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Choudhary S, Abongwa M, Kashyap SS, Verma S, Mair GR, Kulke D, Martin RJ, Robertson AP. Nodulisporic acid produces direct activation and positive allosteric modulation of AVR-14B, a glutamate-gated chloride channel from adult Brugia malayi. Proc Natl Acad Sci U S A 2022; 119:e2111932119. [PMID: 35969762 PMCID: PMC9407656 DOI: 10.1073/pnas.2111932119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
Glutamate-gated chloride channels (GluCls) are unique to invertebrates and are targeted by macrocyclic lactones. In this study, we cloned an AVR-14B GluCl subunit from adult Brugia malayi, a causative agent of lymphatic filariasis in humans. To elucidate this channel's pharmacological properties, we used Xenopus laevis oocytes for expression and performed two-electrode voltage-clamp electrophysiology. The receptor was gated by the natural ligand L-glutamate (effective concentration, 50% [EC50] = 0.4 mM) and ivermectin (IVM; EC50 = 1.8 nM). We also characterized the effects of nodulisporic acid (NA) on Bma-AVR-14B and NA-produced dual effects on the receptor as an agonist and a type II positive allosteric modulator. Here we report characterization of the complex activity of NA on a nematode GluCl. Bma-AVR-14B demonstrated some unique pharmacological characteristics. IVM did not produce potentiation of L-glutamate-mediated responses but instead, reduced the channel's sensitivity for the ligand. Further electrophysiological exploration showed that IVM (at a moderate concentration of 0.1 nM) functioned as an inhibitor of both agonist and positive allosteric modulatory effects of NA. This suggests that IVM and NA share a complex interaction. The pharmacological properties of Bma-AVR-14B indicate that the channel is an important target of IVM and NA. In addition, the unique electrophysiological characteristics of Bma-AVR-14B could explain the observed variation in drug sensitivities of various nematode parasites. We have also shown the inhibitory effects of IVM and NA on adult worm motility using Worminator. RNA interference (RNAi) knockdown suggests that AVR-14 plays a role in influencing locomotion in B. malayi.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Melanie Abongwa
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Sudhanva S. Kashyap
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Saurabh Verma
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Gunnar R. Mair
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Daniel Kulke
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Richard J. Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Alan P. Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
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Ricciardi A, Bennuru S, Tariq S, Kaur S, Wu W, Elkahloun AG, Arakelyan A, Shaik J, Dorward DW, Nutman TB, Tolouei Semnani R. Extracellular vesicles released from the filarial parasite Brugia malayi downregulate the host mTOR pathway. PLoS Negl Trop Dis 2021; 15:e0008884. [PMID: 33411714 PMCID: PMC7790274 DOI: 10.1371/journal.pntd.0008884] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022] Open
Abstract
We have previously shown that the microfilarial (mf) stage of Brugia malayi can inhibit the mammalian target of rapamycin (mTOR; a conserved serine/threonine kinase critical for immune regulation and cellular growth) in human dendritic cells (DC) and we have proposed that this mTOR inhibition is associated with the DC dysfunction seen in filarial infections. Extracellular vesicles (EVs) contain many proteins and nucleic acids including microRNAs (miRNAs) that might affect a variety of intracellular pathways. Thus, EVs secreted from mf may elucidate the mechanism by which the parasite is able to modulate the host immune response during infection. EVs, purified from mf of Brugia malayi and confirmed by size through nanoparticle tracking analysis, were assessed by miRNA microarrays (accession number GSE157226) and shown to be enriched (>2-fold, p-value<0.05, FDR = 0.05) for miR100, miR71, miR34, and miR7. The microarray analysis compared mf-derived EVs and mf supernatant. After confirming their presence in EVs using qPCR for these miRNA targets, web-based target predictions (using MIRPathv3, TarBAse and MicroT-CD) predicted that miR100 targeted mTOR and its downstream regulatory protein 4E-BP1. Our previous data with live parasites demonstrated that mf downregulate the phosphorylation of mTOR and its downstream effectors. Additionally, our proteomic analysis of the mf-derived EVs revealed the presence of proteins commonly found in these vesicles (data are available via ProteomeXchange with identifier PXD021844). We confirmed internalization of mf-derived EVs by human DCs and monocytes using confocal microscopy and flow cytometry, and further demonstrated through flow cytometry, that mf-derived EVs downregulate the phosphorylation of mTOR in human monocytes (THP-1 cells) to the same degree that rapamycin (a known mTOR inhibitor) does. Our data collectively suggest that mf release EVs that interact with host cells, such as DC, to modulate host responses. Lymphatic filariasis, a neglected tropical disease caused by parasitic worms which affects millions of individuals, represents an important public health concern due to its high morbidity that significantly diminishes quality of life. The parasite is able to establish a chronic infection by manipulating its host’s immune responses. The larval mf stage of the parasite is of particular interest as the parasites are present in the peripheral blood and in constant contact with the host’s immune cells. We decided to investigate the role of mf-derived EVs in the modulation of human antigen presenting cells during infection. We showed that mf release EVs that are similar to exosomes, and these parasite vesicles are readily internalized by human DC. The mf-derived EVs possess a unique miRNA profile and are enriched in miRNAs that can target the mTOR pathway. We have also demonstrated that purified mf-derived EVs are capable of inhibiting mTOR signaling in human monocytes. Collectively, our results suggest that mf release exosome-like vesicles that modulate the immune metabolism of host antigen presenting cells.
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Affiliation(s)
- Alessandra Ricciardi
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
- * E-mail:
| | - Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Sameha Tariq
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Sukhbir Kaur
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, United States of America
| | - Weiwei Wu
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, United States of America
| | - Abdel G. Elkahloun
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, United States of America
| | - Anush Arakelyan
- Section of Intracellular Interactions, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, United States of America
| | - Jahangheer Shaik
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - David W. Dorward
- RML Microscopy Unit, RML Research Technologies Section, National Institute of Allergy and Infectious Diseases, NIH, Hamilton, Montana, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Roshanak Tolouei Semnani
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
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Hertz MI, Glaessner PM, Rush A, Budge PJ. Brugia malayi galectin 2 is a tandem-repeat type galectin capable of binding mammalian polysaccharides. Mol Biochem Parasitol 2019; 235:111233. [PMID: 31738955 DOI: 10.1016/j.molbiopara.2019.111233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/13/2022]
Abstract
Galectins are among the most abundant excretory/secretory (ES) products of filarial worms, but their role in filarial biology is poorly understood. Galectin-2 (Lec-2), a major component of Brugia malayi extracellular vesicles, is released by filarial worms, and was recently identified in the serum of persons with loiasis. We therefore sought to clone and characterize Lec-2, and to develop reagents to examine its potential as a biomarker and its role in parasite biology. We cloned and expressed recombinant B. malayi Lec-2 (rBmLec-2), generated a Lec-2-specific monoclonal antibody (4B4), and used it to confirm the presence of Lec-2 in B. malayi ES products and whole worm lysate. We show that Lec-2 is absent in B. malayi oocytes, and increases in concentration as embryos mature. Recombinant BmLec-2 hemagglutinates rabbit red blood cells at concentrations less than 1 μg/mL, and this is abrogated by single amino acid substitutions in the predicted carbohydrate recognition domains. rBmLec-2 binds multiple LacNAc oligosaccharides on a mammalian carbohydrate array. Sera from 17/23 (78 %) persons with microfilaremic loiasis and 4/10 (40 %) persons with bancroftian filariasis had detectable antibody to Lec-2 by western blot. Our studies confirm the functionality of BmLec-2 and indicate anti-Lec-2 antibody responses are common in persons with filariasis. These studies set the stage for further examination of the role of Lec-2 in filarial biology and in filarial-host interactions.
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Affiliation(s)
- Marla I Hertz
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States.
| | - Philip M Glaessner
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Amy Rush
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Philip J Budge
- Infectious Diseases Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
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Mersha FB, Cortes LK, Luck AN, McClung CM, Ruse CI, Taron CH, Foster JM. Computational and experimental analysis of the glycophosphatidylinositol-anchored proteome of the human parasitic nematode Brugia malayi. PLoS One 2019; 14:e0216849. [PMID: 31513600 PMCID: PMC6742230 DOI: 10.1371/journal.pone.0216849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/20/2019] [Indexed: 12/05/2022] Open
Abstract
Further characterization of essential systems in the parasitic filarial nematode Brugia malayi is needed to better understand its biology, its interaction with its hosts, and to identify critical components that can be exploited to develop novel treatments. The production of glycophosphatidylinositol-anchored proteins (GPI-APs) is essential for eukaryotic cellular and physiological function. In addition, GPI-APs perform many important roles for cells. In this study, we characterized the B. malayi GPI-anchored proteome using both computational and experimental approaches. We used bioinformatic strategies to show the presence or absence of B. malayi GPI-AP biosynthetic pathway genes and to compile a putative B. malayi GPI-AP proteome using available prediction programs. We verified these in silico analyses using proteomics to identify GPI-AP candidates prepared from the surface of intact worms and from membrane enriched extracts. Our study represents the first description of the GPI-anchored proteome in B. malayi and lays the groundwork for further exploration of this essential protein modification as a target for novel anthelmintic therapeutic strategies.
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Affiliation(s)
- Fana B. Mersha
- New England Biolabs, Ipswich MA, United States of America
| | | | - Ashley N. Luck
- New England Biolabs, Ipswich MA, United States of America
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Voronin D, Schnall E, Grote A, Jawahar S, Ali W, Unnasch TR, Ghedin E, Lustigman S. Pyruvate produced by Brugia spp. via glycolysis is essential for maintaining the mutualistic association between the parasite and its endosymbiont, Wolbachia. PLoS Pathog 2019; 15:e1008085. [PMID: 31568486 PMCID: PMC6791551 DOI: 10.1371/journal.ppat.1008085] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/14/2019] [Accepted: 09/16/2019] [Indexed: 01/01/2023] Open
Abstract
Human parasitic nematodes are the causative agents of lymphatic filariasis (elephantiasis) and onchocerciasis (river blindness), diseases that are endemic to more than 80 countries and that consistently rank in the top ten for the highest number of years lived with disability. These filarial nematodes have evolved an obligate mutualistic association with an intracellular bacterium, Wolbachia, a symbiont that is essential for the successful development, reproduction, and survival of adult filarial worms. Elimination of the bacteria causes adult worms to die, making Wolbachia a primary target for developing new interventional tools to combat filariases. To further explore Wolbachia as a promising indirect macrofilaricidal drug target, the essential cellular processes that define the symbiotic Wolbachia-host interactions need to be identified. Genomic analyses revealed that while filarial nematodes encode all the enzymes necessary for glycolysis, Wolbachia does not encode the genes for three glycolytic enzymes: hexokinase, 6-phosphofructokinase, and pyruvate kinase. These enzymes are necessary for converting glucose into pyruvate. Wolbachia, however, has the full complement of genes required for gluconeogenesis starting with pyruvate, and for energy metabolism via the tricarboxylic acid cycle. Therefore, we hypothesized that Wolbachia might depend on host glycolysis to maintain a mutualistic association with their parasitic host. We did conditional experiments in vitro that confirmed that glycolysis and its end-product, pyruvate, sustain this symbiotic relationship. Analysis of alternative sources of pyruvate within the worm indicated that the filarial lactate dehydrogenase could also regulate the local intracellular concentration of pyruvate in proximity to Wolbachia and thus help control bacterial growth via molecular interactions with the bacteria. Lastly, we have shown that the parasite's pyruvate kinase, the enzyme that performs the last step in glycolysis, could be a potential novel anti-filarial drug target. Establishing that glycolysis is an essential component of symbiosis in filarial worms could have a broader impact on research focused on other intracellular bacteria-host interactions where the role of glycolysis in supporting intracellular survival of bacteria has been reported.
