgren, T. & Francis, M. S. (2019). Measurement of Yersinia translocon pore formation in erythrocytes. In: Viveka Vadyvaloo and Matthew B. Lawrenz (Ed.), Pathogenic Yersinia: methods and protocols (pp. 211-229). New York, NY, U.S.A.: Humana Press
Open this publication in new window or tab >>Measurement of Yersinia translocon pore formation in erythrocytes
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2019 (English)In: Pathogenic Yersinia: methods and protocols / [ed] Viveka Vadyvaloo and Matthew B. Lawrenz, New York, NY, U.S.A.: Humana Press, 2019, p. 211-229Chapter in book (Refereed)
Abstract [en]

Many Gram-negative pathogens produce a type III secretion system capable of intoxicating eukaryotic cells with immune-modulating effector proteins. Fundamental to this injection process is the prior secretion of two translocator proteins destined for injectisome translocon pore assembly within the host cell plasma membrane. It is through this pore that effectors are believed to travel to gain access to the host cell interior. Yersinia species especially pathogenic to humans and animals assemble this translocon pore utilizing two hydrophobic translocator proteins-YopB and YopD. Although a full molecular understanding of the biogenesis, function and regulation of this translocon pore and subsequent effector delivery into host cells remains elusive, some of what we know about these processes can be attributed to studies of bacterial infections of erythrocytes. Herein we describe the methodology of erythrocyte infections by Yersinia, and how analysis of the resultant contact-dependent hemolysis can serve as a relative measurement of YopB- and YopD-dependent translocon pore formation.

Place, publisher, year, edition, pages
New York, NY, U.S.A.: Humana Press, 2019
Series
Methods in Molecular Biology, ISSN 1064-3745, E-ISSN 1940-6029 ; 2010
Keywords
Biogenesis, Contact-dependent hemolysis, Effector recognition and intracellular delivery, Function and regulation, Host immune response, Membrane integration, Type III translocon pore complex
National Category
Microbiology in the medical area Microbiology Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Microbiology; Molecular Biology; Infectious Diseases
Identifiers
urn:nbn:se:umu:diva-161385 (URN)10.1007/978-1-4939-9541-7_15 (DOI)31177441 (PubMedID)978-1-4939-9540-0 (ISBN)
Funder
Swedish Research Council, 2014-2105Swedish Research Council, 2009-5628
Available from: 2019-07-03 Created: 2019-07-03 Last updated: 2019-07-03Bibliographically approved
Bamyaci, S., Ekestubbe, S., Nordfelth, R., Erttmann, S. F., Edgren, T. & Forsberg, Å. (2018). YopN Is Required for Efficient Effector Translocation and Virulence in Yersinia pseudotuberculosis. Infection and Immunity, 86(8), Article ID e00957-17.
Open this publication in new window or tab >>YopN Is Required for Efficient Effector Translocation and Virulence in Yersinia pseudotuberculosis
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2018 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 86, no 8, article id e00957-17Article in journal (Refereed) Published
Abstract [en]

Type III secretion systems (T3SSs) are used by various Gram-negative pathogens to subvert the host defense by a host cell contact-dependent mechanism to secrete and translocate virulence effectors. While the effectors differ between pathogens and determine the pathogenic life style, the overall mechanism of secretion and translocation is conserved. T3SSs are regulated at multiple levels, and some secreted substrates have also been shown to function in regulation. In Yersinia, one of the substrates, YopN, has long been known to function in the host cell contact-dependent regulation of the T3SS. Prior to contact, through its interaction with TyeA, YopN blocks secretion. Upon cell contact, TyeA dissociates from YopN, which is secreted by the T3SS, resulting in the induction of the system. YopN has also been shown to be translocated into target cells by a T3SS-dependent mechanism. However, no intracellular function has yet been assigned to YopN. The regulatory role of YopN involves the N-terminal and C-terminal parts, while less is known about the role of the central region of YopN. Here, we constructed different in-frame deletion mutants within the central region. The deletion of amino acids 76 to 181 resulted in an unaltered regulation of Yop expression and secretion but triggered reduced YopE and YopH translocation within the first 30 min after infection. As a consequence, this deletion mutant lost its ability to block phagocytosis by macrophages. In conclusion, we were able to differentiate the function of YopN in translocation and virulence from its function in regulation.

