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Chitin contributes to the formation of a feeding structure in a predatory nematode. Curr Biol 2023; 33:15-27.e6. [PMID: 36460010 DOI: 10.1016/j.cub.2022.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/20/2022] [Accepted: 11/04/2022] [Indexed: 12/03/2022]
Abstract
Some nematode predators and parasites form teeth-like denticles that are histologically different from vertebrate teeth, but their biochemical composition remains elusive. Here, we show a role of chitin in the formation of teeth-like denticles in Pristionchus pacificus, a model system for studying predation and feeding structure plasticity. Pristionchus forms two alternative mouth morphs with one tooth or two teeth, respectively. The P. pacificus genome encodes two chitin synthases, with the highly conserved chs-2 gene being composed of 60 exons forming at least four isoforms. Generating CRISPR-Cas9-based gene knockouts, we found that Ppa-chs-2 mutations that eliminate the chitin-synthase domain are lethal. However, mutations in the C terminus result in viable but teethless worms, with severe malformation of the mouth. Similarly, treatment with the chitin-synthase inhibitor Nikkomycin Z also results in teethless animals. Teethless worms can feed on various bacterial food sources but are incapable of predation. High-resolution transcriptomics revealed that Ppa-chs-2 expression is controlled by the sulfatase-encoding developmental switch Ppa-eud-1. This study indicates a key role of chitin in the formation of teeth-like denticles and the complex feeding apparatus in nematodes.
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2
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Sanprasert V, Charuchaibovorn S, Nuchprayoon S. The Genetic Polymorphisms of 24 Base Pair Duplication and Point G102S of Human Chitotriosidase to Bancroftian Filariasis at the Thai⁻Myanmar Border. Pathogens 2019; 8:pathogens8010041. [PMID: 30934653 PMCID: PMC6470825 DOI: 10.3390/pathogens8010041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/15/2019] [Accepted: 03/20/2019] [Indexed: 11/30/2022] Open
Abstract
Lymphatic filariasis, caused by lymphatic filarial parasites, Wuchereria bancrofti, and Brugia malayi, causes significant morbidity and disability to 120 million people in the tropics and subtropics. Chitin has an important role for embryogenesis in adult worms and is a component of microfilaria sheath. Human chitotriosidase (CHIT1) is a chitin-degrading enzyme which provides a protective role against chitin-containing pathogens. Here, we determined the association of CHIT1 polymorphisms with susceptibility to bancroftian filariasis (BF) in 88 individuals at the Thai–Myanmar border. Two common polymorphisms of CHIT1, contributing inactive CHIT protein, including 24 base pair (24 bp) duplication in exon 10, and p. G102S in exon 4 were genotyped by allele-specific Polymerase Chain Reaction (PCR) and PCR sequencing, respectively. Unexpectedly, genotype frequencies of 24 bp duplication insertion homozygous (INS/INS) were significantly higher in endemic normal (EN) (40.0%) than BF patients (31.4%). In contrast, genotype frequencies of p. G102S homozygous (A/A) in BF patients (21.6%) was higher than in EN (19.0%) without statistical difference. Mutant allele frequencies of 24 bp duplication were 0.6125 (98/160) and p. G102S were 0.392 (69/176). Genotype and allele frequencies of CHIT1, 24 bp duplication, and p. G102S, showed no association with BF patients.
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Affiliation(s)
- Vivornpun Sanprasert
- Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
- Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Sarit Charuchaibovorn
- Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Surang Nuchprayoon
- Lymphatic Filariasis and Tropical Medicine Research Unit, Chulalongkorn Medical Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
- Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
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3
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Chen Q, Peng D. Nematode Chitin and Application. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1142:209-219. [PMID: 31102248 DOI: 10.1007/978-981-13-7318-3_10] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Plant-parasitic nematode infection is a global problem for agriculture and forestry. There is clearly a need for novel nematicides, because of the pitifully small repertoire of nematicides available and the effectiveness of losing or environmental prohibition of these nematicides. Chitin is the essential component of nematode eggshell and pharynx. The disturbance of chitin synthesis or hydrolysis led to nematode embryonic lethal, laying defective eggs or moulting failure. Thus, the key components in the chitin metabolic process are promising targets for anti-nematode agent's development. In this chapter, we focus on chitin and chitin synthase of nematodes, chitinases and their roles in nematode survival and application of chitin in nematode control.
