1
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Choudhury QJ, Ambati S, Link CD, Lin X, Lewis ZA, Meagher RB. Dectin-3-targeted antifungal liposomes efficiently bind and kill diverse fungal pathogens. Mol Microbiol 2023; 120:723-739. [PMID: 37800599 PMCID: PMC10823756 DOI: 10.1111/mmi.15174] [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: 02/10/2023] [Revised: 08/22/2023] [Accepted: 09/21/2023] [Indexed: 10/07/2023]
Abstract
DectiSomes are anti-infective drug-loaded liposomes targeted to pathogenic cells by pathogen receptors including the Dectins. We have previously used C-type lectin (CTL) pathogen receptors Dectin-1, Dectin-2, and DC-SIGN to target DectiSomes to the extracellular oligoglycans surrounding diverse pathogenic fungi and kill them. Dectin-3 (also known as MCL, CLEC4D) is a CTL pathogen receptor whose known cognate ligands are partly distinct from other CTLs. We expressed and purified a truncated Dectin-3 polypeptide (DEC3) comprised of its carbohydrate recognition domain and stalk region. We prepared amphotericin B (AmB)-loaded pegylated liposomes (AmB-LLs) and coated them with this isoform of Dectin-3 (DEC3-AmB-LLs), and we prepared control liposomes coated with bovine serum albumin (BSA-AmB-LLs). DEC3-AmB-LLs bound to the exopolysaccharide matrices of Candida albicans, Rhizopus delemar (formerly known as R. oryzae), and Cryptococcus neoformans from one to several orders of magnitude more strongly than untargeted AmB-LLs or BSA-AmB-LLs. The data from our quantitative fluorescent binding assays were standardized using a CellProfiler program, AreaPipe, that was developed for this purpose. Consistent with enhanced binding, DEC3-AmB-LLs inhibited and/or killed C. albicans and R. delemar more efficiently than control liposomes and significantly reduced the effective dose of AmB. In conclusion, Dectin-3 targeting has the potential to advance our goal of building pan-antifungal DectiSomes.
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Affiliation(s)
| | - Suresh Ambati
- Department of GeneticsUniversity of GeorgiaAthensGeorgiaUSA
| | - Collin D. Link
- Department of MicrobiologyUniversity of GeorgiaAthensGeorgiaUSA
| | - Xiaorong Lin
- Department of MicrobiologyUniversity of GeorgiaAthensGeorgiaUSA
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2
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Chen L, Zhang L, Xie Y, Wang Y, Tian X, Fang W, Xue X, Wang L. Confronting antifungal resistance, tolerance, and persistence: Advances in drug target discovery and delivery systems. Adv Drug Deliv Rev 2023; 200:115007. [PMID: 37437715 DOI: 10.1016/j.addr.2023.115007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/01/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023]
Abstract
Human pathogenic fungi pose a serious threat to human health and safety. Unfortunately, the limited number of antifungal options is exacerbated by the continuous emergence of drug-resistant variants, leading to frequent drug treatment failures. Recent studies have also highlighted the clinical importance of other modes of fungal survival of antifungal treatment, including drug tolerance and persistence, pointing to the complexity of the fungal response to antifungal drugs. A lack of understanding of the fungal drug response has hampered the identification of new targets, the development of alternative antifungal strategies and the design of appropriate delivery systems. In this review we summarize recent advances in the study of antifungal resistance, tolerance and persistence, with an emphasis on promising drug targets and drug delivery systems that may yield important insights into the development of new or improved antifungal therapies against fungal infections.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Lanyue Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yuyan Xie
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yiting Wang
- College of Life Sciences, Hebei University, Baoding, Hebei 071002, China
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wenxia Fang
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, 530007, Guangxi, China
| | - Xinying Xue
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100038, China; Department of Respiratory and Critical Care, Weifang Medical College, 261053, Weifang, Shandong, China.
