1
|
Batani G, Vezzani G, Lashchuk S, Allaoui A, Cardamone D, Raso MM, Boero E, Roscioli E, Ridelfi M, Gasperini G, Pizza M, Rossi O, Berlanda Scorza F, Micoli F, Rappuoli R, Sala C. Development of a visual Adhesion/Invasion Inhibition Assay to assess the functionality of Shigella-specific antibodies. Front Immunol 2024; 15:1374293. [PMID: 38680489 PMCID: PMC11045934 DOI: 10.3389/fimmu.2024.1374293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 04/01/2024] [Indexed: 05/01/2024] Open
Abstract
Introduction Shigella is the etiologic agent of a bacillary dysentery known as shigellosis, which causes millions of infections and thousands of deaths worldwide each year due to Shigella's unique lifestyle within intestinal epithelial cells. Cell adhesion/invasion assays have been extensively used not only to identify targets mediating host-pathogen interaction, but also to evaluate the ability of Shigella-specific antibodies to reduce virulence. However, these assays are time-consuming and labor-intensive and fail to assess differences at the single-cell level. Objectives and methods Here, we developed a simple, fast and high-content method named visual Adhesion/Invasion Inhibition Assay (vAIA) to measure the ability of anti-Shigellaantibodies to inhibit bacterial adhesion to and invasion of epithelial cells by using the confocal microscope Opera Phenix. Results We showed that vAIA performed well with a pooled human serum from subjects challenged with S. sonnei and that a specific anti-IpaD monoclonal antibody effectively reduced bacterial virulence in a dose-dependent manner. Discussion vAIA can therefore inform on the functionality of polyclonal and monoclonal responses thereby supporting the discovery of pathogenicity mechanisms and the development of candidate vaccines and immunotherapies. Lastly, this assay is very versatile and may be easily applied to other Shigella species or serotypes and to different pathogens.
Collapse
Affiliation(s)
- Giampiero Batani
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Giacomo Vezzani
- GlaxoSmithKline (GSK) Vaccines Institute for Global Health (GVGH), Siena, Italy
| | - Sabrina Lashchuk
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Abdelmounaaim Allaoui
- The Microbiology Laboratory, University Mohammed VI Polytechnic, Ben, Guerir, Morocco
| | - Dario Cardamone
- Data Science for Health Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | | | - Elena Boero
- GlaxoSmithKline (GSK) Vaccines Institute for Global Health (GVGH), Siena, Italy
| | - Emanuele Roscioli
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Matteo Ridelfi
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Gianmarco Gasperini
- GlaxoSmithKline (GSK) Vaccines Institute for Global Health (GVGH), Siena, Italy
| | - Mariagrazia Pizza
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Omar Rossi
- GlaxoSmithKline (GSK) Vaccines Institute for Global Health (GVGH), Siena, Italy
| | | | - Francesca Micoli
- GlaxoSmithKline (GSK) Vaccines Institute for Global Health (GVGH), Siena, Italy
| | | | - Claudia Sala
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| |
Collapse
|
2
|
Oh C, Verma A, Hafeez M, Hogland B, Aachoui Y. Shigella OspC3 suppresses murine cytosolic LPS sensing. iScience 2021; 24:102910. [PMID: 34409271 PMCID: PMC8361271 DOI: 10.1016/j.isci.2021.102910] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/09/2021] [Accepted: 07/23/2021] [Indexed: 12/18/2022] Open
Abstract
Shigella flexneri, a cytosol-invasive gram-negative pathogen, deploys an array of type III-secreted effector proteins to evade host cell defenses. Caspase-11 and its human ortholog caspase-4 detect cytosolic lipopolysaccharide (LPS) and trigger gasdermin D-mediated pyroptosis to eliminate intra-cytoplasmic bacterial threats. However, the role of caspase-11 in combating S. flexneri is unclear. The Shigella T3SS effector OspC3 reportedly suppresses cytosolic LPS sensing by inhibiting caspase-4 but not caspase-11 activity. Surprisingly, we found that S. flexneri also uses OspC3 to inhibit murine caspase-11 activity. Mechanistically, we found that OspC3 binds only to primed caspase-11. Importantly, we demonstrate that S. flexneri employs OspC3 to prevent caspase-11-mediated pyroptosis in neutrophils, enabling bacteria to disseminate and evade clearance following intraperitoneal challenge. In contrast, S. flexneri lacking OspC3 is attenuated in a caspase-11- and gasdermin D-dependent fashion. Overall, our study reveals that OspC3 suppresses cytosolic LPS detection in a broad array of mammals. S. flexneri T3SS-secreted OspC3 suppresses cytosolic LPS sensing by caspase-11 OspC3 binds to caspase-11 in a priming-dependent manner S. flexneri employs OspC3 to prevent caspase-11-mediated pyroptosis in neutrophils Neutrophil caspase-11 is essential in defense against S. flexneri ΔOspC3 in vivo
Collapse
Affiliation(s)
- Changhoon Oh
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Responses, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Ambika Verma
