Prof. Anat Herskovits

 

Bacteria-Virus Cooperation: Redefining Host-Pathogen Interactions

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Research Overview

Our laboratory investigates a fundamental question in microbiology: How do bacteria and their integrated viruses (prophages) interact to influence bacterial infection? Our work has revealed unexpected cooperative relationships that challenge traditional views of bacteria-virus interactions and open new avenues of research and directions for therapeutic intervention.

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Our model organism- Listeria monocytogenes

Listeria monocytogenes is an intracellular pathogen, the causative agent of Listeriosis disease. This bacterium can transition from living in soil to invading human cells, essentially transforming from an environmental microbe into a sophisticated pathogen. What makes it particularly fascinating is its ability to hijack host cell machineries, such as the actin polymerization machinery, which allows it to propel itself through cells using actin "rockets" and spread directly from cell to cell, effectively hiding from the immune system.

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In our lab, we've discovered something extraordinary: Listeria has evolved cooperative relationships with its integrated viruses (prophages), using them as precise genetic switches to control its infection process. This finding opens up a whole new understanding of how bacteria and viruses can work together rather than just having a predator-prey relationship.

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Listeria is an excellent experimental model- it's easy to grow in the lab, genetically tractable, and its infection process can be studied in detail. We use Listeria to study pathogen-phage interactions upon infection of mammalian cells and their adaptation to the mammalian environment. It's like having a window into the complex world of bacteria-phage adaptation and evolution.

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​Key Discoveries

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1. Active Lysogeny: A New Paradigm

We discovered that prophages can function as sophisticated genetic switches rather than just being passive DNA elements or destructive agents. This phenomenon, which we termed "active lysogeny," represents a fundamental shift in our understanding of bacteria-virus relationships. In Listeria monocytogenes, a prophage precisely excises from and reintegrates into a bacterial gene (comK) to control bacterial infection processes without triggering viral reproduction.

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2. Coordination of Viral Elements

We uncovered a remarkable system where multiple viral elements within bacteria coordinate their activities through a shared regulatory system – e.g., the MpaR metalloprotease. This master regulator orchestrates the behaviour of different viral elements to enhance bacterial survival and infection capability, demonstrating a new level of bacteria-virus cooperation.

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3. Evolutionary Adaptation of Viruses to Their Host

Our research revealed how viral elements have evolved to enhance bacterial infection rather than prioritizing their own reproduction – an intriguing example of evolution driving cooperation rather than conflict. This adaptation suggests long-term co-evolution between bacteria and viruses in the context of host infection.

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Current Research Directions

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• Investigating the molecular mechanisms controlling phage responses in the mammalian environment
• Identifying new bacterial-viral regulatory networks
• Studying the evolution of bacteria-virus cooperation
• Detailed characterization of inter-phage regulatory circuits
• Understanding the mechanisms that uphold poly-lysogeny in L. monocytogenes
• Development of therapeutic approaches targeting bacteria-virus interactions

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Scientific Impact​

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• Understanding of bacteria-phage evolution and adaptation
• Development of new concepts in host-pathogen interactions
• Discovery of new mechanisms in bacterial gene regulation
• Identification of novel therapeutic targets

 

 

Specialized Listeria monocytogenes produce tailocins to provide a population-level competitive growth advantage.

Sigal N, Lichtenstein-Wolfheim R, Schlussel S, Azulay G, Borovok I, Holdengraber V, Elad N, Wolf SG, Zalk R, Zarivach R, Frank GA, Herskovits AA.Nat Microbiol. 2024 Oct;9(10):2727-2737. doi: 10.1038/s41564-024-01793-9. Epub 2024 Sep 19.PMID: 39300324

 

Metabolism of the Gram-Positive Bacterial Pathogen Listeria monocytogenes.

Sauer JD, Herskovits AA, O'Riordan MXD.Microbiol Spectr. 2019 Jul;7(4):10.1128/microbiolspec.gpp3-0066-2019. doi: 10.1128/microbiolspec.GPP3-0066-2019.PMID: 31418407 Free PMC article. Review.

A new perspective on lysogeny: prophages as active regulatory switches of bacteria.

Feiner R, Argov T, Rabinovich L, Sigal N, Borovok I, Herskovits AA.Nat Rev Microbiol. 2015 Oct;13(10):641-50. doi: 10.1038/nrmicro3527.PMID: 26373372 Review.

 

Temperate bacteriophages as regulators of host behavior.

Argov T, Azulay G, Pasechnek A, Stadnyuk O, Ran-Sapir S, Borovok I, Sigal N, Herskovits AA.Curr Opin Microbiol. 2017 Aug;38:81-87. doi: 10.1016/j.mib.2017.05.002. Epub 2017 May 23.PMID: 28544996 Review.

 

Bone Marrow-Derived Macrophage (BMDM ) Infection by Listeria monocytogenes.

