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Kader Chowdhury QMM, Islam S, Narayanan L, Ogunleye SC, Wang S, Thu D, Freitag NE, Lawrence ML, Abdelhamed H. An insight into the role of branched-chain α-keto acid dehydrogenase (BKD) complex in branched-chain fatty acid biosynthesis and virulence of Listeria monocytogenes. J Bacteriol 2024; 206:e0003324. [PMID: 38899896 PMCID: PMC11270904 DOI: 10.1128/jb.00033-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Listeria monocytogenes is a foodborne bacterial pathogen that causes listeriosis. Positive regulatory factor A (PrfA) is a pleiotropic master activator of virulence genes of L. monocytogenes that becomes active upon the entry of the bacterium into the cytosol of infected cells. L. monocytogenes can survive and multiply at low temperatures; this is accomplished through the maintenance of appropriate membrane fluidity via branched-chain fatty acid (BCFA) synthesis. Branched-chain α-keto acid dehydrogenase (BKD), which is composed of four polypeptides encoded by lpd, bkdA1, bkdA2, and bkdB, is known to play a vital role in BCFA biosynthesis. Here, we constructed BKD-deficient Listeria strains by in-frame deletion of lpd, bkdA1, bkdA2, and bkdB genes. To determine the role in in vivo and in vitro, mouse model challenges, plaque assay in murine L2 fibroblast, and intracellular replication in J744A.1 macrophage were conducted. BKD-deficient strains exhibited defects in BCFA composition, virulence, and PrfA-regulon function within the host cells. Transcriptomics analysis revealed that the transcript level of the PrfA-regulon was lower in ΔbkdA1 strain than those in the wild-type. This study demonstrates that L. monocytogenes strains lacking BKD complex components were defective in PrfA-regulon function, and full activation of wild-type prfA may not occur within host cells in the absence of BKD. Further study will investigate the consequences of BKD deletion on PrfA function through altering BCFA catabolism.IMPORTANCEListeria monocytogenes is the causative agent of listeriosis, a disease with a high mortality rate. In this study, we have shown that the deletion of BKD can impact the function of PrfA and the PrfA-regulon. The production of virulence proteins within host cells is necessary for L. monocytogenes to promote its intracellular survival and is likely dependent on membrane integrity. We thus report a link between L. monocytogenes membrane integrity and the function of PrfA. This knowledge will increase our understanding of L. monocytogenes pathogenesis, which may provide insight into the development of antimicrobial agents.
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Affiliation(s)
- Q M Monzur Kader Chowdhury
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Shamima Islam
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Lakshmi Narayanan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Seto C. Ogunleye
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Shangshang Wang
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, Mississippi, USA
| | - Dinh Thu
- Tyson Foods, R&D Ingredient Solutions, Springdale, Arkansas, USA
| | - Nancy E. Freitag
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Mark L. Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
| | - Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA
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Lu Y, Mei N, Ying Y, Wang D, Li X, Zhao Y, Zhu Y, Shen S, Yin B. Bacteria-Based Nanoprobes for Cancer Therapy. Int J Nanomedicine 2024; 19:759-785. [PMID: 38283198 PMCID: PMC10821665 DOI: 10.2147/ijn.s438164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 01/04/2024] [Indexed: 01/30/2024] Open
Abstract
Surgical removal together with chemotherapy and radiotherapy has used to be the pillars of cancer treatment. Although these traditional methods are still considered as the first-line or standard treatments, non-operative situation, systemic toxicity or resistance severely weakened the therapeutic effect. More recently, synthetic biological nanocarriers elicited substantial interest and exhibited promising potential for combating cancer. In particular, bacteria and their derivatives are omnipotent to realize intrinsic tumor targeting and inhibit tumor growth with anti-cancer agents secreted and immune response. They are frequently employed in synergistic bacteria-mediated anticancer treatments to strengthen the effectiveness of anti-cancer treatment. In this review, we elaborate on the development, mechanism and advantage of bacterial therapy against cancer and then systematically introduce the bacteria-based nanoprobes against cancer and the recent achievements in synergistic treatment strategies and clinical trials. We also discuss the advantages as well as the limitations of these bacteria-based nanoprobes, especially the questions that hinder their application in human, exhibiting this novel anti-cancer endeavor comprehensively.
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Affiliation(s)
- Yiping Lu
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Nan Mei
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Yinwei Ying
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Dongdong Wang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Xuanxuan Li
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Yajing Zhao
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Yuqi Zhu
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Shun Shen
- Pharmacy Department, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, People’s Republic of China
- Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, People’s Republic of China
| | - Bo Yin
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China
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Macedo-da-Silva J, Rosa-Fernandes L, Gomes VDM, Santiago VF, Santos DM, Molnar CMS, Barboza BR, de Souza EE, Marques RF, Boscardin SB, Durigon EL, Marinho CRF, Wrenger C, Marie SKN, Palmisano G. Protein Arginylation Is Regulated during SARS-CoV-2 Infection. Viruses 2023; 15:v15020290. [PMID: 36851505 PMCID: PMC9964439 DOI: 10.3390/v15020290] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/09/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND In 2019, the world witnessed the onset of an unprecedented pandemic. By February 2022, the infection by SARS-CoV-2 has already been responsible for the death of more than 5 million people worldwide. Recently, we and other groups discovered that SARS-CoV-2 infection induces ER stress and activation of the unfolded protein response (UPR) pathway. Degradation of misfolded/unfolded proteins is an essential element of proteostasis and occurs mainly in lysosomes or proteasomes. The N-terminal arginylation of proteins is characterized as an inducer of ubiquitination and proteasomal degradation by the N-degron pathway. RESULTS The role of protein arginylation during SARS-CoV-2 infection was elucidated. Protein arginylation was studied in Vero CCL-81, macrophage-like THP1, and Calu-3 cells infected at different times. A reanalysis of in vivo and in vitro public omics data combined with immunoblotting was performed to measure levels of arginyl-tRNA-protein transferase (ATE1) and its substrates. Dysregulation of the N-degron pathway was specifically identified during coronavirus infections compared to other respiratory viruses. We demonstrated that during SARS-CoV-2 infection, there is an increase in ATE1 expression in Calu-3 and Vero CCL-81 cells. On the other hand, infected macrophages showed no enzyme regulation. ATE1 and protein arginylation was variant-dependent, as shown using P1 and P2 viral variants and HEK 293T cells transfection with the spike protein and receptor-binding domains (RBD). In addition, we report that ATE1 inhibitors, tannic acid and merbromine (MER) reduce viral load. This finding was confirmed in ATE1-silenced cells. CONCLUSIONS We demonstrate that ATE1 is increased during SARS-CoV-2 infection and its inhibition has potential therapeutic value.
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Affiliation(s)
- Janaina Macedo-da-Silva
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Livia Rosa-Fernandes
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
- Laboratory of Experimental Immunoparasitology, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Vinicius de Morais Gomes
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Veronica Feijoli Santiago
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Deivid Martins Santos
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | | | - Bruno Rafael Barboza
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Edmarcia Elisa de Souza
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Rodolfo Ferreira Marques
- Laboratory of Antigen Targeting for Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Silvia Beatriz Boscardin
- Laboratory of Antigen Targeting for Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Edison Luiz Durigon
- Laboratory of Clinical and Molecular Virology, Department of Microbiology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Claudio Romero Farias Marinho
- Laboratory of Experimental Immunoparasitology, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Suely Kazue Nagahashi Marie
- Laboratory of Molecular and Cellular Biology (LIM 15), Department of Neurology, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 01246-903, Brazil
| | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
- School of Natural Sciences, Macquarie University, Sydney 2109, Australia
- Correspondence: or ; Tel.: +55-11-99920-8662
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The molecular mechanisms of listeriolysin O-induced lipid membrane damage. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183604. [PMID: 33722646 DOI: 10.1016/j.bbamem.2021.183604] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/05/2021] [Accepted: 03/05/2021] [Indexed: 12/22/2022]
Abstract
Listeria monocytogenes is an intracellular food-borne pathogen that causes listeriosis, a severe and potentially life-threatening disease. Listeria uses a number of virulence factors to proliferate and spread to various cells and tissues. In this process, three bacterial virulence factors, the pore-forming protein listeriolysin O and phospholipases PlcA and PlcB, play a crucial role. Listeriolysin O belongs to a family of cholesterol-dependent cytolysins that are mostly expressed by gram-positive bacteria. Its unique structural features in an otherwise conserved three-dimensional fold, such as the acidic triad and proline-glutamate-serine-threonine-like sequence, enable the regulation of its intracellular activity as well as distinct extracellular functions. The stability of listeriolysin O is pH- and temperature-dependent, and this provides another layer of control of its activity in cells. Moreover, many recent studies have demonstrated a unique mechanism of pore formation by listeriolysin O, i.e., the formation of arc-shaped oligomers that can subsequently fuse to form membrane defects of various shapes and sizes. During listerial invasion of host cells, these membrane defects can disrupt phagosome membranes, allowing bacteria to escape into the cytosol and rapidly multiply. The activity of listeriolysin O is profoundly dependent on the amount and accessibility of cholesterol in the lipid membrane, which can be modulated by the phospholipase PlcB. All these prominent features of listeriolysin O play a role during different stages of the L. monocytogenes life cycle by promoting the proliferation of the pathogen while mitigating excessive damage to its replicative niche in the cytosol of the host cell.