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Responses, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Mohib Hafeez
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Responses, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.,Department of Biology, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Brandon Hogland
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Responses, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Youssef Aachoui
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Responses, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| |
Collapse
|
3
|
Wen J, Xuan B, Liu Y, Wang L, He L, Meng X, Zhou T, Wang Y. Updating the NLRC4 Inflammasome: from Bacterial Infections to Autoimmunity and Cancer. Front Immunol 2021; 12:702527. [PMID: 34276697 PMCID: PMC8283967 DOI: 10.3389/fimmu.2021.702527] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/17/2021] [Indexed: 01/07/2023] Open
Abstract
Inflammasomes comprise a family of cytosolic multi-protein complexes that modulate the activation of cysteine-aspartate-specific protease 1 (caspase-1) and promote the maturation and secretion of interleukin (IL)-1β and IL-18, leading to an inflammatory response. Different types of inflammasomes are defined by their sensor protein which recognizes pathogenic ligands and then directs inflammasome assembly. Although the specific molecular mechanisms underlying the activation of most inflammasomes are still unclear, NLRC4 inflammasomes have emerged as multifaceted agents of the innate immune response, playing important roles in immune defense against a variety of pathogens. Other studies have also expanded the scope of NLRC4 inflammasomes to include a range of inherited human autoimmune diseases as well as proposed roles in cancer. In this review article, we provide an updated overview of NLRC4 inflammasomes, describing their composition, activation mechanisms and roles in both microbial infections and other disease conditions.
Collapse
Affiliation(s)
- Jiexia Wen
- Department of Central Laboratory, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Bin Xuan
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Yang Liu
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Liwei Wang
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Li He
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Xiangcai Meng
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Tao Zhou
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Yimin Wang
- Department of Central Laboratory, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China.,Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| |
Collapse
|
4
|
The NLRP1 Inflammasome in Human Skin and Beyond. Int J Mol Sci 2020; 21:ijms21134788. [PMID: 32640751 PMCID: PMC7370280 DOI: 10.3390/ijms21134788] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
Inflammasomes represent a group of protein complexes that contribute to host defense against pathogens and repair processes upon the induction of inflammation. However, aberrant and chronic inflammasome activation underlies the pathology of numerous common inflammatory diseases. Inflammasome assembly causes activation of the protease caspase-1 which in turn activates proinflammatory cytokines and induces a lytic type of cell death termed pyroptosis. Although NLRP1 (NACHT, leucine-rich repeat and pyrin domain containing 1) was the first inflammasome sensor, described almost 20 years ago, the molecular mechanisms underlying its activation and the resulting downstream events are incompletely understood. This is partially a consequence of the poor conservation of the NLRP1 pathway between human and mice. Moreover, recent evidence demonstrates a complex and multi-stage mechanism of NLRP1 inflammasome activation. In contrast to other inflammasome sensors, NLRP1 possesses protease activity required for proteolytic self-cleavage and activation mediated by the function-to-find domain (FIIND). CARD8 is a second FIIND protein and is expressed in humans but not in mice. In immune cells and AML (acute myeloid leukemia) cells, the anti-cancer drug talabostat induces CARD8 activation and causes caspase-1-dependent pyroptosis. In contrast, in human keratinocytes talabostat induces NLRP1 activation and massive proinflammatory cytokine activation. NLRP1 is regarded as the principal inflammasome sensor in human keratinocytes and UVB radiation induces its activation, which is believed to underlie the induction of sunburn. Moreover, gain-of-function mutations of NLRP1 cause inflammatory skin syndromes and a predisposition for the development of skin cancer. SNPs (single nucleotide polymorphisms) of NLRP1 are associated with several (auto)inflammatory diseases with a major skin phenotype, such as psoriasis or vitiligo. Here, we summarize knowledge about NLRP1 with emphasis on its role in human keratinocytes and skin. Due to its accessibility, pharmacological targeting of NLRP1 activation in epidermal keratinocytes represents a promising strategy for the treatment of the numerous patients suffering from NLRP1-dependent inflammatory skin conditions and cancer.
