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Ruocco V, Grünwald-Gruber C, Rad B, Tscheliessnig R, Hammel M, Strasser R. Effects of N-glycans on the structure of human IgA2. Front Mol Biosci 2024; 11:1390659. [PMID: 38645274 PMCID: PMC11026580 DOI: 10.3389/fmolb.2024.1390659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 03/22/2024] [Indexed: 04/23/2024] Open
Abstract
The transition of IgA antibodies into clinical development is crucial because they have the potential to create a new class of therapeutics with superior pathogen neutralization, cancer cell killing, and immunomodulation capacity compared to IgG. However, the biological role of IgA glycans in these processes needs to be better understood. This study provides a detailed biochemical, biophysical, and structural characterization of recombinant monomeric human IgA2, which varies in the amount/locations of attached glycans. Monomeric IgA2 antibodies were produced by removing the N-linked glycans in the CH1 and CH2 domains. The impact of glycans on oligomer formation, thermal stability, and receptor binding was evaluated. In addition, we performed a structural analysis of recombinant IgA2 in solution using Small Angle X-Ray Scattering (SAXS) to examine the effect of glycans on protein structure and flexibility. Our results indicate that the absence of glycans in the Fc tail region leads to higher-order aggregates. SAXS, combined with atomistic modeling, showed that the lack of glycans in the CH2 domain results in increased flexibility between the Fab and Fc domains and a different distribution of open and closed conformations in solution. When binding with the Fcα-receptor, the dissociation constant remains unaltered in the absence of glycans in the CH1 or CH2 domain, compared to the fully glycosylated protein. These results provide insights into N-glycans' function on IgA2, which could have important implications for developing more effective IgA-based therapeutics in the future.
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Affiliation(s)
- Valentina Ruocco
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Clemens Grünwald-Gruber
- Core Facility Mass Spectrometry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Behzad Rad
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Rupert Tscheliessnig
- Division of Biophysics, Gottfried-Schatz-Research-Center, Medical University of Graz, Graz, Austria
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
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2
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Wang Y, Xiao J. Recent advances in the molecular understanding of immunoglobulin A. FEBS J 2024. [PMID: 38329005 DOI: 10.1111/febs.17089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/11/2024] [Accepted: 01/31/2024] [Indexed: 02/09/2024]
Abstract
Immunoglobulin A (IgA) plays a crucial role in the human immune system, particularly in mucosal immunity. IgA antibodies that target the mucosal surface are made up of two to five IgA monomers linked together by the joining chain, forming polymeric molecules. These IgA polymers are transported across mucosal epithelial cells by the polymeric immunoglobulin receptor pIgR, resulting in the formation of secretory IgA (SIgA). This review aims to explore recent advancements in our molecular understanding of IgA, with a specific focus on SIgA, and the interaction between IgA and pathogen molecules.
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Affiliation(s)
- Yuxin Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Junyu Xiao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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3
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Croucher NJ, Campo JJ, Le TQ, Pablo JV, Hung C, Teng AA, Turner C, Nosten F, Bentley SD, Liang X, Turner P, Goldblatt D. Genomic and panproteomic analysis of the development of infant immune responses to antigenically-diverse pneumococci. Nat Commun 2024; 15:355. [PMID: 38191887 PMCID: PMC10774285 DOI: 10.1038/s41467-023-44584-2] [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: 08/03/2023] [Accepted: 12/19/2023] [Indexed: 01/10/2024] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. This study characterises the immunoglobulin G (IgG) repertoire recognising pneumococci from birth to 24 months old (mo) in a prospectively-sampled cohort of 63 children using a panproteome array. IgG levels are highest at birth, due to transplacental transmission of maternal antibodies. The subsequent emergence of responses to individual antigens exhibit distinct kinetics across the cohort. Stable differences in the strength of individuals' responses, correlating with maternal IgG concentrations, are established by 6 mo. By 12 mo, children develop unique antibody profiles that are boosted by re-exposure. However, some proteins only stimulate substantial responses in adults. Integrating genomic data on nasopharyngeal colonisation demonstrates rare pneumococcal antigens can elicit strong IgG levels post-exposure. Quantifying such responses to the diverse core loci (DCL) proteins is complicated by cross-immunity between variants. In particular, the conserved N terminus of DCL protein zinc metalloprotease B provokes the strongest early IgG responses. DCL proteins' ability to inhibit mucosal immunity likely explains continued pneumococcal carriage despite hosts' polyvalent antibody repertoire. Yet higher IgG levels are associated with reduced incidence, and severity, of pneumonia, demonstrating the importance of the heterogeneity in response strength and kinetics across antigens and individuals.