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Abstract
The Gram-positive pathogen Listeria monocytogenes is able to promote its entry into a diverse range of mammalian host cells by triggering plasma membrane remodeling, leading to bacterial engulfment. Upon cell invasion, L. monocytogenes disrupts its internalization vacuole and translocates to the cytoplasm, where bacterial replication takes place. Subsequently, L. monocytogenes uses an actin-based motility system that allows bacterial cytoplasmic movement and cell-to-cell spread. L. monocytogenes therefore subverts host cell receptors, organelles and the cytoskeleton at different infection steps, manipulating diverse cellular functions that include ion transport, membrane trafficking, post-translational modifications, phosphoinositide production, innate immune responses as well as gene expression and DNA stability.
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Coelho C, Brown L, Maryam M, Vij R, Smith DFQ, Burnet MC, Kyle JE, Heyman HM, Ramirez J, Prados-Rosales R, Lauvau G, Nakayasu ES, Brady NR, Hamacher-Brady A, Coppens I, Casadevall A. Listeria monocytogenes virulence factors, including listeriolysin O, are secreted in biologically active extracellular vesicles. J Biol Chem 2019; 294:1202-1217. [PMID: 30504226 PMCID: PMC6349127 DOI: 10.1074/jbc.ra118.006472] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/28/2018] [Indexed: 01/25/2023] Open
Abstract
Outer membrane vesicles produced by Gram-negative bacteria have been studied for half a century but the possibility that Gram-positive bacteria secrete extracellular vesicles (EVs) was not pursued until recently due to the assumption that the thick peptidoglycan cell wall would prevent their release to the environment. However, following their discovery in fungi, which also have cell walls, EVs have now been described for a variety of Gram-positive bacteria. EVs purified from Gram-positive bacteria are implicated in virulence, toxin release, and transference to host cells, eliciting immune responses, and spread of antibiotic resistance. Listeria monocytogenes is a Gram-positive bacterium that causes listeriosis. Here we report that L. monocytogenes produces EVs with diameters ranging from 20 to 200 nm, containing the pore-forming toxin listeriolysin O (LLO) and phosphatidylinositol-specific phospholipase C (PI-PLC). Cell-free EV preparations were toxic to mammalian cells, the murine macrophage cell line J774.16, in a LLO-dependent manner, evidencing EV biological activity. The deletion of plcA increased EV toxicity, suggesting PI-PLC reduced LLO activity. Using simultaneous metabolite, protein, and lipid extraction (MPLEx) multiomics we characterized protein, lipid, and metabolite composition of bacterial cells and secreted EVs and found that EVs carry the majority of listerial virulence proteins. Using immunogold EM we detected LLO at several organelles within infected human epithelial cells and with high-resolution fluorescence imaging we show that dynamic lipid structures are released from L. monocytogenes during infection. Our findings demonstrate that L. monocytogenes uses EVs for toxin release and implicate these structures in mammalian cytotoxicity.
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Affiliation(s)
- Carolina Coelho
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205, , To whom correspondence may be addressed:
Hopkins Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205. E-mail:
| | - Lisa Brown
- the Department of Microbiology and Immunology and
| | - Maria Maryam
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Raghav Vij
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Daniel F. Q. Smith
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Meagan C. Burnet
- the Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, and
| | - Jennifer E. Kyle
- the Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, and
| | - Heino M. Heyman
- the Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, and
| | - Jasmine Ramirez
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | | | - Gregoire Lauvau
- the Department of Microbiology and Immunology and ,Division of Infectious Diseases of the Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - Ernesto S. Nakayasu
- the Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, and
| | - Nathan R. Brady
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Anne Hamacher-Brady
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Isabelle Coppens
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Arturo Casadevall
- From the W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205, ,the Department of Microbiology and Immunology and ,Division of Infectious Diseases of the Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, , Supported by National Institutes of Health Grants 5R01HL059842, 5R01AI033774, 5R37AI033142, and 5R01AI052733. To whom correspondence may be addressed:
Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205. E-mail:
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Chen C, Nguyen BN, Mitchell G, Margolis SR, Ma D, Portnoy DA. The Listeriolysin O PEST-like Sequence Co-opts AP-2-Mediated Endocytosis to Prevent Plasma Membrane Damage during Listeria Infection. Cell Host Microbe 2019; 23:786-795.e5. [PMID: 29902442 DOI: 10.1016/j.chom.2018.05.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/23/2018] [Accepted: 05/11/2018] [Indexed: 10/14/2022]
Abstract
Listeriolysin O (LLO) is a cholesterol-dependent cytolysin that mediates escape of Listeria monocytogenes from a phagosome, enabling growth of the bacteria in the host cell cytosol. LLO contains a PEST-like sequence that prevents it from killing infected cells, but the mechanism involved is unknown. We found that the LLO PEST-like sequence was necessary to mediate removal of LLO from the interior face of the plasma membrane, where it coalesces into discrete puncta. LLO interacts with Ap2a2, an adaptor protein involved in endocytosis, via its PEST-like sequence, and Ap2a2-dependent endocytosis is required to prevent LLO-induced cytotoxicity. An unrelated PEST-like sequence from a human G protein-coupled receptor (GPCR), which also interacts with Ap2a2, could functionally complement the PEST-like sequence in L. monocytogenes LLO. These data revealed that LLO co-opts the host endocytosis machinery to protect the integrity of the host plasma membrane during L. monocytogenes infection.
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Affiliation(s)
- Chen Chen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Brittney N Nguyen
- Graduate Group in Microbiology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Gabriel Mitchell
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shally R Margolis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Darren Ma
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Daniel A Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA.
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Nguyen BN, Peterson BN, Portnoy DA. Listeriolysin O: A phagosome-specific cytolysin revisited. Cell Microbiol 2019; 21:e12988. [PMID: 30511471 DOI: 10.1111/cmi.12988] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 12/17/2022]
Abstract
Listeriolysin O (LLO) is an essential determinant of Listeria monocytogenes pathogenesis that mediates the escape of L. monocytogenes from host cell vacuoles, thereby allowing replication in the cytosol without causing appreciable cell death. As a member of the cholesterol-dependent cytolysin (CDC) family of pore-forming toxins, LLO is unique in that it is secreted by a facultative intracellular pathogen, whereas all other CDCs are produced by pathogens that are largely extracellular. Replacement of LLO with other CDCs results in strains that are extremely cytotoxic and 10,000-fold less virulent in mice. LLO has structural and regulatory features that allow it to function intracellularly without causing cell death, most of which map to a unique N-terminal region of LLO referred to as the proline, glutamic acid, serine, threonine (PEST)-like sequence. Yet, while LLO has unique properties required for its intracellular site of action, extracellular LLO, like other CDCs, affects cells in a myriad of ways. Because all CDCs form pores in cholesterol-containing membranes that lead to rapid Ca2+ influx and K+ efflux, they consequently trigger a wide range of host cell responses, including mitogen-activated protein kinase activation, histone modification, and caspase-1 activation. There is no debate that extracellular LLO, like all other CDCs, can stimulate multiple cellular activities, but the primary question we wish to address in this perspective is whether these activities contribute to L. monocytogenes pathogenesis.
