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Buhlheller C, Sagmeister T, Grininger C, Gubensäk N, Sleytr UB, Usón I, Pavkov-Keller T. SymProFold: Structural prediction of symmetrical biological assemblies. Nat Commun 2024; 15:8152. [PMID: 39294115 DOI: 10.1038/s41467-024-52138-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 08/28/2024] [Indexed: 09/20/2024] Open
Abstract
Symmetry in nature often emerges from self-assembly processes and serves a wide range of functions. Cell surface layers (S-layers) form symmetrical lattices on many bacterial and archaeal cells, playing essential roles such as facilitating cell adhesion, evading the immune system, and protecting against environmental stress. However, the experimental structural characterization of these S-layers is challenging due to their self-assembly properties and high sequence variability. In this study, we introduce the SymProFold pipeline, which utilizes the high accuracy of AlphaFold-Multimer predictions to derive symmetrical assemblies from protein sequences, specifically focusing on two-dimensional S-layer arrays and spherical viral capsids. The pipeline tests all known symmetry operations observed in these systems (p1, p2, p3, p4, and p6) and identifies the most likely symmetry for the assembly. The predicted models were validated using available experimental data at the cellular level, and additional crystal structures were obtained to confirm the symmetry and interfaces of several SymProFold assemblies. Overall, the SymProFold pipeline enables the determination of symmetric protein assemblies linked to critical functions, thereby opening possibilities for exploring functionalities and designing targeted applications in diverse fields such as nanotechnology, biotechnology, medicine, and materials and environmental sciences.
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Affiliation(s)
- Christoph Buhlheller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- Medical University of Graz, Graz, Austria
| | - Theo Sagmeister
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Nina Gubensäk
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Uwe B Sleytr
- Institute of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Isabel Usón
- Structural Biology Unit, Institute of Molecular Biology of Barcelona, Spanish National Research Council, Barcelona, Spain
- ICREA, Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria.
- BioTechMed-Graz, University of Graz, Graz, Austria.
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Sagmeister T, Gubensäk N, Buhlheller C, Grininger C, Eder M, Ðordić A, Millán C, Medina A, Murcia PAS, Berni F, Hynönen U, Vejzović D, Damisch E, Kulminskaya N, Petrowitsch L, Oberer M, Palva A, Malanović N, Codée J, Keller W, Usón I, Pavkov-Keller T. The molecular architecture of Lactobacillus S-layer: Assembly and attachment to teichoic acids. Proc Natl Acad Sci U S A 2024; 121:e2401686121. [PMID: 38838019 PMCID: PMC11181022 DOI: 10.1073/pnas.2401686121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/26/2024] [Indexed: 06/07/2024] Open
Abstract
S-layers are crystalline arrays found on bacterial and archaeal cells. Lactobacillus is a diverse family of bacteria known especially for potential gut health benefits. This study focuses on the S-layer proteins from Lactobacillus acidophilus and Lactobacillus amylovorus common in the mammalian gut. Atomic resolution structures of Lactobacillus S-layer proteins SlpA and SlpX exhibit domain swapping, and the obtained assembly model of the main S-layer protein SlpA aligns well with prior electron microscopy and mutagenesis data. The S-layer's pore size suggests a protective role, with charged areas aiding adhesion. A highly similar domain organization and interaction network are observed across the Lactobacillus genus. Interaction studies revealed conserved binding areas specific for attachment to teichoic acids. The structure of the SlpA S-layer and the suggested incorporation of SlpX as well as its interaction with teichoic acids lay the foundation for deciphering its role in immune responses and for developing effective treatments for a variety of infectious and bacteria-mediated inflammation processes, opening opportunities for targeted engineering of the S-layer or lactobacilli bacteria in general.