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Affiliation(s)
- Denis Voronin
- Molecular Parasitology, New York Blood Center, New York, New York, United States of America
| | - Emily Schnall
- Molecular Parasitology, New York Blood Center, New York, New York, United States of America
| | - Alexandra Grote
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Shabnam Jawahar
- Molecular Parasitology, New York Blood Center, New York, New York, United States of America
| | - Waleed Ali
- Molecular Parasitology, New York Blood Center, New York, New York, United States of America
| | - Thomas R. Unnasch
- Center for Global Health Infectious Disease Research, University of South Florida, College of Public Health, Tampa, Florida, United States of America
| | - Elodie Ghedin
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
- College of Global Public Health, New York University, New York, New York, United States of America
| | - Sara Lustigman
- Molecular Parasitology, New York Blood Center, New York, New York, United States of America
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Flynn AF, Joyce MG, Taylor RT, Bennuru S, Lindrose AR, Sterling SL, Morris CP, Nutman TB, Mitre E. Intestinal UDP-glucuronosyltransferase as a potential target for the treatment and prevention of lymphatic filariasis. PLoS Negl Trop Dis 2019; 13:e0007687. [PMID: 31513587 PMCID: PMC6742224 DOI: 10.1371/journal.pntd.0007687] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 08/05/2019] [Indexed: 11/19/2022] Open
Abstract
Lymphatic filariasis (LF), a morbid disease caused by the tissue-invasive nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori, affects millions of people worldwide. Global eradication efforts have significantly reduced worldwide prevalence, but complete elimination has been hampered by limitations of current anti-filarial drugs and the lack of a vaccine. The goal of this study was to evaluate B. malayi intestinal UDP-glucuronosyltransferase (Bm-UGT) as a potential therapeutic target. To evaluate whether Bm-UGT is essential for adult filarial worms, we inhibited its expression using siRNA. This resulted in a 75% knockdown of Bm-ugt mRNA for 6 days and almost complete suppression of detectable Bm-UGT by immunoblot. Reduction in Bm-UGT expression resulted in decreased worm motility for 6 days, 70% reduction in microfilaria release from adult worms, and significant reduction in adult worm metabolism as detected by MTT assays. Because prior allergic-sensitization to a filarial antigen would be a contraindication for its use as a vaccine candidate, we tested plasma from infected and endemic normal populations for Bm-UGT-specific IgE using a luciferase immunoprecipitation assay. All samples (n = 35) tested negative. We then tested two commercially available medicines known to be broad inhibitors of UGTs, sulfinpyrazone and probenecid, for in vitro activity against B. malayi. There were marked macrofilaricidal effects at concentrations achievable in humans and very little effect on microfilariae. In addition, we observed that probenecid and sulfinpyrazone exhibit a synergistic macrofilaricidal effect when used in combination with albendazole. The results of this study demonstrate that Bm-UGT is an essential protein for adult worm survival. Lack of prior IgE sensitization in infected and endemic populations suggest it may be a feasible vaccine candidate. The finding that sulfinpyrazone and probenecid have in vitro effects against adult B. malayi worms suggests that these medications have promise as potential macrofilaricides in humans.
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Affiliation(s)
- Alexander F. Flynn
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - M. Gordon Joyce
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, United States of America
| | - Rebekah T. Taylor
- Department of Biology, Frostburg State University, Frostburg, Maryland, United States of America
| | - Sasisekhar Bennuru
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alyssa R. Lindrose
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Spencer L. Sterling
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - C. Paul Morris
- Department of Pathology, Johns Hopkins Hospital, Baltimore Maryland, United States of America
| | - Thomas B. Nutman
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Edward Mitre
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
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Ballesteros C, Geary JF, Mackenzie CD, Geary TG. Characterization of Divalent Metal Transporter 1 (DMT1) in Brugia malayi suggests an intestinal-associated pathway for iron absorption. Int J Parasitol Drugs Drug Resist 2018; 8:341-349. [PMID: 29957332 PMCID: PMC6038845 DOI: 10.1016/j.ijpddr.2018.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 01/12/2023]
Abstract
Lymphatic filariasis and onchocerciasis are neglected parasitic diseases which pose a threat to public health in tropical and sub-tropical regions. Strategies for control and elimination of these diseases by mass drug administration (MDA) campaigns are designed to reduce symptoms of onchocerciasis and transmission of both parasites to eventually eliminate the burden on public health. Drugs used for MDA are predominantly microfilaricidal, and prolonged rounds of treatment are required for eradication. Understanding parasite biology is crucial to unravelling the complex processes involved in host-parasite interactions, disease transmission, parasite immune evasion, and the emergence of drug resistance. In nematode biology, large gaps still exist in our understanding of iron metabolism, iron-dependent processes and their regulation. The acquisition of iron from the host is a crucial determinant of the success of a parasitic infection. Here we identify a filarial ortholog of Divalent Metal Transporter 1 (DMT1), a member of a highly conserved family of NRAMP proteins that play an essential role in the transport of ferrous iron in many species. We cloned and expressed the B. malayi NRAMP ortholog in the iron-deficient fet3fet4 strain of Saccharomyces cerevisiae, performed qPCR to estimate stage-specific expression, and localized expression of this gene by immunohistochemistry. Results from functional iron uptake assays showed that expression of this gene in the iron transport-deficient yeast strain significantly rescued growth in low-iron medium. DMT1 was highly expressed in adult female and male B. malayi and Onchocerca volvulus. Immunolocalization revealed that DMT1 is expressed in the intestinal brush border, lateral chords, and reproductive tissues of males and females, areas also inhabited by Wolbachia. We hypothesize based on our results that DMT1 in B. malayi functions as an iron transporter. The presence of this transporter in the intestine supports the hypothesis that iron acquisition by adult females requires oral ingestion and suggests that the intestine plays a functional role in at least some aspects of nutrient uptake.
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Affiliation(s)
- Cristina Ballesteros
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - James F Geary
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Charles D Mackenzie
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Timothy G Geary
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
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Liu C, Mhashilkar AS, Chabanon J, Xu S, Lustigman S, Adams JH, Unnasch TR. Development of a toolkit for piggyBac-mediated integrative transfection of the human filarial parasite Brugia malayi. PLoS Negl Trop Dis 2018; 12:e0006509. [PMID: 29782496 PMCID: PMC5983866 DOI: 10.1371/journal.pntd.0006509] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/01/2018] [Accepted: 05/08/2018] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The human filarial parasites cause diseases that are among the most important causes of morbidity in the developing world. The elimination programs targeting these infections rely on a limited number of drugs, making the identification of new chemotherapeutic agents a high priority. The study of these parasites has lagged due to the lack of reverse genetic methods. METHODOLOGY/PRINCIPAL FINDINGS We report a novel co-culture method that results in developmentally competent infective larvae of one of the human filarial parasites (Brugia malayi) and describe a method to efficiently transfect the larval stages of this parasite. We describe the production of constructs that result in integrative transfection using the piggyBac transposon system, and a selectable marker that can be used to identify transgenic parasites. We describe the production and use of dual reporter plasmids containing both a secreted luciferase selectable marker and fluorescent protein reporters that will be useful to study temporal and spatial patterns of gene expression. CONCLUSIONS/SIGNIFICANCE The methods and constructs reported here will permit the efficient production of integrated transgenic filarial parasite lines, allowing reverse genetic technologies to be applied to all life cycle stages of the parasite.
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Affiliation(s)
- Canhui Liu
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
| | - Amruta S. Mhashilkar
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
| | - Johan Chabanon
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
| | - Shulin Xu
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
| | - Sara Lustigman
- Molecular Parasitology, New York Blood Center, New York, NY, United States of America
| | - John H. Adams
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
| | - Thomas R. Unnasch
- Center for Global Health Infectious Disease Research, Department of Global Health, University of South Florida, Tampa, FL, United States of America
- * E-mail:
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9
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Venugopal G, Mueller M, Hartmann S, Steinfelder S. Differential immunomodulation in human monocytes versus macrophages by filarial cystatin. PLoS One 2017; 12:e0188138. [PMID: 29141050 PMCID: PMC5687743 DOI: 10.1371/journal.pone.0188138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 11/01/2017] [Indexed: 12/19/2022] Open
Abstract
Parasitic nematodes have evolved powerful immunomodulatory molecules to enable their survival in immunocompetent hosts by subverting immune responses and minimizing pathological processes. One filarial molecule known to counteract host immune responses by inducing IL-10 and regulatory macrophages in mice is filarial cystatin. During a patent filarial infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive. The microfilarial larval stage was formerly shown to induce human regulatory monocytes and macrophages. Thus, here we aim was to determine how filarial cystatin of the human pathogenic filaria Brugia malayi (BmCPI-2) contributes to immune hyporesponsiveness in human monocytes and macrophages elicited by microfilaria. For this purpose, filarial cystatin was depleted from microfilarial lysate (Mf). Detecting the immunomodulatory potential of cystatin-depleted Mf revealed that IL-10, but not IL-8 and IL-6 induction in monocytes and macrophages is dependent on the presence of cystatin. In addition, the Mf-induced expression of the regulatory surface markers PD-L1 and PD-L2 in human monocytes, but not in macrophages, is dependent on cystatin. While Mf-treated monocytes result in decreased CD4+ T-cell proliferation in a co-culture assay, stimulation of T-cells with human monocytes treated with cystatin-depleted Mf lead to a restoration of CD4+ T-cell proliferation. Moreover, IL-10 induction by cystatin within Mf was dependent on p38 and ERK in macrophages, but independent of the ERK pathway in monocytes. These findings indicate that filarial nematodes differentially trigger and exploit various signaling pathways to induce immunomodulation in different myeloid cell subsets.