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Affiliation(s)
- Brittney N Nguyen
- Graduate Group in Microbiology, University of California, Berkeley, Berkeley, California
| | - Bret N Peterson
- Graduate Group in Microbiology, University of California, Berkeley, Berkeley, California
| | - Daniel A Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California.,Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California
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Intracellular Delivery: An Overview. TARGETED INTRACELLULAR DRUG DELIVERY BY RECEPTOR MEDIATED ENDOCYTOSIS 2019. [DOI: 10.1007/978-3-030-29168-6_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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11
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Flickinger JC, Rodeck U, Snook AE. Listeria monocytogenes as a Vector for Cancer Immunotherapy: Current Understanding and Progress. Vaccines (Basel) 2018; 6:E48. [PMID: 30044426 PMCID: PMC6160973 DOI: 10.3390/vaccines6030048] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/21/2018] [Accepted: 07/23/2018] [Indexed: 01/10/2023] Open
Abstract
Listeria monocytogenes, a Gram-positive facultative anaerobic bacterium, is becoming a popular vector for cancer immunotherapy. Indeed, multiple vaccines have been developed utilizing modified Listeria as a tool for generating immune responses against a variety of cancers. Moreover, over a dozen clinical trials testing Listeria cancer vaccines are currently underway, which will help to understand the utility of Listeria vaccines in cancer immunotherapy. This review aims to summarize current views on how Listeria-based vaccines induce potent antitumor immunity and the current state of Listeria-based cancer vaccines in clinical trials.
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Affiliation(s)
- John C Flickinger
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| | - Ulrich Rodeck
- Department of Dermatology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| | - Adam E Snook
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
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Osborne SE, Brumell JH. Listeriolysin O: from bazooka to Swiss army knife. Philos Trans R Soc Lond B Biol Sci 2018. [PMID: 28630160 DOI: 10.1098/rstb.2016.0222] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Listeria monocytogenes (Lm) is a Gram-positive facultative intracellular pathogen. Infections in humans can lead to listeriosis, a systemic disease with a high mortality rate. One important mechanism of Lm dissemination involves cell-to-cell spread after bacteria have entered the cytosol of host cells. Listeriolysin O (LLO; encoded by the hly gene) is a virulence factor present in Lm that plays a central role in the cell-to-cell spread process. LLO is a member of the cholesterol-dependent cytolysin (CDC) family of toxins that were initially thought to promote disease largely by inducing cell death and tissue destruction-essentially acting like a 'bazooka'. This view was supported by structural studies showing CDCs can form large pores in membranes. However, it is now appreciated that LLO has many subtle activities during Lm infection of host cells, and many of these likely do not involve large pores, but rather small membrane perforations. It is also appreciated that membrane repair pathways of host cells play a major role in limiting membrane damage by LLO and other toxins. LLO is now thought to represent a 'Swiss army knife', a versatile tool that allows Lm to induce many membrane alterations and cellular responses that promote bacterial dissemination during infection.This article is part of the themed issue 'Membrane pores: from structure and assembly, to medicine and technology'.
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Affiliation(s)
- Suzanne E Osborne
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
| | - John H Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8 .,Sickkids IBD Centre, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S 1A8
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Ghafari S, Komeilian M, Hashemi MS, Oushani S, Rigi G, Rashidieh B, Yarahmadi K, Khoddam F. Molecular docking based screening of Listeriolysin-O for improved inhibitors. Bioinformation 2017; 13:160-163. [PMID: 28690383 PMCID: PMC5498783 DOI: 10.6026/97320630013160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/23/2017] [Accepted: 04/23/2017] [Indexed: 12/30/2022] Open
Abstract
Listeriolysine-O (LLO) is a 50KDa protein responsible for Listeria monocytogenes pathogenicity. The structure of LLO (PDB ID: 4CDB) with domains D1 to D4 is known. Therefore, it is of interest to identify conserved regions among LLO variants for destabilizing oligomerization (50 mer complex) of its monomers using appropriate inhibitors. Therefore, it is of interest to identify suitable inhibitors for inhibiting LLO. Previous reports suggest the use of flavanoids like compounds for inhibiting LLO. Our interest is to identify improved compounds to destabilize LLO oligomerization. We used a library (Zinc database) containing 200,000 drug-like compounds against LLO using molecular docking based screening. This resulted in five hits that were further analyzed for pharmacological properties. The hit #1 (2-methyloctadecane- 1, 3, 4-triol) was further refined using appropriate modifications for creating a suitable pharmacophore model LLO inhibition. The modified compound (1-(4-Cyclopent-3-enyl-6, 7-dihydroxy-8-hydroxymethyl-nona-2, 8-dienylideneamino)-penta-1,4-dien-3-one) shows fitting binding properties with LLO with no undesirable pharmacological properties such as toxicity.
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Affiliation(s)
| | | | | | | | - Garshasb Rigi
- Department of Biology, Faculty of Science, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran
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Jiang Y, Lee J, Lee JH, Lee JW, Kim JH, Choi WH, Yoo YD, Cha-Molstad H, Kim BY, Kwon YT, Noh SA, Kim KP, Lee MJ. The arginylation branch of the N-end rule pathway positively regulates cellular autophagic flux and clearance of proteotoxic proteins. Autophagy 2016; 12:2197-2212. [PMID: 27560450 DOI: 10.1080/15548627.2016.1222991] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The N-terminal amino acid of a protein is an essential determinant of ubiquitination and subsequent proteasomal degradation in the N-end rule pathway. Using para-chloroamphetamine (PCA), a specific inhibitor of the arginylation branch of the pathway (Arg/N-end rule pathway), we identified that blocking the Arg/N-end rule pathway significantly impaired the fusion of autophagosomes with lysosomes. Under ER stress, ATE1-encoded Arg-tRNA-protein transferases carry out the N-terminal arginylation of the ER heat shock protein HSPA5 that initially targets cargo proteins, along with SQSTM1, to the autophagosome. At the late stage of autophagy, however, proteasomal degradation of arginylated HSPA5 might function as a critical checkpoint for the proper progression of autophagic flux in the cells. Consistently, the inhibition of the Arg/N-end rule pathway with PCA significantly elevated levels of MAPT and huntingtin aggregates, accompanied by increased numbers of LC3 and SQSTM1 puncta. Cells treated with the Arg/N-end rule inhibitor became more sensitized to proteotoxic stress-induced cytotoxicity. SILAC-based quantitative proteomics also revealed that PCA significantly alters various biological pathways, including cellular responses to stress, nutrient, and DNA damage, which are also closely involved in modulation of autophagic responses. Thus, our results indicate that the Arg/N-end rule pathway may function to actively protect cells from detrimental effects of cellular stresses, including proteotoxic protein accumulation, by positively regulating autophagic flux.
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Affiliation(s)
- Yanxialei Jiang
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea
| | - Jeeyoung Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Jung Hoon Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Joon Won Lee
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Ji Hyeon Kim
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Won Hoon Choi
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Young Dong Yoo
- b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Hyunjoo Cha-Molstad
- c World Class Institute, Korea Research Institute of Bioscience and Biotechnology , Ochang, Cheongwon , Korea
| | - Bo Yeon Kim
- c World Class Institute, Korea Research Institute of Bioscience and Biotechnology , Ochang, Cheongwon , Korea
| | - Yong Tae Kwon
- b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Sue Ah Noh
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Kwang Pyo Kim
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Min Jae Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
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Kaufmann SH, Dorhoi A. Molecular Determinants in Phagocyte-Bacteria Interactions. Immunity 2016; 44:476-491. [DOI: 10.1016/j.immuni.2016.02.014] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 01/28/2016] [Accepted: 02/17/2016] [Indexed: 12/24/2022]
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16
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Lee JH, Jiang Y, Kwon YT, Lee MJ. Pharmacological Modulation of the N-End Rule Pathway and Its Therapeutic Implications. Trends Pharmacol Sci 2015; 36:782-797. [PMID: 26434644 DOI: 10.1016/j.tips.2015.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 07/13/2015] [Accepted: 07/16/2015] [Indexed: 11/26/2022]
Abstract
The N-end rule pathway is a proteolytic system in which single N-terminal amino acids of short-lived substrates determine their metabolic half-lives. Substrates of this pathway have been implicated in the pathogenesis of many diseases, including malignancies, neurodegeneration, and cardiovascular disorders. This review provides a comprehensive overview of current knowledge about the mechanism and functions of the N-end rule pathway. Pharmacological strategies for the modulation of target substrate degradation are also reviewed, with emphasis on their in vivo implications. Given the rapid advances in structural and biochemical understanding of the recognition components (N-recognins) of the N-end rule pathway, small-molecule inhibitors and activating ligands of N-recognins emerge as therapeutic agents with novel mechanisms of action.
