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Sheikh SY, Hassan F, Shukla D, Bala S, Faruqui T, Akhter Y, Khan AR, Nasibullah M. A review on potential therapeutic targets for the treatment of leishmaniasis. Parasitol Int 2024; 100:102863. [PMID: 38272301 DOI: 10.1016/j.parint.2024.102863] [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: 05/30/2023] [Revised: 12/22/2023] [Accepted: 01/21/2024] [Indexed: 01/27/2024]
Abstract
Leishmania, a protozoan parasite, is responsible for the occurrence of leishmaniasis, a disease that is prevalent in tropical regions. Visceral Leishmaniasis (VL), also known as kala-azar in Asian countries, is one of the most significant forms of VL, along with Cutaneous Leishmaniasis (CL) and Mucocutaneous Leishmaniasis (ML). Management of this condition typically entails the use of chemotherapy as the sole therapeutic option. The current treatments for leishmaniasis present several drawbacks, including a multitude of side effects, prolonged treatment duration, disparate efficacy across different regions, and the emergence of resistance. To address this urgent need, it is imperative to identify alternative treatments that are both safer and more effective. The identification of appropriate pharmacological targets in conjunction with biological pathways constitutes the initial stage of drug discovery. In this review, we have addressed the key metabolic pathways that represent potential pharmacological targets as well as prominent treatment options for leishmaniasis.
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Affiliation(s)
- Sabahat Yasmeen Sheikh
- Department of Chemistry, Integral University, Dasauli, Kursi road, Lucknow 226026, India
| | - Firoj Hassan
- Department of Chemistry, Integral University, Dasauli, Kursi road, Lucknow 226026, India
| | - Deepanjali Shukla
- Department of Chemistry, Integral University, Dasauli, Kursi road, Lucknow 226026, India
| | - Shashi Bala
- Department of Chemistry, Lucknow University, Lucknow 226026, India
| | - Tabrez Faruqui
- Department of Biosciences, Integral University, Lucknow 226026, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, India
| | - Abdul Rahman Khan
- Department of Chemistry, Integral University, Dasauli, Kursi road, Lucknow 226026, India
| | - Malik Nasibullah
- Department of Chemistry, Integral University, Dasauli, Kursi road, Lucknow 226026, India.
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2
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Britten NS, Butler JA. Ruthenium metallotherapeutics: novel approaches to combatting parasitic infections. Curr Med Chem 2022; 29:5159-5178. [DOI: 10.2174/0929867329666220401105444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/15/2022] [Accepted: 01/24/2022] [Indexed: 11/22/2022]
Abstract
Human parasitic infections cause a combined global mortality rate of over one million people per annum and represent some of the most challenging diseases for medical intervention. Current chemotherapeutic strategies often require prolonged treatment, coupled with subsequent drug-induced cytotoxic morbidity to the host, while resistance generation is also a major concern. Metals have been used extensively throughout the history of medicine, with more recent applications as anticancer and antimicrobial agents. Ruthenium metallotherapeutic antiparasitic agents are highly effective at targeting a range of key parasites, including the causative agents of malaria, trypanosomiasis, leishmaniasis, amoebiasis, toxoplasmosis and other orphan diseases, while demonstrating lower cytotoxicity profiles than current treatment strategies. Generally, such compounds also demonstrate activity against multiple cellular target sites within parasites, including inhibition of enzyme function, cell membrane perturbation, and alterations to metabolic pathways, therefore reducing the opportunity for resistance generation. This review provides a comprehensive and subjective analysis of the rapidly developing area of ruthenium metal-based antiparasitic chemotherapeutics, in the context of rational drug design and potential clinical approaches to combatting human parasitic infections.
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Affiliation(s)
- Nicole S. Britten
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
| | - Jonathan A. Butler
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
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3
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Guerrero-Hernández J, Bobes RJ, García-Varela M, Castellanos-Gonzalez A, Laclette JP. Identification and functional characterization of the siRNA pathway in Taenia crassiceps by silencing Enolase A. Acta Trop 2022; 225:106197. [PMID: 34688628 DOI: 10.1016/j.actatropica.2021.106197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 09/01/2021] [Accepted: 10/13/2021] [Indexed: 12/30/2022]
Abstract
A gene silencing procedure on cysticerci of the taeniid cestode Taenia crassiceps is described. This is the first time this technique is reported in this species that is widely used as an animal model for human cysticercosis. Genome database searches were performed in order to find out if relevant genes involved in gene silencing and non-coding RNA processing, Argonaute and Dicer (AGO and Dcr) are present in T. crassiceps. We found three AGO and two Dcr orthologues that were designed TcAGO1, Tc2 and Tc3, as well as TcDcr1 and TcDcr2. In order to elucidate the evolutionary relationships of T. crassiceps TcAGO and TcDcr genes, separate phylogenetic analyses were carried out for each, including AGO and Dcr orthologues of other 20 platyhelminthes. Our findings showed a close phylogenetic relationship of TcAGO and TcDcr with those previously described for Echinococcus spp. Our RT-PCR studies demonstrated expression of all TcAGO and TcDcr orthologues. Our results show that the gene silencing machinery in T. crassiceps is functionally active by inducing silencing of TcEnoA (∼90%). These results clearly show that gene silencing using siRNAs can be used as a molecular methodology to study gene function in taeniid cestodes.