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Affiliation(s)
- Gopinath Venugopal
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
| | - Marion Mueller
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
| | - Susanne Hartmann
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
| | - Svenja Steinfelder
- Institute of Immunology, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany
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Verma SK, Arora A, Murthy PK. Recombinant Calponin of human filariid Brugia malayi: Secondary structure and immunoprophylactic potential. Vaccine 2017; 35:5201-5208. [PMID: 28789852 DOI: 10.1016/j.vaccine.2017.07.105] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/09/2017] [Accepted: 07/27/2017] [Indexed: 11/29/2022]
Abstract
In the search for potential vaccine candidates for the control of human lymphatic filariasis, we recently identified calponin-like protein, that regulates actin/myosin interactions, in a proinflammatory fraction F8 (45.24-48.64kDa) of Brugia malayi adult worms. In the present study, the gene was cloned, expressed, and the recombinant Calponin of B. malayi (r-ClpBm) was prepared and characterized. r-ClpBm bears homology with OV9M of Onchocerca volvulus, a non-lymphatic filariid that causes loss of vision and cutaneous pathology. r-ClpBm was found to be a ∼45kDa protein that folds into a predominantly α-helix conformation. The protective efficacy of r-ClpBm against B. malayi infection in Mastomys coucha was investigated by assessing the course of microfilaraemia and adult worm burden in the host immunized with r-ClpBm and subsequently infected with infective third stage larvae (L3). Expression of the Calponin was detected in all life stages (microfilariae, L3, L4, L5 and adults) of the parasite and immunization with r-ClpBm partially protected M. coucha against establishment of infection as inferred by ∼42% inhibition in parasite burden. Upregulated cellular proliferation, TNF-α, IFN-γ, IL-1β, IL-4, nitric oxide (NO) release, expression of iNOS, and specific IgG, IgG1 and IgG2b in immunized animals correlated with parasitological findings. r-ClpBm immunization caused degranulation in majority of mast cells indicating possible involvement of mast cell products in reducing the parasite survival. It appears that complex mechanisms including Th1, Th2, NO and mast cells are involved in the clearance of infection. To the best of our knowledge this is the first report on cloning, expression of the gene and purification of r-ClpBm, determination of its secondary structure and its ability to partially prevent establishment of B. malayi infection. Thus, r-ClpBm may further be studied and developed in combination with other protective molecules of B. malayi as a component of potential filarial cocktail vaccine candidate.
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Affiliation(s)
- Shiv K Verma
- Division of Parasitology, CSIR-Central Drug Research Institute, New Campus, BS 10/1, Sector 10, Jankipuram Extension, Lucknow 226 031, India.
| | - Ashish Arora
- Division of Molecular and Structural Biology, CSIR-Central Drug Research Institute, New Campus, BS 10/1, Sector 10, Jankipuram Extension, Lucknow 226 031, India
| | - P Kalpana Murthy
- Division of Parasitology, CSIR-Central Drug Research Institute, New Campus, BS 10/1, Sector 10, Jankipuram Extension, Lucknow 226 031, India.
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Verma S, Kashyap SS, Robertson AP, Martin RJ. Functional genomics in Brugia malayi reveal diverse muscle nAChRs and differences between cholinergic anthelmintics. Proc Natl Acad Sci U S A 2017; 114:5539-5544. [PMID: 28487481 PMCID: PMC5448196 DOI: 10.1073/pnas.1619820114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many techniques for studying functional genomics of important target sites of anthelmintics have been restricted to Caenorhabditis elegans because they have failed when applied to animal parasites. To overcome these limitations, we have focused our research on the human nematode parasite Brugia malayi, which causes elephantiasis. Here, we combine single-cell PCR, whole muscle cell patch clamp, motility phenotyping (Worminator), and dsRNA for RNAi for functional genomic studies that have revealed, in vivo, four different muscle nAChRs (M-, L-, P-, and N-). The cholinergic anthelmintics had different selectivities for these receptors. We show that motility and patch-clamp responses to levamisole and pyrantel, but not morantel or nicotine, require the unc-38 and/or unc-29 genes. Derquantel behaved as a competitive antagonist and distinguished M-nAChRs activated by morantel (Kb 13.9 nM), P-nAChRs activated by pyrantel (Kb 126 nM), and L-nAChRs activated by levamisole (Kb 0.96 µM) and bephenium. Derquantel was a noncompetitive antagonist of nicotine, revealing N-type nAChRs. The presence of four diverse nAChRs on muscle is perhaps surprising and not predicted from the C. elegans model. The diverse nAChRs represent distinguishable drug targets with different functions: Knockdown of unc-38+unc-29 (L- and/or P-receptors) inhibited motility but knockdown of acr-16+acr-26 (M- and/or N-receptors) did not.
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Affiliation(s)
- Saurabh Verma
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011
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Farghaly AM, Abd El-Hai Afify H, Abd El-Raouf Taha A, Mostafa E. DEVELOPMENT OF AN IN VITRO RNAI TO INVESTIGATE GENE FUNCTION IN BRUGIA MALAYI. J Egypt Soc Parasitol 2016; 46:717-728. [PMID: 30230767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The RNA interference (RNAi) has the ability to turn off individual gene expression. So, it affords a remarkably specific tool for studying the effects of genes. It is regarded as a direct approach for determining such gene/genes functions and offers a valuable tool for modern drug discovery. The study aimed to develop in vitro RNAil in Brugia malayi with particular interest to study the function of Brugia malayi avr-14 (Bm-avr-14) and Brugia malayi f-tubulin (Bm-fi-tubulin) genes. Bm-avr-14 is a gene encoding glutamate gated chloride channel (GluCl) which binds ivermectin and Bm-β-tubulin is a gene encoding β-tubulin which binds albendazole. Adult female worms were soaked in heterogeneous short interfering RNA (hsiRNA) with interest to study the role of two genes Bm-avr-14 and Bm-β-tubulin. Then, we assessed the knock down effects of target genes using worminator system and real time PCR. We found that worms treated with hsiRNA of Bm-avr-14 had a significant reduction in microfilariae (mf) production in comparison with untreated worms or worms treated with hsiRNA of green fluorescent protein (GFP). No significant reduction in mf production with Bm-β-tubulin gene was obtained. There were no changes in the movement of adults treated with either Bm-avr-14 or Bm- β-tubulin hsiRNAs. Inconsistent RNAi mediated suppression was achieved with Bm-avr-14 and Bm-β- tubulin using real time PCR. The data may be helpful in assessment of drug target potential of genes.
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Gupta J, Misra S, Misra-Bhattacharya S. Immunization with Brugia malayi Myosin as Heterologous DNA Prime Protein Boost Induces Protective Immunity against B. malayi Infection in Mastomys coucha. PLoS One 2016; 11:e0164991. [PMID: 27828973 PMCID: PMC5102438 DOI: 10.1371/journal.pone.0164991] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 10/04/2016] [Indexed: 12/12/2022] Open
Abstract
The current control strategies employing chemotherapy with diethylcarbamazine, ivermectin and albendazole have reduced transmission in some filaria-endemic areas, there is growing interest for complementary approaches, such as vaccines especially in light of threat of parasite developing resistance to mainstay drugs. We earlier demonstrated recombinant heavy chain myosin of B. malayi (Bm-Myo) as a potent vaccine candidate whose efficacy was enhanced by heterologous DNA prime/protein boost (Myo-pcD+Bm-Myo) vaccination in BALB/c mice. BALB/c mouse though does not support the full developmental cycle of B. malayi, however, the degree of protection may be studied in terms of transformation of challenged infective larvae (L3) to next stage (L4) with an ease of delineating the generated immunological response of host. In the current investigation, DNA vaccination with Bm-Myo was therefore undertaken in susceptible rodent host, Mastomys coucha (M. coucha) which sustains the challenged L3 and facilitates their further development to sexually mature adult parasites with patent microfilaraemia. Immunization schedule consisted of Myo-pcD and Myo-pcD+Bm-Myo followed by B. malayi L3 challenge and the degree of protection was evaluated by observing microfilaraemia as well as adult worm establishment. Myo-pcD+Bm-Myo immunized animals not only developed 78.5% reduced blood microfilarial density but also decreased adult worm establishment by 75.3%. In addition, 75.4% of the recovered live females revealed sterilization over those of respective control animals. Myo-pcD+Bm-Myo triggered higher production of specific IgG and its isotypes which induced marked cellular adhesion and cytotoxicity (ADCC) to microfilariae (mf) and L3 in vitro. Both Th1 and Th2 cytokines were significantly up-regulated displaying a mixed immune response conferring considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a potential vaccination method against LF.
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Affiliation(s)
- Jyoti Gupta
- Division of Parasitology, CSIR-Central Drug Research Institute, BS 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow-226031, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Sweta Misra
- Division of Parasitology, CSIR-Central Drug Research Institute, BS 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow-226031, India
- Academy of Scientific and Innovative Research, New Delhi, India
| | - Shailja Misra-Bhattacharya
- Division of Parasitology, CSIR-Central Drug Research Institute, BS 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow-226031, India
- Academy of Scientific and Innovative Research, New Delhi, India
- * E-mail: ;
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Khatri V, Amdare N, Yadav RS, Tarnekar A, Goswami K, Reddy MVR. Brugia malayi abundant larval transcript 2 protein treatment attenuates experimentally-induced colitis in mice. Indian J Exp Biol 2015; 53:732-739. [PMID: 26669016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Helminths are known to modulate host's immunity by suppressing host protective pro-inflammatory responses. Such immunomodulatory effects have been experimentally shown to have therapeutic implications in immune mediated disorders. In the present study, we have explored a filarial protein i.e. Brugia malayi recombinant abundant larval transcript 2 (rBmALT2) for its therapeutic effect in dextran sodium sulfate (DSS) induced colitis in mouse model. The immunomodulatory activity of rBmALT-2 was initially confirmed by demonstrating that it suppressed the lipopolysaccharide (LPS) induced nitric oxide synthesis and down-regulated the expression of pro-inflammatory cytokines in vitro by peritoneal exudate cells of mice. Treatment with rBmALT2 reduced severity of colitis associated with significant reduction in weight loss, disease activity, colon damage, mucosal edema and histopathological score including myeloperoxidase activity in colon tissues. rBmALT2 was comparatively more effective in attenuation of colitis when used in the preventive mode than when used for curative purpose. The therapeutic effect of rBmALT2 was found to be associated with downregulation of IFN-γ, IL-6, IL-17 and upregulation of IL-10 cytokines. These results provide strong experimental evidence that BmALT2 could be a potential alternative therapeutic agent in colitis.
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Zamanian M, Fraser LM, Agbedanu PN, Harischandra H, Moorhead AR, Day TA, Bartholomay LC, Kimber MJ. Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi. PLoS Negl Trop Dis 2015; 9:e0004069. [PMID: 26401956 PMCID: PMC4581865 DOI: 10.1371/journal.pntd.0004069] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/18/2015] [Indexed: 01/28/2023] Open
Abstract
Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30-120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed new therapeutic strategies and unearth stage-specific diagnostic biomarkers.
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Affiliation(s)
- Mostafa Zamanian
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Lisa M Fraser
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Prince N Agbedanu
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Hiruni Harischandra
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Andrew R Moorhead
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Tim A Day
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Lyric C Bartholomay
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michael J Kimber
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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16
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Abstract
Acetylcholine receptors (AChRs) are required for body movement in parasitic nematodes and are targets of “classical” anthelmintic drugs such as levamisole and pyrantel and of newer drugs such as tribendimidine and derquantel. While neurotransmission explains the effects of these drugs on nematode movement, their effects on parasite reproduction are unexplained. The levamisole AChR type (L-AChRs) in Caenorhabditis elegans is comprised of five subunits: Cel-UNC-29, Cel-UNC-38, Cel-UNC-63, Cel-LEV-1 and Cel-LEV-8. The genome of the filarial parasite Brugia malayi contains nine AChRs subunits including orthologues of Cel-unc-29, Cel-unc-38, and Cel-unc-63. We performed in situ hybridization with RNA probes to localize the expression of five AChR genes (Bm1_35890-Bma-unc-29, Bm1_20330-Bma-unc-38, Bm1_38195-Bma-unc-63, Bm1_48815-Bma-acr-26 and Bm1_40515-Bma-acr-12) in B. malayi adult worms. Four of these genes had similar expression patterns with signals in body muscle, developing embryos, spermatogonia, uterine wall adjacent to stretched microfilariae, wall of Vas deferens, and lateral cord. Three L-AChR subunit genes (Bma-unc-29, Bma-unc-38 and Bma-unc-63) were expressed in body muscle, which is a known target of levamisole. Bma-acr-12 was co-expressed with these levamisole subunit genes in muscle, and this suggests that its protein product may form receptors with other alpha subunits. Bma-acr-26 was expressed in male muscle but not in female muscle. Strong expression signals of these genes in early embryos and gametes in uterus and testis suggest that AChRs may have a role in nervous system development of embryogenesis and spermatogenesis. This would be consistent with embryotoxic effects of drugs that target these receptors in filarial worms. Our data show that the expression of these receptor genes is tightly regulated with regard to localization in adult worms and developmental stage in embryos and gametes. These results may help to explain the broad effects of drugs that target AChRs in filarial worms. Expression patterns of Brugia malayi AChR subunit genes studied by in situ hybridization. All genes highly expressed in developing embryos and sperm precursors. Highly expressed in the walls of uterus and Vas deferens with mature offspring. Four of five genes expressed in body muscle of adult worms. Expression patterns shed new light on the action of anthelmintics in filarial parasites.
