1
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Wang PP, Jiang X, Bai J, Yang F, Yu X, Wu Y, Zheng W, Zhang Y, Cui L, Liu F, Zhu X, Cao Y. Characterization of PSOP26 as an ookinete surface antigen with improved transmission-blocking activity when fused with PSOP25. Parasit Vectors 2022; 15:175. [PMID: 35606790 PMCID: PMC9125894 DOI: 10.1186/s13071-022-05294-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 04/18/2022] [Indexed: 11/26/2022] Open
Abstract
Background The Plasmodium zygote-to-ookinete developmental transition is an essential step for establishing an infection in the mosquito vector, and antigens expressed during this stage are potential targets for transmission-blocking vaccines (TBVs). The secreted ookinete protein 26 (PSOP26) is a newly identified ookinete surface protein. The anti-PSOP26 serum has moderate transmission-blocking activity, indicating the benefit of further investigating this protein as a target for TBVs. Methods The function of psop26 was analyzed by targeted gene disruption. A chimeric PSOP25-PSOP26 protein was expressed in the Escherichia coli system. The PSOP25-PSOP26 fusion protein, along with mixed (PSOP25 + PSOP26) or single proteins (PSOP26 or PSOP25), were used for the immunization of mice. The antibody titers and immunogenicity of individual sera were analyzed by enzyme-linked immunoassay (ELISA), indirect immunofluorescence assay (IFA), and Western blot. The transmission-blocking activity of sera from different immunization schemes was assessed using in vitro and in vivo assays. Results PSOP26 is a surface protein expressed in Plasmodium gametes and ookinetes. The protein is dispensable for asexual blood-stage development, gametogenesis, and zygote formation, but is essential for the zygote-to-ookinete developmental transition. Specifically, both the prevalence of infections and oocyst densities were decreased in mosquitoes fed on psop26-null mutants. Mixtures of individual PSOP25 and PSOP26 fragments (PSOP25 + PSOP26), as well as chimeras (PSOP25-PSOP26), elicited high antibody levels in mice, with no immunological interference. Antisera against the mixed and fusion proteins elicited higher transmission-reducing activity (TRA) than antisera against the single PSOP26 antigen, but comparable to antisera against PSOP25 antigen alone. Conclusions PSOP26 plays a critical role in the zygote-to-ookinete developmental transition. PSOP25 is a promising TBV candidate that could be used alone to target the ookinete stage. Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05294-8.
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Affiliation(s)
- Peng-Peng Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.,Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Xuefeng Jiang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Jie Bai
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Fan Yang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Xinxin Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Wenqi Zheng
- Department of Clinical Laboratory, Affiliated Hospital of Inner Mongolian Medical University, Inner Mongolia, Huhhot, 150000, China
| | - Yongzhe Zhang
- Department of Pathogen Biology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.,Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612-9415, USA
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Xiaotong Zhu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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2
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Kaur H, Garber L, Murphy JW, Vinetz JM. Structure–function analysis of cysteine residues in the
plasmodium falciparum
chitinase,
PfCHT1. Protein Sci 2022; 31:e4289. [PMID: 35481637 PMCID: PMC8994504 DOI: 10.1002/pro.4289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 11/11/2022]
Abstract
The Plasmodium ookinete uses chitinase activity to penetrate the acellular, chitin-containing peritrophic matrix to invade the mosquito vector. Plasmodium ookinetes from different parasite clades secrete two structurally distinct forms of chitinase, one, a short form lacking a C-terminal putative chitin-binding domain (CBD), the other, a long form with both proenzyme and C-terminal putative chitin-binding domains. Here, we structurally and functionally characterize the three cysteines in the short chitinase of the human-infecting malaria parasite, P. falciparum testing the hypothesis that one unpaired cysteine would not contribute to chitinase-specific enzymatic activity which would identify this residue as potentially involved in intermolecular disulfide bonding and heteromultimeric invasion complex formation as previously described. To test this hypothesis, we produced and characterized recombinant wild-type and cysteine-mutation PfCHT1 proteins in E. coli and used biophysical and enzymatic approaches to examine their enzymatic activities and chitin-binding affinities. The cysteine-203 PfCHT1 mutation had no effect on chitinolytic and chitin-binding functions. The cysteine-220 and cysteine-230 mutants were enzymatically inactive and did not bind to chitin. The artificial intelligence-based protein prediction algorithm, AlphaFold, correctly identified the involvement of cys-220 and cys-230 in the intramolecular disulfide linkages key to maintaining properly folded chitinase structural integrity. AlphaFold predicted that cys-203 cysteine is surface exposed and thus involved in intermolecular protein-protein interaction. Production of the cys-to-ser 203 PfCHT1 mutant facilitated recombinant protein production. Future cellular and biochemical studies are needed to further understand details of Plasmodium ookinete mosquito midgut invasion.
