1
|
Tondi S, Siena E, Essaghir A, Bozzetti B, Bechtold V, Scaillet A, Clemente B, Marrocco M, Sammicheli C, Tavarini S, Micoli F, Oldrini D, Pezzicoli A, Di Fede M, Brazzoli M, Ulivieri C, Schiavetti F. Molecular Signature of Monocytes Shaped by the Shigella sonnei 1790-Generalized Modules for Membrane Antigens Vaccine. Int J Mol Sci 2024; 25:1116. [PMID: 38256189 PMCID: PMC10816432 DOI: 10.3390/ijms25021116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Shigellosis, an acute gastroenteritis infection caused by Shigella species, remains a public health burden in developing countries. Recently, many outbreaks due to Shigella sonnei multidrug-resistant strains have been reported in high-income countries, and the lack of an effective vaccine represents a major hurdle to counteract this bacterial pathogen. Vaccine candidates against Shigella sonnei are under clinical development, including a Generalized Modules for Membrane Antigens (GMMA)-based vaccine. The mechanisms by which GMMA-based vaccines interact and activate human immune cells remain elusive. Our previous study provided the first evidence that both adaptive and innate immune cells are targeted and functionally shaped by the GMMA-based vaccine. Here, flow cytometry and confocal microscopy analysis allowed us to identify monocytes as the main target population interacting with the S. sonnei 1790-GMMA vaccine on human peripheral blood. In addition, transcriptomic analysis of this cell population revealed a molecular signature induced by 1790-GMMA mostly correlated with the inflammatory response and cytokine-induced processes. This also impacts the expression of genes associated with macrophages' differentiation and T cell regulation, suggesting a dual function for this vaccine platform both as an antigen carrier and as a regulator of immune cell activation and differentiation.
Collapse
Affiliation(s)
- Serena Tondi
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Emilio Siena
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Ahmed Essaghir
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Benoît Bozzetti
- Preclinical Research & Development, GSK, 1330 Rixensart, Belgium
| | - Viviane Bechtold
- Preclinical Research & Development, GSK, 1330 Rixensart, Belgium
| | - Aline Scaillet
- Preclinical Research & Development, GSK, 1330 Rixensart, Belgium
| | - Bruna Clemente
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Mariateresa Marrocco
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | | | - Simona Tavarini
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Francesca Micoli
- GSK Vaccines Institute for Global Health S.R.L. (GVGH), 53100 Siena, Italy
| | - Davide Oldrini
- GSK Vaccines Institute for Global Health S.R.L. (GVGH), 53100 Siena, Italy
| | | | - Martina Di Fede
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Michela Brazzoli
- Preclinical Research & Development, GSK, 53100 Siena, Italy; (S.T.)
| | - Cristina Ulivieri
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | | |
Collapse
|
2
|
Monteiro R, Chafsey I, Caccia N, Ageorges V, Leroy S, Viala D, Hébraud M, Livrelli V, Pizza M, Pezzicoli A, Desvaux M. Specific Proteomic Identification of Collagen-Binding Proteins in Escherichia coli O157:H7: Characterisation of OmpA as a Potent Vaccine Antigen. Cells 2023; 12:1634. [PMID: 37371104 DOI: 10.3390/cells12121634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/02/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Escherichia coli is a versatile commensal species of the animal gut that can also be a pathogen able to cause intestinal and extraintestinal infections. The plasticity of its genome has led to the evolution of pathogenic strains, which represent a threat to global health. Additionally, E. coli strains are major drivers of antibiotic resistance, highlighting the urgent need for new treatment and prevention measures. The antigenic and structural heterogeneity of enterohaemorrhagic E. coli colonisation factors has limited their use for the development of effective and cross-protective vaccines. However, the emergence of new strains that express virulence factors deriving from different E. coli diarrhoeagenic pathotypes suggests that a vaccine targeting conserved proteins could be a more effective approach. In this study, we conducted proteomics analysis and functional protein characterisation to identify a group of proteins potentially involved in the adhesion of E. coli O157:H7 to the extracellular matrix and intestinal epithelial cells. Among them, OmpA has been identified as a highly conserved and immunogenic antigen, playing a significant role in the adhesion phenotype of E. coli O157:H7 and in bacterial aggregation. Furthermore, antibodies raised against recombinant OmpA effectively reduced the adhesion of E. coli O157:H7 to intestinal epithelial cells. The present work highlights the role of OmpA as a potent antigen for the development of a vaccine against intestinal pathogenic E. coli.
Collapse
Affiliation(s)
- Ricardo Monteiro
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
- GSK, 53100 Siena, Italy
- Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, 4150-564 Porto, Portugal
| | - Ingrid Chafsey
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | - Nelly Caccia
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | | | - Sabine Leroy
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
| | - Didier Viala
- INRAE, Metabolism Exploration Platform, Proteomic Component (PFEMcp), 63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- INRAE, UCA, UMR0454 MEDIS, 63000 Clermont-Ferrand, France
- INRAE, Metabolism Exploration Platform, Proteomic Component (PFEMcp), 63122 Saint-Genès Champanelle, France
| | | | - Mariagrazia Pizza
- GSK, 53100 Siena, Italy
- Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | | | | |
Collapse
|
3
|
Manca B, Buffi G, Magri G, Del Vecchio M, Taddei AR, Pezzicoli A, Giuliani M. Functional characterization of the gonococcal polyphosphate pseudo-capsule. PLoS Pathog 2023; 19:e1011400. [PMID: 37216411 DOI: 10.1371/journal.ppat.1011400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 05/03/2023] [Indexed: 05/24/2023] Open
Abstract
Neisseria gonorrhoeae is an exclusively human pathogen able to evade the host immune system through multiple mechanisms. Gonococci accumulate a large portion of phosphate moieties as polyphosphate (polyP) on the exterior of the cell. Although its polyanionic nature has suggested that it may form a protective shield on the cell surface, its role remains controversial. Taking advantage of a recombinant His-tagged polyP-binding protein, the presence of a polyP pseudo-capsule in gonococcus was demonstrated. Interestingly, the polyP pseudo-capsule was found to be present in specific strains only. To investigate its putative role in host immune evasion mechanisms, such as resistance to serum bactericidal activity, antimicrobial peptides and phagocytosis, the enzymes involved in polyP metabolism were genetically deleted, generating mutants with altered polyP external content. The mutants with lower polyP content on their surface compared to the wild-type strains, became sensitive to complement-mediated killing in presence of normal human serum. Conversely, naturally serum sensitive strains that did not display a significant polyP pseudo-capsule became resistant to complement in the presence of exogenous polyP. The presence of polyP pseudo-capsule was also critical in the protection from antibacterial activity of cationic antimicrobial peptide, such as cathelicidin LL-37. Results showed that the minimum bactericidal concentration was lower in strains lacking polyP than in those harboring the pseudo-capsule. Data referring to phagocytic killing resistance, assessed by using neutrophil-like cells, showed a significant decrease in viability of mutants lacking polyP on their cell surface in comparison to the wild-type strain. The addition of exogenous polyP overturned the killing phenotype of sensitive strains suggesting that gonococcus could exploit environmental polyP to survive to complement-mediated, cathelicidin and intracellular killing. Taken together, data presented here indicate an essential role of the polyP pseudo-capsule in the gonococcal pathogenesis, opening new perspective on gonococcal biology and more effective treatments.