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Affiliation(s)
- Ben-Wen Li
- Corresponding author. Washington University School of Medicine, Infectious Diseases Division, 4444 Forest Park Blvd, St. Louis, MO 63108, USA.
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17
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Abstract
Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in C. elegans and the human hookworm Necator americanus. We illustrate how analyzing and comparing metabolism at the level of pathway modules can improve existing knowledge of nematode metabolic potential and can provide parasitism related insights. Our reconstruction and comparison of nematode metabolic pathways at a pan-phylum and inter-phylum level enabled determination of phylogenetic restrictions and differential expression of pathways. A visualization of our results is available at http://nematode.net and the program for identification of module completeness (modDFS) is freely available at SourceForge. The methods reported will help biologists to predict biochemical potential of any organism with available deduced proteome, to direct experiments and test hypotheses. We reconstructed metabolic pathways of 23 organisms including 13 nematode species, using their complete deduced protein coding sequences and compared them to 10 non-nematodes. We observed that metabolic potential availability is concomitant with phylogenetic and/or ecological similarity, with the exceptions providing interesting case studies. We also studied changes in metabolic profiles under different developmental stages of 4 nematode species using stage-specific transcriptomic data. A comparison of the variation patterns in these profiles led to recognition of modules that share metabolic profiles at various life-cycle stages or during development. The undertaken analysis improved genome annotation and the obtained results provided insight into parasitism, resulting in identification of taxonomically-restricted pathways and enzymes that may provide new mechanisms for control of nematode infections.
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Affiliation(s)
- Rahul Tyagi
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Bruce A. Rosa
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Warren G. Lewis
- Division of Infectious Disease, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Infectious Disease, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Verma M, Pathak M, Shahab M, Singh K, Mitra K, Misra-Bhattacharya S. Moxidectin causes adult worm mortality of human lymphatic filarial parasite Brugia malayi in rodent models. Folia Parasitol (Praha) 2014; 61:561-570. [PMID: 25651699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Moxidectin is a macrocyclic lactone belonging to milbemycin family closely related to ivermectin and is currently progressing towards Phase III clinical trial against human infection with the filaria Onchocerca volvulus (Leuckart, 1894). There is a single report on the microfilaricidal and embryostatic activity of moxidectin in case of the human lymphatic filarial parasite Brugia malayi (Brug, 1927) in Mastomys coucha (Smith) but without any adulticidal action. In the present study, the in vitro and in vivo antifilarial efficacy of moxidectin was evaluated on, B. malayi. In vitro moxidectin showed 100% reduction in adult female worm motility at 0.6 μM concentration within 7 days with 68% inhibition in the reduction of MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye) (which is used to detect viability of worms). A 50% inhibitory concentration (IC50) of moxidectin for adult female parasite was 0.242 μM, for male worm 0.186 μM and for microfilaria IC50 was 0.813 μM. In adult B. malayi-transplanted primary screening model (Meriones unguiculatus Milne-Edwards), moxidectin at a single optimal dose of 20 mg/kg by oral and subcutaneous route was found effective on both adult parasites and microfilariae. In secondary screening (M coucha, subcutaneously inoculated with infective larvae), moxidectin at the same dose by subcutaneous route brought about death of 49% of adult worms besides causing sterilisation in 54% of the recovered live female worms. The treated animals exhibited a continuous and sustained reduction in peripheral blood microfilaraemia throughout the observation period of 90 days. The mechanism of action of moxidectin is suggested to be similar to avermectins. The in silico studies were also designed to explore the interaction of moxidectin with glutamate-gated chloride channels of B. malayi. The docking results revealed a close interaction of moxidectin with various GluCl ligand sites of B. malayi.
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Khor BY, Tye GJ, Lim TS, Noordin R, Choong YS. The structure and dynamics of BmR1 protein from Brugia malayi: in silico approaches. Int J Mol Sci 2014; 15:11082-99. [PMID: 24950179 PMCID: PMC4100200 DOI: 10.3390/ijms150611082] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/25/2014] [Accepted: 06/04/2014] [Indexed: 12/27/2022] Open
Abstract
Brugia malayi is a filarial nematode, which causes lymphatic filariasis in humans. In 1995, the disease has been identified by the World Health Organization (WHO) as one of the second leading causes of permanent and long-term disability and thus it is targeted for elimination by year 2020. Therefore, accurate filariasis diagnosis is important for management and elimination programs. A recombinant antigen (BmR1) from the Bm17DIII gene product was used for antibody-based filariasis diagnosis in "Brugia Rapid". However, the structure and dynamics of BmR1 protein is yet to be elucidated. Here we study the three dimensional structure and dynamics of BmR1 protein using comparative modeling, threading and ab initio protein structure prediction. The best predicted structure obtained via an ab initio method (Rosetta) was further refined and minimized. A total of 5 ns molecular dynamics simulation were performed to investigate the packing of the protein. Here we also identified three epitopes as potential antibody binding sites from the molecular dynamics average structure. The structure and epitopes obtained from this study can be used to design a binder specific against BmR1, thus aiding future development of antigen-based filariasis diagnostics to complement the current diagnostics.
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Affiliation(s)
- Bee Yin Khor
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia.
| | - Gee Jun Tye
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia.
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia.
| | - Rahmah Noordin
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia.
| | - Yee Siew Choong
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Minden, Penang 11800, Malaysia.
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Choi YJ, Aliota MT, Mayhew GF, Erickson SM, Christensen BM. Dual RNA-seq of parasite and host reveals gene expression dynamics during filarial worm-mosquito interactions. PLoS Negl Trop Dis 2014; 8:e2905. [PMID: 24853112 PMCID: PMC4031193 DOI: 10.1371/journal.pntd.0002905] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/14/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Parasite biology, by its very nature, cannot be understood without integrating it with that of the host, nor can the host response be adequately explained without considering the activity of the parasite. However, due to experimental limitations, molecular studies of parasite-host systems have been predominantly one-sided investigations focusing on either of the partners involved. Here, we conducted a dual RNA-seq time course analysis of filarial worm parasite and host mosquito to better understand the parasite processes underlying development in and interaction with the host tissue, from the establishment of infection to the development of infective-stage larva. METHODOLOGY/PRINCIPAL FINDINGS Using the Brugia malayi-Aedes aegypti system, we report parasite gene transcription dynamics, which exhibited a highly ordered developmental program consisting of a series of cyclical and state-transitioning temporal patterns. In addition, we contextualized these parasite data in relation to the concurrent dynamics of the host transcriptome. Comparative analyses using uninfected tissues and different host strains revealed the influence of parasite development on host gene transcription as well as the influence of the host environment on parasite gene transcription. We also critically evaluated the life-cycle transcriptome of B. malayi by comparing developmental stages in the mosquito relative to those in the mammalian host, providing insight into gene expression changes underpinning the mosquito-borne parasitic lifestyle of this heteroxenous parasite. CONCLUSIONS/SIGNIFICANCE The data presented herein provide the research community with information to design wet lab experiments and select candidates for future study to more fully dissect the whole set of molecular interactions of both organisms in this mosquito-filarial worm symbiotic relationship. Furthermore, characterization of the transcriptional program over the complete life cycle of the parasite, including stages within the mosquito, could help devise novel targets for control strategies.
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Affiliation(s)
- Young-Jun Choi
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Matthew T. Aliota
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - George F. Mayhew
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Sara M. Erickson
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Bruce M. Christensen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Joseph SK, Verma SK, Verma R, Saxena JK, Srivastava M, Murthy PK. Anti-inflammatory BmAFI of Brugia malayi modulates IgE, histamine and histamine receptor responses in Mastomys coucha. Acta Trop 2013; 127:82-6. [PMID: 23603670 DOI: 10.1016/j.actatropica.2013.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 03/03/2013] [Accepted: 04/11/2013] [Indexed: 11/29/2022]
Abstract
We recently reported that BmAFI, an anti-inflammatory fraction of Brugia malayi adult worm supports parasite development in the hostile peritoneal cavity (p.c.) of Mastomys coucha through a modified Th2 type of response that includes IL-13 and IgE response and anti-inflammatory IL-10 cytokine milieu. In the present study we investigated IgE related responses such as histamine release and modulation of histamine receptors 1 and 2 (HR1 and HR2) by presensitization with BmAFI of M. coucha infected with B. malayi. Sensitization with BmAFI alone enhanced IgE, histamine and HR2, but decreased HR1. Exposure of these animals to infection produced an IgE response that was inversely related to the parasite burden, and decreased histamine conc., and HR1 and HR2 expression. However, there was an early small increase in HR1 expression for a short period after exposure to infection. As expected, BmAFI sensitization supported parasite survival and development in the hostile p.c. of the host. These findings further establish that BmAFI decreases inflammatory/Th1 response and modulates Th2 responses to favour survival and development of the parasite in the hostile p.c. of the host and that IgE and histamine play an important role in this.
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Affiliation(s)
- Sujith K Joseph
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow 226001, India
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Melnikow E, Xu S, Liu J, Bell AJ, Ghedin E, Unnasch TR, Lustigman S. A potential role for the interaction of Wolbachia surface proteins with the Brugia malayi glycolytic enzymes and cytoskeleton in maintenance of endosymbiosis. PLoS Negl Trop Dis 2013; 7:e2151. [PMID: 23593519 PMCID: PMC3617236 DOI: 10.1371/journal.pntd.0002151] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/22/2013] [Indexed: 11/19/2022] Open
Abstract
The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis.
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Affiliation(s)
- Elena Melnikow
- Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - Shulin Xu
- Department of Global Health, University of South Florida, Tampa, Florida, United States of America
| | - Jing Liu
- Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - Aaron J. Bell
- Electron Microscopy, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - Elodie Ghedin
- Department of Computational & Systems Biology, Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Thomas R. Unnasch
- Department of Global Health, University of South Florida, Tampa, Florida, United States of America
| | - Sara Lustigman
- Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America
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Shrivastava N, Nag JK, Misra-Bhattacharya S. Molecular characterization of NAD+-dependent DNA ligase from Wolbachia endosymbiont of lymphatic filarial parasite Brugia malayi. PLoS One 2012; 7:e41113. [PMID: 22815933 PMCID: PMC3397958 DOI: 10.1371/journal.pone.0041113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 06/21/2012] [Indexed: 11/19/2022] Open
Abstract
The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD(+)-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD(+)-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA) for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD(+)-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH) and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid) was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies.