Keywords
phagocytosis, type III secretion, Yersinia, YopN, virulence
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:umu:diva-150354 (URN)10.1128/IAI.00957-17 (DOI)000439474900006 ()29760214 (PubMedID)
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2019-01-09Bibliographically approved
Ho, O., Rogne, P., Edgren, T., Wolf-Watz, H., Login, F. & Wolf-Watz, M. (2017). Characterization of the Ruler Protein Interaction Interface on the Substrate Specificity SwitchProtein in the Yersinia Type III Secretion System. Journal of Biological Chemistry, 292(8), 3299-3311
Open this publication in new window or tab >>Characterization of the Ruler Protein Interaction Interface on the Substrate Specificity SwitchProtein in the Yersinia Type III Secretion System
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2017 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 292, no 8, p. 3299-3311Article, review/survey (Refereed) Published
Abstract [en]

Many pathogenic Gram-negative bacteria use the type III secretion system (T3SS) to deliver effector proteins into eukaryotic host cells. In Yersinia the switch to secretion of effector proteins is induced first after that intimate contact between the bacterium and its eukaryotic targetcell has been established and the T3SS proteins YscP and YscU are playing a central role in thisprocess. Here we identify the molecular details of the YscP binding site on YscU by means o fnuclear magnetic resonance (NMR) spectroscopy. The binding interface is centeredon the C-terminal domain of YscU. Disruptingthe YscU/YscP interaction by introducing point mutations at the interaction interface significantly reduced the secretion of effector proteins and HeLa cell cytotoxicity. Interestingly, the bindingof YscP to the slowly self-cleaving YscU variantP264A conferred significant protection againstauto-proteolysis. The YscP mediated inhibition of YscU auto-proteolysis suggest that the cleavage event may act as a timing switch in the regulationof early vs. late T3SS substrates. We also show that YscUC binds to the inner-rod protein YscI with a Kd of 3.8 μM and with one-to-one stoichiometry. The significant similarity between different members of the YscU, YscP, YscI families suggests that the protein-protein interactions discussed in this study are alsorelevant for other T3SS-containing Gram-negative bacteria.

National Category
Biochemistry and Molecular Biology
Research subject
Biochemistry
Identifiers
urn:nbn:se:umu:diva-130048 (URN)10.1074/jbc.M116.770255 (DOI)000395538800021 ()
Available from: 2017-01-11 Created: 2017-01-11 Last updated: 2018-06-09Bibliographically approved
Wang, H., Avican, K., Fahlgren, A., Erttmann, S. F., Nuss, A. M., Dersch, P., . . . Wolf-Watz, H. (2016). Increased plasmid copy number is essential for Yersinia T3SS function and virulence. Science, 353(6298), 492-495
Open this publication in new window or tab >>Increased plasmid copy number is essential for Yersinia T3SS function and virulence
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2016 (English)In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 353, no 6298, p. 492-495Article in journal (Refereed) Published
Abstract [en]

Pathogenic bacteria have evolved numerous virulence mechanisms that are essential for establishing infections. The enterobacterium Yersinia uses a type III secretion system (T3SS) encoded by a 70-kilobase, low-copy, IncFII-class virulence plasmid. We report a novel virulence strategy in Y. pseudotuberculosis in which this pathogen up-regulates the plasmid copy number during infection. We found that an increased dose of plasmid-encoded genes is indispensable for virulence and substantially elevates the expression and function of the T3SS. Remarkably, we observed direct, tight coupling between plasmid replication and T3SS function. This regulatory pathway provides a framework for further exploration of the environmental sensing mechanisms of pathogenic bacteria.