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Affiliation(s)
- Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, W12 0BZ, UK.
| | - Joseph J Campo
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Timothy Q Le
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Jozelyn V Pablo
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Christopher Hung
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Andy A Teng
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Claudia Turner
- Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, 9V54+8FQ, Cambodia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - François Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Stephen D Bentley
- Parasites & Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Xiaowu Liang
- Antigen Discovery Inc, 1 Technology Drive, Irvine, CA, 92618, USA
| | - Paul Turner
- Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, 9V54+8FQ, Cambodia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - David Goldblatt
- Great Ormond Street Institute of Child Health, University College London, London, WC1N 1EH, UK
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4
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Hockenberry A, Slack E, Stadtmueller BM. License to Clump: Secretory IgA Structure-Function Relationships Across Scales. Annu Rev Microbiol 2023; 77:645-668. [PMID: 37713459 DOI: 10.1146/annurev-micro-032521-041803] [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] [Indexed: 09/17/2023]
Abstract
Secretory antibodies are the only component of our adaptive immune system capable of attacking mucosal pathogens topologically outside of our bodies. All secretory antibody classes are (a) relatively resistant to harsh proteolytic environments and (b) polymeric. Recent elucidation of the structure of secretory IgA (SIgA) has begun to shed light on SIgA functions at the nanoscale. We can now begin to unravel the structure-function relationships of these molecules, for example, by understanding how the bent conformation of SIgA enables robust cross-linking between adjacent growing bacteria. Many mysteries remain, such as the structural basis of protease resistance and the role of noncanonical bacteria-IgA interactions. In this review, we explore the structure-function relationships of IgA from the nano- to the metascale, with a strong focus on how the seemingly banal "license to clump" can have potent effects on bacterial physiology and colonization.
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Affiliation(s)
- Alyson Hockenberry
- Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Dübendorf, Switzerland
- Department of Environmental Systems Science (D-USYS), ETH Zürich, Zürich, Switzerland;
| | - Emma Slack
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland;
- Botnar Research Centre for Child Health, Basel, Switzerland
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Beth M Stadtmueller
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, and Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, USA;
- Department of Biomedical and Translational Sciences, Carle Illinois College of Medicine, University of Illinois, Urbana, Illinois, USA
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5
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Robinson RE, Mitsi E, Nikolaou E, Pojar S, Chen T, Reiné J, Nyazika TK, Court J, Davies K, Farrar M, Gonzalez-Dias P, Hamilton J, Hill H, Hitchins L, Howard A, Hyder-Wright A, Lesosky M, Liatsikos K, Matope A, McLenaghan D, Myerscough C, Murphy A, Solórzano C, Wang D, Burhan H, Gautam M, Begier E, Theilacker C, Beavon R, Anderson AS, Gessner BD, Gordon SB, Collins AM, Ferreira DM. Human Infection Challenge with Serotype 3 Pneumococcus. Am J Respir Crit Care Med 2022; 206:1379-1392. [PMID: 35802840 DOI: 10.1164/rccm.202112-2700oc] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Rationale: Streptococcus pneumoniae serotype 3 (SPN3) is a cause of invasive pneumococcal disease and associated with low carriage rates. Following the introduction of pediatric 13-valent pneumococcal conjugate vaccine (PCV13) programs, SPN3 declines are less than other vaccine serotypes and incidence has increased in some populations coincident with a shift in predominant circulating SPN3 clade, from I to II. A human challenge model provides an effective means for assessing the impact of PCV13 on SPN3 in the upper airway. Objectives: To establish SPN3's ability to colonize the nasopharynx using different inoculum clades and doses, and the safety of an SPN3 challenge model. Methods: In a human challenge study involving three well-characterized and antibiotic-sensitive SPN3 isolates (PFESP306 [clade Ia], PFESP231 [no clade], and PFESP505 [clade II]), inoculum doses (10,000, 20,000, 80,000, and 160,000 cfu/100 μl) were escalated until maximal colonization rates were achieved, with concurrent acceptable safety. Measurement and Main Results: Presence and density of experimental SPN3 nasopharyngeal colonization in nasal wash samples, assessed using microbiological culture and molecular methods, on Days 2, 7, and 14 postinoculation. A total of 96 healthy participants (median age 21, interquartile range 19-25) were inoculated (n = 6-10 per dose group, 10 groups). Colonization rates ranged from 30.0-70.0% varying with dose and isolate. 30.0% (29/96) reported mild symptoms (82.8% [24/29] developed a sore throat); one developed otitis media requiring antibiotics. No serious adverse events occurred. Conclusions: An SPN3 human challenge model is feasible and safe with comparable carriage rates to an established Serotype 6B human challenge model. SPN3 carriage may cause mild upper respiratory symptoms.