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Affiliation(s)
- Nidhi Shrivastava
- Division of Parasitology, Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Jeetendra Kumar Nag
- Division of Parasitology, Central Drug Research Institute, Lucknow, Uttar Pradesh, India
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Choi YJ, Ghedin E, Berriman M, McQuillan J, Holroyd N, Mayhew GF, Christensen BM, Michalski ML. A deep sequencing approach to comparatively analyze the transcriptome of lifecycle stages of the filarial worm, Brugia malayi. PLoS Negl Trop Dis 2011; 5:e1409. [PMID: 22180794 PMCID: PMC3236722 DOI: 10.1371/journal.pntd.0001409] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/19/2011] [Indexed: 11/19/2022] Open
Abstract
Background Developing intervention strategies for the control of parasitic nematodes continues to be a significant challenge. Genomic and post-genomic approaches play an increasingly important role for providing fundamental molecular information about these parasites, thus enhancing basic as well as translational research. Here we report a comprehensive genome-wide survey of the developmental transcriptome of the human filarial parasite Brugia malayi. Methodology/Principal Findings Using deep sequencing, we profiled the transcriptome of eggs and embryos, immature (≤3 days of age) and mature microfilariae (MF), third- and fourth-stage larvae (L3 and L4), and adult male and female worms. Comparative analysis across these stages provided a detailed overview of the molecular repertoires that define and differentiate distinct lifecycle stages of the parasite. Genome-wide assessment of the overall transcriptional variability indicated that the cuticle collagen family and those implicated in molting exhibit noticeably dynamic stage-dependent patterns. Of particular interest was the identification of genes displaying sex-biased or germline-enriched profiles due to their potential involvement in reproductive processes. The study also revealed discrete transcriptional changes during larval development, namely those accompanying the maturation of MF and the L3 to L4 transition that are vital in establishing successful infection in mosquito vectors and vertebrate hosts, respectively. Conclusions/Significance Characterization of the transcriptional program of the parasite's lifecycle is an important step toward understanding the developmental processes required for the infectious cycle. We find that the transcriptional program has a number of stage-specific pathways activated during worm development. In addition to advancing our understanding of transcriptome dynamics, these data will aid in the study of genome structure and organization by facilitating the identification of novel transcribed elements and splice variants. Lymphatic filariasis, also known as elephantiasis, is a tropical disease affecting over 120 million people worldwide. More than 40 million people live with painful, disfiguring symptoms that can cause severe debilitation and social stigma. The disease is caused by infection with thread-like filarial nematodes (roundworms) that have a complex parasitic lifecycle involving both human and mosquito hosts. In the study, the authors profiled the transcriptome (the set of genes transcribed into messenger RNA rather than all of those in the genome) of the human filarial worm Brugia malayi in different lifecyle stages using deep sequencing technology. The analysis revealed major transitions in RNA expression from eggs through larval stages to adults. Using statistical approaches, the authors identified groups of genes with distinct life stage dependent transcriptional patterns, with particular emphasis on genes displaying sex-biased or germline-enriched patterns and those displaying significant changes during larval development. This study presents a first comprehensive analysis of the lifecycle transcriptome of B. malayi, providing fundamental molecular information that should help researchers better understand parasite biology and could provide clues for the development of more effective interventions.
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Affiliation(s)
- Young-Jun Choi
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Elodie Ghedin
- Department of Computational and Systems Biology, Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Matthew Berriman
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Jacqueline McQuillan
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nancy Holroyd
- The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - George F. Mayhew
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Bruce M. Christensen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michelle L. Michalski
- Department of Biology and Microbiology, University of Wisconsin Oshkosh, Oshkosh, Wisconsin, United States of America
- * E-mail:
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Landmann F, Voronin D, Sullivan W, Taylor MJ. Anti-filarial activity of antibiotic therapy is due to extensive apoptosis after Wolbachia depletion from filarial nematodes. PLoS Pathog 2011; 7:e1002351. [PMID: 22072969 PMCID: PMC3207916 DOI: 10.1371/journal.ppat.1002351] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 09/19/2011] [Indexed: 11/18/2022] Open
Abstract
Filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility and viability and thus has great promise as a novel approach for treating filarial diseases. However, little is known concerning the basis for this mutualistic relationship. Here we demonstrate using whole mount confocal microscopy that an immediate response to Wolbachia depletion is extensive apoptosis in the adult germline, and in the somatic cells of the embryos, microfilariae and fourth-stage larvae (L4). Surprisingly, apoptosis occurs in the majority of embryonic cells that had not been infected prior to antibiotic treatment. In addition, no apoptosis occurs in the hypodermal chords, which are populated with large numbers of Wolbachia, although disruption of the hypodermal cytoskeleton occurs following their depletion. Thus, the induction of apoptosis upon Wolbachia depletion is non-cell autonomous and suggests the involvement of factors originating from Wolbachia in the hypodermal chords. The pattern of apoptosis correlates closely with the nematode tissues and processes initially perturbed following depletion of Wolbachia, embryogenesis and long-term sterilization, which are sustained for several months until the premature death of the adult worms. Our observations provide a cellular mechanism to account for the sustained reductions in microfilarial loads and interruption of transmission that occurs prior to macrofilaricidal activity following antibiotic therapy of filarial nematodes.
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Affiliation(s)
- Frederic Landmann
- Department of Molecular, Cell and Developmental Biology, Sinsheimer Labs, University of California, Santa Cruz, California, United States of America
| | - Denis Voronin
- Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - William Sullivan
- Department of Molecular, Cell and Developmental Biology, Sinsheimer Labs, University of California, Santa Cruz, California, United States of America
| | - Mark J. Taylor
- Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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26
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Weinkopff T, Lammie P. Lack of evidence for the direct activation of endothelial cells by adult female and microfilarial excretory-secretory products. PLoS One 2011; 6:e22282. [PMID: 21829611 PMCID: PMC3149047 DOI: 10.1371/journal.pone.0022282] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 06/23/2011] [Indexed: 11/19/2022] Open
Abstract
Lymphangiectasia (dilation of the lymphatic vessel (LV)) is pathognomonic for lymphatic filariasis. In both infected humans and animal models of infection, lymphangiectasia is not restricted to the site of the worm nest, but is found along the infected vessel. These observations argue that soluble products secreted by the worm could be mediating this effect by activating the lymphatic endothelial cells (LEC) lining the vessel. We tested the ability of filarial Excretory-Secretory products to activate LECs, but were unable to detect a direct effect of the Excretory-Secretory products on the activation of LEC as assessed by a variety of approaches including cellular proliferation, cell surface molecule expression and cytokine and growth factor production (although other mediators used as positive controls did induce these effects). Collectively, these results do not support the hypothesis that Excretory-Secretory products directly activate LECs.
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Affiliation(s)
- Tiffany Weinkopff
- Department of Cell Biology, University of Georgia, Athens, Georgia, United States of America.
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27
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Bennuru S, Meng Z, Ribeiro JMC, Semnani RT, Ghedin E, Chan K, Lucas DA, Veenstra TD, Nutman TB. Stage-specific proteomic expression patterns of the human filarial parasite Brugia malayi and its endosymbiont Wolbachia. Proc Natl Acad Sci U S A 2011; 108:9649-54. [PMID: 21606368 PMCID: PMC3111283 DOI: 10.1073/pnas.1011481108] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Global proteomic analyses of pathogens have thus far been limited to unicellular organisms (e.g., protozoa and bacteria). Proteomic analyses of most eukaryotic pathogens (e.g., helminths) have been restricted to specific organs, specific stages, or secretomes. We report here a large-scale proteomic characterization of almost all the major mammalian stages of Brugia malayi, a causative agent of lymphatic filariasis, resulting in the identification of more than 62% of the products predicted from the Bm draft genome. The analysis also yielded much of the proteome of Wolbachia, the obligate endosymbiont of Bm that also expressed proteins in a stage-specific manner. Of the 11,610 predicted Bm gene products, 7,103 were definitively identified from adult male, adult female, blood-borne and uterine microfilariae, and infective L3 larvae. Among the 4,956 gene products (42.5%) inferred from the genome as "hypothetical," the present study was able to confirm 2,336 (47.1%) as bona fide proteins. Analysis of protein families and domains coupled with stage-specific expression highlight the important pathways that benefit the parasite during its development in the host. Gene set enrichment analysis identified extracellular matrix proteins and those with immunologic effects as enriched in the microfilarial and L3 stages. Parasite sex- and stage-specific protein expression identified those pathways related to parasite differentiation and demonstrates stage-specific expression by the Bm endosymbiont Wolbachia as well.
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Affiliation(s)
- Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.
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28
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Bailey M, Chauhan C, Liu C, Unnasch TR. The role of polymorphisms in the spliced leader addition domain in determining promoter activity in Brugia malayi. Mol Biochem Parasitol 2010; 176:37-41. [PMID: 21111761 DOI: 10.1016/j.molbiopara.2010.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 11/18/2022]
Abstract
Previous studies of Brugia malayi promoters have suggested that they are unusual in that they lack the CAAT or TATAA boxes that are often emblematic of eucaryotic core promoter domains. Instead, the region surrounding the spliced leader (SL) addition site appears to function as the core promoter domain in B. malayi. To test the hypothesis that polymorphisms in this SL addition domain are important determinants of promoter activity, a series of domain swap mutants were prepared replacing the SL addition domain of the B. malayi 13kDa large subunit ribosomal protein (BmRPL13) with those of other ribosomal protein (RP) promoters exhibiting a wide range of activities. These constructs were then tested for promoter activity in a homologous transient transfection system. On average, polymorphisms in the SL addition domain were found to be responsible for 80% of the variation in promoter activity exhibited by the RP promoters tested. Essentially all of this effect could be attributable to polymorphisms in the 10nt located directly upstream of the SL addition site. A comparison of the sequence of this domain to the promoter activity exhibited by the domain swap mutants suggested that promoter activity was related to the number of T residues present in the coding strand of the upstream domain. Confirming this, mutation of the upstream domain of the promoter of the BmRPS4 gene to a homogeneous stretch of 10 T residues resulted in a significant increase in promoter activity.
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Affiliation(s)
- Michelle Bailey
- Global Health Research Program, Department of Global Health, University of South Florida, Tampa, FL 33612, United States
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29
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Liu C, Chauhan C, Katholi CR, Unnasch TR. The splice leader addition domain represents an essential conserved motif for heterologous gene expression in B. malayi. Mol Biochem Parasitol 2009; 166:15-21. [PMID: 19428668 PMCID: PMC2680783 DOI: 10.1016/j.molbiopara.2009.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 02/10/2009] [Accepted: 02/11/2009] [Indexed: 11/28/2022]
Abstract
Two promoters from the human filarial parasite Brugia malayi have been mapped in detail. The essential domains of both promoters lacked canonical eukaryotic core promoter motifs. However, the largest contiguous essential domain in both promoters flanked and included the splice leader addition site. These findings suggested that the region flanking the trans-splicing addition site might represent a conserved core domain in B. malayi promoters. To test this hypothesis, the putative promoters of 12 trans-spliced genes encoding ribosomal protein homologues from B. malayi were isolated and tested for activity in a B. malayi transient transfection system. Of the 12 domains examined, 11 produced detectable reporter gene activity. Mutant constructs of the six most active promoters were prepared in which the spliced leader acceptor site and the 10 nt upstream and downstream of the site were deleted. All deletion constructs exhibited >90% reduction in reporter gene activity relative to their respective wild type sequences. A conserved pyrimidine-rich tract was located directly upstream from the spliced leader splice acceptor site which contained a conserved T residue located at position -3. Mutation of the entire polypyrimidine tract or the conserved T individually resulted in the loss of over 90% of reporter gene activity. In contrast, mutation of the splice acceptor site did not significantly reduce promoter activity. These data suggest that the region surrounding the splice acceptor site in the ribosomal promoters represents a conserved essential domain which functions independently of splice leader addition.