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Affiliation(s)
- Julio Guerrero-Hernández
- Biomedical Research Institute. Universidad Nacional Autónoma de México, México, 04510, Coyoacán, Cd. de México, México
| | - Raúl J Bobes
- Biomedical Research Institute. Universidad Nacional Autónoma de México, México, 04510, Coyoacán, Cd. de México, México
| | - Martín García-Varela
- Biology Institute. Universidad Nacional Autónoma de México, 04510, Coyoacán, Cd. de México, México
| | - Alejandro Castellanos-Gonzalez
- Division of Infectious Diseases, University of Texas Medical Branch, United States; Center for Tropical Diseases, University of Texas Medical Branch, United States..
| | - Juan P Laclette
- Biomedical Research Institute. Universidad Nacional Autónoma de México, México, 04510, Coyoacán, Cd. de México, México.
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4
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Morotti ALM, Martins-Teixeira MB, Carvalho I. Protozoan Parasites Glycosylphosphatidylinositol Anchors: Structures, Functions and Trends for Drug Discovery. Curr Med Chem 2019; 26:4301-4322. [PMID: 28748758 DOI: 10.2174/0929867324666170727110801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glycosylphosphatidylinositol (GPI) anchors are molecules located on cell membranes of all eukaryotic organisms. Proteins, enzymes, and other macromolecules which are anchored by GPIs are essential elements for interaction between cells, and are widely used by protozoan parasites when compared to higher eukaryotes. METHODS More than one hundred references were collected to obtain broad information about mammalian and protozoan parasites' GPI structures, biosynthetic pathways, functions and attempts to use these molecules as drug targets against parasitic diseases. Differences between GPI among species were compared and highlighted. Strategies for drug discovery and development against protozoan GPI anchors were discussed based on what has been reported on literature. RESULTS There are many evidences that GPI anchors are crucial for parasite's survival and interaction with hosts' cells. Despite all GPI anchors contain a conserved glycan core, they present variations regarding structural features and biosynthetic pathways between organisms, which could offer adequate selectivity to validate GPI anchors as drug targets. Discussion was developed with focus on the following parasites: Trypanosoma brucei, Trypanosoma cruzi, Leishmania, Plasmodium falciparum and Toxoplasma gondii, causative agents of tropical neglected diseases. CONCLUSION This review debates the main variances between parasitic and mammalian GPI anchor biosynthesis and structures, as well as clues for strategic development for new anti-parasitic therapies based on GPI anchors.
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Affiliation(s)
- Ana Luísa Malaco Morotti
- School of Pharmaceutical Sciences of Ribeirao Preto - University of Sao Paulo, Sao Paulo, Brazil
| | | | - Ivone Carvalho
- School of Pharmaceutical Sciences of Ribeirao Preto - University of Sao Paulo, Sao Paulo, Brazil
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5
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In silico and in vitro comparative activity of green tea components against Leishmania infantum. J Glob Antimicrob Resist 2019; 18:187-194. [DOI: 10.1016/j.jgar.2019.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/17/2019] [Accepted: 02/12/2019] [Indexed: 01/07/2023] Open
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Chordia N, Lakhawat K, Kumar A. Identification of Drug Target Properties and its validation on Helicobacter pylori. CANADIAN JOURNAL OF BIOTECHNOLOGY 2017. [DOI: 10.24870/cjb.2017-000101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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7
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The role of GlcNAc-PI-de-N-acetylase gene by gene knockout through homologous recombination and its consequences on survival, growth and infectivity of Leishmania major in in vitro and in vivo conditions. Acta Trop 2016; 154:63-72. [PMID: 26571069 DOI: 10.1016/j.actatropica.2015.10.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 10/18/2015] [Accepted: 10/27/2015] [Indexed: 11/20/2022]
Abstract
At present, there are no efficacious vaccines or effective drugs against leishmaniasis; therefore new and innovative control methods are urgently required. One way to achieve this important goal is through using reverse genetic engineering to evaluate important enzymes, proteins and macromolecules. One of the most important enzymes for Glycosylphosphatidylinositol (GPI) biosynthetic pathways is GlcNAc-PI-de-N-acetylase (GPI12). The molecular constructs were cloned in Escherichia coli strain Top 10 and confirmed by molecular methods and were transfected by electroporation into Leishmania major. We demonstrated that two alleles of the GPI12 gene in L. major were successfully removed and enabling the generation of a null mutant, which supports the idea that GPI12 is not an essential gene for the growth and survival of Leishmania and the homozygous knockouts of Leishmania are able to survive. We were able to produce a mutant parasite that caused no damaged to the host. Further investigations are essential to check the safety profile in laboratory animals.