Collapse
Affiliation(s)
- Benedetta Manca
- Pharmacy and Biotechnology Department (FaBiT), University of Bologna, Bologna, Italy C/O GSK, Siena, Italy
| | | | | | | | - Anna Rita Taddei
- Centre for High Instruments, Electron Microscopy Section, University of Tuscia, Viterbo, Italy
| | | | | |
Collapse
|
4
|
Wang Z, Enotarpi J, Buffi G, Pezzicoli A, Gstöttner CJ, Nicolardi S, Balducci E, Fabbrini M, Romano MR, van der Marel GA, del Bino L, Adamo R, Codée JDC. Chemical Synthesis and Immunological Evaluation of Fragments of the Multiantennary Group-Specific Polysaccharide of Group B Streptococcus. JACS Au 2022; 2:1724-1735. [PMID: 35911445 PMCID: PMC9327088 DOI: 10.1021/jacsau.2c00302] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Group B Streptococcus (GBS) is a Gram-positive bacterium and the most common cause of neonatal blood and brain infections. At least 10 different serotypes exist, that are characterized by their different capsular polysaccharides. The Group B carbohydrate (GBC) is shared by all serotypes and therefore attractive be used in a glycoconjugate vaccine. The GBC is a highly complex multiantennary structure, composed of rhamnose rich oligosaccharides interspaced with glucitol phosphates. We here report the development of a convergent approach to assemble a pentamer, octamer, and tridecamer fragment of the termini of the antennae. Phosphoramidite chemistry was used to fuse the pentamer and octamer fragments to deliver the 13-mer GBC oligosaccharide. Nuclear magnetic resonance spectroscopy of the generated fragments confirmed the structures of the naturally occurring polysaccharide. The fragments were used to generate model glycoconjugate vaccine by coupling with CRM197. Immunization of mice delivered sera that was shown to be capable of recognizing different GBS strains. The antibodies raised using the 13-mer conjugate were shown to recognize the bacteria best and the serum raised against this GBC fragment-mediated opsonophagocytic killing best, but in a capsule dependent manner. Overall, the GBC 13-mer was identified to be a highly promising antigen for incorporation into future (multicomponent) anti-GBS vaccines.
Collapse
Affiliation(s)
- Zhen Wang
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Jacopo Enotarpi
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Giada Buffi
- GSK
Siena Italy, Via Fiorentina
1 Siena 53100, Italy
| | | | - Christoph J. Gstöttner
- Center
for Proteomics and Metabolomics, Leiden
University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Simone Nicolardi
- Center
for Proteomics and Metabolomics, Leiden
University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | | | | | | | | | | | - Roberto Adamo
- GSK
Siena Italy, Via Fiorentina
1 Siena 53100, Italy
| | - Jeroen D. C. Codée
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| |
Collapse
|
5
|
Monteiro R, Chafsey I, Ageorges V, Leroy S, Chambon C, Hébraud M, Livrelli V, Pizza M, Pezzicoli A, Desvaux M. The Secretome landscape of Escherichia coli O157:H7: Deciphering the cell-surface, outer membrane vesicle and extracellular subproteomes. J Proteomics 2020; 232:104025. [PMID: 33160105 DOI: 10.1016/j.jprot.2020.104025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 12/14/2022]
Abstract
Among diarrheagenic E. coli (DEC), enterohaemorrhagic E. coli (EHEC) are the most virulent anthropozoonotic agents. The ability of bacterial cells to functionally interact with their surrounding essentially relies on the secretion of different protein effectors. To experimentally determine the repertoire of extracytoproteins in E. coli O157:H7, a subproteomic analysis was performed not only considering the extracellular milieu but the cell surface and outer membrane vesicles. Following a secretome-based approach, the proteins trafficking from the interior to the exterior of the cell were depicted considering cognate protein transport systems and subcellular localisation. Label-free quantitative analysis of the proteosurfaceome, proteovesiculome and exoproteome from E. coli O157:H7 grown in three different nutrient media revealed differential protein expression profiles and allowed defining the core and variant subproteomes. Network analysis further revealed the higher abundance of some protein clusters in chemically defined medium over rich complex medium, especially related to some outer membrane proteins, ABC transport and Type III secretion systems. This first comprehensive study of the EHEC secretome unravels the profound influence of environmental conditions on the extracytoplasmic proteome, provides new insight in the physiology of E. coli O157:H7 and identifies potentially important molecular targets for the development of preventive strategies against EHEC/STEC. SIGNIFICANCE: Escherichia coli O157:H7 is responsible for severe diarrhoea especially in young children. Despite years of investigations, the global view of the extracytoplasmic proteins expressed in this microorganism was eluded. To provide the first comprehensive view of the secretome landscape of E. coli O157:H7, the exoproteome, proteosurfaceome and proteovesiculome were profiled using growth conditions most likely to induce changes in bacterial protein secretion. The profound influence of growth conditions on the extracytoplasmic proteome was unravelled and allowed identifying the core and variant subproteomes. Besides new insight in the physiology of enterohaemorrhagic E. coli, these proteins potentially constitute important molecular targets for the development of preventive strategies.
Collapse
Affiliation(s)
- Ricardo Monteiro
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France; GSK, Siena, Italy
| | - Ingrid Chafsey
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Valentin Ageorges
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Christophe Chambon
- INRAE, Plate-Forme d'Exploration du Métabolisme, QuaPA, F-63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France; INRAE, Plate-Forme d'Exploration du Métabolisme, QuaPA, F-63122 Saint-Genès Champanelle, France
| | - Valérie Livrelli
- Université Clermont-Auvergne, INSERM, INRAE, M2ISH, F-63000 Clermont-ferrand, France
| | | | | | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.
| |
Collapse
|
6
|
Moramarco F, Pezzicoli A, Salvini L, Leuzzi R, Pansegrau W, Balducci E. A LONELY GUY protein of Bordetella pertussis with unique features is related to oxidative stress. Sci Rep 2019; 9:17016. [PMID: 31745120 PMCID: PMC6864091 DOI: 10.1038/s41598-019-53171-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/21/2019] [Indexed: 01/17/2023] Open
Abstract
The Gram-negative bacterium B. pertussis is the causative agent of whooping cough. This infection is re-emerging and new features related to Bordetella pathogenesis and microbiology could be relevant to defeat it. Therefore, we focused our attention on BP1253, a predicted exported protein from B. pertussis erroneously classified as lysine decarboxylase. We showed that BP1253 shares the highly conserved motif PGGxGTxxE and the key catalytic amino-acid residues with newly structurally characterized "LONELY GUY" (LOG) proteins. Biochemical studies have confirmed that this protein functions as a cytokinin-activating enzyme since it cleaves the N-glycosidic linkage between the base and the ribose, leading to the formation of free bases, which are the active form of plant hormones called cytokinins. Remarkably, BP1253 selectively binds monophosphate nucleotides such as AMP, GMP and CMP, showing a wider variety in binding capacity compared to other LOGs. Cytokinin production studies performed with B. pertussis have revealed 6-O-methylguanine to be the physiological product of BP1253 in agreement with the higher activity of the enzyme towards GMP. 6-O-methylguanine is likely to be responsible for the increased sensitivity of B. pertussis to oxidative stress. Although BP1253 has a primary sequence resembling the hexameric type-II LOGs, the dimeric state and the presence of specific amino-acids suggests that BP1253 can be classified as a novel type-II LOG. The discovery of a LOG along with its product 6-O-methylguanine in the human pathogen B. pertussis may lead to the discovery of unexplored functions of LOGs, broadening their role beyond plants.