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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Alder-Rangel A, Bailão AM, Herrera-Estrella A, Rangel AEA, Gácser A, Gasch AP, Campos CBL, Peters C, Camelim F, Verde F, Gadd GM, Braus G, Eisermann I, Quinn J, Latgé JP, Aguirre J, Bennett JW, Heitman J, Nosanchuk JD, Partida-Martínez LP, Bassilana M, Acheampong MA, Riquelme M, Feldbrügge M, Keller NP, Keyhani NO, Gunde-Cimerman N, Nascimento R, Arkowitz RA, Mouriño-Pérez RR, Naz SA, Avery SV, Basso TO, Terpitz U, Lin X, Rangel DEN. The IV International Symposium on Fungal Stress and the XIII International Fungal Biology Conference. Fungal Biol 2023; 127:1157-1179. [PMID: 37495306 DOI: 10.1016/j.funbio.2023.04.006] [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: 04/02/2023] [Accepted: 04/24/2023] [Indexed: 07/28/2023]
Abstract
For the first time, the International Symposium on Fungal Stress was joined by the XIII International Fungal Biology Conference. The International Symposium on Fungal Stress (ISFUS), always held in Brazil, is now in its fourth edition, as an event of recognized quality in the international community of mycological research. The event held in São José dos Campos, SP, Brazil, in September 2022, featured 33 renowned speakers from 12 countries, including: Austria, Brazil, France, Germany, Ghana, Hungary, México, Pakistan, Spain, Slovenia, USA, and UK. In addition to the scientific contribution of the event in bringing together national and international researchers and their work in a strategic area, it helps maintain and strengthen international cooperation for scientific development in Brazil.
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Affiliation(s)
| | - Alexandre Melo Bailão
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Alfredo Herrera-Estrella
- Unidad de Genómica Avanzada-Langebio, Centro de Investigación y de Estudios Avanzados Del IPN, Irapuato, Guanajuato, Mexico
| | | | - Attila Gácser
- HCEMM-USZ Fungal Pathogens Research Group, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Audrey P Gasch
- Center for Genomic Science Innovation, University of Wisconsin Madison, Madison, WI, USA
| | - Claudia B L Campos
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José Dos Campos, SP, Brazil
| | - Christina Peters
- Deutsche Forschungsgemeinschaft (DFG), Office Latin America, São Paulo, SP, Brazil
| | - Francine Camelim
- German Academic Exchange Service (DAAD), DWIH, Sao Paulo, SP, Brazil
| | - Fulvia Verde
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Geoffrey Michael Gadd
- Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
| | - Gerhard Braus
- Institute for Microbiology and Genetics, Department of Molecular Microbiology and Genetics, Goettingen Center for Molecular Biosciences, University of Goettingen, Goettingen, Germany
| | - Iris Eisermann
- The Sainsbury Laboratory, University of East Anglia, Norwich, England, UK
| | - Janet Quinn
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, England, UK
| | - Jean-Paul Latgé
- Institute of Molecular Biology and Biotechnology FORTH and School of Medicine, University of Crete Heraklion, Greece
| | - Jesus Aguirre
- Departamento de Biología Celular y Del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autonoma de México, Mexico City, Mexico
| | - Joan W Bennett
- Department of Plant Biology, Rutgers, State University of New Jersey, New Brunswick, NJ, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Joshua D Nosanchuk
- Departments of Medicine and Microbiology and Immunology, Albert Einstein College of Medicine, The Bronx, NY, USA
| | | | - Martine Bassilana
- Institute of Biology Valrose, University Côte D'Azur, CNRS, INSERM, Nice, France
| | | | - Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Mexico
| | - Michael Feldbrügge
- Institute of Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Nancy P Keller
- Department of Medical Microbiology, Department of Plant Pathology, University of Wisconsin, Madison, WI, USA
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Raquel Nascimento
- Deutsche Forschungsgemeinschaft (DFG), Office Latin America, São Paulo, SP, Brazil
| | - Robert A Arkowitz
- Institute of Biology Valrose, University Côte D'Azur, CNRS, INSERM, Nice, France
| | - Rosa Reyna Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Mexico
| | - Sehar Afshan Naz
- Lab of Applied Microbiology and Clinical Mycology, Department of Microbiology, Federal Urdu University of Arts, Science and Technology, Gulshan Iqbal, Karachi, Pakistan
| | - Simon V Avery
- School of Life and Environmental Sciences, University of Nottingham, Nottingham, England, UK
| | - Thiago Olitta Basso
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Ulrich Terpitz
- Department of Biotechnology and Biophysics, Theodor-Boveri-Institute, Biocenter, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA, USA
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Ma Z, Wang X, Li C. Advances in anti-invasive fungal drug delivery systems. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:318-327. [PMID: 37476943 PMCID: PMC10409907 DOI: 10.3724/zdxbyxb-2023-0030] [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: 01/20/2023] [Accepted: 05/31/2023] [Indexed: 07/22/2023]
Abstract