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Affiliation(s)
- Ryan E Robinson
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
| | - Elena Mitsi
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Elissavet Nikolaou
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Sherin Pojar
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Tao Chen
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jesús Reiné
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Tinashe K Nyazika
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - James Court
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Kelly Davies
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Madlen Farrar
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Josh Hamilton
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Helen Hill
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Lisa Hitchins
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ashleigh Howard
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Angela Hyder-Wright
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
| | - Maia Lesosky
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Agnes Matope
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Daniella McLenaghan
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Annabel Murphy
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Carla Solórzano
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Duolao Wang
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Hassan Burhan
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
| | - Manish Gautam
- Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
| | | | | | | | | | | | - Stephen B Gordon
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Malawi Liverpool Wellcome Research Programme, Blantyre, Malawi
| | - Andrea M Collins
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
| | - Daniela M Ferreira
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
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6
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Redzic JS, Rahkola J, Tran N, Holyoak T, Lee E, Martín-Galiano AJ, Meyer N, Zheng H, Eisenmesser E. A substrate-induced gating mechanism is conserved among Gram-positive IgA1 metalloproteases. Commun Biol 2022; 5:1190. [PMID: 36336763 PMCID: PMC9637739 DOI: 10.1038/s42003-022-04173-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022] Open
Abstract
The mucosal adaptive immune response is dependent on the production of IgA antibodies and particularly IgA1, yet opportunistic bacteria have evolved mechanisms to specifically block this response by producing IgA1 proteases (IgA1Ps). Our lab was the first to describe the structures of a metal-dependent IgA1P (metallo-IgA1P) produced from Gram-positive Streptococcus pneumoniae both in the absence and presence of its IgA1 substrate through cryo-EM single particle reconstructions. This prior study revealed an active-site gating mechanism reliant on substrate-induced conformational changes to the enzyme that begged the question of whether such a mechanism is conserved among the wider Gram-positive metallo-IgA1P subfamily of virulence factors. Here, we used cryo-EM to characterize the metallo-IgA1P of a more distantly related family member from Gemella haemolysans, an emerging opportunistic pathogen implicated in meningitis, endocarditis, and more recently bacteremia in the elderly. While the substrate-free structures of these two metallo-IgA1Ps exhibit differences in the relative starting positions of the domain responsible for gating substrate, the enzymes have similar domain orientations when bound to IgA1. Together with biochemical studies that indicate these metallo-IgA1Ps have similar binding affinities and activities, these data indicate that metallo-IgA1P binding requires the specific IgA1 substrate to open the enzymes for access to their active site and thus, largely conform to an "induced fit" model.
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Affiliation(s)
- Jasmina S Redzic
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, School of Medicine, Aurora, CO, 80045, USA
| | - Jeremy Rahkola
- Mucosal and Vaccine Research Program Colorado, Division of Infectious Disease, University of Colorado Denver School of Medicine and Denver Veterans Affairs Medical Center, Aurora, CO, 80045, USA
| | - Norman Tran
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Todd Holyoak
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Eunjeong Lee
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, School of Medicine, Aurora, CO, 80045, USA
| | | | - Nancy Meyer
- Pacific Northwest Cryo-EM Center, Oregon Health and Science University, Portland, OR, 97201, USA
| | - Hongjin Zheng
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, School of Medicine, Aurora, CO, 80045, USA
| | - Elan Eisenmesser
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, School of Medicine, Aurora, CO, 80045, USA.
