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Crawford C, Liporagi-Lopes L, Coelho C, Santos Junior SR, Moraes Nicola A, Wear MP, Vij R, Oscarson S, Casadevall A. Semisynthetic Glycoconjugate Vaccine Candidates against Cryptococcus neoformans. ACS Infect Dis 2024; 10:2089-2100. [PMID: 38819951 PMCID: PMC11184550 DOI: 10.1021/acsinfecdis.4c00094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 05/07/2024] [Accepted: 05/21/2024] [Indexed: 06/02/2024]
Abstract
Cryptococcus neoformans is a fungus classified by the World Health Organization as a critically important pathogen, which poses a significant threat to immunocompromised individuals. In this study, we present the chemical synthesis and evaluation of two semisynthetic vaccine candidates targeting the capsular polysaccharide glucuronoxylomannan (GXM) of C. neoformans. These semisynthetic glycoconjugate vaccines contain an identical synthetic decasaccharide (M2 motif) antigen. This antigen is present in serotype A strains, which constitute 95% of the clinical cryptococcosis cases. This synthetic oligosaccharide was conjugated to two proteins (CRM197 and Anthrax 63 kDa PA) and tested for immunogenicity in mice. The conjugates elicited a specific antibody response that bound to the M2 motif but also exhibited additional cross-reactivity toward M1 and M4 GXM motifs. Both glycoconjugates produced antibodies that bound to GXM in ELISA assays and to live fungal cells. Mice immunized with the CRM197 glycoconjugate produced weakly opsonic antibodies and displayed trends toward increased median survival relative to mice given a mock PBS injection (18 vs 15 days, p = 0.06). These findings indicate promise, achieving a successful vaccine demands further optimization of the glycoconjugate. This antigen could serve as a component in a multivalent GXM motif vaccine.
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Affiliation(s)
- Conor
J. Crawford
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield, Dublin D04 V1W8, Ireland
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Livia Liporagi-Lopes
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Carolina Coelho
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Samuel R. Santos Junior
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - André Moraes Nicola
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Maggie P. Wear
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Raghav Vij
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
| | - Stefan Oscarson
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield, Dublin D04 V1W8, Ireland
| | - Arturo Casadevall
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore 21205, Maryland, United States
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2
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McConnell SA, Casadevall A. Immunoglobulin constant regions provide stabilization to the paratope and enforce epitope specificity. J Biol Chem 2024; 300:107397. [PMID: 38763332 PMCID: PMC11215335 DOI: 10.1016/j.jbc.2024.107397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/09/2024] [Indexed: 05/21/2024] Open
Abstract
Constant domains in antibody molecules at the level of the Fab (CH1 and CL) have long been considered to be simple scaffolding elements that physically separate the paratope-defining variable (V) region from the effector function-mediating constant (C) regions. However, due to recent findings that C domains of different isotypes can modulate the fine specificity encoded in the V region, elucidating the role of C domains in shaping the paratope and influencing specificity is a critical area of interest. To dissect the relative contributions of each C domain to this phenomenon, we generated antibody fragments with different C regions omitted, using a set of antibodies targeting capsular polysaccharides from the fungal pathogen, Cryptococcus neoformans. Antigen specificity mapping and functional activity measurements revealed that V region-only antibody fragments exhibited poly-specificity to antigenic variants and extended to recognition of self-antigens, while measurable hydrolytic activity of the capsule was greatly attenuated. To better understand the mechanistic origins of the remarkable loss of specificity that accompanies the removal of C domains from identical paratopes, we performed molecular dynamics simulations which revealed increased paratope plasticity in the scFv relative to the corresponding Fab. Together, our results provide insight into how the remarkable specificity of immunoglobulins is governed and maintained at the level of the Fab through the enforcement of structural restrictions on the paratope by CH1 domains.
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Affiliation(s)
- Scott A McConnell
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
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3
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Kodadek T. Catalytic Protein Inhibitors. Angew Chem Int Ed Engl 2024; 63:e202316726. [PMID: 38064411 DOI: 10.1002/anie.202316726] [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: 11/03/2023] [Indexed: 01/13/2024]
Abstract
Many of the highest priority targets in a wide range of disease states are difficult-to-drug proteins. The development of reversible small molecule inhibitors for the active sites of these proteins with sufficient affinity and residence time on-target is an enormous challenge. This has engendered interest in strategies to increase the potency of a given protein inhibitor by routes other than further improvement in gross affinity. Amongst these, the development of catalytic protein inhibitors has garnered the most attention and investment, particularly with respect to protein degraders, which catalyze the destruction of the target protein. This article discusses the genesis of the burgeoning field of catalytic inhibitors, the current state of the art, and exciting future directions.