Collapse
Affiliation(s)
- Filippo Moramarco
- GSK Vaccines, Via Fiorentina 1, 53100, Siena, Italy.,Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Belmeloro 6, Bologna, 40126, Italy
| | | | - Laura Salvini
- Toscana Life Sciences Foundation, Via Fiorentina 1, 53100, Siena, Italy
| | | | | | - Enrico Balducci
- School of Biosciences and Veterinary Medicine, University of Camerino, via Gentile III da Varano, 62032, Camerino, Italy.
| |
Collapse
|
7
|
Monteiro R, Chafsey I, Leroy S, Chambon C, Hébraud M, Livrelli V, Pizza M, Pezzicoli A, Desvaux M. Differential biotin labelling of the cell envelope proteins in lipopolysaccharidic diderm bacteria: Exploring the proteosurfaceome of Escherichia coli using sulfo-NHS-SS-biotin and sulfo-NHS-PEG4-bismannose-SS-biotin. J Proteomics 2018; 181:16-23. [PMID: 29609094 DOI: 10.1016/j.jprot.2018.03.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/15/2018] [Accepted: 03/23/2018] [Indexed: 12/28/2022]
Abstract
Surface proteins are the major factor for the interaction between bacteria and its environment, playing an important role in infection, colonisation, virulence and adaptation. However, the study of surface proteins has proven difficult mainly due to their hydrophobicity and/or relatively low abundance compared with cytoplasmic proteins. To overcome these issues new proteomic strategies have been developed, such as cell-surface protein labelling using biotinylation reagents. Sulfo-NHS-SS-biotin is the most commonly used reagent to investigate the proteins expressed at the cell surface of various organisms but its use in lipopolysaccharidic diderm bacteria (archetypical Gram-negative bacteria) remains limited to a handful of species. While generally pass over in silence, some periplasmic proteins, but also some inner membrane lipoproteins, integral membrane proteins and cytoplasmic proteins (cytoproteins) are systematically identified following this approach. To limit cell lysis and diffusion of the sulfo-NHS-SS-biotin through the outer membrane, biotin labelling was tested over short incubation times and proved to be as efficient for 1 min at room temperature. To further limit labelling of protein located below the outer membrane, the use of high-molecular weight sulfo-NHS-PEG4-bismannose-SS-biotin appeared to recover differentially cell-envelope proteins compared to low-molecular weight sulfo-NHS-SS-biotin. Actually, the sulfo-NHS-SS-biotin recovers at a higher extent the proteins completely or partly exposed in the periplasm than sulfo-NHS-PEG4-bismannose-SS-biotin, namely periplasmic and integral membrane proteins as well as inner membrane and outer membrane lipoproteins. These results highlight that protein labelling using biotinylation reagents of different sizes provides a sophisticated and accurate way to differentially explore the cell envelope proteome of lipopolysaccharidic diderm bacteria. SIGNIFICANCE While generally pass over in silence, some periplasmic proteins, inner membrane lipoproteins (IMLs), integral membrane proteins (IMPs) and cytoplasmic proteins (cytoproteins) are systematically identified following cell-surface biotin labelling in lipopolysaccharidic diderm bacteria (archetypal Gram-negative bacteria). The use of biotinylation molecules of different sizes, namely sulfo-NHS-SS-biotin and sulfo-NHS-PEG4-bismannose-SS-biotin, was demonstrated to provide a sophisticated and accurate way to differentially explore the cell envelope proteome of lipopolysaccharidic diderm bacteria.
Collapse
Affiliation(s)
- Ricardo Monteiro
- Université Clermont Auvergne, INRA, UMR454 MEDiS, F-63000 Clermont-Ferrand, France; GSK, Via Fiorentina 1, 53100 Siena, Italy
| | - Ingrid Chafsey
- Université Clermont Auvergne, INRA, UMR454 MEDiS, F-63000 Clermont-Ferrand, France
| | - Sabine Leroy
- Université Clermont Auvergne, INRA, UMR454 MEDiS, F-63000 Clermont-Ferrand, France
| | - Christophe Chambon
- INRA, Plate-Forme d'Exploration du Métabolisme, F-63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- Université Clermont Auvergne, INRA, UMR454 MEDiS, F-63000 Clermont-Ferrand, France; INRA, Plate-Forme d'Exploration du Métabolisme, F-63122 Saint-Genès Champanelle, France
| | - Valérie Livrelli
- Centre de Recherche en Nutrition Humaine Auvergne, UMR UCA INSERM U1071, USC-INRA 2018, Clermont Université - Université d'Auvergne, Faculté de Pharmacie, CHU Clermont-Ferrand, Service Bactériologie Mycologie Parasitologie, Clermont-Ferrand, France
| | | | | | - Mickaël Desvaux
- Université Clermont Auvergne, INRA, UMR454 MEDiS, F-63000 Clermont-Ferrand, France.
| |
Collapse
|
8
|
Di Fede M, Biagini M, Cartocci E, Parillo C, Greco A, Martinelli M, Marchi S, Pezzicoli A, Delany I, Rossi Paccani S. Neisseria Heparin Binding Antigen is targeted by the human alternative pathway C3-convertase. PLoS One 2018; 13:e0194662. [PMID: 29579105 PMCID: PMC5868813 DOI: 10.1371/journal.pone.0194662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/07/2018] [Indexed: 11/18/2022] Open
Abstract
Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein specific for Neisseria and constitutes one of the three main protein antigens of the Bexsero vaccine. Meningococcal and human proteases, cleave NHBA protein upstream or downstream of a conserved Arg-rich region, respectively. The cleavage results in the release of the C-terminal portion of the protein. The C-terminal fragment originating from the processing of meningococcal proteases, referred to as C2 fragment, exerts a toxic effect on endothelial cells altering the endothelial permeability. In this work, we reported that recombinant C2 fragment has no influence on the integrity of human airway epithelial cell monolayers, consistent with previous findings showing that Neisseria meningitidis traverses the epithelial barrier without disrupting the junctional structures. We showed that epithelial cells constantly secrete proteases responsible for a rapid processing of C2 fragment, generating a new fragment that does not contain the Arg-rich region, a putative docking domain reported to be essential for C2-mediated toxic effect. Moreover, we found that the C3-convertase of the alternative complement pathway is one of the proteases responsible for this processing. Overall, our data provide new insights on the cleavage of NHBA protein during meningococcal infection. NHBA cleavage may occur at different stages of the infection, and it likely has a different role depending on the environment the bacterium is interacting with.
Collapse
|
9
|
Cioncada R, Maddaluno M, Vo HTM, Woodruff M, Tavarini S, Sammicheli C, Tortoli M, Pezzicoli A, De Gregorio E, Carroll MC, D’Oro U, Piccioli D. Vaccine adjuvant MF59 promotes the intranodal differentiation of antigen-loaded and activated monocyte-derived dendritic cells. PLoS One 2017; 12:e0185843. [PMID: 29088224 PMCID: PMC5663329 DOI: 10.1371/journal.pone.0185843] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 09/20/2017] [Indexed: 01/09/2023] Open
Abstract
MF59 is an oil-in-water emulsion adjuvant approved for human influenza vaccination in European Union. The mode of action of MF59 is not fully elucidated yet, but results from several years of investigation indicate that MF59 establishes an immunocompetent environment at injection site which promotes recruitment of immune cells, including antigen presenting cells (APCs), that are facilitated to engulf antigen and transport it to draining lymph node (dLN) where the antigen is accumulated. In vitro studies showed that MF59 promotes the differentiation of monocytes to dendritic cells (Mo-DCs). Since after immunization with MF59, monocytes are rapidly recruited both at the injection site and in dLN and appear to have a morphological change toward a DC-like phenotype, we asked whether MF59 could play a role in inducing differentiation of Mo-DC in vivo. To address this question we immunized mice with the auto-fluorescent protein Phycoerythrin (PE) as model antigen, in presence or absence of MF59. We measured the APC phenotype and their antigen uptake within dLNs, the antigen distribution within the dLN compartments and the humoral response to PE. In addition, using Ovalbumin as model antigen, we measured the capacity of dLN APCs to induce antigen-specific CD4 T cell proliferation. Here, we show, for the first time, that MF59 promotes differentiation of Mo-DCs within dLNs from intranodal recruited monocytes and we suggest that this differentiation could take place in the medullary compartment of the LN. In addition we show that the Mo-DC subset represents the major source of antigen-loaded and activated APCs within the dLN when immunizing with MF59. Interestingly, this finding correlates with the enhanced triggering of antigen-specific CD4 T cell response induced by LN APCs. This study therefore demonstrates that MF59 is able to promote an immunocompetent environment also directly within the dLN, offering a novel insight on the mechanism of action of vaccine adjuvants based on emulsions.