Collapse
|
5
|
Abstract
ABSTRACT
Shigella
is a genus of Gram-negative enteropathogens that have long been, and continue to be, an important public health concern worldwide. Over the past several decades,
Shigella
spp. have also served as model pathogens in the study of bacterial pathogenesis, and
Shigella flexneri
has become one of the best-studied pathogens on a molecular, cellular, and tissue level. In the arms race between
Shigella
and the host immune system,
Shigella
has developed highly sophisticated mechanisms to subvert host cell processes in order to promote infection, escape immune detection, and prevent bacterial clearance. Here, we give an overview of
Shigella
pathogenesis while highlighting innovative techniques and methods whose application has significantly advanced our understanding of
Shigella
pathogenesis in recent years.
Collapse
|
6
|
Sandstrom A, Mitchell PS, Goers L, Mu EW, Lesser CF, Vance RE. Functional degradation: A mechanism of NLRP1 inflammasome activation by diverse pathogen enzymes. Science 2019; 364:science.aau1330. [PMID: 30872533 PMCID: PMC6532986 DOI: 10.1126/science.aau1330] [Citation(s) in RCA: 240] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/05/2018] [Accepted: 03/05/2019] [Indexed: 12/14/2022]
Abstract
Inflammasomes are multiprotein platforms that initiate innate immunity by recruitment and activation of caspase-1. The NLRP1B inflammasome is activated upon direct cleavage by the anthrax lethal toxin protease. However, the mechanism by which cleavage results in NLRP1B activation is unknown. In this study, we find that cleavage results in proteasome-mediated degradation of the amino-terminal domains of NLRP1B, liberating a carboxyl-terminal fragment that is a potent caspase-1 activator. Proteasome-mediated degradation of NLRP1B is both necessary and sufficient for NLRP1B activation. Consistent with our functional degradation model, we identify IpaH7.8, a Shigella flexneri ubiquitin ligase secreted effector, as an enzyme that induces NLRP1B degradation and activation. Our results provide a unified mechanism for NLRP1B activation by diverse pathogen-encoded enzymatic activities.
Collapse
Affiliation(s)
- Andrew Sandstrom
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
| | - Patrick S Mitchell
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA
| | - Lisa Goers
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Broad Institute of Harvard and MIT, Cambridge, MA, USA.,Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Edward W Mu
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA
| | - Cammie F Lesser
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Broad Institute of Harvard and MIT, Cambridge, MA, USA.,Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Russell E Vance
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA. .,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
| |
Collapse
|
7
|
Abstract
Shigella is a leading cause of dysentery worldwide, responsible for up to 165 million cases of shigellosis each year. Shigella is also recognised as an exceptional model pathogen to study key issues in cell biology and innate immunity. Several infection models have been useful to explore Shigella biology; however, we still lack information regarding the events taking place during the Shigella infection process in vivo Here, we discuss a selection of mechanistic insights recently gained from studying Shigella infection of zebrafish (Danio rerio), with a focus on cytoskeleton rearrangements and cellular immunity. We also discuss how infection of zebrafish can be used to investigate new concepts underlying infection control, including emergency granulopoiesis and the use of predatory bacteria to combat antimicrobial resistance. Collectively, these insights illustrate how Shigella infection of zebrafish can provide fundamental advances in our understanding of bacterial pathogenesis and vertebrate host defence. This information should also provide vital clues for the discovery of new therapeutic strategies against infectious disease in humans.
Collapse
Affiliation(s)
- Gina M Duggan
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Serge Mostowy
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
8
|
Abstract
Shigella flexneri, a Gram-negative enteroinvasive pathogen, causes inflammatory destruction of the human intestinal epithelium. Infection by S. flexneri has been well-studied in vitro and is a paradigm for bacterial interactions with the host immune system. Recent work has revealed that components of the cytoskeleton have important functions in innate immunity and inflammation control. Septins, highly conserved cytoskeletal proteins, have emerged as key players in innate immunity to bacterial infection, yet septin function in vivo is poorly understood. Here, we use S. flexneri infection of zebrafish (Danio rerio) larvae to study in vivo the role of septins in inflammation and infection control. We found that depletion of Sept15 or Sept7b, zebrafish orthologs of human SEPT7, significantly increased host susceptibility to bacterial infection. Live-cell imaging of Sept15-depleted larvae revealed increasing bacterial burdens and a failure of neutrophils to control infection. Strikingly, Sept15-depleted larvae present significantly increased activity of Caspase-1 and more cell death upon S. flexneri infection. Dampening of the inflammatory response with anakinra, an antagonist of interleukin-1 receptor (IL-1R), counteracts Sept15 deficiency in vivo by protecting zebrafish from hyper-inflammation and S. flexneri infection. These findings highlight a new role for septins in host defence against bacterial infection, and suggest that septin dysfunction may be an underlying factor in cases of hyper-inflammation.
Collapse
|