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Affiliation(s)
- Canhui Liu
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL
| | - Chitra Chauhan
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL
| | - Charles R. Katholi
- Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, Al
| | - Thomas R. Unnasch
- Global Health Infectious Disease Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL
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30
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Xie DF, Fang Z, Huang WQ, Shen Q, Tong HY, Xu BS. [Cloning and eukaryotic expression of the gene encoding myosin from Brugia malayi]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2008; 26:482-484. [PMID: 19288931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Total RNA was extracted from periodic microfilariae of Brugia malayi and its myosin partial gene (Bm-M55) was amplified by RT-PCR. The PCR product was cloned and then subcloned into pcDNA3.1 (+)vector. The recombinant eukaryotic plasmids were screened and identified by digestion with restriction enzyme and PCR amplification, and was transfected into COS-7 cells subsequently. The expressed protein was identified by SDS-PAGE. Bm-M55 mRNA was highly expressed in transfected COS-7 cells. The deduced amino acid sequence showed to be identical with that of Bm-M55, and the recombinant protein was about Mr 55000.
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Affiliation(s)
- Dong-fang Xie
- Department of Parasitology, School of Basic Medical Sciences, Nantong University, Nantong 226001, China
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31
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de Oliveira A, Katholi CR, Unnasch TR. Characterization of the promoter of the Brugia malayi 12kDa small subunit ribosomal protein (RPS12) gene. Int J Parasitol 2008; 38:1111-9. [PMID: 18364245 PMCID: PMC2577030 DOI: 10.1016/j.ijpara.2008.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 02/11/2008] [Accepted: 02/13/2008] [Indexed: 11/18/2022]
Abstract
Unravelling gene regulatory mechanisms in human filarial parasites will require an understanding of their basic promoter structure. Only a single promoter from a human filarial parasite has been characterised in detail, the 70 kDa heat shock promoter of Brugia malayi (BmHSP70). This promoter was found to lack features found in a typical eukaryotic promoter. To determine if this was unique to the BmHSP70 promoter, a detailed analysis was undertaken of the promoter for the B. malayi small subunit 12 kDa ribosomal protein (BmRPS12) gene. The BmRPS12 promoter contained a unique tandem repeat structure. Deletion of these repeats resulted in the loss of 80% of promoter activity. Block replacement mutagenesis identified five regions outside the repeat which were essential for promoter activity. No predicted binding sites for proteins that normally associate with the typical eukaryotic core promoter domains were found in the essential domains or the repeat region. However, the repeat region contained many putative binding sites for GATAA transcription factor family proteins. Of 20 upstream domains of other ribosomal protein genes, one contained a repeat structure similar to that found in the BmRPS12 promoter, and the majority encoded putative GATAA transcription factor binding sites. This study demonstrates that the BmRPS12 promoter, like the BmHSP70 promoter, is distinct from a typical eukaryotic promoter.
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Affiliation(s)
- Ana de Oliveira
- Gorgas Center for Geographic Medicine, University of Alabama at Birmingham, USA
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32
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Anand SB, Murugan V, Prabhu PR, Anandharaman V, Reddy MVR, Kaliraj P. Comparison of immunogenicity, protective efficacy of single and cocktail DNA vaccine of Brugia malayi abundant larval transcript (ALT-2) and thioredoxin peroxidase (TPX) in mice. Acta Trop 2008; 107:106-12. [PMID: 18547532 DOI: 10.1016/j.actatropica.2008.04.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 04/18/2008] [Accepted: 04/22/2008] [Indexed: 11/30/2022]
Abstract
Although DNA vaccines have several advantages over conventional vaccines, antibody production and protection are often not adequate, particularly in single plasmid vaccine formulation. In the present study we evaluated the efficacy of a cocktail vaccine based on plasmids encoding larval (L3) stage-specific Brugia malayi abundant larval transcript (BmALT-2) and antioxidant detoxification enzyme B. malayi thioredoxin peroxidase (BmTPX) to induce antibodies, protective efficacy and cell-mediated immune response in mice. Mice immunized with cocktail DNA vaccines containing the pVAX ALT-2+TPX developed higher titers of anti-BmALT-2+TPX (1:5000) antibodies, compared to the mice immunized with single DNA vaccine of pVAX ALT-2 or pVAX TPX (1:2000). Correlating with this, the mice administered with cocktail vaccine induced up to 78% of cytotoxicity against B. malayi mf. This cytotoxicity was high compared to 34% induced by the pVAX-ALT2 or 37% by pVAX-TPX. Moreover, cocktail vaccination of mice resulted in significantly higher level of cellular proliferative response associated with raised levels of IFN-gamma that skewed towards Th1 type of response compared to vaccination using either of the components. Taken together, these data suggest that the combination of two or more antigens maybe an effective vaccine development strategy to improve protection and immunogenicity against human lymphatic filariasis.
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Sahare KN, Anandharaman V, Meshram VG, Meshram SU, Gajalakshmi D, Goswami K, Reddy MVR. In vitro effect of four herbal plants on the motility of Brugia malayi microfilariae. Indian J Med Res 2008; 127:467-471. [PMID: 18653910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND & OBJECTIVE Disease burden due to lymphatic filariasis is disproportionately high despite mass drug administration with conventional drugs. Usage of herbal drugs in traditional medicine is quite well known but largely empirical. Hence the present study was designed to screen the in vitro antifilarial effect of four herbal plants on Brugia malayi. METHODS Motility of microfilariae of B. malayi after incubation for 48 h with aqueous/methanol extracts of Vitex negundo L. (roots), Butea monosperma L. (roots and leaves), Ricinus communis L. (leaves), and Aegle marmelos Corr. (leaves) was explored in the concentration range of 20 to 100 ng/ml for possible antifilarial effect by comparing with suitable solvent control. RESULTS Butea monosperma leaves and roots, Vitex negundo root and Aegle marmelo leaves showed significant inhibition of motility of microfilariae as compared to controls whereas inhibitory activity demonstrated by Ricinus communis L. leaves was not significant. Antifilarial effects imparted by all these extracts were found to be a function of their relative concentrations. Inhibitory concentrations (IC(50)) for the plant extracts with significant antifilarial activity against Brugia malayi microfilariae in in vitro system have been derived to be 82, 83 and 70 ng/ml for Vitex negundo L., Butea monosperma L. and Aegle marmelos Corr. respectively. INTERPRETATION & CONCLUSION The present study recorded significant antifilarial effect of all plant extracts studied except for Ricinus communis L. leaves and contributes to the development of database for novel drug candidates for human lymphatic filariasis.
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Affiliation(s)
- K N Sahare
- P.G. Department of Microbiology & Rajiv Gandhi Biotechnology Centre, RTM, Nagpur University, Nagpur
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34
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Jiang D, Li BW, Fischer PU, Weil GJ. Localization of gender-regulated gene expression in the filarial nematode Brugia malayi. Int J Parasitol 2007; 38:503-12. [PMID: 18001741 DOI: 10.1016/j.ijpara.2007.09.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/13/2007] [Accepted: 09/17/2007] [Indexed: 11/17/2022]
Abstract
We used in situ hybridization (ISH) to localize expression of gender-biased genes in the filarial parasite Brugia malayi that were previously identified by microarray analysis and quantitative reverse transcriptase PCR (qRT-PCR). We studied seven genes with male-biased expression, 11 genes with female-biased expression, and one control gene with equal expression in males and females. RNA probes were hybridized to frozen sections of adult worms. ISH confirmed gender-biased expression for all 18 of the differentially expressed genes and non-biased expression for the control. We identified six patterns of expression for these genes. As expected, most of the gender-biased genes were expressed in reproductive organs, developing gametes and embryos. Hybridization signal intensities correlated with relative mRNA levels as assessed by qRT-PCR. Some of the differentially expressed genes had tightly regulated expression patterns. For example, a high mobility group protein gene (Bm-hmg) was exclusively expressed in developing larvae in females. Expression was first detected in late stage oocytes, peaked in morula stage embryos and no signal was detected in late pretzel stage or in stretched microfilariae. Another female up-regulated gene (microfilarial sheath protein Bm-shp-1) was exclusively expressed in the epithelium of uterine sections that contained morulae or early pretzel embryos. No signal was detected in other female structures, in late embryos or in male worms. This result suggests that microfilarial sheath proteins are produced by the uterus epithelium and not by embryos. Transcripts of the male-upregulated major sperm protein-1 (Bm-msp-1) were detected in spermatocytes in the early spermatogenesis zone and in spermatids but not in spermatozoa in the vas deferens. Thus, ISH provides a means to independently confirm differential expression of genes identified by other methods. In addition, localization patterns provide insight regarding the function of known or novel genes in the parasite.
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Affiliation(s)
- Daojun Jiang
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, Campus Box 8051, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
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35
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Gnanasekar M, Ramaswamy K. Translationally controlled tumor protein of Brugia malayi functions as an antioxidant protein. Parasitol Res 2007; 101:1533-40. [PMID: 17687568 PMCID: PMC2366903 DOI: 10.1007/s00436-007-0671-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 07/10/2007] [Indexed: 10/23/2022]
Abstract
Translationally controlled tumor protein (TCTP) is one of the most abundantly expressed proteins in the filarial parasites as well as in the other organisms. Several functions have been suggested for TCTP family of proteins ranging from calcium binding to histamine release function. However, its physiological function is still a mystery. Previous studies showed that the expression of TCTP is increased several-fold during oxidative stress. In the present work, we report the putative antioxidant function of Brugia malayi TCTP (BmTCTP). When tested in vitro, rBmTCTP could be reduced by a variety of reducing agents including thioredoxin. Such reduced form of rBmTCTP was able to protect DNA from oxidative damage, suggesting that BmTCTP may have an antioxidant function in the parasite. Sequence analysis of filarial TCTPs revealed that there are three cysteine amino acids located in the central portion of the protein. Subsequent targeted residue modification studies showed that these cysteine residues in rBmTCTP are critical for its antioxidant function. To determine the significance of this finding, rBmTCTP was overexpressed in vivo in Escherichia coli and subjected to oxidative stress. These studies showed that rBmTCTP significantly protected cells form oxidative damage. Taken together, these findings suggest that BmTCTP might be functioning as a non-classical antioxidant protein in the filarial parasites.