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Affiliation(s)
- Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Yanxialei Jiang
- Department of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Yong Tae Kwon
- Protein Metabolism Medical Research Center, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Protein Metabolism Medical Research Center, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea; Neuroscience Research Institute, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.
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17
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Park SE, Kim JM, Seok OH, Cho H, Wadas B, Kim SY, Varshavsky A, Hwang CS. Control of mammalian G protein signaling by N-terminal acetylation and the N-end rule pathway. Science 2015; 347:1249-1252. [PMID: 25766235 PMCID: PMC4748709 DOI: 10.1126/science.aaa3844] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Rgs2, a regulator of G proteins, lowers blood pressure by decreasing signaling through Gαq. Human patients expressing Met-Leu-Rgs2 (ML-Rgs2) or Met-Arg-Rgs2 (MR-Rgs2) are hypertensive relative to people expressing wild-type Met-Gln-Rgs2 (MQ-Rgs2). We found that wild-type MQ-Rgs2 and its mutant, MR-Rgs2, were destroyed by the Ac/N-end rule pathway, which recognizes N(α)-terminally acetylated (Nt-acetylated) proteins. The shortest-lived mutant, ML-Rgs2, was targeted by both the Ac/N-end rule and Arg/N-end rule pathways. The latter pathway recognizes unacetylated N-terminal residues. Thus, the Nt-acetylated Ac-MX-Rgs2 (X = Arg, Gln, Leu) proteins are specific substrates of the mammalian Ac/N-end rule pathway. Furthermore, the Ac/N-degron of Ac-MQ-Rgs2 was conditional, and Teb4, an endoplasmic reticulum (ER) membrane-embedded ubiquitin ligase, was able to regulate G protein signaling by targeting Ac-MX-Rgs2 proteins for degradation through their N(α)-terminal acetyl group.
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Affiliation(s)
- Sang-Eun Park
- Department of Life Sciences, Pohang University of Science and
Technology, Pohang, Gyeongbuk 790-784, South Korea
| | - Jeong-Mok Kim
- Department of Life Sciences, Pohang University of Science and
Technology, Pohang, Gyeongbuk 790-784, South Korea
| | - Ok-Hee Seok
- Department of Life Sciences, Pohang University of Science and
Technology, Pohang, Gyeongbuk 790-784, South Korea
| | - Hanna Cho
- Department of Life Sciences, Pohang University of Science and
Technology, Pohang, Gyeongbuk 790-784, South Korea
| | - Brandon Wadas
- Division of Biology and Biological Engineering, California Institute
of Technology, Pasadena, CA 91125, USA
| | - Seon-Young Kim
- Medical Genomics Research Center, KRIBB, Daejeon, South Korea
- Department of Functional Genomics, University of Science and
Technology, Daejeon, South Korea
| | - Alexander Varshavsky
- Division of Biology and Biological Engineering, California Institute
of Technology, Pasadena, CA 91125, USA
| | - Cheol-Sang Hwang
- Department of Life Sciences, Pohang University of Science and
Technology, Pohang, Gyeongbuk 790-784, South Korea
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18
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Alomairi J, Bonacci T, Ghigo E, Soubeyran P. Alterations of host cell ubiquitination machinery by pathogenic bacteria. Front Cell Infect Microbiol 2015; 5:17. [PMID: 25774357 PMCID: PMC4343185 DOI: 10.3389/fcimb.2015.00017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/09/2015] [Indexed: 11/13/2022] Open
Abstract
Response of immune and non-immune cells to pathogens infections is a very dynamic process. It involves the activation/modulation of many pathways leading to actin remodeling, membrane engulfing, phagocytosis, vesicle trafficking, phagolysosome formation, aiming at the destruction of the intruder. These sophisticated and rapid mechanisms rely on post-translational modifications (PTMs) of key host cells' factors, and bacteria have developed various strategies to manipulate them to favor their survival. Among these important PTMs, ubiquitination has emerged as a major mediator/modulator/regulator of host cells response to infections that pathogens have also learned to use for their own benefit. In this mini-review, we summarize our current knowledge about the normal functions of ubiquitination during host cell infection, and we detail its hijacking by model pathogens to escape clearance and to proliferate.
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Affiliation(s)
- Jaafar Alomairi
- Cellular Stress, Centre de Recherche en Carcérologie de Marseille, INSERM UMR 1068, CNRS UMR 7258, Aix-Marseille University and Institut Paoli-Calmettes Marseille, France ; Infections, Gender and Pregnancy Laboratory, URMITE-IRD198, INSERM U1095, CNRS UMR7278, Aix-Marseille University Marseille, France
| | - Thomas Bonacci
- Cellular Stress, Centre de Recherche en Carcérologie de Marseille, INSERM UMR 1068, CNRS UMR 7258, Aix-Marseille University and Institut Paoli-Calmettes Marseille, France
| | - Eric Ghigo
- Infections, Gender and Pregnancy Laboratory, URMITE-IRD198, INSERM U1095, CNRS UMR7278, Aix-Marseille University Marseille, France
| | - Philippe Soubeyran
- Cellular Stress, Centre de Recherche en Carcérologie de Marseille, INSERM UMR 1068, CNRS UMR 7258, Aix-Marseille University and Institut Paoli-Calmettes Marseille, France
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Ciolacu L, Nicolau AI, Wagner M, Rychli K. Listeria monocytogenes isolated from food samples from a Romanian black market show distinct virulence profiles. Int J Food Microbiol 2014; 209:44-51. [PMID: 25241012 DOI: 10.1016/j.ijfoodmicro.2014.08.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 02/06/2023]
Abstract
Listeria monocytogenes is a facultative intracellular foodborne pathogen responsible for listeriosis. In a recent study, in which we investigated neglected exogenous routes of transmission of foodborne pathogens into the European Union, we have isolated 15 L. monocytogenes strains in food products, which were imported from the Republic of Moldavia to Romania and illegally sold at a local market. The aim of this study was to characterize the subtype and virulence potential of these 15 L. monocytogenes strains. Multilocus sequence typing revealed that these L. monocytogenes strains belong to six different sequence types (ST2, ST8, ST9, ST20, ST121 and ST155). In addition, in vitro virulence assays using human intestinal epithelial Caco2 and macrophage-like THP1 cells showed a high strain variability regarding the invasion efficiency in Caco2 cells (0.98-2.78%) and the intracellular growth rate in both cell types. Both ST121 strains and the ST9 isolate were unable to invade Caco2 cells, and all ST155 strains showed no proliferation inside macrophages and revealed low cytotoxicity. Furthermore we performed sequence analysis of three main virulence factors: PrfA, internalin A (InlA) and listeriolysin O (LLO). The Romanian food isolates showed a high diversity in the InlA and LLO amino acid sequences, whereas the amino acid sequence of PrfA of all strains was identical. Overall, the amino acid sequences of PrfA, InlA and LLO were identical for strains belonging to the same ST. We detected in total 30 different amino acid substitutions, resulting in seven different InlA variants, two of which have not yet been described. The three strains, which were unable to invade Caco2 cells, harboured a premature stop codon resulting in truncated InlA. Furthermore, we detected four different amino acid substitutions in the LLO sequence, which are present in four variants. The number of LLO mutations correlates negatively with intracellular growth in Caco2 and THP1 cells and subsequently with cytotoxicity. In conclusion, we show that L. monocytogenes isolated from food samples from a Romanian black market show distinct virulence profiles, due to a high diversity in the amino acid sequence of main virulence factors.