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Affiliation(s)
- Thomas Kodadek
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 120 Scripps Way, Jupiter, FL 33458, USA
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4
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Marglous S, Brown CE, Padler-Karavani V, Cummings RD, Gildersleeve JC. Serum antibody screening using glycan arrays. Chem Soc Rev 2024; 53:2603-2642. [PMID: 38305761 PMCID: PMC7616341 DOI: 10.1039/d3cs00693j] [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] [Indexed: 02/03/2024]
Abstract
Humans and other animals produce a diverse collection of antibodies, many of which bind to carbohydrate chains, referred to as glycans. These anti-glycan antibodies are a critical part of our immune systems' defenses. Whether induced by vaccination or natural exposure to a pathogen, anti-glycan antibodies can provide protection against infections and cancers. Alternatively, when an immune response goes awry, antibodies that recognize self-glycans can mediate autoimmune diseases. In any case, serum anti-glycan antibodies provide a rich source of information about a patient's overall health, vaccination history, and disease status. Glycan microarrays provide a high-throughput platform to rapidly interrogate serum anti-glycan antibodies and identify new biomarkers for a variety of conditions. In addition, glycan microarrays enable detailed analysis of the immune system's response to vaccines and other treatments. Herein we review applications of glycan microarray technology for serum anti-glycan antibody profiling.
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Affiliation(s)
- Samantha Marglous
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Claire E Brown
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Vered Padler-Karavani
- Department of Cell Research and Immunology, Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel.
| | - Richard D Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, USA.
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
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5
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Hargett AA, Azurmendi HF, Crawford CJ, Wear MP, Oscarson S, Casadevall A, Freedberg DI. The structure of a C. neoformans polysaccharide motif recognized by protective antibodies: A combined NMR and MD study. Proc Natl Acad Sci U S A 2024; 121:e2315733121. [PMID: 38330012 PMCID: PMC10873606 DOI: 10.1073/pnas.2315733121] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/02/2023] [Indexed: 02/10/2024] Open
Abstract
Cryptococcus neoformans is a fungal pathogen responsible for cryptococcosis and cryptococcal meningitis. The C. neoformans' capsular polysaccharide and its shed exopolysaccharide function both as key virulence factors and to protect the fungal cell from phagocytosis. Currently, a glycoconjugate of these polysaccharides is being explored as a vaccine to protect against C. neoformans infection. In this study, NOE and J-coupling values from NMR experiments were consistent with a converged structure of the synthetic decasaccharide, GXM10-Ac3, calculated from MD simulations. GXM10-Ac3 was designed as an extension of glucuronoxylomannan (GXM) polysaccharide motif (M2) which is common in the clinically predominant serotype A strains and is recognized by protective forms of GXM-specific monoclonal antibodies. The M2 motif is a hexasaccharide with a three-residue α-mannan backbone, modified by β-(1→2)-xyloses (Xyl) on the first two mannoses (Man) and a β-(1→2)-glucuronic acid (GlcA) on the third Man. Combined NMR and MD analyses reveal that GXM10-Ac3 adopts an extended structure, with Xyl/GlcA branches alternating sides along the α-mannan backbone. O-acetyl esters also alternate sides and are grouped in pairs. MD analysis of a twelve M2-repeating unit polymer supports the notion that the GXM10-Ac3 structure is uniformly represented throughout the polysaccharide. This derived GXM model displays high flexibility while maintaining a structural identity, yielding insights to further explore intermolecular interactions between polysaccharides, interactions with anti-GXM mAbs, and the cryptococcal polysaccharide architecture.
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Affiliation(s)
- Audra A. Hargett
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Hugo F. Azurmendi
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Conor J. Crawford
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD21205
- Centre for Synthesis and Chemical Biology, University College Dublin, Dublin 4, Ireland
| | - Maggie P. Wear
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD21205
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Dublin 4, Ireland
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD21205
| | - Darón I. Freedberg
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993
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Crawford C, Guazzelli L, McConnell SA, McCabe O, d’Errico C, Greengo SD, Wear MP, Jedlicka AE, Casadevall A, Oscarson S. Synthetic Glycans Reveal Determinants of Antibody Functional Efficacy against a Fungal Pathogen. ACS Infect Dis 2024; 10:475-488. [PMID: 37856427 PMCID: PMC10862557 DOI: 10.1021/acsinfecdis.3c00447] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Indexed: 10/21/2023]
Abstract
Antibodies play a vital role in the immune response to infectious diseases and can be administered passively to protect patients. In the case of Cryptococcus neoformans, a WHO critical priority fungal pathogen, infection results in antibodies targeting capsular glucuronoxylomannan (GXM). These antibodies yield protective, non-protective, and disease-enhancing outcomes when administered passively. However, it was unknown how these distinct antibodies recognized their antigens at the molecular level, leading to the hypothesis that they may target different GXM epitopes. To test this hypothesis, we constructed a microarray containing 26 glycans representative of those found in highly virulent cryptococcal strains and utilized it to study 16 well-characterized monoclonal antibodies. Notably, we found that protective and non-protective antibodies shared conserved reactivity to the M2 motif of GXM, irrespective of the strain used in infection or GXM-isolated to produce a conjugate vaccine. Here, only two antibodies, 12A1 and 18B7, exhibited diverse trivalent GXM motif reactivity. IgG antibodies associated with protective responses showed cross-reactivity to at least two GXM motifs. This molecular understanding of antibody binding epitopes was used to map the antigenic diversity of two Cryptococcus neoformans strains, which revealed the exceptional complexity of fungal capsular polysaccharides. A multi-GXM motif vaccine holds the potential to effectively address this antigenic diversity. Collectively, these findings underscore the context-dependent nature of antibody function and challenge the classification of anti-GXM epitopes as either "protective" or "non-protective".