National Category
Microbiology in the medical area Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-125586 (URN)10.1126/science.aaf7501 (DOI)000380583600042 ()27365311 (PubMedID)
Available from: 2016-09-19 Created: 2016-09-13 Last updated: 2018-06-07Bibliographically approved
Erttmann, S. F., Härtlova, A., Sloniecka, M., Raffi, F. A. M., Hosseinzadeh, A., Edgren, T., . . . Gekara, N. O. (2016). Loss of the DNA Damage Repair Kinase ATM Impairs Inflammasome-Dependent Anti-Bacterial Innate Immunity. Immunity, 45(1), 106-118
Open this publication in new window or tab >>Loss of the DNA Damage Repair Kinase ATM Impairs Inflammasome-Dependent Anti-Bacterial Innate Immunity
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2016 (English)In: Immunity, ISSN 1074-7613, E-ISSN 1097-4180, Vol. 45, no 1, p. 106-118Article in journal (Refereed) Published
Abstract [en]

The ATM kinase is a central component of the DNA damage repair machinery and redox balance. ATM dysfunction results in the multisystem disease ataxia-telangiectasia (AT). A major cause of mortality in AT is respiratory bacterial infections. Whether ATM deficiency causes innate immune defects that might contribute to bacterial infections is not known. Here we have shown that loss of ATM impairs inflammasome- dependent anti-bacterial innate immunity. Cells from AT patients or Atm(-/-) mice exhibited diminished interleukin-1 beta (IL-1 beta) production in response to bacteria. In vivo, Atm(-/-) mice were more susceptible to pulmonary S. pneumoniae infection in a manner consistent with inflammasome defects. Our data indicate that such defects were due to oxidative inhibition of inflammasome complex assembly. This study reveals an unanticipated function of reactive oxygen species (ROS) in negative regulation of inflammasomes and proposes a theory for the notable susceptibility of AT patients to pulmonary bacterial infection.

National Category
Immunology in the medical area
Identifiers
urn:nbn:se:umu:diva-125590 (URN)10.1016/j.immuni.2016.06.018 (DOI)000380749000014 ()27421701 (PubMedID)
Available from: 2016-09-23 Created: 2016-09-13 Last updated: 2018-06-07Bibliographically approved
Ekestubbe, S., Bröms, J. E., Edgren, T., Fällman, M., Francis, M. S. & Forsberg, Å. (2016). The amino-terminal part of the needle-tip translocator LcrV of Yersinia pseudotuberculosis is required for early targeting of YopH and in vivo virulence. Frontiers in Cellular and Infection Microbiology, 6, Article ID 175.
Open this publication in new window or tab >>The amino-terminal part of the needle-tip translocator LcrV of Yersinia pseudotuberculosis is required for early targeting of YopH and in vivo virulence
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2016 (English)In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 6, article id 175Article in journal (Refereed) Published
Abstract [en]

Type III secretion systems (T3SS) are dedicated to targeting anti-host effector proteins into the cytosol of the host cell to promote bacterial infection. Delivery of the effectors requires three specific translocator proteins, of which the hydrophilic translocator, LcrV, is located at the tip of the T3SS needle and is believed to facilitate insertion of the two hydrophobic translocators into the host cell membrane. Here we used Yersinia as a model to study the role of LcrV in T3SS mediated intracellular effector targeting. Intriguingly, we identified N-terminal IcrV mutants that, similar to the wild-type protein, efficiently promoted expression, secretion and intracellular levels of Yop effectors, yet they were impaired in their ability to inhibit phagocytosis by J774 cells. In line with this, the YopH mediated dephosphorylation of Focal Adhesion Kinase early after infection was compromised when compared to the wild type strain. This suggests that the mutants are unable to promote efficient delivery of effectors to their molecular targets inside the host cell upon host cell contact. The significance of this was borne out by the fact that the mutants were highly attenuated for virulence in the systemic mouse infection model. Our study provides both novel and significant findings that establish a role for LcrV in early targeting of effectors in the host cell.