Boichis E, Ran Sapir S, Herskovits AA.Methods Mol Biol. 2022;2427:83-93. doi: 10.1007/978-1-0716-1971-1_8.PMID: 35619027

Active Lysogeny in Listeria Monocytogenes Is a Bacteria-Phage Adaptive Response in the Mammalian Environment.

Pasechnek A, Rabinovich L, Stadnyuk O, Azulay G, Mioduser J, Argov T, Borovok I, Sigal N, Herskovits AA.Cell Rep. 2020 Jul 28;32(4):107956. doi: 10.1016/j.celrep.2020.107956.PMID: 32726621 Free PMC article.

 

A dual-function phage regulator controls the response of cohabiting phage elements via regulation of the bacterial SOS response.

Azulay G, Pasechnek A, Stadnyuk O, Ran-Sapir S, Fleisacher AM, Borovok I, Sigal N, Herskovits AA.Cell Rep. 2022 Apr 19;39(3):110723. doi: 10.1016/j.celrep.2022.110723.PMID: 35443160 Free PMC article.

A Metzincin and TIMP-Like Protein Pair of a Phage Origin Sensitize Listeria monocytogenes to Phage Lysins and Other Cell Wall Targeting Agents.

Boichis E, Sigal N, Borovok I, Herskovits AA.Microorganisms. 2021 Jun 18;9(6):1323. doi: 10.3390/microorganisms9061323.PMID: 34207021 Free PMC article.

Generation of Markerless Gene Deletion Mutants in Listeria monocytogenes Using a Mutated pheS for Counterselection.

Ran Sapir S, Boichis E, Herskovits AA.Methods Mol Biol. 2022;2427:3-10. doi: 10.1007/978-1-0716-1971-1_1.PMID: 35619020

 

Coordination of cohabiting phage elements supports bacteria-phage cooperation.

Argov T, Sapir SR, Pasechnek A, Azulay G, Stadnyuk O, Rabinovich L, Sigal N, Borovok I, Herskovits AA.Nat Commun. 2019 Nov 21;10(1):5288. doi: 10.1038/s41467-019-13296-x.PMID: 31754112 Free PMC article.

 

Listeria monocytogenes TcyKLMN Cystine/Cysteine Transporter Facilitates Glutathione Synthesis and Virulence Gene Expression.

Brenner M, Friedman S, Haber A, Livnat-Levanon N, Borovok I, Sigal N, Lewinson O, Herskovits AA.mBio. 2022 Jun 28;13(3):e0044822. doi: 10.1128/mbio.00448-22. Epub 2022 Apr 18.PMID: 35435705 Free PMC article.

 

L-glutamine Induces Expression of Listeria monocytogenes Virulence Genes.

Haber A, Friedman S, Lobel L, Burg-Golani T, Sigal N, Rose J, Livnat-Levanon N, Lewinson O, Herskovits AA.PLoS Pathog. 2017 Jan 23;13(1):e1006161. doi: 10.1371/journal.ppat.1006161. eCollection 2017 Jan.PMID: 28114430 Free PMC article.

Membrane chaperone SecDF plays a role in the secretion of Listeria monocytogenes major virulence factors.

Burg-Golani T, Pozniak Y, Rabinovich L, Sigal N, Nir Paz R, Herskovits AA.J Bacteriol. 2013 Dec;195(23):5262-72. doi: 10.1128/JB.00697-13. Epub 2013 Sep 20.PMID: 24056100 Free PMC article.

 

Bacterial ligands generated in a phagosome are targets of the cytosolic innate immune system.

Herskovits AA, Auerbuch V, Portnoy DA.PLoS Pathog. 2007 Mar;3(3):e51. doi: 10.1371/journal.ppat.0030051.PMID: 17397264 Free PMC article.

 

Prophage excision activates Listeria competence genes that promote phagosomal escape and virulence.

Rabinovich L, Sigal N, Borovok I, Nir-Paz R, Herskovits AA.Cell. 2012 Aug 17;150(4):792-802. doi: 10.1016/j.cell.2012.06.036.PMID: 22901809 Free article.

 

Listeria monocytogenes multidrug resistance transporters and cyclic di-AMP, which contribute to type I interferon induction, play a role in cell wall stress.

Kaplan Zeevi M, Shafir NS, Shaham S, Friedman S, Sigal N, Nir Paz R, Boneca IG, Herskovits AA.J Bacteriol. 2013 Dec;195(23):5250-61. doi: 10.1128/JB.00794-13. Epub 2013 Sep 20.PMID: 24056102 Free PMC article.

 

Accumulation of endoplasmic membranes and novel membrane-bound ribosome-signal recognition particle receptor complexes in Escherichia coli.

Herskovits AA, Shimoni E, Minsky A, Bibi E.J Cell Biol. 2002 Nov 11;159(3):403-10. doi: 10.1083/jcb.200204144. Epub 2002 Nov 4.PMID: 12417577 Free PMC article.