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Affiliation(s)
- Conor
J. Crawford
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield D04 V1W8, Dublin 4, Ireland
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Lorenzo Guazzelli
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield D04 V1W8, Dublin 4, Ireland
| | - Scott A. McConnell
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Orla McCabe
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield D04 V1W8, Dublin 4, Ireland
| | - Clotilde d’Errico
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield D04 V1W8, Dublin 4, Ireland
| | - Seth D. Greengo
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Maggie P. Wear
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Anne E. Jedlicka
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Arturo Casadevall
- Department
of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Stefan Oscarson
- Centre
for Synthesis and Chemical Biology, University
College Dublin, Belfield D04 V1W8, Dublin 4, Ireland
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7
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Crawford CJ, Liporagi-Lopes L, Coelho C, Santos SR, Nicola AM, Wear MP, Vij R, Oscarson S, Casadevall A. Semi-synthetic glycoconjugate vaccine candidate against Cryptococcus neoformans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.02.578725. [PMID: 38352552 PMCID: PMC10862886 DOI: 10.1101/2024.02.02.578725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Cryptococcus neoformans is a fungus classified by the World Health Organization as a critically important pathogen, posing a significant threat to immunocompromised individuals. In this study, we present the chemical synthesis and evaluation of two semi-synthetic vaccine candidates targeting the capsular polysaccharide glucuronoxylomannan (GXM) of C. neoformans. These semi-synthetic glycoconjugate vaccines contain the identical synthetic decasaccharide (M2 motif) antigen. This motif is present in serotype A strains, which constitute 95% of clinical cryptococcosis cases. This synthetic oligosaccharide was conjugated to two proteins (CRM197 and Anthrax 63 kDa PA) and tested for immunogenicity in mice. The conjugates elicited a specific antibody response that bound to the M2 motif but also exhibited additional cross-reactivity towards M1 and M4 GXM motifs. Both glycoconjugates produced antibodies that bound to GXM in ELISA assays and to live fungal cells. Mice immunized with the CRM197 glycoconjugate produced opsonic antibodies and displayed trends toward increased median survival relative to mice given a mock PBS injection (18 vs 15 days, p = 0.06). While these findings indicate promise, achieving a successful vaccine demands further optimization of the glycoconjugate. It could serve as a component in a multi-valent GXM motif vaccine, enhancing both strength and breadth of immune responses.
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Affiliation(s)
- Conor J Crawford
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, Ireland
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
- Present Address: Max Planck Institute of Colloids and Interfaces, Am Mühlenberg1, 14476 Potsdam, Germany
| | - Livia Liporagi-Lopes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
- Present Address: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
- Present Address: MRC Centre for Medical Mycology, University of Exeter, Exeter Devon UK
| | - Samuel R Santos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - André Moraes Nicola
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
- Present Address: Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Maggie P Wear
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Raghav Vij
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
- Present address: Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, Ireland
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health 615 North Wolfe Street, Baltimore, MD 21205, USA
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8
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Wear MP, McConnell SA, Greengo SD, Lopes LL, Casadevall A. Methods of Cryptococcal Polysaccharide Analysis Using ELISA. Methods Mol Biol 2024; 2775:239-255. [PMID: 38758322 DOI: 10.1007/978-1-0716-3722-7_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
One of the standard assays for the fungal pathogen Cryptococcus neoformans is the glucuronoxylomannan (GXM) ELISA. This assay utilizes monoclonal antibodies targeted against the critical virulence factor, the polysaccharide (PS) capsule. GXM ELISA is one of the most used assays in the field used for diagnosis of cryptococcal infection, quantification of PS content, and determination of binding specificity for antibodies. Here we present three variations of the GXM ELISA used by our group-indirect, capture, and competition ELISAs. We have also provided some history, perspective, and notes on these methods, which we hope will help the reader choose, and implement, the best assay for their research.While it has long been referred to as the GXM ELISA, we also suggest a name update to better reflect our updated understanding of the polysaccharide antigens targeted by this assay. The Cryptococcal PS ELISA is a more accurate description of this set of methodologies and the antigens they measure. Finally, we discuss the limitations of this assay and put forth future plans for expanding the antigens assayed by ELISA.