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Affiliation(s)
- Theo Sagmeister
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | - Nina Gubensäk
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | | | | | - Markus Eder
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | - Anđela Ðordić
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | - Claudia Millán
- Structural Biology Unit, Institute of Molecular Biology of Barcelona, Spanish National Research Council, Barcelona08028, Spain
| | - Ana Medina
- Structural Biology Unit, Institute of Molecular Biology of Barcelona, Spanish National Research Council, Barcelona08028, Spain
| | - Pedro Alejandro Sánchez Murcia
- Laboratory of Computer-Aided Molecular Design, Division of Medicinal Chemistry, Otto-Loewi Research Center, Medical University of Graz, Graz, Austria8010
| | - Francesca Berni
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Leiden2333, The Netherlands
| | - Ulla Hynönen
- Department of Basic Veterinary Sciences, Division of Microbiology and Epidemiology, University of Helsinki, Helsinki00100, Finland
| | - Djenana Vejzović
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | - Elisabeth Damisch
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | | | - Lukas Petrowitsch
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
- Field of Excellence BioHealth, University of Graz, Graz8010, Austria
- BioTechMed-Graz, University of Graz, Graz8010, Austria
| | - Airi Palva
- Department of Basic Veterinary Sciences, Division of Microbiology and Epidemiology, University of Helsinki, Helsinki00100, Finland
| | - Nermina Malanović
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
- Field of Excellence BioHealth, University of Graz, Graz8010, Austria
- BioTechMed-Graz, University of Graz, Graz8010, Austria
| | - Jeroen Codée
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Leiden2333, The Netherlands
| | - Walter Keller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
- Field of Excellence BioHealth, University of Graz, Graz8010, Austria
- BioTechMed-Graz, University of Graz, Graz8010, Austria
| | - Isabel Usón
- Structural Biology Unit, Institute of Molecular Biology of Barcelona, Spanish National Research Council, Barcelona08028, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona08003, Spain
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria8010
- Field of Excellence BioHealth, University of Graz, Graz8010, Austria
- BioTechMed-Graz, University of Graz, Graz8010, Austria
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Bendinelli P, De Noni I, Cattaneo S, Silvetti T, Brasca M, Piazzalunga F, Donetti E, Ferraretto A. Surface layer proteins from Lactobacillus helveticus ATCC® 15009™ affect the gut barrier morphology and function. Tissue Barriers 2023:2289838. [PMID: 38059583 DOI: 10.1080/21688370.2023.2289838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023] Open
Abstract
Paraprobiotics and postbiotics represent a valid alternative to probiotic strains for ameliorating and preserving a healthy intestinal epithelial barrier (IEB). The present study investigated the effects of surface layer proteins (S-layer) of the dairy strain Lactobacillus helveticus ATCC® 15009™ (Lb ATCC® 15009™), as paraprobiotic, on the morpho-functional modulation of IEB in comparison to live or heat-inactivated Lb ATCC® 15009™ in an in vitro co-culture of Caco-2/HT-29 70/30 cells. Live or heat-inactivated Lb ATCC® 15009™ negatively affected transepithelial electrical resistance (TEER) and paracellular permeability, and impaired the distribution of Claudin-1, a tight junction (TJ) transmembrane protein, as detected by immunofluorescence (IF). Conversely, the addition of the S-layer improved TEER and decreased permeability in physiological conditions in co-cultures with basal TEER lower than 50 ohmcm2, indicative of a more permeable physiological IEB known as leaky gut. Transmission electron microscopy (TEM) and IF analyses suggested that the S-layer induces a structural TJ rearrangement and desmosomes' formation. S-layer also restored TEER and permeability in the presence of LPS, but not of a mixture of pro-inflammatory cytokines (TNF-α plus IFN-γ). IF analyses showed an increase in Claudin-1 staining when LPS and S-layer were co-administered with respect to LPS alone; in addition, the S-layer counteracted the reduction of alkaline phosphatase detoxification activity and the enhancement of pro-inflammatory interleukin-8 release both induced by LPS. Altogether, these data corroborate a paraprobiotic role of S-layer from Lb ATCC® 15009™ as a possible candidate for therapeutic and prophylactic uses in conditions related to gastrointestinal health and correlated with extra-intestinal disorders.