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7
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Lee E, Redzic JS, Nemkov T, Saviola AJ, Dzieciatkowska M, Hansen KC, D’Alessandro A, Dinarello C, Eisenmesser EZ. Human and Bacterial Toll-Interleukin Receptor Domains Exhibit Distinct Dynamic Features and Functions. Molecules 2022; 27:4494. [PMID: 35889366 PMCID: PMC9318647 DOI: 10.3390/molecules27144494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 02/04/2023] Open
Abstract
Toll-interleukin receptor (TIR) domains have emerged as critical players involved in innate immune signaling in humans but are also expressed as potential virulence factors within multiple pathogenic bacteria. However, there has been a shortage of structural studies aimed at elucidating atomic resolution details with respect to their interactions, potentially owing to their dynamic nature. Here, we used a combination of biophysical and biochemical studies to reveal the dynamic behavior and functional interactions of a panel of both bacterial TIR-containing proteins and mammalian receptor TIR domains. Regarding dynamics, all three bacterial TIR domains studied here exhibited an inherent exchange that led to severe resonance line-broadening, revealing their intrinsic dynamic nature on the intermediate NMR timescale. In contrast, the three mammalian TIR domains studied here exhibited a range in terms of their dynamic exchange that spans multiple timescales. Functionally, only the bacterial TIR domains were catalytic towards the cleavage of NAD+, despite the conservation of the catalytic nucleophile on human TIR domains. Our development of NMR-based catalytic assays allowed us to further identify differences in product formation for gram-positive versus gram-negative bacterial TIR domains. Differences in oligomeric interactions were also revealed, whereby bacterial TIR domains self-associated solely through their attached coil-coil domains, in contrast to the mammalian TIR domains that formed homodimers and heterodimers through reactive cysteines. Finally, we provide the first atomic-resolution studies of a bacterial coil-coil domain and provide the first atomic model of the TIR domain from a human anti-inflammatory IL-1R8 protein that undergoes a slow inherent exchange.
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Affiliation(s)
- Eunjeong Lee
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Jasmina S. Redzic
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Monika Dzieciatkowska
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Kirk C. Hansen
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
| | - Charles Dinarello
- Department of Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA;
- Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Elan Z. Eisenmesser
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, 12801 E 17th Ave, Aurora, CO 80045, USA; (E.L.); (J.S.R.); (T.N.); (A.J.S.); (M.D.); (K.C.H.); (A.D.)
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8
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Haubrich BA, Nayyab S, Gallati M, Hernandez J, Williams C, Whitman A, Zimmerman T, Li Q, Chen Y, Zhou CZ, Basu A, Reid CW. Inhibition of Streptococcus pneumoniae growth by masarimycin. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35467499 DOI: 10.1099/mic.0.001182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Despite renewed interest, development of chemical biology methods to study peptidoglycan metabolism has lagged in comparison to the glycobiology field in general. To address this, a panel of diamides were screened against the Gram-positive bacterium Streptococcus pneumoniae to identify inhibitors of bacterial growth. The screen identified the diamide masarimycin as a bacteriostatic inhibitor of S. pneumoniae growth with an MIC of 8 µM. The diamide inhibited detergent-induced autolysis in a concentration-dependent manner, indicating perturbation of peptidoglycan degradation as the mode-of-action. Cell based screening of masarimycin against a panel of autolysin mutants, identified a higher MIC against a ΔlytB strain lacking an endo-N-acetylglucosaminidase involved in cell division. Subsequent biochemical and phenotypic analyses suggested that the higher MIC was due to an indirect interaction with LytB. Further analysis of changes to the cell surface in masarimycin treated cells identified the overexpression of several moonlighting proteins, including elongation factor Tu which is implicated in regulating cell shape. Checkerboard assays using masarimycin in concert with additional antibiotics identified an antagonistic relationship with the cell wall targeting antibiotic fosfomycin, which further supports a cell wall mode-of-action.