 

Listeria monocytogenes 6-Phosphogluconolactonase mutants induce increased activation of a host cytosolic surveillance pathway.

Crimmins GT, Schelle MW, Herskovits AA, Ni PP, Kline BC, Meyer-Morse N, Iavarone AT, Portnoy DA.Infect Immun. 2009 Jul;77(7):3014-22. doi: 10.1128/IAI.01511-08. Epub 2009 Apr 27.PMID: 19398547 Free PMC article.

Listeria monocytogenes multidrug resistance transporters activate a cytosolic surveillance pathway of innate immunity.

Crimmins GT, Herskovits AA, Rehder K, Sivick KE, Lauer P, Dubensky TW Jr, Portnoy DA.Proc Natl Acad Sci U S A. 2008 Jul 22;105(29):10191-6. doi: 10.1073/pnas.0804170105. Epub 2008 Jul 16.PMID: 18632558 Free PMC article.

Controlled branched-chain amino acids auxotrophy in Listeria monocytogenes allows isoleucine to serve as a host signal and virulence effector.

Brenner M, Lobel L, Borovok I, Sigal N, Herskovits AA.PLoS Genet. 2018 Mar 12;14(3):e1007283. doi: 10.1371/journal.pgen.1007283. eCollection 2018 Mar.PMID: 29529043 Free PMC article.

An Effective Counterselection System for Listeria monocytogenes and Its Use To Characterize the Monocin Genomic Region of Strain 10403S.

Argov T, Rabinovich L, Sigal N, Herskovits AA.Appl Environ Microbiol. 2017 Mar 2;83(6):e02927-16. doi: 10.1128/AEM.02927-16. Print 2017 Mar 15.PMID: 28039138 Free PMC article.

 

The Unc93b1 mutation 3d disrupts exogenous antigen presentation and signaling via Toll-like receptors 3, 7 and 9.

Tabeta K, Hoebe K, Janssen EM, Du X, Georgel P, Crozat K, Mudd S, Mann N, Sovath S, Goode J, Shamel L, Herskovits AA, Portnoy DA, Cooke M, Tarantino LM, Wiltshire T, Steinberg BE, Grinstein S, Beutler B.Nat Immunol. 2006 Feb;7(2):156-64. doi: 10.1038/ni1297. Epub 2006 Jan 15.PMID: 16415873

The metabolic regulator CodY links Listeria monocytogenes metabolism to virulence by directly activating the virulence regulatory gene prfA.

Lobel L, Sigal N, Borovok I, Belitsky BR, Sonenshein AL, Herskovits AA.Mol Microbiol. 2015 Feb;95(4):624-44. doi: 10.1111/mmi.12890. Epub 2014 Dec 30.PMID: 25430920 Free PMC article.

 

Systems Level Analyses Reveal Multiple Regulatory Activities of CodY Controlling Metabolism, Motility and Virulence in Listeria monocytogenes.

Lobel L, Herskovits AA.PLoS Genet. 2016 Feb 19;12(2):e1005870. doi: 10.1371/journal.pgen.1005870. eCollection 2016 Feb.PMID: 26895237 Free PMC article.

RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells.

Sigal N, Pasechnek A, Herskovits AA.J Vis Exp. 2016 Jun 4;(112):54044. doi: 10.3791/54044.PMID: 27341521 Free PMC article.

 

Metabolic Genetic Screens Reveal Multidimensional Regulation of Virulence Gene Expression in Listeria monocytogenes and an Aminopeptidase That Is Critical for PrfA Protein Activation.

Friedman S, Linsky M, Lobel L, Rabinovich L, Sigal N, Herskovits AA.Infect Immun. 2017 May 23;85(6):e00027-17. doi: 10.1128/IAI.00027-17. Print 2017 Jun.PMID: 28396325 Free PMC article.

The human P-glycoprotein transporter enhances the type I interferon response to Listeria monocytogenes infection.

Sigal N, Kaplan Zeevi M, Weinstein S, Peer D, Herskovits AA.Infect Immun. 2015 Jun;83(6):2358-68. doi: 10.1128/IAI.00380-15. Epub 2015 Mar 30.PMID: 25824830 Free PMC article.

Listeria monocytogenes MDR transporters are involved in LTA synthesis and triggering of innate immunity during infection.

Tadmor K, Pozniak Y, Burg Golani T, Lobel L, Brenner M, Sigal N, Herskovits AA.Front Cell Infect Microbiol. 2014 Feb 25;4:16. doi: 10.3389/fcimb.2014.00016. eCollection 2014.PMID: 24611134 Free PMC article.

Integrative genomic analysis identifies isoleucine and CodY as regulators of Listeria monocytogenes virulence.

Lobel L, Sigal N, Borovok I, Ruppin E, Herskovits AA.PLoS Genet. 2012 Sep;8(9):e1002887. doi: 10.1371/journal.pgen.1002887. Epub 2012 Sep 6.PMID: 22969433 Free PMC article.