Keywords
LcrV, type III secretion system, YopH, translocation, pore formation, Yersinia pseudotuberculosis, virulence
National Category
Microbiology in the medical area Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Identifiers
urn:nbn:se:umu:diva-130149 (URN)10.3389/fcimb.2016.00175 (DOI)000389194200001 ()
Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2018-06-09Bibliographically approved
Costa, T., Amer, A., Farag, S., Wolf-Watz, H., Fällman, M., Fahlgren, A., . . . Francis, M. (2013). Type III secretion translocon assemblies that attenuate Yersinia virulence. Cellular Microbiology, 15(7), 1088-1110
Open this publication in new window or tab >>Type III secretion translocon assemblies that attenuate Yersinia virulence
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2013 (English)In: Cellular Microbiology, ISSN 1462-5814, E-ISSN 1462-5822, Vol. 15, no 7, p. 1088-1110Article in journal (Refereed) Published
Abstract [en]

Type III secretion enables bacteria to intoxicate eukaryotic cells with anti-host effectors. A class of secreted cargo are the two hydrophobic translocators that form a translocon pore in the host cell plasma membrane through which the translocated effectors may gain cellular entry. In pathogenic Yersinia, YopB and YopD shape this translocon pore. Here, four in cis yopD mutations were constructed to disrupt a predicted α-helix motif at the C-terminus. Mutants YopD(I262P) and YopD(K267P) poorly localized Yop effectors into target eukaryotic cells and failed to resist uptake and killing by immune cells. These defects were due to deficiencies in host-membrane insertion of the YopD-YopB translocon. Mutants YopD(A263P) and YopD(A270P) had no measurable in vitro translocation defect, even though they formed smaller translocon pores in erythrocyte membranes. Despite this, all four mutants were attenuated in a mouse infection model. Hence, YopD variants have been generated that can spawn translocons capable of targeting effectors in vitro, yet were bereft of any lethal effect in vivo. Therefore, Yop translocators may possess other in vivo functions that extend beyond being a portal for effector delivery into host cells.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2013
Keywords
virulence, coiled-coil, effector delivery, pore formation, regulation, YopD
National Category
Microbiology Biochemistry and Molecular Biology Microbiology in the medical area
Research subject
Infectious Diseases; Microbiology; Molecular Biology
Identifiers
urn:nbn:se:umu:diva-67117 (URN)10.1111/cmi.12100 (DOI)000320394800004 ()
Funder
Swedish Research Council
Note

This work, performed within the framework of the Umea Centre for Microbial Research-Linnaeus Program, was supported by grants from the Carl Tryggers Foundation for Scientific Research (M. S. F.), Swedish Research Council (H.W.-W., M. F., T. E., M. S. F.), Foundation for Medical Research at Umea University (M. S. F.) and J C Kempe Memorial Fund (T. R. C., A. A. A.).

Available from: 2013-03-13 Created: 2013-03-13 Last updated: 2019-11-12Bibliographically approved
Edgren, T., Forsberg, Å., Rosqvist, R. & Wolf-Watz, H. (2012). Type III Secretion in Yersinia: Injectisome or Not?. PLoS pathogens, 8(5), e1002669
Open this publication in new window or tab >>Type III Secretion in Yersinia: Injectisome or Not?
2012 (English)In: PLoS pathogens, ISSN 1553-7374, Vol. 8, no 5, p. e1002669-Article in journal (Refereed) Published
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:umu:diva-55608 (URN)10.1371/journal.ppat.1002669 (DOI)000305322900007 ()22589714 (PubMedID)
Available from: 2012-05-29 Created: 2012-05-23 Last updated: 2018-06-08Bibliographically approved
Thorslund, S. E., Edgren, T., Pettersson, J., Nordfelth, R., Sellin, M. E., Ivanova, E., . . . Fällman, M. (2011). The RACK1 signaling scaffold protein selectively interacts with Yersinia pseudotuberculosis virulence function. PLoS ONE, 6(2), e16784
Open this publication in new window or tab >>The RACK1 signaling scaffold protein selectively interacts with Yersinia pseudotuberculosis virulence function
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2011 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 2, p. e16784-Article in journal (Refereed) Published
Abstract [en]