Collapse
Affiliation(s)
| | | | | | - Matthew Woodruff
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | | | | | | | | | | | - Michael C. Carroll
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Ugo D’Oro
- GSK Vaccines, Siena, Italy
- * E-mail: (DP); (UDO)
| | | |
Collapse
|
10
|
Vacca I, Del Tordello E, Gasperini G, Pezzicoli A, Di Fede M, Rossi Paccani S, Marchi S, Mubaiwa TD, Hartley-Tassell LE, Jennings MP, Seib KL, Masignani V, Pizza M, Serruto D, Aricò B, Delany I. Neisserial Heparin Binding Antigen (NHBA) Contributes to the Adhesion of Neisseria meningitidis to Human Epithelial Cells. PLoS One 2016; 11:e0162878. [PMID: 27780200 PMCID: PMC5079597 DOI: 10.1371/journal.pone.0162878] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/30/2016] [Indexed: 11/19/2022] Open
Abstract
Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein ubiquitously expressed by Neisseria meningitidis strains and an antigen of the Bexsero® vaccine. NHBA binds heparin through a conserved Arg-rich region that is the target of two proteases, the meningococcal NalP and human lactoferrin (hLf). In this work, in vitro studies showed that recombinant NHBA protein was able to bind epithelial cells and mutations of the Arg-rich tract abrogated this binding. All N-terminal and C-terminal fragments generated by NalP or hLf cleavage, regardless of the presence or absence of the Arg-rich region, did not bind to cells, indicating that a correct positioning of the Arg-rich region within the full length protein is crucial. Moreover, binding was abolished when cells were treated with heparinase III, suggesting that this interaction is mediated by heparan sulfate proteoglycans (HSPGs). N. meningitidis nhba knockout strains showed a significant reduction in adhesion to epithelial cells with respect to isogenic wild-type strains and adhesion of the wild-type strain was inhibited by anti-NHBA antibodies in a dose-dependent manner. Overall, the results demonstrate that NHBA contributes to meningococcal adhesion to epithelial cells through binding to HSPGs and suggest a possible role of anti-Bexsero® antibodies in the prevention of colonization.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Tsisti D. Mubaiwa
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | | | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | | | | | | | | | | |
Collapse
|
11
|
Marrazzo P, Maccari S, Taddei A, Bevan L, Telford J, Soriani M, Pezzicoli A. 3D Reconstruction of the Human Airway Mucosa In Vitro as an Experimental Model to Study NTHi Infections. PLoS One 2016; 11:e0153985. [PMID: 27101006 PMCID: PMC4839639 DOI: 10.1371/journal.pone.0153985] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/06/2016] [Indexed: 12/04/2022] Open
Abstract
We have established an in vitro 3D system which recapitulates the human tracheo-bronchial mucosa comprehensive of the pseudostratified epithelium and the underlying stromal tissue. In particular, we reported that the mature model, entirely constituted of primary cells of human origin, develops key markers proper of the native tissue such as the mucociliary differentiation of the epithelial sheet and the formation of the basement membrane. The infection of the pseudo-tissue with a strain of NonTypeable Haemophilus influenzae results in bacteria association and crossing of the mucus layer leading to an apparent targeting of the stromal space where they release large amounts of vesicles and form macro-structures. In summary, we propose our in vitro model as a reliable and potentially customizable system to study mid/long term host-pathogen processes.
Collapse
Affiliation(s)
| | - Silvia Maccari
- GSK Vaccines S.r.l., via Fiorentina 1, 53100, Siena, Italy
| | - Annarita Taddei
- Interdepartmental Centre for Electron Microscopy, Tuscia University, Viterbo, Italy
| | - Luke Bevan
- Respiratory Disease Area, Novartis Institutes for BioMedical Research, Horsham, RH12 5AB, United Kingdom
| | - John Telford
- GSK Vaccines S.r.l., via Fiorentina 1, 53100, Siena, Italy
| | - Marco Soriani
- GSK Vaccines S.r.l., via Fiorentina 1, 53100, Siena, Italy
- * E-mail: (AP); (MS)
| | - Alfredo Pezzicoli
- GSK Vaccines S.r.l., via Fiorentina 1, 53100, Siena, Italy
- * E-mail: (AP); (MS)
| |
Collapse
|
12
|
Ahmed SS, Volkmuth W, Duca J, Corti L, Pallaoro M, Pezzicoli A, Karle A, Rigat F, Rappuoli R, Narasimhan V, Julkunen I, Vuorela A, Vaarala O, Nohynek H, Pasini FL, Montomoli E, Trombetta C, Adams CM, Rothbard J, Steinman L. Antibodies to influenza nucleoprotein cross-react with human hypocretin receptor 2. Sci Transl Med 2016; 7:294ra105. [PMID: 26136476 DOI: 10.1126/scitranslmed.aab2354] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The sleep disorder narcolepsy is linked to the HLA-DQB1*0602 haplotype and dysregulation of the hypocretin ligand-hypocretin receptor pathway. Narcolepsy was associated with Pandemrix vaccination (an adjuvanted, influenza pandemic vaccine) and also with infection by influenza virus during the 2009 A(H1N1) influenza pandemic. In contrast, very few cases were reported after Focetria vaccination (a differently manufactured adjuvanted influenza pandemic vaccine). We hypothesized that differences between these vaccines (which are derived from inactivated influenza viral proteins) explain the association of narcolepsy with Pandemrix-vaccinated subjects. A mimic peptide was identified from a surface-exposed region of influenza nucleoprotein A that shared protein residues in common with a fragment of the first extracellular domain of hypocretin receptor 2. A significant proportion of sera from HLA-DQB1*0602 haplotype-positive narcoleptic Finnish patients with a history of Pandemrix vaccination (vaccine-associated narcolepsy) contained antibodies to hypocretin receptor 2 compared to sera from nonnarcoleptic individuals with either 2009 A(H1N1) pandemic influenza infection or history of Focetria vaccination. Antibodies from vaccine-associated narcolepsy sera cross-reacted with both influenza nucleoprotein and hypocretin receptor 2, which was demonstrated by competitive binding using 21-mer peptide (containing the identified nucleoprotein mimic) and 55-mer recombinant peptide (first extracellular domain of hypocretin receptor 2) on cell lines expressing human hypocretin receptor 2. Mass spectrometry indicated that relative to Pandemrix, Focetria contained 72.7% less influenza nucleoprotein. In accord, no durable antibody responses to nucleoprotein were detected in sera from Focetria-vaccinated nonnarcoleptic subjects. Thus, differences in vaccine nucleoprotein content and respective immune response may explain the narcolepsy association with Pandemrix.
Collapse
Affiliation(s)
- Syed Sohail Ahmed
- Global Clinical Sciences, Novartis Vaccines Srl, Siena 53100, Italy.