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Affiliation(s)
- Qi Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Deliang Peng
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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Hwang DS, Lee MC, Kyung DH, Kim HS, Han J, Kim IC, Puthumana J, Lee JS. WAFs lead molting retardation of naupliar stages with down-regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus. Comp Biochem Physiol C Toxicol Pharmacol 2017; 193:9-17. [PMID: 27939724 DOI: 10.1016/j.cbpc.2016.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/22/2016] [Accepted: 12/02/2016] [Indexed: 01/10/2023]
Abstract
Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P<0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4-5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus.
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Affiliation(s)
- Dae-Sik Hwang
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Min-Chul Lee
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Do-Hyun Kyung
- Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 04763, South Korea
| | - Hui-Su Kim
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Jeonghoon Han
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Il-Chan Kim
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, South Korea
| | - Jayesh Puthumana
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
| | - Jae-Seong Lee
- Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
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5
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Greven H, Kaya M, Baran T. The presence of α-chitin in Tardigrada with comments on chitin in the Ecdysozoa. ZOOL ANZ 2016. [DOI: 10.1016/j.jcz.2016.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Souza-Ferreira PS, Mansur JF, Berni M, Moreira MF, dos Santos RE, Araújo HMM, de Souza W, Ramos IB, Masuda H. Chitin deposition on the embryonic cuticle of Rhodnius prolixus: the reduction of CHS transcripts by CHS-dsRNA injection in females affects chitin deposition and eclosion of the first instar nymph. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 51:101-109. [PMID: 24412274 DOI: 10.1016/j.ibmb.2013.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 06/03/2023]
Abstract
In a previous study, we found that the embryonic cuticle of Rhodnius prolixus is a chitin-based structure that helps the first instar nymph to hatch from the chorion. Here, we investigated how the reduction of transcripts induced by CHS dsRNA injection affects R. prolixus embryogenesis and eclosion. Deposition of chitin in the embryonic cuticle begins later at embryogenesis, around day 8, and ends approximately at day 15, when the insects are ready for eclosion. In R. prolixus, chitin deposition follows pari passu with the synthesis of the chitin synthase mRNA, indicating a regulation at the transcriptional level. The reduction of the chitin synthase gene transcripts by the injection of CHS dRNA prevented chitin deposition during embryonic cuticle formation, being lethal to hatching nymphs, which end up dying while stuck in the chorionic border trying to leave the chorion. The successful eclosion rates were reduced by 60% in animals treated with CHS dsRNA when compared to animals injected with a control (dsRNA no related gene or water). We found that the harmful effects on oviposition and eclosion are possibly due to changes in the structure of the embryonic cuticle, as observed by directly comparing the morphology of control and chitin-deficient embryonic cuticles under the transmission electron microscope. The lack of chitin and changes in its morphological characteristics appears to alter the embryonic cuticle physiology and functionality. Additionally, we observed that the effects of CHS dRNA treatment on R. prolixus females lasted up to 3 egg-laying cycles (∼100 days), pointing to R. prolixus as a useful model for developmental studies.
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Affiliation(s)
- Paula S Souza-Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Juliana F Mansur
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil
| | - Matheus Berni
- Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, 21941-970 Rio de Janeiro, RJ, Brazil
| | - Monica F Moreira
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil
| | - Roberto Eizemberg dos Santos
- Universidade Federal do Rio de Janeiro, Escola de Educação Física e Desportos, 21941599 Rio de Janeiro, RJ, Brazil
| | - Helena M Marcolla Araújo
- Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, 21941-970 Rio de Janeiro, RJ, Brazil
| | - Wanderley de Souza
- Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Isabela B Ramos
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil
| | - Hatisaburo Masuda
- Universidade Federal do Rio de Janeiro, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil.
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Gene expression analysis distinguishes tissue-specific and gender-related functions among adult Ascaris suum tissues. Mol Genet Genomics 2013; 288:243-60. [PMID: 23572074 DOI: 10.1007/s00438-013-0743-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 03/19/2013] [Indexed: 12/15/2022]
Abstract
Over a billion people are infected by Ascaris spp. intestinal parasites. To clarify functional differences among tissues of adult A. suum, we compared gene expression by various tissues of these worms by expression microarray methods. The A. suum genome was sequenced and assembled to allow generation of microarray elements. Expression of over 40,000 60-mer elements was investigated in a variety of tissues from both male and female adult worms. Nearly 50 percent of the elements for which signal was detected exhibited differential expression among different tissues. The unique profile of transcripts identified for each tissue clarified functional distinctions among tissues, such as chitin binding in the ovary and peptidase activity in the intestines. Interestingly, hundreds of gender-specific elements were characterized in multiple non-reproductive tissues of female or male worms, with most prominence of gender differences in intestinal tissue. A. suum genes from the same family were frequently expressed differently among tissues. Transcript abundance for genes specific to A. suum, by comparison to Caenorhabditis elegans, varied to a greater extent among tissues than for genes conserved between A. suum and C. elegans. Analysis using C. elegans protein interaction data identified functional modules conserved between these two nematodes, resulting in identification of functional predictions of essential subnetworks of protein interactions and how these networks may vary among nematode tissues. A notable finding was very high module similarity between adult reproductive tissues and intestine. Our results provide the most comprehensive assessment of gene expression among tissues of a parasitic nematode to date.