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Affiliation(s)
- Maggie P Wear
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Scott A McConnell
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Seth D Greengo
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Livia Liporagi Lopes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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9
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Abstract
The structural complexity of glycans poses a serious challenge in the chemical synthesis of glycosides, oligosaccharides and glycoconjugates. Glycan complexity, determined by composition, connectivity, and configuration far exceeds what nature achieves with nucleic acids and proteins. Consequently, glycoside synthesis ranks among the most complex tasks in organic synthesis, despite involving only a simple type of bond-forming reaction. Here, we introduce the fundamental principles of glycoside bond formation and summarize recent advances in glycoside bond formation and oligosaccharide synthesis.
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Affiliation(s)
- Conor J Crawford
- Department of Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Peter H Seeberger
- Department of Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
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10
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Liu Y, Han G, Gong J, Hua X, Zhu Q, Zhou S, Jiang L, Li Q, Liu S. Intramolecular fluorescence resonance energy transfer strategy for accurate detection of AFP-L3% and improved diagnosis of hepatocellular carcinoma. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 300:122950. [PMID: 37295202 DOI: 10.1016/j.saa.2023.122950] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/17/2023] [Accepted: 05/27/2023] [Indexed: 06/12/2023]
Abstract
Early and accurate diagnosis of hepatocellular carcinoma (HCC) is of significant importance for improving the survival rate and quality of life for HCC patients. The combined detection of alpha-fetoprotein (AFP) and alpha-fetoprotein-L3 (AFP-L3), namely AFP-L3%, can greatly improve the accuracy of HCC diagnosis compared with AFP detection. Herein, we developed a novel intramolecular fluorescence resonance energy transfer (FRET) strategy for sequential detection of AFP and AFP-specific core fucose to improve the diagnosis accuracy of HCC. Firstly, fluorescence-labeled AFP aptamer (AFP Apt-FAM) was used to specifically recognize all AFP isoforms, and total AFP was quantitatively determined using fluorescence intensity of FAM. Then, 4-((4-(dimethylamino)phenyl)azo)benzoic acid (Dabcyl) labeled lectins (PhoSL-Dabcyl) were used to specifically recognize the core fucose expressed on AFP-L3 that does not bind to other AFP isoforms. The combination of FAM and Dabcyl on the same AFP molecule could generate FRET effect, thereby quenching the fluorescence signal of FAM and quantitatively determining AFP-L3. After that, AFP-L3% was calculated according to the ratio of AFP-L3 to AFP. With this strategy, the concentration of total AFP, AFP-L3 isoform as well as the AFP-L3% were sensitively detected. Detection limits of 0.66 and 0.186 ng/mL were obtained for AFP and AFP-L3 in human serum, respectively. Clinical human serum test results showed that AFP- L3 % test was more accurate than AFP assay to distinguish healthy people, HCC patients and benign liver disease patients. Therefore, the proposed strategy is simple, sensitive and selective, which can improve the accuracy of early diagnosis of HCC, and has good clinical application potential.
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Affiliation(s)
- Yu Liu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, Sichuan 610068, China
| | - Gaohua Han
- Taizhou People's Hospital Affiliated to Nanjing Medical University, Taizhou 225300, China
| | - Jing Gong
- Collaborative Innovation Center of Tumor Marker Detection Technology, Equipment and Diagnosis Therapy Integration in Universities of Shandong, Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, China
| | - Xin Hua
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Environmental Medicine Engineering, Ministry of Education, State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
| | - Qian Zhu
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Environmental Medicine Engineering, Ministry of Education, State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Sisi Zhou
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Environmental Medicine Engineering, Ministry of Education, State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Ling Jiang
- Collaborative Innovation Center of Tumor Marker Detection Technology, Equipment and Diagnosis Therapy Integration in Universities of Shandong, Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, China
| | - Quan Li
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, Sichuan 610068, China.