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Affiliation(s)
- Munirathinam Gnanasekar
- Department of Biomedical Sciences, College of Medicine, University of Illinois, Rockford, IL 61107, USA
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36
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Thomson N, Crossman L, Bentley S. Bacterial home from home. Nat Rev Microbiol 2006; 4:168-70. [PMID: 16528802 DOI: 10.1038/nrmicro1367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nicholas Thomson
- Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
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37
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Krithika KN, Dabir P, Kulkarni S, Anandharaman V, Reddy MVR. Identification of 38kDa Brugia malayi microfilarial protease as a vaccine candidate for lymphatic filariasis. Indian J Exp Biol 2005; 43:759-68. [PMID: 16187525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A FPLC purified 38kDa protease (Bm mf S-7) isolated from B. malayi microfilarial soluble antigen was identified. It showed pronounced reactivity with sera collected from 'putatively immune' asymptomatic and amicrofilaraemic individuals residing in an endemic area for bancroftian filariasis. Further the immune protective activity of Bm mf S-7 antigen was evaluated in susceptible hosts, jirds (Meriones unguiculatus) against B. malayi filarial infection. The antigen showed 89% cytotoxicity against mf and 87-89% against infective (L3) larvae in in vitro antibody dependent cellular cytotoxicity Assay (ADCC) and in situ micropore chamber methods. Bm mf S-7 immunized jirds after challenge infection showed 81.5% reduction in the adult worm burden. The present study has shown that, the 38kDa microfilarial proteases (Bm mf S-7) could stimulate a strong protective immune response against microfilariae and infective larvae in jird model to block the transmission of filariasis. Analysis of IgG subclasses against Bm mf S-7 revealed a significant increase in IgG2 and IgG3 antibodies in endemic normals. Lymphocyte proliferation to Bm mf S-7 was significantly high in endemic normal group as compared to that in clinical and microfilarial carriers. Significantly enhanced levels of IFN-gamma in the culture supernatant of PBMC of endemic normals followed by stimulation with Bm mf S-7 suggest that the cellular response in this group is skewed towards Th 1 type.
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MESH Headings
- Animals
- Antibodies, Helminth/chemistry
- Antibodies, Helminth/isolation & purification
- Antigens, Helminth/chemistry
- Antigens, Helminth/isolation & purification
- Brugia malayi/metabolism
- Chromatography, Affinity
- Chromatography, Liquid
- Cytokines/metabolism
- Electrophoresis, Polyacrylamide Gel
- Elephantiasis, Filarial/prevention & control
- Elephantiasis, Filarial/therapy
- Humans
- Immune System
- Immunoblotting
- Immunoglobulin G/chemistry
- Interferon-gamma/metabolism
- Interleukin-10/metabolism
- Interleukin-4/metabolism
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Microfilariae/metabolism
- Peptide Hydrolases/chemistry
- Peptide Hydrolases/pharmacology
- Th1 Cells/immunology
- Time Factors
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Affiliation(s)
- K N Krithika
- Department of Biochemistry & Jamnalal Bajaj Tropical Disease Research Centre, Mahatma Gandhi Institute of Medical Sciences, Sewagram 442 102, India
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38
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Abstract
Polymerase chain reaction is the most widely used method for in vitro DNA amplification. However, it requires thermocycling to separate two DNA strands. In vivo, DNA is replicated by DNA polymerases with various accessory proteins, including a DNA helicase that acts to separate duplex DNA. We have devised a new in vitro isothermal DNA amplification method by mimicking this in vivo mechanism. Helicase-dependent amplification (HDA) utilizes a DNA helicase to generate single-stranded templates for primer hybridization and subsequent primer extension by a DNA polymerase. HDA does not require thermocycling. In addition, it offers several advantages over other isothermal DNA amplification methods by having a simple reaction scheme and being a true isothermal reaction that can be performed at one temperature for the entire process. These properties offer a great potential for the development of simple portable DNA diagnostic devices to be used in the field and at the point-of-care.
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Affiliation(s)
- Myriam Vincent
- New England Biolabs, 32 Tozer Road, Beverly, Massachusetts 01915, USA
| | - Yan Xu
- New England Biolabs, 32 Tozer Road, Beverly, Massachusetts 01915, USA
| | - Huimin Kong
- New England Biolabs, 32 Tozer Road, Beverly, Massachusetts 01915, USA
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39
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Rajan TV, Paciorkowski N, Kalajzic I, McGuiness C. Ascorbic acid is a requirement for the morphogenesis of the human filarial parasite Brugia malayi. J Parasitol 2003; 89:868-70. [PMID: 14533709 DOI: 10.1645/ge-3137rn] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The nematode parasites Wuchereria bancrofti, Brugia malayi, and B. timori cause a disease in humans known as lymphatic filariasis, which afflicts approximately 120 million people worldwide. The parasites enter the human host from the mosquito either as L3 or as infective larvae and subsequently differentiate through 2 molts. In this article, we show that B. malayi depends on an exogenous source of vitamin C to complete the L3 to L4 molt, a critical morphogenic step in its life cycle. Brugia malayi apparently belongs to a small group of living organisms that depend on an exogenous source of vitamin C. This group includes only primates (including man) and guinea pigs among mammals.
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Affiliation(s)
- T V Rajan
- Department of Pathology, UConn Health Center, Farmington, Connecticut 06030-3105, USA.
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40
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Hirzmann J, Hintz M, Kasper M, Shresta TR, Taubert A, Conraths FJ, Geyer R, Stirm S, Zahner H, Hobom G. Cloning and expression analysis of two mucin-like genes encoding microfilarial sheath surface proteins of the parasitic nematodes Brugia and Litomosoides. J Biol Chem 2002; 277:47603-12. [PMID: 12356773 DOI: 10.1074/jbc.m205770200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In several filarial genera the first stage larvae (microfilariae) are enclosed by an eggshell-derived sheath that provides a major interface between the parasite and the host immune system. Analysis of the polypeptide constituents of the microfilarial sheath from the cotton rat filaria Litomosoides sigmodontis identified two abundant surface glycoproteins: Shp3a and Shp3. The corresponding genes and the orthologues of the human parasite Brugia malayi and the rodent filaria Brugia pahangi were cloned and sequenced. They encode secreted, mucin-like proteins with N-terminal Ser/Thr-rich repeats and a C-terminal anchor domain rich in aromatic amino acids. About 75% of the protein molecular masses result from post-translational modifications. The Ser/Thr-rich motifs are supposed to serve as targets for dimethylaminoethanol-phosphate substitutions. These modifications were detected only on the sheaths of the late developmental stage of stretched microfilariae, corresponding with the expression of the proteins in the epithelium of the distal part of the uterus and the specific transcription of shp3 and shp3a in the anterior female worm segment. Genomic analysis of all three species demonstrated a conserved linkage of the two genes. Their transcripts undergo cis- and trans-splicing. The transcription start sites of the primary transcripts were determined for the L. sigmodontis genes. The core promoter regions are remarkably conserved between the paralogue genes Ls-shp3a and Ls-shp3 and their orthologues in Brugia, implicating conserved regulatory elements.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Brugia malayi/metabolism
- Brugia pahangi/metabolism
- Carbohydrates/chemistry
- Chromatography, Gas
- Cloning, Molecular
- DNA, Complementary/metabolism
- Female
- Filarioidea/metabolism
- Male
- Models, Genetic
- Molecular Sequence Data
- Monosaccharides/chemistry
- Mucins/chemistry
- Mucins/genetics
- Mucins/metabolism
- Promoter Regions, Genetic
- Protein Structure, Tertiary
- RNA/metabolism
- Rats
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Homology, Amino Acid
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Transcription, Genetic
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41
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Zang X, Taylor P, Wang JM, Meyer DJ, Scott AL, Walkinshaw MD, Maizels RM. Homologues of human macrophage migration inhibitory factor from a parasitic nematode. Gene cloning, protein activity, and crystal structure. J Biol Chem 2002; 277:44261-7. [PMID: 12221083 DOI: 10.1074/jbc.m204655200] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cytokines are the molecular messengers of the vertebrate immune system, coordinating the local and systemic immune responses to infective organisms. We report here functional and structural data on cytokine-like proteins from a eukaryotic pathogen. Two homologues of the human cytokine macrophage migration inhibitory factor (MIF) have been isolated from the parasitic nematode Brugia malayi. Both molecules (Bm-MIF-1 and Bm-MIF-2) show parallel functions to human MIF. They are chemotactic for human monocytes and activate them to produce IL-8, TNF-alpha, and endogenous MIF. The human and nematode MIF homologues share a tautomerase enzyme activity, which is in each case abolished by the mutation of the N-terminal proline residue. The crystal structure of Bm-MIF-2 at 1.8-A resolution has been determined, revealing a trimeric assembly with an inner pore created by beta-stranded sheets from each subunit. Both biological activity and crystal structure reveal remarkable conservation between a human cytokine and its parasite counterpart despite the considerable phylogenetic divide among these organisms. The strength of the similarity implies that MIF-mediated pathways play an important role in nematode immune evasion strategies.
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Affiliation(s)
- Xingxing Zang
- Institute of Cell, Animal & Population Biology, University of Edinburgh, United Kingdom.
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42
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Abstract
Brugia malayi is a filarial nematode parasite that causes lymphatic filariasis, a disease that affects millions of people in the tropics. Sexual reproduction of filarial worms occurs within the lymphatic vessels of the human host and is crucial for transmission of the parasite to the mosquito vector. We have previously identified several B. malayi genes that exhibit apparent gender-specific expression. One of these had significant sequence similarity to the Ascaris suum embryo-associated fatty acid binding protein, As-p18. The full length cDNA for the B. malayi female-associated fatty acid binding protein (Bm-FAB-1) encodes a 17.8 kDa protein (excluding a signal peptide) with 70% sequence identity with mature As-p18 and significant similarity to Caenorhabditis elegans and mammalian fatty acid-binding proteins (FABPs). Antibodies raised to Bm-FAB-1 bound to developing embryos within female worms, especially around early embryo cells and the surfaces of immature worms within eggs. Functional studies showed that recombinant Bm-FAB-1 binds to several long chain fatty acids including oleate, but not retinol. Taken together, these results demonstrate that Bm-FAB-1 is a member of an unusual nematode-specific, secreted lipid binding protein family. The existence of a novel class of lipid binding proteins in nematode embryos raises the possibility that drugs targeting these proteins could be developed with broad activity against nematode parasites of medical and veterinary importance.
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Affiliation(s)
- Michelle L Michalski
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA.
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43
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Gnanasekar M, Rao KVN, Chen L, Narayanan RB, Geetha M, Scott AL, Ramaswamy K, Kaliraj P. Molecular characterization of a calcium binding translationally controlled tumor protein homologue from the filarial parasites Brugia malayi and Wuchereria bancrofti. Mol Biochem Parasitol 2002; 121:107-18. [PMID: 11985867 DOI: 10.1016/s0166-6851(02)00027-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have cloned homologues of the mammalian translationally controlled tumor protein (TCTP) from the human filarial parasites Wuchereria bancrofti and Brugia malayi. TCTP genes from B. malayi and W. bancrofti were expressed in a T7 promoter vector as histidine tagged fusion proteins. Both the recombinant B. malayi TCTP (rBm-TCTP) and recombinant W. bancrofti TCTP (rWb-TCTP) have a molecular mass of approximately 28 kDa with the histidine tag. Sequence analyses showed that there is a 98% similarity between the two filarial TCTPs at amino acid levels and are immunologically cross-reactive. Analysis of soluble proteins from various lifecycle stages of B. malayi suggested that the expression of Bm-TCTP might be differentially regulated and occurs in multimeric form. Recombinant TCTP were found to form multimers in solution under non-reducing conditions. The tendency for filarial TCTPs to become multimers was predicted by the presence of the Lupas coiled coil structure in their sequence. Despite the absence of a signal sequence, Bm-TCTP is present abundantly in the excretory/secretions (ES) of microfilariae. Characterization studies showed that both Bm- and Wb-TCTPs are calcium-binding proteins and have histamine-releasing function in vitro. When injected intraperitoneally both the filarial TCTPs induced inflammatory infiltration of eosinophils into the peritoneal cavity of mice suggesting that the filarial TCTPs may have a role in the allergic inflammatory responses associated with filarial infections.