Currently, the first-line drugs for invasive fungal infections (IFI), such as amphotericin B, fluconazole and itraconazole, have drawbacks including poor water solubility, low bioavailability, and severe side effects. Using drug delivery systems is a promising strategy to improve the efficacy and safety of traditional antifungal therapy. Synthetic and biomimetic carriers have greatly facilitated the development of targeted delivery systems for antifungal drugs. Synthetic carrier drug delivery systems, such as liposomes, nanoparticles, polymer micelles, and microspheres, can improve the physicochemical properties of antifungal drugs, prolong their circulation time, enhance targeting capabilities, and reduce toxic side effects. Cell membrane biomimetic drug delivery systems, such as macrophage or red blood cell membrane-coated drug delivery systems, retain the membrane structure of somatic cells and confer various biological functions and specific targeting abilities to the loaded antifungal drugs, exhibiting better biocompatibility and lower toxicity. This article reviews the development of antifungal drug delivery systems and their application in the treatment of IFI, and also discusses the prospects of novel biomimetic carriers in antifungal drug delivery.
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Affiliation(s)
- Zhongyi Ma
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
| | - Xinyu Wang
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Chong Li
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
- Medical Research Institute, Southwest University, Chongqing 400715, China.
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Meagher RB, Lewis ZA, Ambati S, Lin X. DectiSomes: C-type lectin receptor-targeted liposomes as pan-antifungal drugs. Adv Drug Deliv Rev 2023; 196:114776. [PMID: 36934519 PMCID: PMC10133202 DOI: 10.1016/j.addr.2023.114776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/19/2023]
Abstract
Combatting the ever-increasing threat from invasive fungal pathogens faces numerous fundamental challenges, including constant human exposure to large reservoirs of species in the environment, the increasing population of immunocompromised or immunosuppressed individuals, the unsatisfactory efficacy of current antifungal drugs and their associated toxicity, and the scientific and economic barriers limiting a new antifungal pipeline. DectiSomes represent a new drug delivery platform that enhances antifungal efficacy for diverse fungal pathogens and reduces host toxicity for current and future antifungals. DectiSomes employ pathogen receptor proteins - C-type lectins - to target drug-loaded liposomes to conserved fungal cognate ligands and away from host cells. DectiSomes represent one leap forward for urgently needed effective pan-antifungal therapy. Herein, we discuss the problems of battling fungal diseases and the state of DectiSome development.
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Affiliation(s)
- Richard B Meagher
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Zachary A Lewis
- Department of Genetics, University of Georgia, Athens, GA 30602, USA; Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Suresh Ambati
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
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6
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LaMastro V, Campbell KM, Gonzalez P, Meng-Saccoccio T, Shukla A. Antifungal liposomes: Lipid saturation and cholesterol concentration impact interaction with fungal and mammalian cells. J Biomed Mater Res A 2023; 111:644-659. [PMID: 36740998 DOI: 10.1002/jbm.a.37501] [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: 10/20/2022] [Revised: 12/24/2022] [Accepted: 12/29/2022] [Indexed: 02/07/2023]
Abstract
Liposomes are lipid-based nanoparticles that have been used to deliver encapsulated drugs for a variety of applications, including treatment of life-threatening fungal infections. By understanding the effect of composition on liposome interactions with both fungal and mammalian cells, new effective antifungal liposomes can be developed. In this study, we investigated the impact of lipid saturation and cholesterol content on fungal and mammalian cell interactions with liposomes. We used three phospholipids with different saturation levels (saturated hydrogenated soy phosphatidylcholine (HSPC), mono-unsaturated 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC), and di-unsaturated 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC)) and cholesterol concentrations ranging from 15% to 40% (w/w) in our liposome formulations. Using flow cytometry, >80% of Candida albicans SC5314 cells were found to interact with all liposome formulations developed, while >50% of clinical isolates tested exhibited interaction with these liposomes. In contrast, POPC-containing formulations exhibited low levels of interaction with murine fibroblasts and human umbilical vein endothelial cells (<30%), while HSPC and PLPC formulations had >50% and >80% interaction, respectively. Further, PLPC formulations caused a significant decrease in mammalian cell viability. Formulations that resulted in low levels of mammalian cell interaction, minimal cytotoxicity, and high levels of fungal cell interaction were then used to encapsulate the antifungal drug, amphotericin B. These liposomes eradicated planktonic C. albicans at drug concentrations lower than free drug, potentially due to the high levels of liposome-C. albicans interaction. Overall, this study provides new insights into the design of liposome formulations towards the development of new antifungal therapeutics.