| | - Songqin Liu
- Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Environmental Medicine Engineering, Ministry of Education, State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
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11
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Hargett AA, Azurmendi HF, Crawford CJ, Wear MP, Oscarson S, Casadevall A, Freedberg DI. The structure of a C. neoformans polysaccharide motif recognized by protective antibodies: A combined NMR and MD study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.06.556507. [PMID: 37732210 PMCID: PMC10508755 DOI: 10.1101/2023.09.06.556507] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Cryptococcus neoformans is a fungal pathogen responsible for cryptococcosis and cryptococcal meningitis. The C. neoformans capsular polysaccharide and shed exopolysaccharide functions both as a key virulence factor and to protect the fungal cell from phagocytosis. Currently, a glycoconjugate of these polysaccharides is being explored as a vaccine to protect against C. neoformans infection. In this combined NMR and MD study, experimentally determined NOEs and J-couplings support a structure of the synthetic decasaccharide, GXM10-Ac3, obtained by MD. GXM10-Ac3 was designed as an extension of glucuronoxylomannan (GXM) polysaccharide motif (M2) which is common in the clinically predominant serotype A strains and is recognized by protective forms of GXM-specific monoclonal antibodies. The M2 motif is characterized by a 6-residue α-mannan backbone repeating unit, consisting of a triad of α-(1→3)-mannoses, modified by β-(1→2)-xyloses on the first two mannoses and a β-(1→2)-glucuronic acid on the third mannose. The combined NMR and MD analyses reveal that GXM10-Ac3 adopts an extended structure, with xylose/glucuronic acid branches alternating sides along the α-mannan backbone. O-acetyl esters also alternate sides and are grouped in pairs. MD analysis of a twelve M2-repeating unit polymer supports the notion that the GXM10-Ac3 structure is uniformly represented throughout the polysaccharide. This experimentally consistent GXM model displays high flexibility while maintaining a structural identity, yielding new insights to further explore intermolecular interactions between polysaccharides, interactions with anti-GXM mAbs, and the cryptococcal polysaccharide architecture.
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Affiliation(s)
- Audra A. Hargett
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Hugo F. Azurmendi
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Conor J. Crawford
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
- Current address: Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Maggie P. Wear
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Darόn I. Freedberg
- Laboratory of Bacterial Polysaccharides, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
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12
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McConnell SA, Sachithanandham J, Mudrak NJ, Zhu X, Farhang PA, Cordero RJB, Wear MP, Shapiro JR, Park HS, Klein SL, Tobian AAR, Bloch EM, Sullivan DJ, Pekosz A, Casadevall A. Spike-protein proteolytic antibodies in COVID-19 convalescent plasma contribute to SARS-CoV-2 neutralization. Cell Chem Biol 2023; 30:726-738.e4. [PMID: 37354908 PMCID: PMC10288624 DOI: 10.1016/j.chembiol.2023.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/23/2023] [Accepted: 05/26/2023] [Indexed: 06/26/2023]
Abstract
Understanding the mechanisms of antibody-mediated neutralization of SARS-CoV-2 is critical in combating the COVID-19 pandemic. Based on previous reports of antibody catalysis, we investigated the proteolysis of spike (S) by antibodies in COVID-19 convalescent plasma (CCP) and its contribution to viral neutralization. Quenched fluorescent peptides were designed based on S epitopes to sensitively detect antibody-mediated proteolysis. We observed epitope cleavage by CCP from different donors which persisted when plasma was heat-treated or when IgG was isolated from plasma. Further, purified CCP antibodies proteolyzed recombinant S domains, as well as authentic viral S. Cleavage of S variants suggests CCP antibody-mediated proteolysis is a durable phenomenon despite antigenic drift. We differentiated viral neutralization occurring via direct interference with receptor binding from that occurring by antibody-mediated proteolysis, demonstrating that antibody catalysis enhanced neutralization. These results suggest that antibody-catalyzed damage of S is an immunologically relevant function of neutralizing antibodies against SARS-CoV-2.
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Affiliation(s)
- Scott A McConnell
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Jaiprasath Sachithanandham
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Nathan J Mudrak
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Xianming Zhu
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Parsa Alba Farhang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Radames J B Cordero
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Maggie P Wear
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Janna R Shapiro
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
| | - Han-Sol Park
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Sabra L Klein
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA; Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
| | - Aaron A R Tobian
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Evan M Bloch
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - David J Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Andrew Pekosz
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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13
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McNamara RP. Catalytic spike antibodies: A new paradigm in neutralization. Cell Chem Biol 2023; 30:701-702. [PMID: 37478826 PMCID: PMC11339862 DOI: 10.1016/j.chembiol.2023.06.025] [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: 06/23/2023] [Revised: 06/27/2023] [Accepted: 06/27/2023] [Indexed: 07/23/2023]
Abstract
In this issue, McConnell et al.10 demonstrate that COVID-19 convalescent plasma (CCP)-derived antibodies can neutralize SARS-CoV-2 by proteolytically cleaving the spike protein. The CCP antibody-mediated catalysis has broader implications beyond COVID-19 and can be applicable in understanding the mechanism of antibody-based neutralization of different pathogens.
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Affiliation(s)
- Ryan P McNamara
- Ragon Institute of Mass General, MIT, and Harvard, 400 Technology Square, Cambridge, MA 02139, USA.