| | - Wayne Volkmuth
- Informatics and Information Technology, Atreca Inc., Redwood City, CA 94063, USA
| | - José Duca
- Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Lorenzo Corti
- Formulation Analytics, Novartis Vaccines Srl, Siena 53100, Italy
| | - Michele Pallaoro
- Formulation Analytics, Novartis Vaccines Srl, Siena 53100, Italy
| | | | - Anette Karle
- Integrated Biologics Profiling Unit, Novartis Pharma AG, Basel 4057, Switzerland
| | - Fabio Rigat
- Quantitative Sciences, Novartis Vaccines Srl, Siena 53100, Italy
| | | | - Vas Narasimhan
- Development, Novartis Vaccines, Cambridge, MA 02139, USA
| | - Ilkka Julkunen
- National Institute for Health and Welfare (THL), Helsinki 00300, Finland. Virology, University of Turku, Turku 20520, Finland
| | - Arja Vuorela
- National Institute for Health and Welfare (THL), Helsinki 00300, Finland
| | - Outi Vaarala
- National Institute for Health and Welfare (THL), Helsinki 00300, Finland
| | - Hanna Nohynek
- National Institute for Health and Welfare (THL), Helsinki 00300, Finland
| | - Franco Laghi Pasini
- Internal Medicine, Policlinico Santa Maria alle Scotte, Azienda Ospedaliera Universitaria Senese, Siena 53100, Italy. Medical Science, Surgery, and Neuroscience, University of Siena, Siena 53100, Italy
| | - Emanuele Montomoli
- Molecular and Developmental Medicine, University of Siena, Siena 53100, Italy. VisMederi Srl, Siena 53100, Italy
| | - Claudia Trombetta
- Molecular and Developmental Medicine, University of Siena, Siena 53100, Italy
| | - Christopher M Adams
- Stanford University Mass Spectrometry, Stanford University School of Medicine, Palo Alto, CA 94305 USA
| | - Jonathan Rothbard
- Immunology, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Lawrence Steinman
- Neurology and Neuroscience, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
13
|
Amerighi F, Valeri M, Donnarumma D, Maccari S, Moschioni M, Taddei A, Lapazio L, Pansegrau W, Buccato S, De Angelis G, Ruggiero P, Masignani V, Soriani M, Pezzicoli A. Identification of a Monoclonal Antibody Against Pneumococcal Pilus 1 Ancillary Protein Impairing Bacterial Adhesion to Human Epithelial Cells. J Infect Dis 2015; 213:516-22. [PMID: 26401026 DOI: 10.1093/infdis/jiv461] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/11/2015] [Indexed: 12/17/2022] Open
Abstract
The adhesion of Streptococcus pneumoniae is a key step during colonization of human respiratory tract mucosae. Here we demonstrate that pneumococcal type I pilus significantly increases the adhesiveness of poorly adhering highly capsulated strains in vitro. Interestingly, preincubation of bacteria with antibodies against the major pilus backbone subunit (RrgB) or the adhesin component (RrgA) impaired pneumococcal association to human epithelial cells. Screening for anti-RrgA monoclonal antibodies specifically affecting the adhesive capacity of S. pneumoniae led to the identification of the monoclonal 11B9/61 antibody, which greatly reduced pilus-dependent cell contact. Proteomic-based epitope mapping of 11B9/61 monoclonal antibody revealed a well-exposed epitope on the D2 domain of RrgA as the target of this functional antibody. The data presented here confirm the importance of pilus I for S. pneumoniae pathogenesis and the potential use of antipilus antibodies to prevent bacterial colonization.
Collapse
Affiliation(s)
| | - Maria Valeri
- Institute for Immunology, University of California-Irvine School of Medicine
| | | | | | | | - Annarita Taddei
- Interdepartmental Centre for Electron Microscopy, University of Tuscia, Viterbo, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Nilo A, Passalacqua I, Fabbrini M, Allan M, Usera A, Carboni F, Brogioni B, Pezzicoli A, Cobb J, Romano MR, Margarit I, Hu QY, Berti F, Adamo R. Correction to Exploring the Effect of Conjugation Site and Chemistry on the Immunogenicity of an anti-Group B Streptococcus Glycoconjugate Vaccine Based on GBS67 Pilus Protein and Type V Polysaccharide. Bioconjug Chem 2015; 26:2167. [PMID: 26355285 DOI: 10.1021/acs.bioconjchem.5b00480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
Prevato M, Cozzi R, Pezzicoli A, Taddei AR, Ferlenghi I, Nandi A, Montomoli E, Settembre EC, Bertholet S, Bonci A, Legay F. An Innovative Pseudotypes-Based Enzyme-Linked Lectin Assay for the Measurement of Functional Anti-Neuraminidase Antibodies. PLoS One 2015; 10:e0135383. [PMID: 26267900 PMCID: PMC4534301 DOI: 10.1371/journal.pone.0135383] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 07/22/2015] [Indexed: 01/16/2023] Open
Abstract
Antibodies (Ab) to neuraminidase (NA) play a role in limiting influenza infection and might help reduce the disease impact. The most widely used serological assay to measure functional anti-NA immune responses is the Enzyme-Linked Lectin Assay (ELLA) which relies on hemagglutinin (HA) mismatched virus reassortants, or detergent treated viruses as the NA source to overcome interference associated with steric hindrance of anti-HA Ab present in sera. The difficulty in producing and handling these reagents, which are not easily adapted for screening large numbers of samples, limits the routine analysis of functional anti-NA Ab in clinical trials. In this study, we produced influenza lentiviral pseudoparticles (PPs) containing only the NA antigen (NA-PPs) with a simple two-plasmid co-transfection system. NA-PPs were characterized and tested as an innovative source of NA in the NA inhibition (NI) assay. Both swine A/California/07/2009 (H1N1) and avian A/turkey/Turkey/01/2005 (H5N1) N1s within NA-PPs retained their sialidase activity and were specifically inhibited by homologous and N1 subtype-specific, heterologous sheep sera. Moreover, A/California/07/2009 N1-PPs were a better source of NA compared to whole live and detergent treated H1N1 viruses in ELLA, likely due to lack of interference by anti-HA Ab, and absence of possible structural modifications caused by treatment with detergent. This innovative assay is safer and applicable to all NAs. Taken together, these results highlight the potential of NA-PPs-based NI assays to be developed as sensitive, flexible, easy to handle and scalable serological tests for routine NA immune response analysis.
Collapse
Affiliation(s)
- Marua Prevato
- University of Siena, Department of Life Sciences, Via A. Moro, 53100, Siena, Italy
| | - Roberta Cozzi
- GSK, Research Center, Via Fiorentina 1, 53100, Siena, Italy
| | | | - Anna Rita Taddei
- Section of Electron Microscopy, Great Equipment Center, Tuscia University, 01100, Viterbo, Italy
| | | | - Avishek Nandi
- GSK, Vaccine Research, Holly Springs, North Carolina, 27540, United States of America
- GSK, Vaccine Research, Cambridge, Massachusetts, 02139, United States of America
| | - Emanuele Montomoli
- University of Siena, Department of Molecular and Developmental Medicine, Via A. Moro, 53100, Siena, Italy
| | - Ethan C. Settembre
- GSK, Vaccine Research, Cambridge, Massachusetts, 02139, United States of America
| | | | | | - Francois Legay
- GSK, Research Center, Via Fiorentina 1, 53100, Siena, Italy
- GSK, Peter Merian Strasse, 4056, Basel, Switzerland
| |
Collapse
|
16
|
Nilo A, Passalacqua I, Fabbrini M, Allan M, Usera A, Carboni F, Brogioni B, Pezzicoli A, Cobb J, Romano MR, Margarit I, Hu QY, Berti F, Adamo R. Exploring the Effect of Conjugation Site and Chemistry on the Immunogenicity of an anti-Group B Streptococcus Glycoconjugate Vaccine Based on GBS67 Pilus Protein and Type V Polysaccharide. Bioconjug Chem 2015; 26:1839-49. [DOI: 10.1021/acs.bioconjchem.5b00365] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Alberto Nilo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Irene Passalacqua
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Monica Fabbrini
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Martin Allan
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Aimee Usera
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Filippo Carboni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Barbara Brogioni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Alfredo Pezzicoli
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Jennifer Cobb
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | | | | | - Qi-Ying Hu
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Francesco Berti
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Roberto Adamo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| |
Collapse
|
17
|
Nilo A, Morelli L, Passalacqua I, Brogioni B, Allan M, Carboni F, Pezzicoli A, Zerbini F, Maione D, Fabbrini M, Romano MR, Hu QY, Margarit I, Berti F, Adamo R. Anti-Group B Streptococcus Glycan-Conjugate Vaccines Using Pilus Protein GBS80 As Carrier and Antigen: Comparing Lysine and Tyrosine-directed Conjugation. ACS Chem Biol 2015; 10:1737-46. [PMID: 25906283 DOI: 10.1021/acschembio.5b00247] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gram-positive Streptococcus agalactiae or group B Streptococcus (GBS) is a leading cause of invasive infections in pregnant women, newborns, and elderly people. Vaccination of pregnant women represents the best strategy for prevention of neonatal disease, and GBS polysaccharide-based conjugate vaccines are currently under clinical testing. The potential of GBS pilus proteins selected by genome-based reverse vaccinology as protective antigens for anti-streptococcal vaccines has also been demonstrated. Dressing pilus proteins with surface glycan antigens could be an attractive approach to extend vaccine coverage. We have recently developed an efficient method for tyrosine-directed ligation of large glycans to proteins via copper-free azide-alkyne [3 + 2] cycloaddition. This method enables targeting of predetermined sites of the protein, ensuring that protein epitopes are preserved prior to glycan coupling and a higher consistency in glycoconjugate batches. Herein, we compared conjugates of the GBS type II polysaccharide (PSII) and the GBS80 pilus protein obtained by classic lysine random conjugation and by the recently developed tyrosine-directed ligation. PSII conjugated to CRM197, a carrier protein used for vaccines in the market, was used as a control. We found that the constructs made from PSII and GBS80 were able to elicit murine antibodies recognizing individually the glycan and protein epitopes on the bacterial surface. The generated antibodies were efficacious in mediating opsonophagocytic killing of strains expressing exclusively PSII or GBS80 proteins. The two glycoconjugates were also effective in protecting newborn mice against GBS infection following vaccination of the dams. Altogether, these results demonstrated that polysaccharide-conjugated GBS80 pilus protein functions as a carrier comparably to CRM197, while maintaining its properties of protective protein antigen. Glycoconjugation and reverse vaccinology can, therefore, be combined to design vaccines with broad coverage. This approach opens a path to a new generation of vaccines. Tyrosine-ligation allows creation of more homogeneous vaccines, correlation of the immune response to defined connectivity points, and fine-tuning of the conjugation site in glycan-protein conjugates.