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Affiliation(s)
- M Gnanasekar
- Department of Biomedical Sciences, University of Illinois College of Medicine, 1601 Parkview Avenue, Rockford, IL 61107, USA
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44
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Abstract
To develop a method for the introduction of DNA into filarial parasites, several methods that have proven successful in other organisms were evaluated for their ability to transform Brugia malayi. Luciferase activity was detectable in embryos bombarded with gold particles coated with a construct consisting of a luciferase reporter gene under the control of the 5S rRNA intergenic spacer (SL promoter). Similar results were seen in adult parasites and infective larvae bombarded with this construct, or in adult female parasites microinjected with the plasmid. In similar experiments employing the SL promoter driving a green fluorescent protein (GFP) reporter, expression of the reporter was detectable in the intrauterine embryos of the microinjected adult parasites, and in the sub-cuticular tissues of biolistically transfected adult female parasites. A similar pattern of GFP expression to that seen in the SL promoter construct transfected parasites was noted in parasites transfected with constructs consisting of the upstream domain derived from an aspartyl aminoacyl tRNA synthetase gene of B. malayi. The ability to transfect B. malayi embryos may provide a foundation for studies of the regulation of gene expression and function in these organisms.
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Affiliation(s)
- Tarig B Higazi
- Division of Geographic Medicine, BBRB 203, University of Alabama at Birmingham, 1530 3rd Ave. South, 35294-2170, USA
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45
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Murray J, Gregory WF, Gomez-Escobar N, Atmadja AK, Maizels RM. Expression and immune recognition of Brugia malayi VAL-1, a homologue of vespid venom allergens and Ancylostoma secreted proteins. Mol Biochem Parasitol 2001; 118:89-96. [PMID: 11704277 DOI: 10.1016/s0166-6851(01)00374-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several important nematode parasites have been found to express members of a gene family variously termed as venom allergen antigen homologue (vah) or Ancylostoma secreted protein (asp). In some cases these products are secreted by infective larval stages and have been suggested to be effective vaccine immunogens. We isolated the corresponding gene from the human filarial nematode, Brugia malayi, by first searching the expressed sequence tag (EST) dataset generated by the Filarial Genome Project and then using gene-specific nondegenerate primers matching the selected gene for PCR, from B. malayi cDNA libraries. We report here the full-length gene sequence, which we have designated as Bm-val-1, for vah/asp-like. The corresponding protein (Bm-VAL-1) contains 232 amino acids in a single homology unit, unlike products from some other species in which there is a tandem repeat. A putative signal sequence is present at the 5' end and there are two potential N-glycosylation sites. Murine antibodies to recombinant Bm-VAL-1 react with a 28 kDa protein in L3 extracts and recombinant Bm-VAL-1 is recognised by murine T cells primed with soluble L3 proteins. Of 82 ESTs corresponding to Bm-val-1, 72 are recorded from the infective larval (L3) stage. However, PCR on the first-strand cDNA from later mammalian stages revealed some expression at most subsequent time points. Over 95% (20/21) of microfilaraemic human filariasis patients are seropositive for antibodies to Bm-VAL-1, with particularly high levels of IgG3 and IgG4 isotypes. The IgG4 subclass may indicate stimulation by adult and/or microfilarial-derived immunogens. The association of Bm-VAL-1 with the infective stage and its recognition by humans exposed to filariasis suggests that further evaluation of this antigen as a vaccine candidate should be performed.
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Affiliation(s)
- J Murray
- Ashworth Laboratories, Institute of Cell, Animal and Population Biology, University of Edinburgh, West Mains Road, EH9 3JT, Edinburgh, UK
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46
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Abstract
Previously we have shown that in the filarial parasite Brugia malayi, stimulation with murine epidermal growth factor (EGF) upregulated the expression of the nuclear GTPase, Ran. In this paper we provide further evidence that filarial parasites possess the ability to respond to mammalian EGF. Stimulation of B. malayi microfilariae with EGF increased transcription of a Raf kinase, increased the physical interaction between Ran and at least eight unidentified proteins, abolished the association of a putative EGF receptor with the nuclear GTPase Ran and enhanced phosphorylation of native microfilarial proteins. In the cattle filarial parasite Setaria digitata, stimulation of adult worms with EGF was probably responsible for up-regulation of a DP-1 family transcription factor. These data suggest that filarial parasites possess the ability to respond to mammalian EGF and that mammalian growth factors may regulate developmental maturation of filarial parasites.
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Affiliation(s)
- S Dissanayake
- Department of Microbiology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates.
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47
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Shukla-Dave A, Degaonkar M, Roy R, Murthy PK, Murthy PS, Raghunathan P, Chatterjee RK. Metabolite mapping of human filarial parasite, Brugia malayi with nuclear magnetic resonance. Magn Reson Imaging 1999; 17:1503-9. [PMID: 10609999 DOI: 10.1016/s0730-725x(99)00091-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Metabolite mapping of human filarial parasite, Brugia malayi was carried out in vitro as well as in situ in host Mastomys coucha by 31P nuclear magnetic resonance (NMR) spectroscopy. Detection of parasites by visualizing contrast spots due to pathologic changes was observed by 1H magnetic resonance imaging (MRI). Major metabolites of adult B. malayi observed by 31P-NMR spectroscopy were of sugar phosphates (SP), phosphomonoesters (PME), glycerophosphoryl-ethanolamine (GPE), -choline (GPC), phosphoenolpyruvate (PEP), inorganic phosphate (Pi), nucleoside diphosphosugar and nucleotides-mono, -di and -tri phosphates. PEP and GPC were present in high concentration; PEP being the major energy reservoir and GPC the major phospholipid in this species of filaria. The 31P NMR spectra of testis of mastomys, showed seven major peaks of SP, PME, phosphocreatine (PCr), phosphodiesters (PDE), Pi, and nucleotides di- and tri-phosphates. The 31P-NMR spectra of testis of B. malayi infected animal also consisted of seven major peaks with significant decrease in the SP and PME peak showing changes in the carbohydrate and lipid metabolism of filaria infected testis. Thus, in vivo 31P MRS provided a non-invasive assessment of tissue bioenergetics and phospholipid metabolism.
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Affiliation(s)
- A Shukla-Dave
- Division of Parasitology, Central Drug Research Institute, Lucknow, India
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48
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Abstract
The calgranulins are a family of calcium- and zinc-binding proteins produced by neutrophils, monocytes, and other cells. Calgranulins are released during inflammatory responses and have antimicrobial activity. Recently, one of the calgranulins, human calgranulin C (CaGC), has been implicated as an important component of the host responses that limit the parasite burden during filarial nematode infections. The goal of this work was to test the hypothesis that human CaGC has biologic activity against filarial parasites. Brugia malayi microfilariae and adults were exposed in vitro to 0.75 to 100 nM recombinant human CaGC. Recombinant CaGC affected adult and larval parasites in a dose-dependent fashion. Microfilariae were more sensitive to the action of CaGC than were adult parasites. At high levels, CaGC was both macrofilariacidal and microfilariacidal. At lower levels, the percentage of parasites killed was dependent on the level of CaGC in the culture system. The larvae not killed had limited motility. The filariastatic effect of low-level CaGC was reversed when the CaGC was removed from the culture system. Immunohistochemical analysis demonstrated that human CaGC accumulated in the cells of the hypodermis-lateral chord of adult and larval parasites. The antifilarial activity of CaGC was not due to the sequestration of zinc. Thus, the cellular and molecular mechanisms that result in the production and release of CaGC in humans may play a key role in the regulation of filarial parasite numbers.
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Affiliation(s)
- J D Gottsch
- Wilmer Ophthalmological Institute, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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49
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Abstract
Brugia malayi is a mosquito-borne filarial nematode that causes lymphatic filariasis and elephantiasis in humans. The purpose of this study was to identify and characterize genes that are expressed differentially in male and female B. malayi in hopes of gaining new insight into the reproductive biology of the parasite. Two approaches were used. A 5' differential display PCR (splice leader differential display PCR, SL DD-PCR) was performed by PCR with splice leader and random primers on cDNA templates, and electronic subtraction was performed on expressed sequence tag (EST) cluster databases developed by the Filarial Genome Project (FGP). Gender-specific expression of candidate clones was confirmed by RT-PCR for six of 22 (27%) clones identified by DD and in seven of 15 (47%) clones identified by electronic subtraction. One clone was identified by both methods. Several female-specific clones had homology to known nematode genes that encode a fatty acid binding protein, a high mobility group protein, an eggshell protein, a glutamate-gated ion channel, and a collagen. However, most of the clones have no significant homology to known genes or proteins in computer databases. This project has confirmed the value of SL DD-PCR and electronic subtraction for analysis of gene expression in filariae. These two complimentary techniques may be generally applicable to the study of gender-specific (and by analogy stage specific) gene expression in other nematodes.
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Affiliation(s)
- M L Michalski
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Raghavan N, Ghosh I, Eisinger WS, Pastrana D, Scott AL. Developmentally regulated expression of a unique small heat shock protein in Brugia malayi. Mol Biochem Parasitol 1999; 104:233-46. [PMID: 10593178 DOI: 10.1016/s0166-6851(99)00150-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A screen of an expression library from the fourth larval stage (L4) of the parasitic nematode Brugia malayi resulted in the identification of a 727 bp full-length cDNA with 29-40% identity to members of the small heat shock family of proteins (Bm-hsp-s1). The open reading frame encoded a protein of approximately 18 kDA (Bm-HSP-s1). An alignment of the Bm-HSP-s1 sequence with the sequences of small HSPs from vertebrate and invertebrate species demonstrated that a majority of the identity was concentrated in the central alpha-crystallin domain. Bm-HSP-s1 was constitutively produced by L4 and adult parasites and at low levels by third-stage larvae (L3), but not by first-stage larvae (microfilariae). In adult parasites, Bm-HSP-s1 was localized to the body wall muscle cells and to the cells of the hypodermis/lateral cord. Bm-HSP-s1 production was induced in adult and L3 incubated at 42 degrees C and in L3s during the developmental transition from vector-stage to vertebrate-stage parasites at 37 degrees C. Neither increased nor decreased temperatures induced Bm-HSP-s1 production in microfilariae. Nitric oxide induced low-level, transient Bm-HSP-s1 synthesis in adults, but not in microfilariae. Bm-HSP-s1 did not function as a molecular chaperone to prevent heat-induced aggregation of a test substrate. The developmentally regulated expression and inducable nature of Bm-HSP-s1 suggests that it may have a stage-restricted role in maintaining parasite homeostasis.
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Affiliation(s)
- N Raghavan
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205, USA
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