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Affiliation(s)
- Brad A Haubrich
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Department of Basic Sciences, Touro University Nevada, College of Osteopathic Medicine, Henderson, NV 89014, USA
| | - Saman Nayyab
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Amherst Department of Molecular and Cellular Biology, University of Massachusetts, 230 Stockbridge Rd Amherst, MA, USA
| | - Mika Gallati
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Jazmeen Hernandez
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Caroline Williams
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Andrew Whitman
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Tahl Zimmerman
- Department of Family and Consumer Sciences, North Carolina A&T State University, Greensboro, NC, USA
| | - Qiong Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Yuxing Chen
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Cong-Zhao Zhou
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Amit Basu
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Christopher W Reid
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
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9
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Mehanny M, Kroniger T, Koch M, Hoppstädter J, Becher D, Kiemer AK, Lehr C, Fuhrmann G. Yields and Immunomodulatory Effects of Pneumococcal Membrane Vesicles Differ with the Bacterial Growth Phase. Adv Healthc Mater 2022; 11:e2101151. [PMID: 34724354 DOI: 10.1002/adhm.202101151] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/22/2021] [Indexed: 12/20/2022]
Abstract
Streptococcus pneumoniae infections are a leading cause of death worldwide. Bacterial membrane vesicles (MVs) are promising vaccine candidates because of the antigenic components of their parent microorganisms. Pneumococcal MVs exhibit low toxicity towards several cell lines, but their clinical translation requires a high yield and strong immunogenic effects without compromising immune cell viability. MVs are isolated during either the stationary phase (24 h) or death phase (48 h), and their yields, immunogenicity and cytotoxicity in human primary macrophages and dendritic cells have been investigated. Death-phase vesicles showed higher yields than stationary-phase vesicles. Both vesicle types displayed acceptable compatibility with primary immune cells and several cell lines. Both vesicle types showed comparable uptake and enhanced release of the inflammatory cytokines, tumor necrosis factor and interleukin-6, from human primary immune cells. Proteomic analysis revealed similarities in vesicular immunogenic proteins such as pneumolysin, pneumococcal surface protein A, and IgA1 protease in both vesicle types, but stationary-phase MVs showed significantly lower autolysin levels than death-phase MVs. Although death-phase vesicles produced higher yields, they lacked superiority to stationary-phase vesicles as vaccine candidates owing to their similar antigenic protein cargo and comparable uptake into primary human immune cells.
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Affiliation(s)
- Mina Mehanny
- Helmholtz Institute for Pharmaceutical Research Saarland Biogenic Nanotherapeutics Group Campus E8.1 Saarbrücken 66123 Germany
- Department of Pharmacy Saarland University Campus E8.1 Saarbrücken 66123 Germany
- Department of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Ain Shams University Cairo 11566 Egypt
| | - Tobias Kroniger
- Center for Functional Genomics of Microbes Department of Microbial Proteomics Institute of Microbiology University Greifswald Greifswald 17489 Germany
| | - Marcus Koch
- INM – Leibniz Institute for New Materials Campus D2.2 Saarbrücken 66123 Germany
| | - Jessica Hoppstädter
- Department of Pharmacy Pharmaceutical Biology Saarland University Saarbrücken 66123 Germany
| | - Dörte Becher
- Center for Functional Genomics of Microbes Department of Microbial Proteomics Institute of Microbiology University Greifswald Greifswald 17489 Germany
| | - Alexandra K. Kiemer
- Department of Pharmacy Pharmaceutical Biology Saarland University Saarbrücken 66123 Germany
| | - Claus‐Michael Lehr
- Department of Pharmacy Saarland University Campus E8.1 Saarbrücken 66123 Germany
- Helmholtz Institute for Pharmaceutical Research Saarland Drug Delivery Department Campus E8.1 Saarbrücken 66123 Germany
| | - Gregor Fuhrmann
- Helmholtz Institute for Pharmaceutical Research Saarland Biogenic Nanotherapeutics Group Campus E8.1 Saarbrücken 66123 Germany
- Department of Pharmacy Saarland University Campus E8.1 Saarbrücken 66123 Germany
- Friedrich‐Alexander‐University Erlangen‐Nürnberg Pharmaceutical Biology Department Biology Staudtstr. 5 Erlangen 91058 Germany
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10