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14
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Canner SW, Shanker S, Gray JJ. Structure-based neural network protein-carbohydrate interaction predictions at the residue level. FRONTIERS IN BIOINFORMATICS 2023; 3:1186531. [PMID: 37409346 PMCID: PMC10318439 DOI: 10.3389/fbinf.2023.1186531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/31/2023] [Indexed: 07/07/2023] Open
Abstract
Carbohydrates dynamically and transiently interact with proteins for cell-cell recognition, cellular differentiation, immune response, and many other cellular processes. Despite the molecular importance of these interactions, there are currently few reliable computational tools to predict potential carbohydrate-binding sites on any given protein. Here, we present two deep learning (DL) models named CArbohydrate-Protein interaction Site IdentiFier (CAPSIF) that predicts non-covalent carbohydrate-binding sites on proteins: (1) a 3D-UNet voxel-based neural network model (CAPSIF:V) and (2) an equivariant graph neural network model (CAPSIF:G). While both models outperform previous surrogate methods used for carbohydrate-binding site prediction, CAPSIF:V performs better than CAPSIF:G, achieving test Dice scores of 0.597 and 0.543 and test set Matthews correlation coefficients (MCCs) of 0.599 and 0.538, respectively. We further tested CAPSIF:V on AlphaFold2-predicted protein structures. CAPSIF:V performed equivalently on both experimentally determined structures and AlphaFold2-predicted structures. Finally, we demonstrate how CAPSIF models can be used in conjunction with local glycan-docking protocols, such as GlycanDock, to predict bound protein-carbohydrate structures.
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Affiliation(s)
- Samuel W. Canner
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States
| | - Sudhanshu Shanker
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Jeffrey J. Gray
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States
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15
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Canner SW, Shanker S, Gray JJ. Structure-Based Neural Network Protein-Carbohydrate Interaction Predictions at the Residue Level. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.531382. [PMID: 36993750 PMCID: PMC10054975 DOI: 10.1101/2023.03.14.531382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Carbohydrates dynamically and transiently interact with proteins for cell-cell recognition, cellular differentiation, immune response, and many other cellular processes. Despite the molecular importance of these interactions, there are currently few reliable computational tools to predict potential carbohydrate binding sites on any given protein. Here, we present two deep learning models named CArbohydrate-Protein interaction Site IdentiFier (CAPSIF) that predict carbohydrate binding sites on proteins: (1) a 3D-UNet voxel-based neural network model (CAPSIF:V) and (2) an equivariant graph neural network model (CAPSIF:G). While both models outperform previous surrogate methods used for carbohydrate binding site prediction, CAPSIF:V performs better than CAPSIF:G, achieving test Dice scores of 0.597 and 0.543 and test set Matthews correlation coefficients (MCCs) of 0.599 and 0.538, respectively. We further tested CAPSIF:V on AlphaFold2-predicted protein structures. CAPSIF:V performed equivalently on both experimentally determined structures and AlphaFold2 predicted structures. Finally, we demonstrate how CAPSIF models can be used in conjunction with local glycan-docking protocols, such as GlycanDock, to predict bound protein-carbohydrate structures.
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Affiliation(s)
- Samuel W. Canner
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States of America
| | - Sudhanshu Shanker
- Dept. of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Jeffrey J. Gray
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States of America
- Dept. of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
- Correspondence: Jeffrey J. Gray,
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16
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Liu Y, Zhang Y, Zhao X, Lu W, Zhong Y, Fu YV. Antifungal Peptide SP1 Damages Polysaccharide Capsule of Cryptococcus neoformans and Enhances Phagocytosis of Macrophages. Microbiol Spectr 2023; 11:e0456222. [PMID: 36916981 PMCID: PMC10100895 DOI: 10.1128/spectrum.04562-22] [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: 11/08/2022] [Accepted: 02/22/2023] [Indexed: 03/16/2023] Open
Abstract
Cryptococcus neoformans is a fungal pathogen which causes nearly half a million deaths worldwide each year. Under host-relevant conditions, it produces a characteristic polysaccharide capsule. The polysaccharide capsule is one of the main virulence factors of C. neoformans, which involves antiphagocytosis and immune responses of the host to cause a lack of an immune. Meanwhile, the polysaccharide capsule is a promising drug target because of the absence of analogs in the host. Here, we demonstrate that antifungal peptide SP1, which is derived from the N terminus of Saccharomyces cerevisiae GAPDH (glyceraldehyde-3-phosphate dehydrogenase), disrupts the polysaccharide capsule of C. neoformans H99. The mechanism is possibly due to the interaction of SP1 with glucuronoxylomannan (GXM). Disruption of the polysaccharide capsule enhances the adhesion and phagocytosis of C. neoformans H99 by macrophages and reduces the replication of C. neoformans H99 within macrophages. Additionally, SP1 exhibits antifungal activity against cryptococcal biofilms associated with the capsular polysaccharides. These findings suggest the potential of SP1 as a drug candidate for the treatment of cryptococcosis. IMPORTANCE C. neoformans is an opportunistic pathogen that causes invasive infections with a high mortality rate. Currently, the clinical drugs available for the treatment of cryptococcosis are limited to amphotericin B, azoles, and flucytosine. Amphotericin is nephrotoxic, and the widespread use of azoles and 5-flucytosine has led to a rapid development of drug resistance in C. neoformans. There is an urgent need to develop new and effective anticryptococcal drugs. Targeting virulence factors is a novel strategy for developing antifungal drugs. The antifungal peptide SP1 is capable of disrupting the polysaccharide capsule, which is a principal virulence factor of C. neoformans. Studying the mechanism by which SP1 damages the polysaccharide capsule and investigating the potential benefits of SP1 in removing C. neoformans from the host provides baseline data to develop a therapeutic strategy against refractory cryptococcal infections. This strategy would involve both inhibiting virulence factors and directly killing C. neoformans cells.