Collapse
Affiliation(s)
- Alberto Nilo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Laura Morelli
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Irene Passalacqua
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Barbara Brogioni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Martin Allan
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Filippo Carboni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Alfredo Pezzicoli
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Francesca Zerbini
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Domenico Maione
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Monica Fabbrini
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | | | - Qi-Ying Hu
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | | | - Francesco Berti
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Roberto Adamo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| |
Collapse
|
18
|
Biagini M, Garibaldi M, Aprea S, Pezzicoli A, Doro F, Becherelli M, Taddei AR, Tani C, Tavarini S, Mora M, Teti G, D'Oro U, Nuti S, Soriani M, Margarit I, Rappuoli R, Grandi G, Norais N. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles. Mol Cell Proteomics 2015; 14:2138-49. [PMID: 26018414 DOI: 10.1074/mcp.m114.045880] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 01/24/2023] Open
Abstract
Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles.
Collapse
Affiliation(s)
- Massimiliano Biagini
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Manuela Garibaldi
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Susanna Aprea
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Alfredo Pezzicoli
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Francesco Doro
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Marco Becherelli
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Anna Rita Taddei
- §Centro Interdipartimentale di Microscopia Elettronica, Università della Tuscia, Viterbo, Italy
| | - Chiara Tani
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Simona Tavarini
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Marirosa Mora
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Giuseppe Teti
- ¶Dipartimento di Scienze Pediatriche, Ginecologiche, Microbiologiche e Biomediche, Università degli Studi di Messina, Messina, Italy
| | - Ugo D'Oro
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Sandra Nuti
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Marco Soriani
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Immaculada Margarit
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Rino Rappuoli
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Guido Grandi
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay
| | - Nathalie Norais
- From the ‡Novartis Vaccines and Diagnostics (a GSK company), Via Fiorentiina 1, 53100 Siena, Itlay;
| |
Collapse
|
19
|
Cantisani R, Pezzicoli A, Cioncada R, Malzone C, De Gregorio E, D'Oro U, Piccioli D. Vaccine adjuvant MF59 promotes retention of unprocessed antigen in lymph node macrophage compartments and follicular dendritic cells. J Immunol 2015; 194:1717-25. [PMID: 25589069 DOI: 10.4049/jimmunol.1400623] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ag retention within lymph nodes (LNs) upon vaccination is critical for the development of adaptive immune responses, because it facilitates the encounter of the Ag with cognate lymphocytes. During a secondary exposure of the immune system to an Ag, immune complexes (ICs) that contain the unprocessed Ag are captured by subcapsular sinus macrophages and are transferred onto follicular dendritic cells, where they persist for weeks, facilitating Ag presentation to cognate memory B cells. The impact of adjuvants on Ag retention within the draining LNs is unknown. In this article, we provide the first evidence, to our knowledge, that the oil-in-water emulsion adjuvant MF59 localizes in subcapsular sinus and medullary macrophage compartments of mouse draining LNs, where it persists for at least 2 wk. In addition, we demonstrate that MF59 promotes accumulation of the unprocessed Ag within these LN compartments and facilitates the consequent deposition of the IC-trapped Ag onto activated follicular dendritic cells. These findings correlate with the ability of MF59 to boost germinal center generation and Ag-specific Ab titers. Our data suggest that the adjuvant effect of MF59 is, at least in part, due to an enhancement of IC-bound Ag retention within the LN and offer insights to improve the efficacy of new vaccine adjuvants.
Collapse
Affiliation(s)
| | | | | | | | | | - Ugo D'Oro
- Novartis Vaccines and Diagnostics, 53100, Siena, Italy
| | | |
Collapse
|
20
|
Gallotta M, Gancitano G, Pietrocola G, Mora M, Pezzicoli A, Tuscano G, Chiarot E, Nardi-Dei V, Taddei AR, Rindi S, Speziale P, Soriani M, Grandi G, Margarit I, Bensi G. SpyAD, a moonlighting protein of group A Streptococcus contributing to bacterial division and host cell adhesion. Infect Immun 2014; 82:2890-901. [PMID: 24778116 PMCID: PMC4097626 DOI: 10.1128/iai.00064-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/15/2014] [Indexed: 11/20/2022] Open
Abstract
Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the spy0269 gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact in vitro with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells in vitro and that Lactococcus lactis expressing Spy0269 on its cell surface could adhere to mammalian cells in vitro and to mice nasal mucosa in vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (Streptococcus pyogenes Adhesion and Division protein).
Collapse
Affiliation(s)
| | | | - Giampiero Pietrocola
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | | | | | | | | | | | - Anna Rita Taddei
- Centre for High Instruments, Electron Microscopy Section, University of Tuscia, Viterbo, Italy
| | - Simonetta Rindi
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | - Pietro Speziale
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | | | - Guido Grandi
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | | | | |
Collapse
|
21
|
Nesta B, Valeri M, Spagnuolo A, Rosini R, Mora M, Donato P, Alteri CJ, Del Vecchio M, Buccato S, Pezzicoli A, Bertoldi I, Buzzigoli L, Tuscano G, Falduto M, Rippa V, Ashhab Y, Bensi G, Fontana MR, Seib KL, Mobley HLT, Pizza M, Soriani M, Serino L. SslE elicits functional antibodies that impair in vitro mucinase activity and in vivo colonization by both intestinal and extraintestinal Escherichia coli strains. PLoS Pathog 2014; 10:e1004124. [PMID: 24809621 PMCID: PMC4014459 DOI: 10.1371/journal.ppat.1004124] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 03/31/2014] [Indexed: 11/18/2022] Open
Abstract
SslE, the Secreted and surface-associated lipoprotein from Escherichia coli, has recently been associated to the M60-like extracellular zinc-metalloprotease sub-family which is implicated in glycan recognition and processing. SslE can be divided into two main variants and we recently proposed it as a potential vaccine candidate. By applying a number of in vitro bioassays and comparing wild type, knockout mutant and complemented strains, we have now demonstrated that SslE specifically contributes to degradation of mucin substrates, typically present in the intestine and bladder. Mutation of the zinc metallopeptidase motif of SslE dramatically impaired E. coli mucinase activity, confirming the specificity of the phenotype observed. Moreover, antibodies raised against variant I SslE, cloned from strain IHE3034 (SslEIHE3034), are able to inhibit translocation of E. coli strains expressing different variants through a mucin-based matrix, suggesting that SslE induces cross-reactive functional antibodies that affect the metallopeptidase activity. To test this hypothesis, we used well-established animal models and demonstrated that immunization with SslEIHE3034 significantly reduced gut, kidney and spleen colonization by strains producing variant II SslE and belonging to different pathotypes. Taken together, these data strongly support the importance of SslE in E. coli colonization of mucosal surfaces and reinforce the use of this antigen as a component of a broadly protective vaccine against pathogenic E. coli species. Escherichia coli are the predominant facultative anaerobe of the human colonic flora. Although intestinal and extraintestinal pathogenic E. coli are phylogenetically and epidemiologically distinct, we recently proposed a number of protective antigens conserved in most E. coli pathotypes. In this study, we have elucidated the function of the most promising of these antigens, SslE, which is characterized by the presence of a M60-like domain representative of a new extracellular zinc-metalloprotease sub-family. In particular, in vitro analysis of the ability of an sslE knockout mutant strain to transverse an agar-based mucin matrix revealed that SslE is essential to E. coli mucinase activity. Evidence showing that SslE induces functional antibodies, preventing both in vitro mucin degradation but also in vivo gut, kidney and spleen colonization, further support the hypothesis that SslE may facilitate E. coli colonization by favoring the penetration of the sterile inner mucus layer leading to interaction with host cells. Finally, the ability of SslE to also induce protective immunity against sepsis, linked to its presence among different pathotypes, supports the use of such an antigen as a broadly protective E. coli vaccine candidate.