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Tuft S, Somerville TF, Li JPO, Neal T, De S, Horsburgh MJ, Fothergill JL, Foulkes D, Kaye S. Bacterial keratitis: identifying the areas of clinical uncertainty. Prog Retin Eye Res 2021; 89:101031. [PMID: 34915112 DOI: 10.1016/j.preteyeres.2021.101031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/24/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022]
Abstract
Bacterial keratitis is a common corneal infection that is treated with topical antimicrobials. By the time of presentation there may already be severe visual loss from corneal ulceration and opacity, which may persist despite treatment. There are significant differences in the associated risk factors and the bacterial isolates between high income and low- or middle-income countries, so that general management guidelines may not be appropriate. Although the diagnosis of bacterial keratitis may seem intuitive there are multiple uncertainties about the criteria that are used, which impacts the interpretation of investigations and recruitment to clinical studies. Importantly, the concept that bacterial keratitis can only be confirmed by culture ignores the approximately 50% of cases clinically consistent with bacterial keratitis in which investigations are negative. The aetiology of these culture-negative cases is unknown. Currently, the estimation of bacterial susceptibility to antimicrobials is based on data from systemic administration and achievable serum or tissue concentrations, rather than relevant corneal concentrations and biological activity in the cornea. The provision to the clinician of minimum inhibitory concentrations of the antimicrobials for the isolated bacteria would be an important step forward. An increase in the prevalence of antimicrobial resistance is a concern, but the effect this has on disease outcomes is yet unclear. Virulence factors are not routinely assessed although they may affect the pathogenicity of bacteria within species and affect outcomes. New technologies have been developed to detect and kill bacteria, and their application to bacterial keratitis is discussed. In this review we present the multiple areas of clinical uncertainty that hamper research and the clinical management of bacterial keratitis, and we address some of the assumptions and dogma that have become established in the literature.
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Affiliation(s)
- Stephen Tuft
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK.
| | - Tobi F Somerville
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Ji-Peng Olivia Li
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK.
| | - Timothy Neal
- Department of Clinical Microbiology, Liverpool Clinical Laboratories, Liverpool University Hospital NHS Foundation Trust, Prescot Street, Liverpool, L7 8XP, UK.
| | - Surjo De
- Department of Clinical Microbiology, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, UK.
| | - Malcolm J Horsburgh
- Department of Infection and Microbiomes, University of Liverpool, Crown Street, Liverpool, L69 7BX, UK.
| | - Joanne L Fothergill
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Daniel Foulkes
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Stephen Kaye
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
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11
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Muruganandah V, Kupz A. Immune responses to bacterial lung infections and their implications for vaccination. Int Immunol 2021; 34:231-248. [PMID: 34850883 DOI: 10.1093/intimm/dxab109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 11/28/2021] [Indexed: 11/14/2022] Open
Abstract
The pulmonary immune system plays a vital role in protecting the delicate structures of gaseous exchange against invasion from bacterial pathogens. With antimicrobial resistance becoming an increasing concern, finding novel strategies to develop vaccines against bacterial lung diseases remains a top priority. In order to do so, a continued expansion of our understanding of the pulmonary immune response is warranted. Whilst some aspects are well characterised, emerging paradigms such as the importance of innate cells and inducible immune structures in mediating protection provide avenues of potential to rethink our approach to vaccine development. In this review, we aim to provide a broad overview of both the innate and adaptive immune mechanisms in place to protect the pulmonary tissue from invading bacterial organisms. We use specific examples from several infection models and human studies to depict the varying functions of the pulmonary immune system that may be manipulated in future vaccine development. Particular emphasis has been placed on emerging themes that are less reviewed and underappreciated in vaccine development studies.
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Affiliation(s)
- Visai Muruganandah
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
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Abstract
The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.