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Affiliation(s)
- Luminita Ciolacu
- Institute for Milk Hygiene, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria; "Dunarea de Jos" University of Galati, 47 Domneasca St., 800008 Galaţi, Romania.
| | - Anca Ioana Nicolau
- "Dunarea de Jos" University of Galati, 47 Domneasca St., 800008 Galaţi, Romania.
| | - Martin Wagner
- Institute for Milk Hygiene, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Kathrin Rychli
- Institute for Milk Hygiene, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria.
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20
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Wood LM, Paterson Y. Attenuated Listeria monocytogenes: a powerful and versatile vector for the future of tumor immunotherapy. Front Cell Infect Microbiol 2014; 4:51. [PMID: 24860789 PMCID: PMC4026700 DOI: 10.3389/fcimb.2014.00051] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/04/2014] [Indexed: 12/17/2022] Open
Abstract
For over a century, inactivated or attenuated bacteria have been employed in the clinic as immunotherapies to treat cancer, starting with the Coley's vaccines in the 19th century and leading to the currently approved bacillus Calmette-Guérin vaccine for bladder cancer. While effective, the inflammation induced by these therapies is transient and not designed to induce long-lasting tumor-specific cytolytic T lymphocyte (CTL) responses that have proven so adept at eradicating tumors. Therefore, in order to maintain the benefits of bacteria-induced acute inflammation but gain long-lasting anti-tumor immunity, many groups have constructed recombinant bacteria expressing tumor-associated antigens (TAAs) for the purpose of activating tumor-specific CTLs. One bacterium has proven particularly adept at inducing powerful anti-tumor immunity, Listeria monocytogenes (Lm). Lm is a gram-positive bacterium that selectively infects antigen-presenting cells wherein it is able to efficiently deliver tumor antigens to both the MHC Class I and II antigen presentation pathways for activation of tumor-targeting CTL-mediated immunity. Lm is a versatile bacterial vector as evidenced by its ability to induce therapeutic immunity against a wide-array of TAAs and specifically infect and kill tumor cells directly. It is for these reasons, among others, that Lm-based immunotherapies have delivered impressive therapeutic efficacy in preclinical models of cancer for two decades and are now showing promise clinically. In this review, we will provide an overview of the history leading up to the development of current Lm-based immunotherapies, the advantages and mechanisms of Lm as a therapeutic vaccine vector, the preclinical experience with Lm-based immunotherapies targeting a number of malignancies, and the recent findings from clinical trials along with concluding remarks on the future of Lm-based tumor immunotherapies.
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Affiliation(s)
- Laurence M Wood
- Immunotherapeutics and Biotechnology, Texas Tech University Health Sciences Center Abilene, TX, USA
| | - Yvonne Paterson
- Microbiology, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA ; University of Pennsylvania School of Nursing Philadelphia, PA, USA
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21
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Seveau S. Multifaceted activity of listeriolysin O, the cholesterol-dependent cytolysin of Listeria monocytogenes. Subcell Biochem 2014; 80:161-95. [PMID: 24798012 DOI: 10.1007/978-94-017-8881-6_9] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins that are produced by numerous Gram-positive bacterial pathogens. These toxins are released in the extracellular environment as water-soluble monomers or dimers that bind to cholesterol-rich membranes and assemble into large pore complexes. Depending upon their concentration, the nature of the host cell and membrane (cytoplasmic or intracellular) they target, the CDCs can elicit many different cellular responses. Among the CDCs, listeriolysin O (LLO), which is a major virulence factor of the facultative intracellular pathogen Listeria monocytogenes, is involved in several stages of the intracellular lifecycle of the bacterium and displays unique characteristics. It has long been known that following L. monocytogenes internalization into host cells, LLO disrupts the internalization vacuole, enabling the bacterium to replicate into the host cell cytosol. LLO is then used by cytosolic bacteria to spread from cell to cell, avoiding bacterial exposure to the extracellular environment. Although LLO is continuously produced during the intracellular lifecycle of L. monocytogenes, several processes limit its toxicity to ensure the survival of infected cells. It was previously thought that LLO activity was limited to mediating vacuolar escape during bacterial entry and cell to cell spreading. This concept has been challenged by compelling evidence suggesting that LLO secreted by extracellular L. monocytogenes perforates the host cell plasma membrane, triggering important host cell responses. This chapter provides an overview of the well-established intracellular activity of LLO and the multiple roles attributed to LLO secreted by extracellular L. monocytogenes.
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Affiliation(s)
- Stephanie Seveau
- Department of Microbiology, Department of Microbial Infection and Immunity, The Ohio State University, 484 West, 12th Avenue, Columbus, OH, 43210-1292, USA,
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Sun R, Liu Y. Listeriolysin O as a strong immunogenic molecule for the development of new anti-tumor vaccines. Hum Vaccin Immunother 2013; 9:1058-68. [PMID: 23399758 PMCID: PMC3899140 DOI: 10.4161/hv.23871] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/23/2013] [Accepted: 02/03/2013] [Indexed: 11/19/2022] Open
Abstract
The pore-forming toxin listeriolysin O (LLO), which is produced by Listeria monocytogenes, mediates bacterial phagosomal escape and facilitates bacterial multiplication during infection. This toxin has recently gained attention because of its confirmed role in the controlled and specific modulation of the immune response. Currently, cancer immunotherapies are focused on conquering the immune tolerance induced by poorly immunogenic tumor antigens and eliciting strong, lasting immunological memory. An effective way to achieve these goals is the co-administration of potent immunomodulatory adjuvant components with vaccine vectors. LLO, a toxin that belongs to the family of cholesterol-dependent cytolysins (CDCs), exhibits potent cell type-non-specific toxicity and is a source of dominant CD4(+) and CD8(+) T cell epitopes. According to recent research, in addition to its effective cytotoxicity as a cancer immunotherapeutic drug, the non-specific adjuvant property of LLO makes it promising for the development of efficacious anti-tumor vaccines.
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Affiliation(s)
- Rui Sun
- Department of Pathology; Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences; School of Basic Medicine; Peking Union Medical College; Beijing, P.R. China
| | - Yuqin Liu
- Department of Pathology; Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences; School of Basic Medicine; Peking Union Medical College; Beijing, P.R. China
- Cell Resource Center; Institute of Basic Medical Sciences; Chinese Academy of Medical Sciences; School of Basic Medicine; Peking Union Medical College; Beijing, P.R. China
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Hotze EM, Tweten RK. Membrane assembly of the cholesterol-dependent cytolysin pore complex. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:1028-38. [PMID: 21835159 PMCID: PMC3243806 DOI: 10.1016/j.bbamem.2011.07.036] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 07/24/2011] [Indexed: 12/16/2022]
Abstract
The cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins that are produced, secreted and contribute to the pathogenesis of many species of Gram-positive bacteria. The assembly of the CDC pore-forming complex has been under intense study for the past 20 years. These studies have revealed a molecular mechanism of pore formation that exhibits many novel features. The CDCs form large β-barrel pore complexes that are assembled from 35 to 40 soluble CDC monomers. Pore formation is dependent on the presence of membrane cholesterol, which functions as the receptor for most CDCs. Cholesterol binding initiates significant secondary and tertiary structural changes in the monomers, which lead to the assembly of a large membrane embedded β-barrel pore complex. This review will focus on the molecular mechanism of assembly of the CDC membrane pore complex and how these studies have led to insights into the mechanism of pore formation for other pore-forming proteins. This article is part of a Special Issue entitled: Protein Folding in Membranes.