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Affiliation(s)
- Paola Bendinelli
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Ivano De Noni
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Stefano Cattaneo
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Tiziana Silvetti
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Milan, Italy
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Milan, Italy
| | | | - Elena Donetti
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Anita Ferraretto
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
- Laboratory of Experimental Biochemistry & Molecular Biology, IRCCS Istituto Galeazzi-Sant'Ambrogio, Milan, Italy
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Hietanen E, Tripathi L, Brockmann EC, Merilahti P, Lamminmäki U, Susi P. Isolation and characterization of phage display-derived scFv antibodies against human parechovirus 1 VP0 protein. Sci Rep 2022; 12:13453. [PMID: 35927325 PMCID: PMC9352675 DOI: 10.1038/s41598-022-17678-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/29/2022] [Indexed: 11/25/2022] Open
Abstract
Human parechoviruses (PeVs) are common viruses that are associated with a variety of diseases from mild gastrointestinal and respiratory symptoms to severe central nervous system infections. Until now there has not been antibodies for visualizing parechovirus infection. We used E. coli recombinant PeV-A1-VP0 protein as a target in phage display single chain variable fragment (scFv) antibody library panning. Three rounds of panning allowed identification and isolation of several candidate scFv clones, which tested positive in enzyme-linked immunosorbent assay (ELISA) against VP0. Three scFv clones (scFv-55, -59 and -71) with different CDR-3 sequences were further purified and tested in ELISA, Western blot and immunofluorescence microscopy (IFA) against a set of PeV-A1 isolates and a few isolates representing PeV types 2–6. In IFA, all three scFv binders recognized twenty PeV-A1 isolates. ScFv-55 and -71 also recognized clinical representatives of PeV types 1–6 both in IFA and in capture ELISA, while scFv-59 only recognized PeV-A1, -A2 and -A6. PeV-A1-VP0 (Harris strain) sequence was used to generate a peptide library, which allowed identification of a putative unique conformational antibody epitope with fully conserved flanking regions and a more variable core VVTYDSKL, shared between the scFv antibodies. Sequencing of the VP0 region of virus samples and sequence comparisons against parechoviral sequences in GenBank revealed 107 PeV-A1, -A3, -A8, -A17, -A (untyped) sequences with this exact epitope core sequence, which was most dominant among PeV-A1 isolates. These data suggest the first-time isolation of broad range phage display antibodies against human parechoviruses that may be used in diagnostic antibody development.
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Affiliation(s)
- Eero Hietanen
- Institute of Biomedicine, University of Turku, Turku, Finland
| | - Lav Tripathi
- Institute of Biomedicine, University of Turku, Turku, Finland
| | | | - Pirjo Merilahti
- Institute of Biomedicine, University of Turku, Turku, Finland.,Biovian Ltd, Turku, Finland
| | - Urpo Lamminmäki
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Petri Susi
- Institute of Biomedicine, University of Turku, Turku, Finland.