Collapse
Affiliation(s)
| | - Maria Valeri
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | | | | | | | - Paolo Donato
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | - Christopher J. Alteri
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | | | | | | | | | | | | | | | - Yaqoub Ashhab
- Biotechnology Research Center, Palestine Polytechnic University, Hebron, Palestine
| | | | | | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, Australia
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | - Marco Soriani
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
- * E-mail:
| | - Laura Serino
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| |
Collapse
|
22
|
Capitani N, Ariani F, Amedei A, Pezzicoli A, Matucci A, Vultaggio A, Troilo A, Renieri A, Baldari CT, D' Elios MM. Vav1 haploinsufficiency in a common variable immunodeficiency patient with defective T-cell function. Int J Immunopathol Pharmacol 2012; 25:811-7. [PMID: 23058036 DOI: 10.1177/039463201202500332] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Common variable immunodeficiency (CVID) is a primary immune disorder characterized by impaired antibody production, which is in many instances secondary to defective T cell function (T-CVID). We previously identified a subset of T-CVID patients characterized by defective expression of Vav1, a guanine nucleotide exchanger which couples the T-cell antigen receptor to reorganization of the actin cytoskeleton. Here we have addressed the possibility that an intrinsic defect in the Vav1 gene might underlie the reduction in Vav protein observed in T cells from these patients. We report the identification in one T-CVID patient of a heterozygous deletion in Vav1. The gene deletion, spanning exons 2-27, accounts for the reduction in Vav1 mRNA and protein in T cells from this patient. The disease-related pedigree of this patient suggests a de novo origin of the Vav1 deletion. The findings highlights Vav1 as an autosomal dominant disease gene associated with CVID with defective T-cell function.
Collapse
Affiliation(s)
- N Capitani
- Department of Evolutionary Biology, University of Siena, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Mishra RPN, Mariotti P, Fiaschi L, Nosari S, Maccari S, Liberatori S, Fontana MR, Pezzicoli A, De Falco MG, Falugi F, Altindis E, Serruto D, Grandi G, Bagnoli F. Staphylococcus aureus FhuD2 is involved in the early phase of staphylococcal dissemination and generates protective immunity in mice. J Infect Dis 2012; 206:1041-9. [PMID: 22829645 DOI: 10.1093/infdis/jis463] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Iron availability plays an essential role in staphylococcal pathogenesis. We selected FhuD2, a lipoprotein involved in iron-hydroxamate uptake, as a novel vaccine candidate against Staphylococcus aureus. Unprecedented for staphylococcal lipoproteins, the protein was demonstrated to have a discrete, punctate localization on the bacterial surface. FhuD2 vaccination generated protective immunity against diverse clinical S. aureus isolates in murine infection models. Protection appeared to be associated with functional antibodies that were shown to mediate opsonophagocytosis, to be effective in passive transfer experiments, and to potentially block FhuD2-mediated siderophore uptake. Furthermore, the protein was found to be up-regulated in infected tissues and was required for staphylococcal dissemination and abscess formation. Herein we show that the staphylococcal iron-hydroxamate uptake system is important in invasive infection and functions as an efficacious vaccine target.
Collapse
|
24
|
Pezzicoli A, Ruggiero P, Amerighi F, Telford JL, Soriani M. Exogenous sialic acid transport contributes to group B streptococcus infection of mucosal surfaces. J Infect Dis 2012; 206:924-31. [PMID: 22829646 DOI: 10.1093/infdis/jis451] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
By sequence analysis of available group B streptococcus (GBS) genomes, we discovered a conserved putative operon involved in the catabolism of sialic acid, containing a tripartite transporter formed by two integral membrane components and a sugar-binding unit, named SAL0039. Expression analysis in the presence of different substrates revealed that SAL0039 was specifically upregulated by the presence of sialic acid and downregulated when bacteria were grown in human blood or in the presence of a high concentration of glucose. The role of SAL0039 in sugar transport was supported by the inability of the sal0039 deletion mutant strain to import exogenous sialic acid and to grow in semidefined medium supplemented with this sugar. Furthermore, in vivo evidence showed that the presence of exogenous sialic acid significantly increased the capacity of GBS to infect mice at the mucosal level. These findings suggest that transport of sialic acid may also contribute to GBS infections.
Collapse
|
25
|
Galeotti CL, Bove E, Pezzicoli A, Nogarotto R, Norais N, Pileri S, Lelli B, Falugi F, Balloni S, Tedde V, Chiarot E, Bombaci M, Soriani M, Bracci L, Grandi G, Grifantini R. Surface interactome in Streptococcus pyogenes. Mol Cell Proteomics 2011; 11:M111.015206. [PMID: 22199230 DOI: 10.1074/mcp.m111.015206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Very few studies have so far been dedicated to the systematic analysis of protein interactions occurring between surface and/or secreted proteins in bacteria. Such interactions are expected to play pivotal biological roles that deserve investigation. Taking advantage of the availability of a detailed map of surface and secreted proteins in Streptococcus pyogenes (group A Streptococcus (GAS)), we used protein array technology to define the "surface interactome" in this important human pathogen. Eighty-three proteins were spotted on glass slides in high density format, and each of the spotted proteins was probed for its capacity to interact with any of the immobilized proteins. A total of 146 interactions were identified, 25 of which classified as "reciprocal," namely, interactions that occur irrespective of which of the two partners was immobilized on the chip or in solution. Several of these interactions were validated by surface plasmon resonance and supported by confocal microscopy analysis of whole bacterial cells. By this approach, a number of interesting interactions have been discovered, including those occurring between OppA, DppA, PrsA, and TlpA, proteins known to be involved in protein folding and transport. These proteins, all localizing at the septum, might be part, together with HtrA, of the recently described ExPortal complex of GAS. Furthermore, SpeI was found to strongly interact with the metal transporters AdcA and Lmb. Because SpeI strictly requires zinc to exert its function, this finding provides evidence on how this superantigen, a major player in GAS pathogenesis, can acquire the metal in the host environment, where it is largely sequestered by carrier proteins. We believe that the approach proposed herein can lead to a deeper knowledge of the mechanisms underlying bacterial invasion, colonization, and pathogenesis.