Many Gram-negative bacteria use type III secretion systems to translocate effector proteins into host cells. These effectors interfere with cellular functions in a highly regulated manner resulting in effects that are beneficial for the bacteria. The pathogen Yersinia can resist phagocytosis by eukaryotic cells by translocating Yop effectors into the target cell cytoplasm. This is called antiphagocytosis, and constitutes an important virulence feature of this pathogen since it allows survival in immune cell rich lymphoid organs. We show here that the virulence protein YopK has a role in orchestrating effector translocation necessary for productive antiphagocytosis. We present data showing that YopK influences Yop effector translocation by modulating the ratio of the pore-forming proteins YopB and YopD in the target cell membrane. Further, we show that YopK that can interact with the translocators, is exposed inside target cells and binds to the eukaryotic signaling protein RACK1. This protein is engaged upon Y. pseudotuberculosis-mediated beta1-integrin activation and localizes to phagocytic cups. Cells with downregulated RACK1 levels are protected from antiphagocytosis. This resistance is not due to altered levels of translocated antiphagocytic effectors, and cells with reduced levels of RACK1 are still sensitive to the later occurring cytotoxic effect caused by the Yop effectors. Further, a yopK mutant unable to bind RACK1 shows an avirulent phenotype during mouse infection, suggesting that RACK1 targeting by YopK is a requirement for virulence. Together, our data imply that the local event of Yersinia-mediated antiphagocytosis involves a step where YopK, by binding RACK1, ensures an immediate specific spatial delivery of antiphagocytic effectors leading to productive inhibition of phagocytosis.

Place, publisher, year, edition, pages
San Francisco: Public Library of Science, 2011
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-43212 (URN)10.1371/journal.pone.0016784 (DOI)21347310 (PubMedID)
Available from: 2011-04-22 Created: 2011-04-22 Last updated: 2018-06-08Bibliographically approved
Akopyan, K., Edgren, T., Wang-Edgren, H., Rosqvist, R., Fahlgren, A., Wolf-Watz, H. & Fällman, M. (2011). Translocation of surface-localized effectors in type III secretion. Proceedings of the National Academy of Sciences of the United States of America, 108(4), 1639-1644
Open this publication in new window or tab >>Translocation of surface-localized effectors in type III secretion
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2011 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 108, no 4, p. 1639-1644Article in journal (Refereed) Published
Abstract [en]

Pathogenic Yersinia species suppress the host immune response by using a plasmid-encoded type III secretion system (T3SS) to translocate virulence proteins into the cytosol of the target cells. T3SS-dependent protein translocation is believed to occur in one step from the bacterial cytosol to the target-cell cytoplasm through a conduit created by the T3SS upon target cell contact. Here, we report that T3SS substrates on the surface of Yersinia pseudotuberculosis are translocated into target cells. Upon host cell contact, purified YopH coated on Y. pseudotuberculosis was specifically and rapidly translocated across the target-cell membrane, which led to a physiological response in the infected cell. In addition, translocation of externally added YopH required a functional T3SS and a specific translocation domain in the effector protein. Efficient, T3SS-dependent translocation of purified YopH added in vitro was also observed when using coated Salmonella typhimurium strains, which implies that T3SS-mediated translocation of extracellular effector proteins is conserved among T3SS-dependent pathogens. Our results demonstrate that polarized T3SS-dependent translocation of proteins can be achieved through an intermediate extracellular step that can be reconstituted in vitro. These results indicate that translocation can occur by a different mechanism from the assumed single-step conduit model.

Keywords
bacterial pathogenesis, Yop effector, Ca2+-signaling, neutrophil
Identifiers
urn:nbn:se:umu:diva-43205 (URN)10.1073/pnas.1013888108 (DOI)
Available from: 2011-04-22 Created: 2011-04-22 Last updated: 2018-06-08Bibliographically approved
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