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Affiliation(s)
- Yan Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Yang Zhang
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Xi Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Weilai Lu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Yuxin Zhong
- Department of Pancreatic and Gastric Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yu V. Fu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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17
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Bligh M, Nguyen N, Buck-Wiese H, Vidal-Melgosa S, Hehemann JH. Structures and functions of algal glycans shape their capacity to sequester carbon in the ocean. Curr Opin Chem Biol 2022; 71:102204. [PMID: 36155346 DOI: 10.1016/j.cbpa.2022.102204] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 01/27/2023]
Abstract
Algae synthesise structurally complex glycans to build a protective barrier, the extracellular matrix. One function of matrix glycans is to slow down microorganisms that try to enzymatically enter living algae and degrade and convert their organic carbon back to carbon dioxide. We propose that matrix glycans lock up carbon in the ocean by controlling degradation of organic carbon by bacteria and other microbes not only while algae are alive, but also after death. Data revised in this review shows accumulation of algal glycans in the ocean underscoring the challenge bacteria and other microbes face to breach the glycan barrier with carbohydrate active enzymes. Briefly we also update on methods required to certify the uncertain magnitude and unknown molecular causes of glycan-controlled carbon sequestration in a changing ocean.
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Affiliation(s)
- Margot Bligh
- Max Planck Institute for Marine Microbiology, Bremen, Germany; University of Bremen, MARUM Centre for Marine Environmental Sciences Bremen, Germany
| | - Nguyen Nguyen
- Max Planck Institute for Marine Microbiology, Bremen, Germany; University of Bremen, MARUM Centre for Marine Environmental Sciences Bremen, Germany
| | - Hagen Buck-Wiese
- Max Planck Institute for Marine Microbiology, Bremen, Germany; University of Bremen, MARUM Centre for Marine Environmental Sciences Bremen, Germany
| | - Silvia Vidal-Melgosa
- Max Planck Institute for Marine Microbiology, Bremen, Germany; University of Bremen, MARUM Centre for Marine Environmental Sciences Bremen, Germany
| | - Jan-Hendrik Hehemann
- Max Planck Institute for Marine Microbiology, Bremen, Germany; University of Bremen, MARUM Centre for Marine Environmental Sciences Bremen, Germany.
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18
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The Inflammasome NLRC4 Protects against Cryptococcus gattii by Inducing the Classic Caspase-1 to Activate the Pyroptosis Signal. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:7355485. [PMID: 35340249 PMCID: PMC8942663 DOI: 10.1155/2022/7355485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 02/16/2022] [Indexed: 12/12/2022]
Abstract
Cryptococcus is one of the most pathogenic invasive fungi, and its interaction with the host's natural immunity, especially the role of the inflammasome family, has not been fully elucidated. As an important member of the inflammasome family, NOD-like receptor (NLR) family caspase recruitment domain (CARD) containing 4 (NLRC4) has been proven to protect lungs from damage from a variety of pathogens. In this study, we investigated the protective effect and mechanism of NLRC4 on cryptococcal pulmonary infection using NLRC4-/-mice in vivo and NLRC4-/-macrophages in vitro models stimulated by cryptococcal cells. We apply small animal fluorescence imaging to detect the fungal burden in the lungs and living body micro-CT scans of mice and in vitro tissue micro-CT scans to compare differences in infection foci nodules and histopathological lesions, and the activation of caspase-1 and downstream cytokines were detected by Western bolt and ELISA, etc. The results demonstrated that cryptococcal infection can activate the Nod-like receptors of caspase-1 activation and NLRC4 inflammasomes in macrophages and dendritic cells and affect downstream IL-1β and IL-18 release. After cryptococcal infection, the survival rate, lung fungal burden, and histopathological damage of NLRC4−/− mice were significantly impaired. NLRC4−/− macrophages showed a lower release of inflammatory factors, reactive oxygen species (ROS), and lactate dehydrogenase (LDH). Collectively, our results demonstrated that the activation of caspase-1 and downstream cytokines mediated by NLRC4 inflammasome in immune cells during Cryptococcus infection can enhance pyroptosis of macrophages, affect the phagocytic ability of macrophages, and inhibit the intracellular parasitism of cryptococcus, eventually reducing the burden of fungi.