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Affiliation(s)
- Hargobinder Kaur
- Section of Infectious Diseases, Department of Internal Medicine Yale School of Medicine New Haven Connecticut USA
| | - Laine Garber
- Section of Infectious Diseases, Department of Internal Medicine Yale School of Medicine New Haven Connecticut USA
| | - James W. Murphy
- Department of Pharmacology Yale University School of Medicine New Haven Connecticut USA
| | - Joseph M. Vinetz
- Section of Infectious Diseases, Department of Internal Medicine Yale School of Medicine New Haven Connecticut USA
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3
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Evolutionary insights into the microneme-secreted, chitinase-containing high molecular weight protein complexes involved in Plasmodium invasion of the mosquito midgut. Infect Immun 2021; 90:e0031421. [PMID: 34606368 DOI: 10.1128/iai.00314-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While general mechanisms by which Plasmodium ookinetes invade the mosquito midgut have been studied, details remain to be understood regarding the interface of the ookinete, specifically its barriers to invasion, such as the proteolytic milieu, the chitin-containing, protein cross-linked peritrophic matrix, and the midgut epithelium. Here we review knowledge of Plasmodium chitinases and the mechanisms by which they mediate the ookinete crossing the peritrophic matrix. The integration of new genomic insights into previous findings advances our understanding of Plasmodium evolution. Recently obtained Plasmodium spp. genomic data enable identification of the conserved residues in the experimentally demonstrated hetero-multimeric, high molecular weight complex comprised of a short chitinase covalently linked to binding partners, von Willebrand factor A domain-related protein (WARP) and secreted ookinete adhesive protein (SOAP). Artificial intelligence-based high-resolution structural modeling using the DeepMind AlphaFold algorithm yielded highly informative 3D structures and insights into how short chitinases, WARP, and SOAP may interact at the atomic level to form the ookinete-secreted peritrophic matrix invasion complex. Elucidating the significance of the divergence of ookinete-secreted micronemal proteins among Plasmodium species could lead to a better understanding of ookinete invasion machinery and the co-evolution of Plasmodium-mosquito interactions.
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4
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Kitsou C, Foor SD, Dutta S, Bista S, Pal U. Tick gut barriers impacting tick-microbe interactions and pathogen persistence. Mol Microbiol 2021; 116:1241-1248. [PMID: 34570926 DOI: 10.1111/mmi.14822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/08/2023]
Abstract
Ticks are regarded as one of the most ancient, unique, and highly evolved ectoparasites. They can parasitize diverse vertebrates and transmit a number of widespread infections. Once acquired from infected hosts, many tick-borne pathogens, like Borrelia burgdorferi, are confined within the tick gut lumen and are surrounded by discrete gut barriers. Such barriers include the peritrophic membrane (PM) and the dityrosine network (DTN), which are in close contact with resident microbiota and invading pathogens, influencing their survival within the vector. Herein, we review our current state of knowledge about tick-microbe interactions involving the PM and DTN structures. As a model, we will focus on Ixodes ticks, their microbiome, and the pathogen of Lyme disease. We will address the most salient findings on the structural and physiological roles of these Ixodes gut barriers on microbial interactions, with a comparison to analogous functions in other model vectors, such as mosquitoes. We will distill how this information could be leveraged towards a better understanding of the basic mechanisms of gut biology and tick-microbial interactions, which could contribute to potential therapeutic strategies in response to ticks and tick-borne infections.