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Affiliation(s)
- Eileen M. Hotze
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Rodney K. Tweten
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Development of a single-gene, signature-tag-based approach in combination with alanine mutagenesis to identify listeriolysin O residues critical for the in vivo survival of Listeria monocytogenes. Infect Immun 2012; 80:2221-30. [PMID: 22451517 DOI: 10.1128/iai.06196-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Listeriolysin O (LLO) is a pore-forming toxin of the cholesterol-dependent cytolysin (CDC) family and a primary virulence factor of the intracellular pathogen Listeria monocytogenes. LLO mediates rupture of phagosomal membranes, thereby releasing bacteria into the growth-permissive host cell cytosol. Several unique features of LLO allow its activity to be precisely regulated in order to facilitate phagosomal escape, intracellular growth, and cell-to-cell spread. To improve our understanding of the multifaceted contribution of LLO to the pathogenesis of L. monocytogenes, we developed a screen that combined saturation mutagenesis and signature tags, termed in vivo analysis by saturation mutagenesis and signature tags (IVASS). We generated a library of LLO mutant strains, each harboring a single amino acid substitution and a signature tag, by using the previously described pPL2 integration vector. The signature tags acted as molecular barcodes, enabling high-throughput, parallel analysis of 40 mutants in a single animal and identification of attenuated mutants by negative selection. Using the IVASS technique we were able to screen over 90% of the 505 amino acids present in LLO and identified 60 attenuated mutants. Of these, 39 LLO residues were previously uncharacterized and potentially revealed novel functions of the toxin during infection. The mutants that were subsequently analyzed in vivo each conferred a 2- to 4-orders of magnitude loss in virulence compared to wild type, thereby validating the screening methods. Phenotypic analysis of the LLO mutant library using common in vitro techniques suggested that the functional contributions of some residues could only have been revealed through in vivo analysis.
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25
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Lam GY, Czuczman MA, Higgins DE, Brumell JH. Interactions of Listeria monocytogenes with the Autophagy System of Host Cells. Adv Immunol 2012; 113:7-18. [DOI: 10.1016/b978-0-12-394590-7.00008-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Bavdek A, Kostanjšek R, Antonini V, Lakey JH, Dalla Serra M, Gilbert RJC, Anderluh G. pH dependence of listeriolysin O aggregation and pore-forming ability. FEBS J 2011; 279:126-41. [PMID: 22023160 DOI: 10.1111/j.1742-4658.2011.08405.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Listeriolysin O (LLO) is the major factor implicated in the escape of Listeria monocytogenes from the phagolysosome. It is the only representative of cholesterol-dependent cytolysins that exhibits pH-dependent activity. Despite intense studies of LLO pH-dependence, this feature of the toxin still remains incompletely explained. Here we used fluorescence and CD spectroscopy to show that the structure of LLO is not detectably affected by pH at room temperature. We observed slightly altered haemolytic and permeabilizing activities at different pH values, which we relate to reduced binding of LLO to the lipid membranes. However, alkaline pH and elevated temperatures caused rapid denaturation of LLO. Aggregates of the toxin were able to bind Congo red and Thioflavin T dyes and were visible under transmission electron microscopy as large, amorphous, micrometer-sized assemblies. The aggregates had the biophysical properties of amyloid. Analytical ultracentrifugation indicated dimerization of the protein in acidic conditions, which protects the protein against premature denaturation in the phagolysosome, where toxin activity takes place. We therefore suggest that LLO spontaneously aggregates at the neutral pH found in the host cell cytosol and that this is a major mechanism of LLO inactivation.
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Affiliation(s)
- Andrej Bavdek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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Sriram SM, Kim BY, Kwon YT. The N-end rule pathway: emerging functions and molecular principles of substrate recognition. Nat Rev Mol Cell Biol 2011; 12:735-47. [PMID: 22016057 DOI: 10.1038/nrm3217] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The N-end rule defines the protein-destabilizing activity of a given amino-terminal residue and its post-translational modification. Since its discovery 25 years ago, the pathway involved in the N-end rule has been thought to target only a limited set of specific substrates of the ubiquitin-proteasome system. Recent studies have provided insights into the components, substrates, functions and structural basis of substrate recognition. The N-end rule pathway is now emerging as a major cellular proteolytic system, in which the majority of proteins are born with or acquire specific N-terminal degradation determinants through protein-specific or global post-translational modifications.
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Affiliation(s)
- Shashikanth M Sriram
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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Varshavsky A. The N-end rule pathway and regulation by proteolysis. Protein Sci 2011; 20:1298-345. [PMID: 21633985 PMCID: PMC3189519 DOI: 10.1002/pro.666] [Citation(s) in RCA: 527] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 05/16/2011] [Accepted: 05/18/2011] [Indexed: 01/12/2023]
Abstract
The N-end rule relates the regulation of the in vivo half-life of a protein to the identity of its N-terminal residue. Degradation signals (degrons) that are targeted by the N-end rule pathway include a set called N-degrons. The main determinant of an N-degron is a destabilizing N-terminal residue of a protein. In eukaryotes, the N-end rule pathway is a part of the ubiquitin system and consists of two branches, the Ac/N-end rule and the Arg/N-end rule pathways. The Ac/N-end rule pathway targets proteins containing N(α) -terminally acetylated (Nt-acetylated) residues. The Arg/N-end rule pathway recognizes unacetylated N-terminal residues and involves N-terminal arginylation. Together, these branches target for degradation a majority of cellular proteins. For example, more than 80% of human proteins are cotranslationally Nt-acetylated. Thus most proteins harbor a specific degradation signal, termed (Ac)N-degron, from the moment of their birth. Specific N-end rule pathways are also present in prokaryotes and in mitochondria. Enzymes that produce N-degrons include methionine-aminopeptidases, caspases, calpains, Nt-acetylases, Nt-amidases, arginyl-transferases and leucyl-transferases. Regulated degradation of specific proteins by the N-end rule pathway mediates a legion of physiological functions, including the sensing of heme, oxygen, and nitric oxide; selective elimination of misfolded proteins; the regulation of DNA repair, segregation and condensation; the signaling by G proteins; the regulation of peptide import, fat metabolism, viral and bacterial infections, apoptosis, meiosis, spermatogenesis, neurogenesis, and cardiovascular development; and the functioning of adult organs, including the pancreas and the brain. Discovered 25 years ago, this pathway continues to be a fount of biological insights.
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Affiliation(s)
- Alexander Varshavsky
- 1Division of Biology, California Institute of Technology, Pasadena, California 91125.
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Stavru F, Archambaud C, Cossart P. Cell biology and immunology of Listeria monocytogenes infections: novel insights. Immunol Rev 2011; 240:160-84. [DOI: 10.1111/j.1600-065x.2010.00993.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Abstract
A variety of bacterial intracellular pathogens target the host cell ubiquitin system during invasion, a process that involves transient but fundamental changes in the actin cytoskeleton and plasma membrane. These changes are induced by bacterial proteins, which can be surface associated, secreted or injected directly into the host cell. Here, the invasion strategies of two extensively studied intracellular bacteria, Salmonella enterica serovar Typhimurium and Listeria monocytogenes, are used to illustrate some of the diverse ways by which bacterial pathogens intersect the host cell ubiquitin pathway.
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Affiliation(s)
- Olivia Steele-Mortimer
- Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA.
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Branched-chain fatty acids promote Listeria monocytogenes intracellular infection and virulence. Infect Immun 2010; 78:4667-73. [PMID: 20823206 DOI: 10.1128/iai.00546-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Anteiso-branched-chain fatty acids (BCFA) represent the dominant group of membrane fatty acids and have been established as crucial determinants in resistance against environmental stresses in Listeria monocytogenes, a facultative intracellular pathogen. Here, we investigate the role of anteiso-BCFA in L. monocytogenes virulence by using mutants deficient in branched-chain alpha-keto acid dehydrogenase (BKD), an enzyme complex involved in the synthesis of BCFA. In tissue culture models of infection, anteiso-BCFA contributed to intracellular growth and survival in macrophages and significantly enhanced plaque formation upon prolonged infection in L2 fibroblasts. The intracellular defects observed could be attributed partially to insufficient listeriolysin O (LLO) production, indicating a requirement for anteiso-BCFA in regulating virulence factor production. In a murine model of infection, the BKD-deficient mutant was highly attenuated, further emphasizing the importance of BKD-mediated metabolism in L. monocytogenes virulence. This study demonstrates an underappreciated role for BCFA in bacterial pathogenesis, which may provide insight into the development and application of antimicrobial agents.