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Abstract
Fertilization is a complex process comprised of numerous steps. During fertilization, two highly specialized and differentiated cells (sperm and egg) fuse and subsequently trigger the development of an embryo from a quiescent, arrested oocyte. Molecular interactions between the sperm and egg are necessary for regulating the developmental potential of an oocyte, and precise coordination and regulation of gene expression and protein function are critical for proper embryonic development. The nematode Caenorhabditis elegans has emerged as a valuable model system for identifying genes involved in fertilization and the oocyte-to-embryo transition as well as for understanding the molecular mechanisms that govern these processes. In this review, we will address current knowledge of the molecular underpinnings of gamete interactions during fertilization and the oocyte-to-embryo transition in C. elegans. We will also compare our knowledge of these processes in C. elegans to what is known about similar processes in mammalian, specifically mouse, model systems.
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Affiliation(s)
- Matthew R Marcello
- Waksman Institute and Department of Genetics Rutgers University, Piscataway, NJ 08854, USA.
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Abstract
Filariasis is caused by thread-like nematode worms, classified according to their presence in the vertebrate host. The cutaneous group includes Onchocerca volvulus, Loa loa and Mansonella streptocerca; the lymphatic group includes Wuchereria bancrofti, Brugia malayi and Brugia timori and the body cavity group includes Mansonella perstans and Mansonella ozzardi. Lymphatic filariasis, a mosquito-borne disease, is one of the most prevalent diseases in tropical and subtropical countries and is accompanied by a number of pathological conditions. In recent years, there has been rapid progress in filariasis research, which has provided new insights into the pathogenesis of filarial disease, diagnosis, chemotherapy, the host–parasite relationship and the genomics of the parasite. Together, these insights are assisting the identification of novel drug targets and the discovery of antifilarial agents and candidate vaccine molecules. This review discusses the antifilarial activity of various chemical entities, the merits and demerits of antifilarial drugs currently in use, their mechanisms of action, in addition to antifilarial drug targets and their validation.
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Dixon MJ, Nathubhai A, Andersen OA, van Aalten DMF, Eggleston IM. Solid-phase synthesis of cyclic peptide chitinase inhibitors: SAR of the argifin scaffold. Org Biomol Chem 2009; 7:259-68. [PMID: 19109670 PMCID: PMC2657367 DOI: 10.1039/b815077j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Accepted: 10/06/2008] [Indexed: 12/01/2022]
Abstract
A new, highly efficient, all-solid-phase synthesis of argifin, a natural product cyclic pentapeptide chitinase inhibitor, is reported. The synthesis features attachment of an orthogonally protected Asp residue to the solid support and assembly of the linear peptide chain by Fmoc SPPS prior to cyclisation and side-chain manipulation on-resin. Introduction of the key N-methyl carbamoyl-substituted Arg side chain is achieved via derivatisation of a selectively protected Orn residue, prior to cleavage from the resin and side-chain deprotection. A severe aspartimide side-reaction observed upon final deprotection is circumvented by the use of a novel aqueous acidolysis procedure. The flexibility of the synthesis is demonstrated by the preparation of a series of argifin analogues designed from the X-ray structure of the natural product in complex with a representative family 18 chitinase.