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Rajasekaran R, Chen YPP. Potential therapeutic targets and the role of technology in developing novel antileishmanial drugs. Drug Discov Today 2015; 20:958-68. [PMID: 25936844 DOI: 10.1016/j.drudis.2015.04.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/25/2015] [Accepted: 04/20/2015] [Indexed: 12/11/2022]
Abstract
Leishmaniasis is the most prevalent pathogenic disease in many countries around the world, but there are few drugs available to treat it. Most antileishmanial drugs available are highly toxic, have resistance issues or require hospitalization for their use; therefore, they are not suitable for use in most of the affected countries. Over the past decade, the completion of the genomes of many human pathogens, including that of Leishmania spp., has opened new doors for target identification and validation. Here, we focus on the potential drug targets that can be used for the treatment of leishmaniasis and bring to light how recent technological advances, such as structure-based drug design, structural genomics, and molecular dynamics (MD), can be used to our advantage to develop potent and affordable antileishmanial drugs.
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Affiliation(s)
| | - Yi-Ping Phoebe Chen
- College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia.
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Nagle A, Khare S, Kumar AB, Supek F, Buchynskyy A, Mathison CJN, Chennamaneni N, Pendem N, Buckner FS, Gelb M, Molteni V. Recent developments in drug discovery for leishmaniasis and human African trypanosomiasis. Chem Rev 2014; 114:11305-47. [PMID: 25365529 PMCID: PMC4633805 DOI: 10.1021/cr500365f] [Citation(s) in RCA: 220] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Indexed: 02/08/2023]
Affiliation(s)
- Advait
S. Nagle
- Genomics
Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Shilpi Khare
- Genomics
Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Arun Babu Kumar
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Frantisek Supek
- Genomics
Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Andriy Buchynskyy
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Casey J. N. Mathison
- Genomics
Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
| | - Naveen
Kumar Chennamaneni
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Nagendar Pendem
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Frederick S. Buckner
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Michael
H. Gelb
- Departments of Chemistry, Biochemistry, and Medicine, University
of Washington, Seattle, Washington 98195, United States
| | - Valentina Molteni
- Genomics
Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, United States
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Ghosh D, Stumhofer JS. Do you see what I see: Recognition of protozoan parasites by Toll-like receptors. ACTA ACUST UNITED AC 2014; 9:129-140. [PMID: 25383072 DOI: 10.2174/1573395509666131203225929] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Toll-like receptors (TLRs) are important for recognizing a variety of pathogens, including protozoan parasites, and initiating innate immune responses against them. TLRs are localized on the cell surface as well as in the endosome, and are implicated in innate sensing of these parasites. In this review, we will discuss recent findings on the identification of parasite-derived pathogen associated molecular patterns and the TLRs that bind them. The role of these TLRs in initiating the immune response against protozoan parasitic infections in vivo will be presented in the context of murine models of infection utilizing TLR-deficient mice. Additionally, we will explore evidence that TLRs and genetic variants of TLRs may impact the outcome of these parasitic infections in humans.
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Affiliation(s)
- Debopam Ghosh
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
| | - Jason S Stumhofer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
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11
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Iminosugars: Therapeutic Applications and Synthetic Considerations. TOPICS IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1007/7355_2014_50] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
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12
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Yadav M, Raghupathy R, Saikam V, Dara S, Singh PP, Sawant SD, Mayor S, Vishwakarma RA. Synthesis of non-hydrolysable mimics of glycosylphosphatidylinositol (GPI) anchors. Org Biomol Chem 2014; 12:1163-72. [DOI: 10.1039/c3ob42116c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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In silico and in vitro comparative activity of novel experimental derivatives against Leishmania major and Leishmania infantum promastigotes. Exp Parasitol 2013; 135:208-16. [DOI: 10.1016/j.exppara.2013.07.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/20/2013] [Accepted: 07/08/2013] [Indexed: 11/18/2022]
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14
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Barteneva NS, Maltsev N, Vorobjev IA. Microvesicles and intercellular communication in the context of parasitism. Front Cell Infect Microbiol 2013; 3:49. [PMID: 24032108 PMCID: PMC3764926 DOI: 10.3389/fcimb.2013.00049] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 08/20/2013] [Indexed: 01/18/2023] Open
Abstract
There is a rapidly growing body of evidence that production of microvesicles (MVs) is a universal feature of cellular life. MVs can incorporate microRNA (miRNA), mRNA, mtDNA, DNA and retrotransposons, camouflage viruses/viral components from immune surveillance, and transfer cargo between cells. These properties make MVs an essential player in intercellular communication. Increasing evidence supports the notion that MVs can also act as long-distance vehicles for RNA molecules and participate in metabolic synchronization and reprogramming eukaryotic cells including stem and germinal cells. MV ability to carry on DNA and their general distribution makes them attractive candidates for horizontal gene transfer, particularly between multi-cellular organisms and their parasites; this suggests important implications for the co-evolution of parasites and their hosts. In this review, we provide current understanding of the roles played by MVs in intracellular pathogens and parasitic infections. We also discuss the possible role of MVs in co-infection and host shifting.