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Affiliation(s)
- Chrysoula Kitsou
- Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA
| | - Shelby D Foor
- Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA
| | - Shraboni Dutta
- Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA
| | - Sandhya Bista
- Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA
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5
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Nakayama K, Kimura Y, Kitahara Y, Soga A, Haraguchi A, Hakozaki J, Sugiyama M, Kusakisako K, Fukumoto S, Ikadai H. Role of Plasmodium berghei ookinete surface and oocyst capsule protein, a novel oocyst capsule-associated protein, in ookinete motility. Parasit Vectors 2021; 14:373. [PMID: 34289894 PMCID: PMC8296654 DOI: 10.1186/s13071-021-04868-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 06/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium sp., which causes malaria, must first develop in mosquitoes before being transmitted. Upon ingesting infected blood, gametes form in the mosquito lumen, followed by fertilization and differentiation of the resulting zygotes into motile ookinetes. Within 24 h of blood ingestion, these ookinetes traverse mosquito epithelial cells and lodge below the midgut basal lamina, where they differentiate into sessile oocysts that are protected by a capsule. METHODS We identified an ookinete surface and oocyst capsule protein (OSCP) that is involved in ookinete motility as well as oocyst capsule formation. RESULTS We found that knockout of OSCP in parasite decreases ookinete gliding motility and gradually reduces the number of oocysts. On day 15 after blood ingestion, the oocyst wall was significantly thinner. Moreover, adding anti-OSCP antibodies decreased the gliding speed of wild-type ookinetes in vitro. Adding anti-OSCP antibodies to an infected blood meal also resulted in decreased oocyst formation. CONCLUSION These findings may be useful for the development of a transmission-blocking tool for malaria.
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Affiliation(s)
- Kazuhiko Nakayama
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Yuta Kimura
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Yu Kitahara
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Akira Soga
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, 080-8555, Japan
| | - Asako Haraguchi
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Jun Hakozaki
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Makoto Sugiyama
- Laboratory of Veterinary Anatomy, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Kodai Kusakisako
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan
| | - Shinya Fukumoto
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, 080-8555, Japan
| | - Hiromi Ikadai
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, 034-8628, Japan.
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6
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Viswanath VK, Gore ST, Valiyaparambil A, Mukherjee S, Lakshminarasimhan A. Plasmodium chitinases: revisiting a target of transmission-blockade against malaria. Protein Sci 2021; 30:1493-1501. [PMID: 33934433 DOI: 10.1002/pro.4095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 01/21/2023]
Abstract
Malaria is a life-threatening disease caused by one of the five species of Plasmodium, among which Plasmodium falciparum cause the deadliest form of the disease. Plasmodium species are dependent on a vertebrate host and a blood-sucking insect vector to complete their life cycle. Plasmodium chitinases belonging to the GH18 family are secreted inside the mosquito midgut, during the ookinete stage of the parasite. Chitinases mediate the penetration of parasite through the peritrophic membrane, facilitating access to the gut epithelial layer. In this review, we describe Plasmodium chitinases with special emphasis on chitinases from P. falciparum and P. vivax, the representative examples of the short and long forms of this protein. In addition to the chitinase domain, chitinases belonging to the long form contain a pro-domain and chitin-binding domain. Amino acid sequence alignment of long and short form chitinase domains reveals multiple positions containing variant residues. A subset of these positions was found to be conserved or invariant within long or short forms, indicating the role of these positions in attributing form-specific activity. The reported differences in affinities to allosamidin for P. vivax and P. falciparum were predicted to be due to different residues at two amino acid positions, resulting in altered interactions with the inhibitor. Understanding the role of these amino acids in Plasmodium chitinases will help us elucidate the mechanism of catalysis and the mode of inhibition, which will be the key for identification of potent inhibitors or antibodies demonstrating transmission-blocking activity.
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Affiliation(s)
- Vysakh K Viswanath
- Tata Institute for Genetics and Society, Center at inStem, Bengaluru, India
| | - Suraj T Gore
- Aurigene Discovery Technologies Ltd, Bengaluru, India
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7
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Ukegbu CV, Christophides GK, Vlachou D. Identification of Three Novel Plasmodium Factors Involved in Ookinete to Oocyst Developmental Transition. Front Cell Infect Microbiol 2021; 11:634273. [PMID: 33791240 PMCID: PMC8005625 DOI: 10.3389/fcimb.2021.634273] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/10/2021] [Indexed: 12/11/2022] Open
Abstract
Plasmodium falciparum malaria remains a major cause of global morbidity and mortality, mainly in sub-Saharan Africa. The numbers of new malaria cases and deaths have been stable in the last years despite intense efforts for disease elimination, highlighting the need for new approaches to stop disease transmission. Further understanding of the parasite transmission biology could provide a framework for the development of such approaches. We phenotypically and functionally characterized three novel genes, PIMMS01, PIMMS57, and PIMMS22, using targeted disruption of their orthologs in the rodent parasite Plasmodium berghei. PIMMS01 and PIMMS57 are specifically and highly expressed in ookinetes, while PIMMS22 transcription starts already in gametocytes and peaks in sporozoites. All three genes show strong phenotypes associated with the ookinete to oocyst transition, as their disruption leads to very low numbers of oocysts and complete abolishment of transmission. PIMMS22 has a secondary essential function in the oocyst. Our results enrich the molecular understanding of the parasite-vector interactions and identify PIMMS01, PIMMS57, and PIMMS22 as new targets of transmission blocking interventions.