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Listeria monocytogenes PrsA2 is required for virulence factor secretion and bacterial viability within the host cell cytosol. Infect Immun 2010; 78:4944-57. [PMID: 20823208 DOI: 10.1128/iai.00532-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the course of establishing its replication niche within the cytosol of infected host cells, the facultative intracellular bacterial pathogen Listeria monocytogenes must efficiently regulate the secretion and activity of multiple virulence factors. L. monocytogenes encodes two predicted posttranslocation secretion chaperones, PrsA1 and PrsA2, and evidence suggests that PrsA2 has been specifically adapted for bacterial pathogenesis. PrsA-like chaperones have been identified in a number of Gram-positive bacteria, where they are reported to function at the bacterial membrane-cell wall interface to assist in the folding of proteins translocated across the membrane; in some cases, these proteins have been found to be essential for bacterial viability. In this study, the contributions of PrsA2 and PrsA1 to L. monocytogenes growth and protein secretion were investigated in vitro and in vivo. Neither PrsA2 nor PrsA1 was found to be essential for L. monocytogenes growth in broth culture; however, optimal bacterial viability was found to be dependent upon PrsA2 for L. monocytogenes located within the cytosol of host cells. Proteomic analyses of prsA2 mutant strains in the presence of a mutationally activated allele of the virulence regulator PrfA revealed a critical requirement for PrsA2 activity under conditions of PrfA activation, an event which normally takes place within the host cell cytosol. Despite a high degree of amino acid similarity, no detectable degree of functional overlap was observed between PrsA2 and PrsA1. Our results indicate a critical requirement for PrsA2 under conditions relevant to host cell infection.
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Post-translational modifications in host cells during bacterial infection. FEBS Lett 2010; 584:2748-58. [PMID: 20493189 DOI: 10.1016/j.febslet.2010.05.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 05/10/2010] [Indexed: 12/24/2022]
Abstract
Post-translational modification of proteins is a widespread mechanism used by both prokaryotic and eukaryotic cells to modify the activity of key factors that plays fundamental roles in cellular physiology. This review focuses on how bacterial pathogens can interfere with host post-translational modifications to promote their own survival and replication.
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Sauer JD, Witte CE, Zemansky J, Hanson B, Lauer P, Portnoy DA. Listeria monocytogenes triggers AIM2-mediated pyroptosis upon infrequent bacteriolysis in the macrophage cytosol. Cell Host Microbe 2010; 7:412-9. [PMID: 20417169 DOI: 10.1016/j.chom.2010.04.004] [Citation(s) in RCA: 257] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 03/03/2010] [Accepted: 03/27/2010] [Indexed: 12/29/2022]
Abstract
A host defense strategy against pathogens is the induction of cell death, thereby eliminating the pathogen's intracellular niche. Pyroptosis, one such form of cell death, is dependent on inflammasome activation. In a genetic screen to identify Listeria monocytogenes mutants that induced altered levels of host cell death, we identified a mutation in lmo2473 that caused hyperstimulation of IL-1beta secretion and pyroptosis following bacteriolysis in the macrophage cytosol. In addition, strains engineered to lyse in the cytosol by expression of both bacteriophage holin and lysin or induced to lyse by treatment with ampicillin stimulated pyroptosis. Pyroptosis was independent of the Nlrp3 and Nlrc4 inflammasome receptors but dependent on the inflammasome adaptor ASC and the cytosolic DNA sensor AIM2. Importantly, wild-type L. monocytogenes were also found to lyse, albeit at low levels, and trigger AIM2-dependent pyroptosis. These data suggested that pyroptosis is triggered by bacterial DNA released during cytosolic lysis.
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Affiliation(s)
- John-Demian Sauer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA
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Wood LM, Pan ZK, Shahabi V, Paterson Y. Listeria-derived ActA is an effective adjuvant for primary and metastatic tumor immunotherapy. Cancer Immunol Immunother 2010; 59:1049-1058. [PMID: 20213121 DOI: 10.1007/s00262-010-0830-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Accepted: 02/08/2010] [Indexed: 12/25/2022]
Abstract
Tumor immunotherapy is currently at the cusp of becoming an important aspect of comprehensive cancer treatment in the clinic. However, the need for improved adjuvants to augment immune responses against tumor antigens is always present. In this paper, we characterize the Listeria monocytogenes-derived actin-nucleating protein, ActA, as a novel adjuvant for use in tumor immunotherapy. ActA is a virulence factor that is expressed on the cell surface of L. monocytogenes and facilitates the production of actin tails that propel Listeria throughout the cytosol of an infected host cell. It is believed that this ActA-dependent cytosolic motility allows Listeria to evade adaptive host cell defenses and facilitates its invasion into a proximal uninfected host cell. However, there is evidence that ActA fused to a tumor antigen and delivered by L. monocytogenes can perform a beneficial function in tumor immunotherapy as an adjuvant. Our investigation of this adjuvant activity demonstrates that ActA, either fused to or administered as a mixture with a tumor antigen, can augment anti-tumor immune responses, break immune tolerance and facilitate tumor eradication, which suggests that ActA is not only an effective adjuvant in tumor immunotherapy but can also be applied in a number of therapeutic settings.
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Affiliation(s)
- Laurence M Wood
- University of Pennsylvania, Department of Microbiology, 323 Johnson Pavilion, Philadelphia, PA 19104
| | - Zhen-Kun Pan
- University of Pennsylvania, Department of Microbiology, 323 Johnson Pavilion, Philadelphia, PA 19104
| | - Vafa Shahabi
- Advaxis Inc., The Technology Centre of New Jersey, Suite 117, 675 U.S. Route 1, North Brunswick, NJ 08902
| | - Yvonne Paterson
- University of Pennsylvania, Department of Microbiology, 323 Johnson Pavilion, Philadelphia, PA 19104
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Graciet E, Mesiti F, Wellmer F. Structure and evolutionary conservation of the plant N-end rule pathway. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:741-51. [PMID: 20003166 DOI: 10.1111/j.1365-313x.2009.04099.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal amino acid residue. While some N-terminal residues result in metabolically stable proteins, other, so-called destabilizing residues, lead to rapid protein turnover. The N-end rule pathway, which mediates the recognition and degradation of proteins with N-terminal destabilizing residues, is present in all organisms examined, including prokaryotes. This protein degradation pathway has a hierarchical organization in which some N-terminal residues, called primary destabilizing residues, are directly recognized by specific ubiquitin ligases. Other destabilizing residues, termed secondary and tertiary destabilizing residues, require modifications before the corresponding proteins can be targeted for degradation by ubiquitin ligases. In eukaryotes, the N-end rule pathway is a part of the ubiquitin/proteasome system and is known to play essential roles in a broad range of biological processes in fungi, animals and plants. While the structure of the N-end rule pathway has been extensively studied in yeast and mammals, knowledge of its organization in plants is limited. Using both tobacco and Arabidopsis, we identified the complete sets destabilizing and stabilizing N-terminal residues. We also characterized the hierarchical organization of the plant N-end rule by identifying and determining the specificity of two distinct N-terminal amidohydrolases (Nt-amidases) of Arabidopsis that are essential for the destabilizing activity of the tertiary destabilizing residues Asn and Gln. Our results indicate that both the N-end rule itself and mechanistic aspects of the N-end rule pathway in angiosperms are very similar to those of mammals.
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Affiliation(s)
- Emmanuelle Graciet
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
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Multivalency-assisted control of intracellular signaling pathways: application for ubiquitin- dependent N-end rule pathway. ACTA ACUST UNITED AC 2009; 16:121-31. [PMID: 19246002 DOI: 10.1016/j.chembiol.2009.01.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/04/2009] [Accepted: 01/21/2009] [Indexed: 11/23/2022]
Abstract
Intracellular signaling is often mediated by a family of functionally overlapping signal mediators that contain multiple sites interacting with other proteins or ligands with weak affinity (K(d) > microM). Conjugation of multiple low-affinity ligands into a high-affinity multivalent molecule provides a means to control the entire protein family within a single intracellular pathway. The N-end rule pathway is a ubiquitin (Ub)-dependent proteolytic system where at least four Ub ligases, called N-recognins, have a common domain critical for binding to type 1 (basic) and type 2 (bulky hydrophobic) destabilizing N-terminal residues of substrates as degrons. The recent development of a heterodivalent inhibitor targeting type 1 and type 2 substrate binding sites of the N-recognin family provides new opportunities to manipulate this proteolytic pathway in biochemical and pathophysiological conditions. We overview the N-end rule pathway as an intracellular target for heterodivalent molecules and discuss the basis of thermodynamics and kinetics related to heterodivalent interactions.