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Surface Layer of Lactobacillus helveticus MIMLh5 Promotes Endocytosis by Dendritic Cells. Appl Environ Microbiol 2019; 85:AEM.00138-19. [PMID: 30824443 DOI: 10.1128/aem.00138-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 02/13/2019] [Indexed: 01/09/2023] Open
Abstract
Surface layers (S-layers) are proteinaceous arrays covering the cell walls of numerous bacteria. Their suggested properties, such as interactions with the host immune system, have been only poorly described. Here, we aimed to elucidate the role of the S-layer from the probiotic bacterial strain Lactobacillus helveticus MIMLh5 in the stimulation of murine bone-marrow-derived dendritic cells (DCs). MIMLh5 induced greater production of interferon beta (IFN-β), interleukin 10 (IL-10), and IL-12p70, compared to S-layer-depleted MIMLh5 (naked MIMLh5 [n-MIMLh5]), whereas the isolated S-layer was a poor immunostimulator. No differences in the production of tumor necrosis factor alpha (TNF-α) or IL-1β were found. Inhibition of the mitogen-activated protein kinases JNK1/2, p38, and ERK1/2 modified IL-12p70 production similarly in MIMLh5 and n-MIMLh5, suggesting the induction of the same signaling pathways by the two bacterial preparations. Treatment of DCs with cytochalasin D to inhibit endocytosis before the addition of fluorescently labeled MIMLh5 cells led to a dramatic reduction in the proportion of fluorescence-positive DCs and decreased IL-12 production. Endocytosis and IL-12 production were only marginally affected by cytochalasin D pretreatment when fluorescently labeled n-MIMLh5 was used. Treatment of DCs with fluorescently labeled S-layer-coated polystyrene beads (Sl-beads) resulted in much greater uptake of beads, compared to noncoated beads. Prestimulation of DCs with cytochalasin D reduced the uptake of Sl-beads more than plain beads. These findings indicate that the S-layer plays a role in the endocytosis of MIMLh5 by DCs. In conclusion, this study provides evidence that the S-layer of L. helveticus MIMLh5 is involved in endocytosis of the bacterium, which is important for strong Th1-inducing cytokine production.IMPORTANCE Beneficial microbes may positively affect host physiology at various levels, e.g., by participating in immune system maturation and modulation, boosting defenses and dampening reactions, thus affecting the whole homeostasis. As a consequence, the use of probiotics is increasingly regarded as suitable for more extended applications for health maintenance, not only microbiota balancing. This implies a deep knowledge of the mechanisms and molecules involved in host-microbe interactions, for the final purpose of fine tuning the choice of a probiotic strain for a specific outcome. With this aim, studies targeted to the description of strain-related immunomodulatory effects and the identification of bacterial molecules responsible for specific responses are indispensable. This study provides new insights in the characterization of the food-origin probiotic bacterium L. helveticus MIMLh5 and its S-layer protein as a driver for the cross-talk with DCs.
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Chiron C, Tompkins TA, Burguière P. Flow cytometry: a versatile technology for specific quantification and viability assessment of micro-organisms in multistrain probiotic products. J Appl Microbiol 2018; 124:572-584. [PMID: 29236340 DOI: 10.1111/jam.13666] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/29/2017] [Accepted: 10/18/2017] [Indexed: 01/21/2023]
Abstract
AIMS Classical microbiology techniques are the gold standard for probiotic enumeration. However, these techniques are limited by parameters of time, specificity and incapacity to detect viable but nonculturable (VBNC) micro-organisms and nonviable cells. The aim of the study was to evaluate flow cytometry as a novel method for the specific quantification of viable and nonviable probiotics in multistrain products. METHODS AND RESULTS Custom polyclonal antibodies were produced against five probiotic strains from different species (Bifidobacterium bifidum R0071, Bifidobacterium longum ssp. infantis R0033, Bifidobacterium longum ssp. longum R0175, Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011). Evaluation of specificity confirmed that all antibodies were specific at least at the subspecies level. A flow cytometry method combining specific antibodies and viability assessment with SYTO® 24 and propidium iodide was applied to quantify these strains in three commercial products. Analyses were conducted on two flow cytometry instruments by two operators and compared with classical microbiology using selective media. Results indicated that flow cytometry provides higher cell counts than classical microbiology (P < 0·05) in 73% of cases highlighting the possible presence of VBNC. Equivalent performances (repeatability and reproducibility) were obtained for both methods. CONCLUSIONS This study showed that flow cytometry methods can be applied to probiotic enumeration and viability assessment. Combination with polyclonal antibodies can achieve sufficient specificity to differentiate closely related strains. SIGNIFICANCE AND IMPACT OF THE STUDY Flow cytometry provides absolute and specific quantification of viable and nonviable probiotic strains in a very short time (<2 h) compared with classical techniques (>48 h), bringing efficient tools for research and development and quality control.
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Affiliation(s)
- C Chiron
- Lallemand Health Solutions Inc., Montreal, QC, Canada
| | - T A Tompkins
- Lallemand Health Solutions Inc., Montreal, QC, Canada
| | - P Burguière
- Lallemand Health Solutions Inc., Montreal, QC, Canada
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