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Affiliation(s)
- Mark J. Dixon
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, , Claverton Down, Bath, BA2 7AY, UK. ; Fax: ++ 44 01225 386114
| | - Amit Nathubhai
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, , Claverton Down, Bath, BA2 7AY, UK. ; Fax: ++ 44 01225 386114
| | - Ole A. Andersen
- Division of Molecular and Environmental Microbiology, University of Dundee, Dundee, DD1 5EH, UK
| | - Daan M. F. van Aalten
- Division of Molecular and Environmental Microbiology, University of Dundee, Dundee, DD1 5EH, UK
| | - Ian M. Eggleston
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, , Claverton Down, Bath, BA2 7AY, UK. ; Fax: ++ 44 01225 386114
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Chitinase is stored and secreted from the inner body of microfilariae and has a role in exsheathment in the parasitic nematode Brugia malayi. Mol Biochem Parasitol 2008; 161:55-62. [PMID: 18611418 PMCID: PMC2577134 DOI: 10.1016/j.molbiopara.2008.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 06/09/2008] [Accepted: 06/10/2008] [Indexed: 11/23/2022]
Abstract
Chitinase expression in microfilariae of the parasitic nematode Brugia malayi (B. malayi, Bm) is coincidental with the onset of their infectivity to mosquitoes. An antibody raised to Onchocerca volvulus (O. volvulus, Ov) infective-stage larval chitinase (Ov-CHI-1) was specifically reactive against B. malayi microfilarial chitinase and was used to study the localization of chitinase in B. malayi during microfilarial development and transmission to the insect vector. Immuno-electron microscopy (IEM) was used to demonstrate that the chitinase was confined to the inner body of the microfilariae and furthermore that chitinase was only present in sheathed microfilarial species, although the inner body is present in all species. Observation using the IEM implicates two distinct routes of chitinase secretion from the inner body, via either the pharyngeal thread, or during transmission of the microfilariae to the vector, contained in vesicle-like structures. Many morphological studies have described the structure of the inner body, but no function has been assigned to it as of yet. Although it has been commented that the cells surrounding the inner body and pharyngeal thread are those destined to become the intestine and pharynx and that the inner body represents a store of material. Our studies suggest that chitinase is one such product stored in the inner body and that it is secreted during the exsheathment of the microfilaria in the mosquito.
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Andersen OA, Nathubhai A, Dixon MJ, Eggleston IM, van Aalten DMF. Structure-based dissection of the natural product cyclopentapeptide chitinase inhibitor argifin. ACTA ACUST UNITED AC 2008; 15:295-301. [PMID: 18355729 PMCID: PMC3764403 DOI: 10.1016/j.chembiol.2008.02.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 01/30/2008] [Accepted: 02/05/2008] [Indexed: 11/30/2022]
Abstract
Chitinase inhibitors have chemotherapeutic potential as fungicides, pesticides, and antiasthmatics. Argifin, a natural product cyclopentapeptide, competitively inhibits family 18 chitinases in the nanomolar to micromolar range and shows extensive substrate mimicry. In an attempt to map the active fragments of this large natural product, the cyclopentapeptide was progressively dissected down to four linear peptides and dimethylguanylurea, synthesized using a combination of solution and solid phase peptide synthesis. The peptide fragments inhibit chitinase B1 from Aspergillus fumigatus (AfChiB1), the human chitotriosidase, and chitinase activity in lung homogenates from a murine model of chronic asthma, with potencies ranging from high nanomolar to high micromolar inhibition. X-ray crystallographic analysis of the chitinase-inhibitor complexes revealed that the conformations of the linear peptides were remarkably similar to that of the natural product. Strikingly, the dimethylguanylurea fragment, representing only a quarter of the natural product mass, was found to harbor all significant interactions with the protein and binds with unusually high efficiency. The data provide useful information that could lead to the generation of drug-like, natural product-based chitinase inhibitors.
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Affiliation(s)
- Ole A Andersen
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
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Maruyama R, Velarde NV, Klancer R, Gordon S, Kadandale P, Parry JM, Hang JS, Rubin J, Stewart-Michaelis A, Schweinsberg P, Grant BD, Piano F, Sugimoto A, Singson A. EGG-3 regulates cell-surface and cortex rearrangements during egg activation in Caenorhabditis elegans. Curr Biol 2007; 17:1555-60. [PMID: 17869112 DOI: 10.1016/j.cub.2007.08.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 08/02/2007] [Accepted: 08/03/2007] [Indexed: 01/20/2023]
Abstract
Fertilization triggers egg activation and converts the egg into a developing embryo. The events of this egg-to-embryo transition typically include the resumption of meiosis, the reorganization of the cortical actin cytoskeleton, and the remodeling of the oocyte surface. The factors that regulate sperm-dependent egg-activation events are not well understood. Caenorhabditis elegans EGG-3, a member of the protein tyrosine phosphatase-like (PTPL) family, is essential for regulating cell-surface and cortex rearrangements during egg activation in response to sperm entry. Although fertilization occurred normally in egg-3 mutants, the polarized dispersal of F-actin is altered, a chitin eggshell is not formed, and no polar bodies are produced. EGG-3 is associated with the oocyte plasma membrane in a pattern that is similar to CHS-1 and MBK-2. CHS-1 is required for eggshell deposition, whereas MBK-2 is required for the degradation of maternal proteins during the egg-to-embryo transition. The localization of CHS-1 and EGG-3 are interdependent and both genes were required for the proper localization of MBK-2 in oocytes. Therefore, EGG-3 plays a central role in egg activation by influencing polarized F-actin dynamics and the localization or activity of molecules that are directly involved in executing the egg-to-embryo transition.