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13
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Pathogenesis of IgA Nephropathy: Current Understanding and Implications for Development of Disease-Specific Treatment. J Clin Med 2021; 10:jcm10194501. [PMID: 34640530 PMCID: PMC8509647 DOI: 10.3390/jcm10194501] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/22/2021] [Indexed: 12/20/2022] Open
Abstract
IgA nephropathy, initially described in 1968 as a kidney disease with glomerular “intercapillary deposits of IgA-IgG”, has no disease-specific treatment and is a common cause of kidney failure. Clinical observations and laboratory analyses suggest that IgA nephropathy is an autoimmune disease wherein the kidneys are damaged as innocent bystanders due to deposition of IgA1-IgG immune complexes from the circulation. A multi-hit hypothesis for the pathogenesis of IgA nephropathy describes four sequential steps in disease development. Specifically, patients with IgA nephropathy have elevated circulating levels of IgA1 with some O-glycans deficient in galactose (galactose-deficient IgA1) and these IgA1 glycoforms are recognized as autoantigens by unique IgG autoantibodies, resulting in formation of circulating immune complexes, some of which deposit in glomeruli and activate mesangial cells to induce kidney injury. This proposed mechanism is supported by observations that (i) glomerular immunodeposits in patients with IgA nephropathy are enriched for galactose-deficient IgA1 glycoforms and the corresponding IgG autoantibodies; (ii) circulatory levels of galactose-deficient IgA1 and IgG autoantibodies predict disease progression; and (iii) pathogenic potential of galactose-deficient IgA1 and IgG autoantibodies was demonstrated in vivo. Thus, a better understanding of the structure–function of these immunoglobulins as autoantibodies and autoantigens will enable development of disease-specific treatments.
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14
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Classification, structural biology, and applications of mucin domain-targeting proteases. Biochem J 2021; 478:1585-1603. [DOI: 10.1042/bcj20200607] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/14/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022]
Abstract
Epithelial surfaces throughout the body are coated by mucins, a class of proteins carrying domains characterized by a high density of O-glycosylated serine and threonine residues. The resulting mucosal layers form crucial host-microbe interfaces that prevent the translocation of microbes while also selecting for distinct bacteria via the presented glycan repertoire. The intricate interplay between mucus production and breakdown thus determines the composition of the microbiota maintained within these mucosal environments, which can have a large influence on the host during both homeostasis and disease. Most research to date on mucus breakdown has focused on glycosidases that trim glycan structures to release monosaccharides as a source of nutrients. More recent work has uncovered the existence of mucin-type O-glycosylation-dependent proteases that are secreted by pathogens, commensals, and mutualists to facilitate mucosal colonization and penetration. Additionally, immunoglobulin A (IgA) proteases promote bacterial colonization in the presence of neutralizing secretory IgA through selective cleavage of the heavily O-glycosylated hinge region. In this review, we summarize families of O-glycoproteases and IgA proteases, discuss known structural features, and review applications of these enzymes to glycobiology.
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15
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Hansen AL, Reily C, Novak J, Renfrow MB. Immunoglobulin A Glycosylation and Its Role in Disease. EXPERIENTIA SUPPLEMENTUM (2012) 2021; 112:433-477. [PMID: 34687019 DOI: 10.1007/978-3-030-76912-3_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Human IgA is comprised of two subclasses, IgA1 and IgA2. Monomeric IgA (mIgA), polymeric IgA (pIgA), and secretory IgA (SIgA) are the main molecular forms of IgA. The production of IgA rivals all other immunoglobulin isotypes. The large quantities of IgA reflect the fundamental roles it plays in immune defense, protecting vulnerable mucosal surfaces against invading pathogens. SIgA dominates mucosal surfaces, whereas IgA in circulation is predominately monomeric. All forms of IgA are glycosylated, and the glycans significantly influence its various roles, including antigen binding and the antibody effector functions, mediated by the Fab and Fc portions, respectively. In contrast to its protective role, the aberrant glycosylation of IgA1 has been implicated in the pathogenesis of autoimmune diseases, such as IgA nephropathy (IgAN) and IgA vasculitis with nephritis (IgAVN). Furthermore, detailed characterization of IgA glycosylation, including its diverse range of heterogeneity, is of emerging interest. We provide an overview of the glycosylation observed for each subclass and molecular form of IgA as well as the range of heterogeneity for each site of glycosylation. In many ways, the role of IgA glycosylation is in its early stages of being elucidated. This chapter provides an overview of the current knowledge and research directions.
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Affiliation(s)
- Alyssa L Hansen
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Colin Reily
- Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
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