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Affiliation(s)
- Chiamaka V Ukegbu
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - George K Christophides
- Department of Life Sciences, Imperial College London, London, United Kingdom.,The Cyprus Institute, Nicosia, Cyprus
| | - Dina Vlachou
- Department of Life Sciences, Imperial College London, London, United Kingdom.,The Cyprus Institute, Nicosia, Cyprus
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8
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Patra KP, Kaur H, Kolli SK, Wozniak JM, Prieto JH, Yates JR, Gonzalez DJ, Janse CJ, Vinetz JM. A Hetero-Multimeric Chitinase-Containing Plasmodium falciparum and Plasmodium gallinaceum Ookinete-Secreted Protein Complex Involved in Mosquito Midgut Invasion. Front Cell Infect Microbiol 2021; 10:615343. [PMID: 33489941 PMCID: PMC7821095 DOI: 10.3389/fcimb.2020.615343] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/30/2020] [Indexed: 12/14/2022] Open
Abstract
Malaria parasites are transmitted by Anopheles mosquitoes. During its life cycle in the mosquito vector the Plasmodium ookinete escapes the proteolytic milieu of the post-blood meal midgut by traversing the midgut wall. This process requires penetration of the chitin-containing peritrophic matrix lining the midgut epithelium, which depends in part on ookinete-secreted chitinases. Plasmodium falciparum ookinetes have one chitinase (PfCHT1), whereas ookinetes of the avian-infecting parasite, P. gallinaceum, have two, a long and a short form, PgCHT1 and PgCHT2, respectively. Published data indicates that PgCHT2 forms a high molecular weight (HMW) reduction-sensitive complex; and one binding partner is the ookinete-produced von Willebrand A-domain-containing protein, WARP. Size exclusion chromatography data reported here show that P. gallinaceum PgCHT2 and its ortholog, P. falciparum PfCHT1 are covalently-linked components of a HMW chitinase-containing complex (> 1,300 kDa). Mass spectrometry of ookinete-secreted proteins isolated using a new chitin bead pull-down method identified chitinase-associated proteins in P. falciparum and P. gallinaceum ookinete-conditioned culture media. Mass spectrometry of this complex showed the presence of several micronemal proteins including von Willebrand factor A domain-related protein (WARP), ookinete surface enolase, and secreted ookinete adhesive protein (SOAP). To test the hypothesis that ookinete-produced PfCHT1 can form a high molecular homo-multimer or, alternatively, interacts with P. berghei ookinete-produced proteins to produce an HMW hetero-multimer, we created chimeric P. berghei parasites expressing PfCHT1 to replace PbCHT1, enabling the production of large numbers of PfCHT1-expressing ookinetes. We show that chimeric P. berghei ookinetes express monomeric PfCHT1, but a HMW complex containing PfCHT1 is not present. A better understanding of the chitinase-containing HMW complex may enhance development of next-generation vaccines or drugs that target malaria transmission stages.