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Affiliation(s)
- Rika Maruyama
- Waksman Institute, Department of Genetics, Rutgers University, Piscataway, New Jersey 08854, USA
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Kumar S, Chaudhary K, Foster JM, Novelli JF, Zhang Y, Wang S, Spiro D, Ghedin E, Carlow CKS. Mining predicted essential genes of Brugia malayi for nematode drug targets. PLoS One 2007; 2:e1189. [PMID: 18000556 PMCID: PMC2063515 DOI: 10.1371/journal.pone.0001189] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 10/25/2007] [Indexed: 12/02/2022] Open
Abstract
We report results from the first genome-wide application of a rational drug target selection methodology to a metazoan pathogen genome, the completed draft sequence of Brugia malayi, a parasitic nematode responsible for human lymphatic filariasis. More than 1.5 billion people worldwide are at risk of contracting lymphatic filariasis and onchocerciasis, a related filarial disease. Drug treatments for filariasis have not changed significantly in over 20 years, and with the risk of resistance rising, there is an urgent need for the development of new anti-filarial drug therapies. The recent publication of the draft genomic sequence for B. malayi enables a genome-wide search for new drug targets. However, there is no functional genomics data in B. malayi to guide the selection of potential drug targets. To circumvent this problem, we have utilized the free-living model nematode Caenorhabditis elegans as a surrogate for B. malayi. Sequence comparisons between the two genomes allow us to map C. elegans orthologs to B. malayi genes. Using these orthology mappings and by incorporating the extensive genomic and functional genomic data, including genome-wide RNAi screens, that already exist for C. elegans, we identify potentially essential genes in B. malayi. Further incorporation of human host genome sequence data and a custom algorithm for prioritization enables us to collect and rank nearly 600 drug target candidates. Previously identified potential drug targets cluster near the top of our prioritized list, lending credibility to our methodology. Over-represented Gene Ontology terms, predicted InterPro domains, and RNAi phenotypes of C. elegans orthologs associated with the potential target pool are identified. By virtue of the selection procedure, the potential B. malayi drug targets highlight components of key processes in nematode biology such as central metabolism, molting and regulation of gene expression.
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Affiliation(s)
- Sanjay Kumar
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
| | - Kshitiz Chaudhary
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
| | - Jeremy M. Foster
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
| | - Jacopo F. Novelli
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
| | - Yinhua Zhang
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
| | - Shiliang Wang
- The Institute for Genomic Research, Rockville, Maryland, United States of America
| | - David Spiro
- The Institute for Genomic Research, Rockville, Maryland, United States of America
| | - Elodie Ghedin
- The Institute for Genomic Research, Rockville, Maryland, United States of America
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Clotilde K. S. Carlow
- Division of Parasitology, New England Biolabs, Inc., Ipswich, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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15
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Suzuki M, Sakuda S, Nagasawa H. Identification of chitin in the prismatic layer of the shell and a chitin synthase gene from the Japanese pearl oyster, Pinctada fucata. Biosci Biotechnol Biochem 2007; 71:1735-44. [PMID: 17617722 DOI: 10.1271/bbb.70140] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The shell of the Japanese pearl oyster, Pinctada fucata, consists of two layers, the prismatic layer on the outside and the nacreous layer on the inside, both of which comprise calcium carbonate and organic matrices. Previous studies indicate that the nacreous organic matrix of the central layer of the framework surrounding the aragonite tablet is beta-chitin, but it remains unknown whether organic matrices in the prismatic layer contain chitin or not. In the present study, we identified chitin in the prismatic layer of the Japanese pearl oyster, Pinctada fucata, with a combination of Calcofluor White staining with IR and NMR spectral analyses. Furthermore, we cloned a cDNA encoding chitin synthase (PfCHS1) that produces chitin, contributing to the formation of the framework for calcification in the shell.