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The posttranslocation chaperone PrsA2 contributes to multiple facets of Listeria monocytogenes pathogenesis. Infect Immun 2009; 77:2612-23. [PMID: 19451247 DOI: 10.1128/iai.00280-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Listeria monocytogenes is an intracellular bacterial pathogen whose virulence depends on the regulated expression of numerous secreted bacterial factors. As for other gram-positive bacteria, many proteins secreted by L. monocytogenes are translocated across the bacterial membrane in an unfolded state to the compartment existing between the membrane and the cell wall. This compartment presents a challenging environment for protein folding due to its high density of negative charge, high concentrations of cations, and low pH. We recently identified PrsA2 as a gene product required for L. monocytogenes virulence. PrsA2 was identified based on its increased secretion by strains containing a mutationally activated form of prfA, the key regulator of L. monocytogenes virulence gene expression. The prsA2 gene product is one of at least two predicted peptidyl-prolyl cis/trans-isomerases encoded by L. monocytogenes; these proteins function as posttranslocation protein chaperones and/or foldases. In this study, we demonstrate that PrsA2 plays a unique and important role in L. monocytogenes pathogenesis by promoting the activity and stability of at least two critical secreted virulence factors: listeriolysin O (LLO) and a broad-specificity phospholipase. Loss of PrsA2 activity severely attenuated virulence in mice and impaired bacterial cell-to-cell spread in host cells. In contrast, mutants lacking prsA1 resembled wild-type bacteria with respect to intracellular growth and cell-to-cell spread as well as virulence in mice. PrsA2 is thus distinct from PrsA1 in its unique requirement for the stability and full activity of L. monocytogenes-secreted factors that contribute to host infection.
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Multiple effector mechanisms induced by recombinant Listeria monocytogenes anticancer immunotherapeutics. ADVANCES IN APPLIED MICROBIOLOGY 2009; 66:1-27. [PMID: 19203646 DOI: 10.1016/s0065-2164(08)00801-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Listeria monocytogenes is a facultative intracellular gram-positive bacterium that naturally infects professional antigen presenting cells (APC) to target antigens to both class I and class II antigen processing pathways. This infection process results in the stimulation of strong innate and adaptive immune responses, which make it an ideal candidate for a vaccine vector to deliver heterologous antigens. This ability of L. monocytogenes has been exploited by several researchers over the past decade to specifically deliver tumor-associated antigens that are poorly immunogenic such as self-antigens. This review describes the preclinical studies that have elucidated the multiple immune responses elicited by this bacterium that direct its ability to influence tumor growth.
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Mrsny RJ. Lessons from nature: "Pathogen-Mimetic" systems for mucosal nano-medicines. Adv Drug Deliv Rev 2009; 61:172-92. [PMID: 19146895 DOI: 10.1016/j.addr.2008.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 09/22/2008] [Indexed: 12/13/2022]
Abstract
Mucosal surfaces establish an interface with external environments that provide a protective barrier with the capacity to selectively absorb and secrete materials important for homeostasis of the organism. In man, mucosal surfaces such as those in the gastrointestinal tract, respiratory tree and genitourinary system also represent significant barrier to the successful administration of certain pharmaceutical agents and the delivery of newly designed nano-scale therapeutic systems. This review examines morphological, physiological and biochemical aspects of these mucosal barriers and presents currently understood mechanisms used by a variety of virulence factors used by pathogenic bacteria to overcome various aspects of these mucosal barriers. Such information emphasizes the impediments that biologically active materials must overcome for absorption across these mucosal surfaces and provides a template for strategies to overcome these barriers for the successful delivery of nano-scale bioactive materials, also known as nano-medicines.
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Role of the N-terminal amino acid of Bacillus anthracis lethal factor in lethal toxin cytotoxicity and its effect on the lethal toxin neutralization assay. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1737-41. [PMID: 18815235 DOI: 10.1128/cvi.00081-08] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The cytotoxic activity of lethal factor (LF), a critical reagent used in the cell-based lethal toxin neutralization assay to assess anthrax vaccines, was shown to depend on the identity of its N-terminal amino acid, which plays a role in the targeting of LF to the proteasome for degradation. These results demonstrate that care must be taken to ensure that LF preparations used in standardized cell-based assays are not altered at their N-terminal ends.
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Role of N-terminal amino acids in the potency of anthrax lethal factor. PLoS One 2008; 3:e3130. [PMID: 18769623 PMCID: PMC2518864 DOI: 10.1371/journal.pone.0003130] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Accepted: 08/12/2008] [Indexed: 11/19/2022] Open
Abstract
Anthrax lethal factor (LF) is a Zn(+2)-dependent metalloprotease that cleaves several MAPK kinases and is responsible for the lethality of anthrax lethal toxin (LT). We observed that a recombinant LF (LF-HMA) which differs from wild type LF (LF-A) by the addition of two residues (His-Met) to the native Ala (A) terminus as a result of cloning manipulations has 3-fold lower potency toward cultured cells and experimental animals. We hypothesized that the "N-end rule", which relates the half-life of proteins in cells to the identity of their N-terminal residue, might be operative in the case of LF, so that the N-terminal residue of LF would determine the cytosolic stability and thereby the potency of LF. Mutational studies that replaced the native N-terminal residue of LF with known N-end rule stabilizing or destabilizing residues confirmed that the N-terminal residue plays a significant role in determining the potency of LT for cultured cells and experimental animals. The fact that a commercially-available LF preparation (LF-HMA) that is widely used in basic research studies and for evaluation of vaccines and therapeutics is 3-fold less potent than native LF (LF-A) should be considered when comparing published studies and in the design of future experiments.
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Carrero JA, Vivanco-Cid H, Unanue ER. Granzymes drive a rapid listeriolysin O-induced T cell apoptosis. THE JOURNAL OF IMMUNOLOGY 2008; 181:1365-74. [PMID: 18606691 DOI: 10.4049/jimmunol.181.2.1365] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Listeria monocytogenes protein listeriolysin O (LLO) is a pore-forming protein essential for virulence. Although the major role for LLO is to allow L. monocytogenes entry into the cytosol, it also induces apoptosis of activated lymphocytes, an obligatory cellular response that modulates the infection. Induction of apoptosis by LLO proceeds through a fast, caspase-dependent pathway and a slow, caspase-independent pathway. Polyclonal T cell lines were generated from either normal mice or mice deficient in granzyme and perforin proteins, and then treated with apoptogenic doses of LLO. In this study we show that apoptosis of lymphocytes induced by LLO was characterized by activation of caspases as quickly as 30 min that was dependent on the expression of granzymes. In the absence of granzymes, all parameters of apoptosis such as caspase activation, phosphatidylserine exposure, mitochondrial depolarization, and DNA fragmentation were dramatically reduced in magnitude. Removal of perforin inhibited the apoptotic effect of LLO on cells by approximately 50%. Neutralization of intracellular acidification using chloroquine inhibited the rapid apoptotic death. In agreement with these findings granzyme-deficient mice harbored lower bacterial titers and decrease splenic pathology compared with normal mice following L. monocytogenes infection. Thus, LLO exploits apoptotic enzymes of the adaptive immune response to eliminate immune cells and increase its virulence.
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Affiliation(s)
- Javier A Carrero
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
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Viala JPM, Mochegova SN, Meyer-Morse N, Portnoy DA. A bacterial pore-forming toxin forms aggregates in cells that resemble those associated with neurodegenerative diseases. Cell Microbiol 2008; 10:985-93. [DOI: 10.1111/j.1462-5822.2007.01100.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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