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19
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Wear MP, Jacobs E, Wang S, McConnell S, Bowen A, Strother C, Cordero RJB, Crawford CJ, Casadevall A. Cryptococcus neoformans capsule regrowth experiments reveal dynamics of enlargement and architecture. J Biol Chem 2022; 298:101769. [PMID: 35218774 PMCID: PMC8942833 DOI: 10.1016/j.jbc.2022.101769] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 11/25/2022] Open
Abstract
The polysaccharide capsule of fungal pathogen Cryptococcus neoformans is a critical virulence factor that has historically evaded complete characterization. Cryptococcal polysaccharides are known to either remain attached to the cell as capsular polysaccharides (CPS) or to be shed into the extracellular space as exopolysaccharides (EPS). While many studies have examined the properties of EPS, far less is known about CPS. In this work, we detail the development of a new physical and enzymatic method for the isolation of CPS which can be used to explore the architecture of the capsule and isolated capsular material. We show that sonication or Glucanex enzyme cocktail digestion yields soluble CPS preparations, while use of a French pressure cell press and Glucanex digestion followed by cell disruption removed the capsule and produced cell wall-associated polysaccharide aggregates that we call 'capsule ghosts', implying an inherent organization that allows the CPS to exist independent of the cell wall surface. Since sonication and Glucanex digestion were non-cytotoxic, it was also possible to observe the cryptococcal cells rebuilding their capsule, revealing the presence of reducing-end glycans throughout the capsule. Finally, analysis of DMSO-extracted and sonicated CPS preparations revealed the conservation of previously identified GXM motifs only in the sonicated CPS. Together, these observations provide new insights into capsule architecture and synthesis, consistent with a model in which the capsule is assembled from the cell wall outwards using smaller polymers, which are then compiled into larger ones.
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Affiliation(s)
- Maggie P Wear
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Ella Jacobs
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Siqing Wang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Scott McConnell
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Anthony Bowen
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Camilla Strother
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Radames J B Cordero
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Conor J Crawford
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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20
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Abstract
Invasive fungal diseases are rare in individuals with intact immunity. This, together with the fact that there are only a few species that account for most mycotic diseases, implies a remarkable natural resistance to pathogenic fungi. Mammalian immunity to fungi rests on two pillars, powerful immune mechanisms and elevated temperatures that create a thermal restriction zone for most fungal species. Conditions associated with increased susceptibility generally reflect major disturbances of immune function involving both the cellular and humoral innate and adaptive arms, which implies considerable redundancy in host defense mechanisms against fungi. In general, tissue fungal invasion is controlled through either neutrophil or granulomatous inflammation, depending on the fungal species. Neutrophils are critical against Candida spp. and Aspergillus spp. while macrophages are essential for controlling mycoses due to Cryptococcus spp., Histoplasma spp., and other fungi. The increasing number of immunocompromised patients together with climate change could significantly increase the prevalence of fungal diseases. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland, USA
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21
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Crawford CJ, Qiao Y, Liu Y, Huang D, Yan W, Seeberger PH, Oscarson S, Chen S. Defining the Qualities of High-Quality Palladium on Carbon Catalysts for Hydrogenolysis. Org Process Res Dev 2021; 25:1573-1578. [PMID: 34305386 PMCID: PMC8291771 DOI: 10.1021/acs.oprd.0c00536] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Indexed: 11/30/2022]
Abstract
Palladium-catalyzed hydrogenolysis is often the final step in challenging natural product total syntheses and a key step in industrial processes producing fine chemicals. Here, we demonstrate that there is wide variability in the efficiency of commercial sources of palladium on carbon (Pd/C) resulting in significant differences in selectivity, reaction times, and yields. We identified the physicochemical properties of efficient catalysts for hydrogenolysis: (1) small Pd/PdO particle size (2) homogeneous distribution of Pd/PdO on the carbon support, and (3) palladium oxidation state are good predictors of catalytic efficiency. Now chemists can identify and predict a catalyst's efficiency prior to the use of valuable synthetic material and time.
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Affiliation(s)
- Conor J Crawford
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, Ireland.,Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Yan Qiao
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China
| | - Yequn Liu
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China
| | - Dongmei Huang
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China
| | - Wenjun Yan
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China
| | - Peter H Seeberger
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, Ireland
| | - Shuai Chen
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China
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