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Affiliation(s)
- Michio Suzuki
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
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Broeker K, Fehser S, Moerschbacher BM. Survey and expression analysis of five new chitin synthase genes in the biotrophic rust fungus Puccinia graminis. Curr Genet 2006; 50:295-305. [PMID: 16924501 DOI: 10.1007/s00294-006-0094-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Revised: 07/11/2006] [Accepted: 07/18/2006] [Indexed: 01/29/2023]
Abstract
We have isolated and characterised the first set of chitin synthase genes from a rust fungus, a large group of economically highly important, obligately biotrophic plant pathogens. Puccinia graminis was used as a model organism for the rust fungi which are not well investigated on the molecular level today. One of the major structural components of most fungal cell walls is the chitin polymer which is synthesised by a family of enzymes called chitin synthases. In P. graminis, we have isolated five new chitin synthase genes from four different classes, chsII, chsIIIa, chsIIIb, chsIV, and chsV. The genes contain a high number of introns, unusual for other known fungal chitin synthases. The dinucleic stage of the fungus seems to contain two slightly different genes or alleles for four isoforms. One isoform, chsIIIa, seems to be expressed only in the youngest stages of fungal growth. Analysis of the derived proteins shows that together with other basidiomycete CHS, the pgtCHS form separate subgroups in the phylogenetic tree. This set of five rust chitin synthase genes, with some unusual features compared to known fungal chitin synthases, allows new insights into chitin synthase classification, and may help in the development of novel functional fungicides.
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Affiliation(s)
- Katja Broeker
- Institut für Biochemie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
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Zhang Y, Foster JM, Nelson LS, Ma D, Carlow CKS. The chitin synthase genes chs-1 and chs-2 are essential for C. elegans development and responsible for chitin deposition in the eggshell and pharynx, respectively. Dev Biol 2006; 285:330-9. [PMID: 16098962 DOI: 10.1016/j.ydbio.2005.06.037] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 06/03/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
It is widely accepted that chitin is present in nematodes. However, its precise role in embryogenesis is unclear and it is unknown if chitin is necessary in other nematode tissues. Here, we determined the roles of chitin and the two predicted chitin synthase genes in Caenorhabditis elegans by chitin localization and gene disruption. Using a novel probe, we detected chitin in the eggshell and discovered elaborate chitin localization patterns in the pharyngeal lumen walls. Chitin deposition in these two sites is likely regulated by the activities of chs-1 (T25G3.2) and chs-2 (F48A11.1), respectively. Reducing chs-1 gene activity by RNAi led to eggs that were fragile and permeable to small molecules, and in the most severe case, absence of embryonic cell division. Complete loss of function in a chs-1 deletion resulted in embryos that lacked chitin in their eggshells and failed to divide. These results showed that eggshell chitin provides both mechanical support and chemical impermeability essential to developing embryos. Knocking down chs-2 by RNAi caused a defect in the pharynx and led to L1 larval arrest, indicating that chitin is involved in the development and function of the pharynx.
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Affiliation(s)
- Yinhua Zhang
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
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Arakane Y, Muthukrishnan S, Kramer KJ, Specht CA, Tomoyasu Y, Lorenzen MD, Kanost M, Beeman RW. The Tribolium chitin synthase genes TcCHS1 and TcCHS2 are specialized for synthesis of epidermal cuticle and midgut peritrophic matrix. INSECT MOLECULAR BIOLOGY 2005; 14:453-63. [PMID: 16164601 DOI: 10.1111/j.1365-2583.2005.00576.x] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Functional analysis of the two chitin synthase genes, TcCHS1 and TcCHS2, in the red flour beetle, Tribolium castaneum, revealed unique and complementary roles for each gene. TcCHS1-specific RNA interference (RNAi) disrupted all three types of moult (larval-larval, larval-pupal and pupal-adult) and greatly reduced whole-body chitin content. Exon-specific RNAi showed that splice variant 8a of TcCHS1 was required for both the larval-pupal and pupal-adult moults, whereas splice variant 8b was required only for the latter. TcCHS2-specific RNAi had no effect on metamorphosis or on total body chitin content. However, RNAi-mediated down-regulation of TcCHS2, but not TcCHS1, led to cessation of feeding, a dramatic shrinkage in larval size and reduced chitin content in the midgut.