Collapse
|
26
|
De Angelis G, Moschioni M, Muzzi A, Pezzicoli A, Censini S, Delany I, Lo Sapio M, Sinisi A, Donati C, Masignani V, Barocchi MA. The Streptococcus pneumoniae pilus-1 displays a biphasic expression pattern. PLoS One 2011; 6:e21269. [PMID: 21731688 PMCID: PMC3120856 DOI: 10.1371/journal.pone.0021269] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 05/27/2011] [Indexed: 11/18/2022] Open
Abstract
The Streptococcus pneumoniae pilus-1 is encoded by pilus islet 1 (PI-1), which has three clonal variants (clade I, II and III) and is present in about 30% of clinical pneumococcal isolates. In vitro and in vivo assays have demonstrated that pilus-1 is involved in attachment to epithelial cells and virulence, as well as protection in mouse models of infection. Several reports suggest that pilus-1 expression is tightly regulated and involves the interplay of numerous genetic regulators, including the PI-1 positive regulator RlrA. In this report we provide evidence that pilus expression, when analyzed at the single-cell level in PI-1 positive strains, is biphasic. In fact, the strains present two phenotypically different sub-populations of bacteria, one that expresses the pilus, while the other does not. The proportions of these two phenotypes are variable among the strains tested and are not influenced by genotype, serotype, growth conditions, colony morphology or by the presence of antibodies directed toward the pilus components. Two sub-populations, enriched in pilus expressing or not expressing bacteria were obtained by means of colony selection and immuno-detection methods for five strains. PI-1 sequencing in the two sub-populations revealed the absence of mutations, thus indicating that the biphasic expression observed is not due to a genetic modification within PI-1. Microarray expression profile and western blot analyses on whole bacterial lysates performed comparing the two enriched sub-populations, revealed that pilus expression is regulated at the transcriptional level (on/off regulation), and that there are no other genes, in addition to those encoded by PI-1, concurrently regulated across the strains tested. Finally, we provide evidence that the over-expression of the RrlA positive regulator is sufficient to induce pilus expression in pilus-1 negative bacteria. Overall, the data presented here suggest that the observed biphasic pilus expression phenotype could be an example of bistability in pneumococcus.
Collapse
|
27
|
Santi I, Pezzicoli A, Bosello M, Berti F, Mariani M, Telford JL, Grandi G, Soriani M. Functional characterization of a newly identified group B Streptococcus pullulanase eliciting antibodies able to prevent alpha-glucans degradation. PLoS One 2008; 3:e3787. [PMID: 19023424 PMCID: PMC2582482 DOI: 10.1371/journal.pone.0003787] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 11/04/2008] [Indexed: 01/04/2023] Open
Abstract
Streptococcal pullulanases have been recently proposed as key components of the metabolic machinery involved in bacterial adaptation to host niches. By sequence analysis of the Group B Streptococcus (GBS) genome we found a novel putative surface exposed protein with pullulanase activity. We named such a protein SAP. The sap gene is highly conserved among GBS strains and homologous genes, such as PulA and SpuA, have been described in other pathogenic streptococci. The SAP protein contains two N-terminal carbohydrate-binding motifs, followed by a catalytic domain and a C-terminal LPXTG cell wall-anchoring domain. In vitro analysis revealed that the recombinant form of SAP is able to degrade α-glucan polysaccharides, such as pullulan, glycogen and starch. Moreover, NMR analysis showed that SAP acts as a type I pullulanase. Studies performed on whole bacteria indicated that the presence of α-glucan polysaccharides in culture medium up-regulated the expression of SAP on bacterial surface as confirmed by FACS analysis and confocal imaging. Deletion of the sap gene resulted in a reduced capacity of bacteria to grow in medium containing pullulan or glycogen, but not glucose or maltose, confirming the pivotal role of SAP in GBS metabolism of α-glucans. As reported for other streptococcal pullulanases, we found specific anti-SAP antibodies in human sera from healthy volunteers. Investigation of the functional role of anti-SAP antibodies revealed that incubation of GBS in the presence of sera from animals immunized with SAP reduced the capacity of the bacterium to degrade pullulan. Of interest, anti-SAP sera, although to a lower extent, also inhibited Group A Streptococcus pullulanase activity. These data open new perspectives on the possibility to use SAP as a potential vaccine component inducing functional cross-reacting antibodies interfering with streptococcal infections.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Guido Grandi
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
| | - Marco Soriani
- Novartis Vaccines and Diagnostics Srl, Siena, Italy
- * E-mail:
| |
Collapse
|
28
|
Pezzicoli A, Santi I, Lauer P, Rosini R, Rinaudo D, Grandi G, Telford JL, Soriani M. Pilus backbone contributes to group B Streptococcus paracellular translocation through epithelial cells. J Infect Dis 2008; 198:890-8. [PMID: 18694342 DOI: 10.1086/591182] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
We have recently shown that group B Streptococcus (GBS) crosses the epithelial barrier by a paracellular route. Here, we show that, although deletion of the pilus backbone protein did not affect GBS adhesiveness, it reduced the pathogen's capacity to transcytose through differentiated human epithelial cells. In addition, contrary to our expectation, a strain with a mutant pilus ancillary protein and reduced adhesiveness translocated through the epithelial monolayer in a fashion identical to that of the isogenic wild-type strain. To monitor the localization of pili during GBS paracytosis, we performed 3-dimensional confocal experiments. By this approach, we observed that pili located in the intercellular space ahead of translocating bacteria. These results were also confirmed by a novel in vitro model of GBS infection in which bacteria bind to epithelial surfaces against the action of gravitation. These findings suggest a dual role for pilus components during the critical steps leading to GBS dissemination in the host.
Collapse
|
29
|
Santi I, Scarselli M, Mariani M, Pezzicoli A, Masignani V, Taddei A, Grandi G, Telford JL, Soriani M. BibA: a novel immunogenic bacterial adhesin contributing to group B Streptococcus survival in human blood. Mol Microbiol 2007; 63:754-67. [PMID: 17212592 DOI: 10.1111/j.1365-2958.2006.05555.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By the analysis of the recently sequenced genomes of Group B Streptococcus (GBS) we have identified a novel immunogenic adhesin with anti-phagocytic activity, named BibA. The bibA gene is present in 100% of the 24 GBS strains analysed. BibA-specific IgG were found in human sera from normal healthy donors. The putative protein product is a polypeptide of 630 amino acids containing a helix-rich N-terminal domain, a proline-rich region and a canonical LPXTG cell wall-anchoring domain. BibA is expressed on the surface of several GBS strains, but is also recovered in GBS culture supernatants. BibA specifically binds to human C4-binding protein, a regulator of the classic complement pathway. Deletion of the bibA gene severely reduced the capacity of GBS to survive in human blood and to resist opsonophagocytic killing by human neutrophils. In addition, BibA expression increased the virulence of GBS in a mouse infection model. The role of BibA in GBS adhesion was demonstrated by the impaired ability of a bibA knockout mutant strain to adhere to both human cervical and lung epithelial cells. Furthermore, we calculated that recombinant BibA bound to human epithelial cells of distinct origin with an affinity constant of approximately 10(-8) M for cervical epithelial cells. Hence BibA is a novel multifunctional protein involved in both resistance to phagocytic killing and adhesion to host cells. The identification of this potential new virulence factor represents an important step in the development of strategies to combat GBS-associated infections.
Collapse
Affiliation(s)
- Isabella Santi
- Novartis Vaccines and Diagnostics Srl, Via Fiorentina 1, 53100, Siena, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Pezzicoli A, Ulivieri C, Capitani N, Ventura A, Pelicci P, Baldari CT. Expression in T-cells of the proapoptotic protein p66SHC is controlled by promoter demethylation. Biochem Biophys Res Commun 2006; 349:322-8. [PMID: 16934220 DOI: 10.1016/j.bbrc.2006.08.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Accepted: 08/09/2006] [Indexed: 01/12/2023]
Abstract
p66Shc plays a key role in oxidative stress-induced apoptosis. p66Shc gene expression is tissue-specific and controlled by promoter methylation. In T-cells p66Shc expression is induced by a variety of apoptotic stimuli. We have addressed the mechanisms regulating p66Shc expression in T-cells. We show that the increase in p66Shc protein following stimulation with a Ca2+ ionophore results from enhanced gene expression, which is primarily dependent on DNA replication-independent promoter demethylation. Our data underline the role of CpG methylation in the control of p66Shc gene expression and provide evidence that Ca2+ signaling may lead to epigenetic modifications in nondividing cells.
Collapse
Affiliation(s)
- Alfredo Pezzicoli
- Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | | | | | | | | | | |
Collapse
|