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Affiliation(s)
- Natasha S Barteneva
- Program in Cellular and Molecular Medicine, Children's Hospital Boston and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA. Natasha.Barteneva@ childrens.harvard.edu
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15
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Sanchez LM, Knudsen GM, Hartmann C, De Muylder G, Mascuch SM, Mackey ZB, Gerwick L, Clayton C, McKerrow JH, Linington RG. Examination of the mode of action of the almiramide family of natural products against the kinetoplastid parasite Trypanosoma brucei. JOURNAL OF NATURAL PRODUCTS 2013; 76:630-41. [PMID: 23445522 PMCID: PMC3971013 DOI: 10.1021/np300834q] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Almiramide C is a marine natural product with low micromolar activity against Leishmania donovani, the causative agent of leishmaniasis. We have now shown that almiramide C is also active against the related parasite Trypanosoma brucei, the causative agent of human African trypanosomiasis. A series of activity-based probes have been synthesized to explore both the molecular target of this compound series in T. brucei lysates and site localization through epifluorescence microscopy. These target identification studies indicate that the almiramides likely perturb glycosomal function through disruption of membrane assembly machinery. Glycosomes, which are organelles specific to kinetoplastid parasites, house the first seven steps of glycolysis and have been shown to be essential for parasite survival in the bloodstream stage. There are currently no reported small-molecule disruptors of glycosome function, making the almiramides unique molecular probes for this understudied parasite-specific organelle. Additionally, examination of toxicity in an in vivo zebrafish model has shown that these compounds have little effect on organism development, even at high concentrations, and has uncovered a potential side effect through localization of fluorescent derivatives to zebrafish neuromast cells. Combined, these results further our understanding of the potential value of this lead series as development candidates against T. brucei.
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Affiliation(s)
- Laura M. Sanchez
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Giselle M. Knudsen
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Claudia Hartmann
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - Geraldine De Muylder
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Samantha M. Mascuch
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Zachary B. Mackey
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - James H. McKerrow
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Roger G. Linington
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
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Saikam V, Raghupathy R, Yadav M, Gannedi V, Singh PP, Qazi NA, Sawant SD, Vishwakarma RA. Synthesis of new fluorescently labeled glycosylphosphatidylinositol (GPI) anchors. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Proinflammatory responses by glycosylphosphatidylinositols (GPIs) of Plasmodium falciparum are mainly mediated through the recognition of TLR2/TLR1. Exp Parasitol 2011; 128:205-11. [PMID: 21439957 DOI: 10.1016/j.exppara.2011.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 03/16/2011] [Accepted: 03/19/2011] [Indexed: 11/22/2022]
Abstract
The glycosylphosphatidylinositols (GPIs) of Plasmodium falciparum have been shown to activate macrophages and produce inflammatory responses. The activation of macrophages by malarial GPIs involves engagement of Toll like receptor 2 (TLR2) resulting in the intracellular signaling and production of cytokines. In the present study, we investigated the requirement of TLR1 and TLR6 for the TLR2 mediated cell signaling and proinflammatory cytokine production by macrophages. The data demonstrate that malarial GPIs, which contain three fatty acid substituents, preferentially engage TLR2-TLR1 dimeric pair than TLR2-TLR6, whereas their derivatives, sn-2 lyso GPIs, that contain two fatty acid substituents recognize TLR2-TLR6 with slightly higher selectivity as compared to TLR2-TLR1 heteromeric pair. These results are analogous to the recognition of triacylated bacterial and diacylated mycoplasmal lipoproteins, respectively, by TLR2-TLR1 and TLR2-TLR6 dimers, suggesting that the lipid portions of the microbial GPI ligands play essential role in determining their TLR recognition specificity.
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