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Affiliation(s)
- Y Arakane
- USDA-ARS-Grain Marketing and Production Research Center, Manhattan, KS 66502, USA
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Foster JM, Zhang Y, Kumar S, Carlow CKS. Parasitic nematodes have two distinct chitin synthases. Mol Biochem Parasitol 2005; 142:126-32. [PMID: 15869814 DOI: 10.1016/j.molbiopara.2005.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Accepted: 03/22/2005] [Indexed: 10/25/2022]
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Hogenkamp DG, Arakane Y, Zimoch L, Merzendorfer H, Kramer KJ, Beeman RW, Kanost MR, Specht CA, Muthukrishnan S. Chitin synthase genes in Manduca sexta: characterization of a gut-specific transcript and differential tissue expression of alternately spliced mRNAs during development. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:529-540. [PMID: 15857759 DOI: 10.1016/j.ibmb.2005.01.016] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Revised: 01/24/2005] [Accepted: 01/26/2005] [Indexed: 05/24/2023]
Abstract
Chitin, the linear homopolymer of beta-1,4-linked N-acetylglucosamine, is produced by the enzyme chitin synthase (CHS). In general, this insoluble polysaccharide is found in two major extracellular structures in insects, the cuticle that overlays the epidermis and the peritrophic membrane (PM) that lines the midgut. Based on amino acid sequence similarities, insect CHSs are divided into two classes, A and B, and to date no more than two CHS genes have been identified in any single insect species. In species where both CHSs have been identified, one class A CHS and one class B CHS are always present. This finding suggests that these two genes may encode enzymes that synthesize chitin in different epithelial tissues. In our laboratory, we previously characterized transcripts for a class A CHS gene (MsCHS1) from the tobacco hornworm, Manduca sexta. We observed the expression of this gene in the larval epidermis, suggesting that the encoded enzyme functions to synthesize cuticular chitin. In this paper, we characterize a second chitin synthase gene (MsCHS2) belonging to class B and its cDNA from Manduca and show that it is expressed only in the midgut. This cDNA contains an open reading frame of 4575 nucleotides, which encodes a conceptual protein that is 1524 amino acids in length and is predicted to contain 16 transmembrane spans. Northern blot analysis of RNA isolated from anterior, medial, and posterior sections of the midgut from feeding larvae indicate that MsCHS2 is primarily expressed in the anterior midgut, with transcript levels tapering off in the medial and posterior midgut. Analysis of the MsCHS2 gene sequence indicates the absence of an alternate exon in contrast to the MsCHS1 gene, which yields two transcripts, MsCHS1a and MsCHS1b. RT-PCR analysis of the differential expression of these alternately spliced transcripts reveals that both splice variants are present in the epidermis. However, the ratio of the two alternately spliced transcripts varies during development, with MsCHS1a being generally more predominant. Southern blot analysis using a probe specific for CHS indicated that Manduca has only two CHS genes, akin to other insect species. Results from an analysis of expression of both genes in different tissues and developmental times indicate that the MsCHS1 enzyme is used for the synthesis of chitin in the cuticle and tracheae, whereas MsCHS2 is utilized exclusively for the synthesis of PM-associated chitin in the midgut.
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Affiliation(s)
- David G Hogenkamp
- Department of Biochemistry, Kansas State University, 104 Willard Hall, Manhattan, Kansas 66506, USA
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Abstract
Expressed sequence tag projects have currently produced over 400 000 partial gene sequences from more than 30 nematode species and the full genomic sequences of selected nematodes are being determined. In addition, functional analyses in the model nematode Caenorhabditis elegans have addressed the role of almost all genes predicted by the genome sequence. This recent explosion in the amount of available nematode DNA sequences, coupled with new gene function data, provides an unprecedented opportunity to identify pre-validated drug targets through efficient mining of nematode genomic databases. This article describes the various information sources available and strategies that can expedite this process.
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Affiliation(s)
- Jeremy M Foster
- Molecular Parasitology, New England Biolabs, 32 Tozer Road, Beverly, MA 01915, USA
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Arakane Y, Hogenkamp DG, Zhu YC, Kramer KJ, Specht CA, Beeman RW, Kanost MR, Muthukrishnan S. Characterization of two chitin synthase genes of the red flour beetle, Tribolium castaneum, and alternate exon usage in one of the genes during development. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:291-304. [PMID: 14871625 DOI: 10.1016/j.ibmb.2003.11.004] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2003] [Revised: 11/06/2003] [Accepted: 11/06/2003] [Indexed: 05/24/2023]
Abstract
Two chitin synthase (CHS) genes of the red flour beetle, Tribolium castaneum, were sequenced and their transcription patterns during development examined. By screening a BAC library of genomic DNA from T. castaneum (Tc) with a DNA probe encoding the catalytic domain of a putative Tribolium CHS, several clones that contained CHS genes were identified. Two distinct PCR products were amplified from these BAC clones and confirmed to be highly similar to CHS genes from other insects, nematodes and fungi. The DNA sequences of these genes, TcCHS1 and TcCHS2, were determined by amplification of overlapping PCR fragments from two of the BAC DNAs and mapped to different linkage groups. Each ORF was identified and full-length cDNAs were also amplified, cloned and sequenced. TcCHS1 and TcCHS2 encode transmembrane proteins of 1558 and 1464 amino acids, respectively. The TcCHS1 gene was found to use alternate exons, each encoding 59 amino acids, a feature not found in the TcCHS2 gene. During development, Tribolium expressed TcCHS1 predominantly in the embryonic and pupal stages, whereas TcCHS2 was prevalent in the late larval and adult stages. The alternate exon 8a of TcCHS1 was utilized over a much broader range of development than exon 8b. We propose that the two isoforms of the TcCHS1 enzyme are used predominantly for the formation of chitin in embryonic and pupal cuticles, whereas TcCHS2 is utilized primarily for the synthesis of peritrophic membrane-associated chitin in the midgut.