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Affiliation(s)
- Veronica LaMastro
- School of Engineering, Center for Biomedical Engineering, Brown University, Providence, Rhode Island, USA
| | - Kayla M Campbell
- School of Engineering, Center for Biomedical Engineering, Brown University, Providence, Rhode Island, USA
| | - Peter Gonzalez
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Tobias Meng-Saccoccio
- School of Engineering, Center for Biomedical Engineering, Brown University, Providence, Rhode Island, USA
| | - Anita Shukla
- School of Engineering, Center for Biomedical Engineering, Brown University, Providence, Rhode Island, USA
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Jebastin K, Narayanasamy D. Rationale utilization of phospholipid excipients: a distinctive tool for progressing state of the art in research of emerging drug carriers. J Liposome Res 2022; 33:1-33. [PMID: 35543241 DOI: 10.1080/08982104.2022.2069809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Phospholipids have a high degree of biocompatibility and are deemed ideal pharmaceutical excipients in the development of lipid-based drug delivery systems, because of their unique features (permeation, solubility enhancer, emulsion stabilizer, micelle forming agent, and the key excipients in solid dispersions) they can be used in a variety of pharmaceutical drug delivery systems, such as liposomes, phytosomes, solid lipid nanoparticles, etc. The primary usage of phospholipids in a colloidal pharmaceutical formulation is to enhance the drug's bioavailability with low aqueous solubility [i.e. Biopharmaceutical Classification System (BCS) Class II drugs], Membrane penetration (i.e. BCS Class III drugs), drug uptake and release enhancement or modification, protection of sensitive active pharmaceutical ingredients (APIs) from gastrointestinal degradation, a decrease of gastrointestinal adverse effects, and even masking of the bitter taste of orally delivered drugs are other uses. Phospholipid-based colloidal drug products can be tailored to address a wide variety of product requirements, including administration methods, cost, product stability, toxicity, and efficacy. Such formulations that are also a cost-effective method for developing medications for topical, oral, pulmonary, or parenteral administration. The originality of this review work is that we comprehensively evaluated the unique properties and special aspects of phospholipids and summarized how the individual phospholipids can be utilized in various types of lipid-based drug delivery systems, as well as listing newly marketed lipid-based products, patents, and continuing clinical trials of phospholipid-based therapeutic products. This review would be helpful for researchers responsible for formulation development and research into novel colloidal phospholipid-based drug delivery systems.
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Affiliation(s)
- Koilpillai Jebastin
- Department of Pharmaceutics, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, India
| | - Damodharan Narayanasamy
- Department of Pharmaceutics, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, India
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Choudhury QJ, Ambati S, Lewis ZA, Meagher RB. Targeted Delivery of Antifungal Liposomes to Rhizopus delemar. J Fungi (Basel) 2022; 8:jof8040352. [PMID: 35448583 PMCID: PMC9026866 DOI: 10.3390/jof8040352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/21/2022] [Accepted: 03/28/2022] [Indexed: 12/10/2022] Open
Abstract
Mucormycosis (a.k.a. zygomycosis) is an often-life-threatening disease caused by fungi from the ancient fungal division Mucoromycota. Globally, there are nearly a million people with the disease. Rhizopus spp., and R. delemar (R. oryzae, R. arrhizus) in particular, are responsible for most of the diagnosed cases. Pulmonary, rhino-orbito-cerebral, and invasive mucormycosis are most effectively treated with amphotericin B (AmB) and particularly with liposomal formulations (e.g., AmBisome®). However, even after antifungal therapy, there is still a 50% mortality rate. Hence, there is a critical need to improve therapeutics for mucormycosis. Targeting AmB-loaded liposomes (AmB-LLs) with the pathogen receptor Dectin-1 (DEC1-AmB-LLs) to the beta-glucans expressed on the surface of Aspergillus fumigatus and Candida albicans lowers the effective dose required to kill cells relative to untargeted AmB-LLs. Because Dectin-1 is an immune receptor for R. delemar infections and may bind it directly, we explored the Dectin-1-mediated delivery of liposomal AmB to R. delemar. DEC1-AmB-LLs bound 100- to 1000-fold more efficiently to the exopolysaccharide matrix of R. delemar germlings and mature hyphae relative to AmB-LLs. DEC1-AmB-LLs delivering sub-micromolar concentrations of AmB were an order of magnitude more efficient at inhibiting and/or killing R. delemar than AmB-LLs. Targeted antifungal drug-loaded liposomes have the potential to improve the treatment of mucormycosis.