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Affiliation(s)
- Yasuyuki Arakane
- Grain Marketing and Production Research Center, ARS-USDA, 1515 College Avenue, Manhattan, KS 66502, USA
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Zhu YC, Specht CA, Dittmer NT, Muthukrishnan S, Kanost MR, Kramer KJ. Sequence of a cDNA and expression of the gene encoding a putative epidermal chitin synthase of Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2002; 32:1497-1506. [PMID: 12530217 DOI: 10.1016/s0965-1748(02)00070-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Glycosyltransferases are enzymes that synthesize oligosaccharides, polysaccharides and glycoconjugates. One type of glycosyltransferase is chitin synthase, a very important enzyme in biology, which is utilized by insects, fungi, and other invertebrates to produce chitin, a polysaccharide of beta-1,4-linked N-acetylglucosamine. Chitin is an important component of the insect's exoskeletal cuticle and gut lining. To identify and characterize a chitin synthase gene of the tobacco hornworm, Manduca sexta, degenerate primers were designed from two highly conserved regions in fungal and nematode chitin synthase protein sequences and then used to amplify a similar region from Manduca cDNA. A full-length cDNA of 5152 nucleotides was assembled for the putative Manduca chitin synthase gene, MsCHS1, and sequencing of genomic DNA verified the contiguity of the sequence. The MsCHS1 cDNA has an ORF of 4692 nucleotides that encodes a transmembrane protein of 1564 amino acid residues with a mass of approximately 179 kDa (GenBank no. AY062175). It is most similar, over its entire length of protein sequence, to putative chitin synthases from other insects and nematodes, with 68% identity to enzymes from both the blow fly, Lucilia cuprina, and the fruit fly, Drosophila melanogaster. The similarity with fungal chitin synthases is restricted to the putative catalytic domain, and the MsCHS1 protein has, at equivalent positions, several amino acids that are essential for activity as revealed by mutagenesis of the fungal enzymes. A 5.3-kb transcript of MsCHS1 was identified by northern blot hybridization of RNA from larval epidermis, suggesting that the enzyme functions to make chitin deposited in the cuticle. Further examination by RT-PCR showed that MsCHS1 expression is regulated in the epidermis, with the amount of transcript increasing during phases of cuticle deposition.
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Affiliation(s)
- Yu-Cheng Zhu
- Grain Marketing and Production Research Center, ARS-USDA, 1515 College Avenue, Manhattan, KS 66502, USA
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Harris MT, Fuhrman JA. Structure and expression of chitin synthase in the parasitic nematode Dirofilaria immitis. Mol Biochem Parasitol 2002; 122:231-4. [PMID: 12106879 DOI: 10.1016/s0166-6851(02)00102-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Although lymphatic filariasis remains among the major causes of disability among the tropical infectious diseases, dramatic advances have been made in the approach to its diagnosis, epidemiology and treatment, in our understanding of the molecular composition of the parasites that cause these infections, and in the factors underlying the pathology seen. Superimposing the tools of modern epidemiology, immunology, and molecular biology on field-based clinical trials has allowed the emergence of the concept of elimination of lymphatic filariasis. Much of the important new research emphasizes parasite development in the context of the host response, the importance of both the adult worm and other factors in the pathogenesis of lymphatic filarial disease, the role the Wolbachia endosymbiont holds as both a target for drug treatment and in inducing post-treatment reactions, and the various principles underlying the implementation of control programs.
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Affiliation(s)
- T B Nutman
- Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0425, USA.
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