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Affiliation(s)
- Quanita J. Choudhury
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (Q.J.C.); (Z.A.L.)
| | - Suresh Ambati
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
| | - Zachary A. Lewis
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (Q.J.C.); (Z.A.L.)
| | - Richard B. Meagher
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
- Correspondence:
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Ambati S, Pham T, Lewis ZA, Lin X, Meagher RB. DC-SIGN targets amphotericin B-loaded liposomes to diverse pathogenic fungi. Fungal Biol Biotechnol 2021; 8:22. [PMID: 34952645 PMCID: PMC8709943 DOI: 10.1186/s40694-021-00126-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/17/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Life-threatening invasive fungal infections are treated with antifungal drugs such as Amphotericin B (AmB) loaded liposomes. Our goal herein was to show that targeting liposomal AmB to fungal cells with the C-type lectin pathogen recognition receptor DC-SIGN improves antifungal activity. DC-SIGN binds variously crosslinked mannose-rich and fucosylated glycans and lipomannans that are expressed by helminth, protist, fungal, bacterial and viral pathogens including three of the most life-threatening fungi, Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. Ligand recognition by human DC-SIGN is provided by a carbohydrate recognition domain (CRD) linked to the membrane transit and signaling sequences. Different combinations of the eight neck repeats (NR1 to NR8) expressed in different protein isoforms may alter the orientation of the CRD to enhance its binding to different glycans. RESULTS We prepared two recombinant isoforms combining the CRD with NR1 and NR2 in isoform DCS12 and with NR7 and NR8 in isoform DCS78 and coupled them to a lipid carrier. These constructs were inserted into the membrane of pegylated AmB loaded liposomes AmB-LLs to produce DCS12-AmB-LLs and DCS78-AmB-LLs. Relative to AmB-LLs and Bovine Serum Albumin coated BSA-AmB-LLs, DCS12-AmB-LLs and DCS78-AmB-LLs bound more efficiently to the exopolysaccharide matrices produced by A. fumigatus, C. albicans and C. neoformans in vitro, with DCS12-AmB-LLs performing better than DCS78-AmB-LLs. DCS12-AmB-LLs inhibited and/or killed all three species in vitro significantly better than AmB-LLs or BSA-AmB-LLs. In mouse models of invasive candidiasis and pulmonary aspergillosis, one low dose of DCS12-AmB-LLs significantly reduced the fungal burden in the kidneys and lungs, respectively, several-fold relative to AmB-LLs. CONCLUSIONS DC-SIGN's CRD specifically targeted antifungal liposomes to three highly evolutionarily diverse pathogenic fungi and enhanced the antifungal efficacy of liposomal AmB both in vitro and in vivo. Targeting significantly reduced the effective dose of antifungal drug, which may reduce drug toxicity, be effective in overcoming dose dependent drug resistance, and more effectively kill persister cells. In addition to fungi, DC-SIGN targeting of liposomal packaged anti-infectives have the potential to alter treatment paradigms for a wide variety of pathogens from different kingdoms including protozoans, helminths, bacteria, and viruses which express its cognate ligands.
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Affiliation(s)
- Suresh Ambati
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA.
| | - Tuyetnhu Pham
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Zachary A Lewis
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Richard B Meagher
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
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