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Affiliation(s)
- Kailash P Patra
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Hargobinder Kaur
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Surendra Kumar Kolli
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Jacob M Wozniak
- Department of Pharmacology and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States
| | - Judith Helena Prieto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,Department of Chemistry, Western Connecticut State University, Danbury, CT, United States
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - David J Gonzalez
- Department of Pharmacology and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Joseph M Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
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9
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Ruiz JL, Gómez-Díaz E. The second life of Plasmodium in the mosquito host: gene regulation on the move. Brief Funct Genomics 2020; 18:313-357. [PMID: 31058281 DOI: 10.1093/bfgp/elz007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/08/2019] [Accepted: 03/26/2019] [Indexed: 01/08/2023] Open
Abstract
Malaria parasites face dynamically changing environments and strong selective constraints within human and mosquito hosts. To survive such hostile and shifting conditions, Plasmodium switches transcriptional programs during development and has evolved mechanisms to adjust its phenotype through heterogeneous patterns of gene expression. In vitro studies on culture-adapted isolates have served to set the link between chromatin structure and functional gene expression. Yet, experimental evidence is limited to certain stages of the parasite in the vertebrate, i.e. blood, while the precise mechanisms underlying the dynamic regulatory landscapes during development and in the adaptation to within-host conditions remain poorly understood. In this review, we discuss available data on transcriptional and epigenetic regulation in Plasmodium mosquito stages in the context of sporogonic development and phenotypic variation, including both bet-hedging and environmentally triggered direct transcriptional responses. With this, we advocate the mosquito offers an in vivo biological model to investigate the regulatory networks, transcription factors and chromatin-modifying enzymes and their modes of interaction with regulatory sequences, which might be responsible for the plasticity of the Plasmodium genome that dictates stage- and cell type-specific blueprints of gene expression.
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Affiliation(s)
- José L Ruiz
- Instituto de Parasitología y Biomedicina López-Neyra (IPBLN), Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Elena Gómez-Díaz
- Instituto de Parasitología y Biomedicina López-Neyra (IPBLN), Consejo Superior de Investigaciones Científicas, Granada, Spain
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10
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Canepa GE, Molina-Cruz A, Yenkoidiok-Douti L, Calvo E, Williams AE, Burkhardt M, Peng F, Narum D, Boulanger MJ, Valenzuela JG, Barillas-Mury C. Antibody targeting of a specific region of Pfs47 blocks Plasmodium falciparum malaria transmission. NPJ Vaccines 2018; 3:26. [PMID: 30002917 PMCID: PMC6039440 DOI: 10.1038/s41541-018-0065-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/01/2018] [Accepted: 05/15/2018] [Indexed: 02/07/2023] Open
Abstract
Transmission-blocking vaccines are based on eliciting antibody responses in the vertebrate host that disrupt parasite development in the mosquito vector and prevent malaria transmission. The surface protein Pfs47 is present in Plasmodium falciparum gametocytes and female gametes. The potential of Pfs47 as a vaccine target was evaluated. Soluble full-length recombinant protein, consisting of three domains, was expressed in E. coli as a thioredoxin fusion (T-Pfs47). The protein was immunogenic, and polyclonal and monoclonal antibodies (mAb) were obtained, but they did not confer transmission blocking activity (TBA). All fourteen mAb targeted either domains 1 or 3, but not domain 2 (D2), and immune reactivity to D2 was also very low in polyclonal mouse IgG after T-Pfs47 immunization. Disruption of the predicted disulfide bond in D2, by replacing cysteines for alanines (C230A and C260A), allowed expression of recombinant D2 protein in E. coli. A combination of mAbs targeting D2, and deletion proteins from this domain, allowed us to map a central 52 amino acid (aa) region where antibody binding confers strong TBA (78-99%). This 52 aa antigen is immunogenic and well conserved, with only seven haplotypes world-wide that share 96-98% identity. Neither human complement nor the mosquito complement-like system are required for the observed TBA. A dramatic reduction in ookinete numbers and ookinete-specific transcripts was observed, suggesting that the antibodies are interacting with female gametocytes and preventing fertilization.
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Affiliation(s)
- Gaspar E. Canepa
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Alvaro Molina-Cruz
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Lampouguin Yenkoidiok-Douti
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Eric Calvo
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Adeline E. Williams
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Martin Burkhardt
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Fangni Peng
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2 Canada
| | - David Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Martin J. Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2 Canada
| | - Jesus G. Valenzuela
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Insti6tute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852 USA
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11
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Simões ML, Caragata EP, Dimopoulos G. Diverse Host and Restriction Factors Regulate Mosquito-Pathogen Interactions. Trends Parasitol 2018; 34:603-616. [PMID: 29793806 DOI: 10.1016/j.pt.2018.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
Mosquitoes transmit diseases that seriously impact global human health. Despite extensive knowledge of the life cycles of mosquito-borne parasites and viruses within their hosts, control strategies have proven insufficient to halt their spread. An understanding of the relationships established between such pathogens and the host tissues they inhabit is therefore paramount for the development of new strategies that specifically target these interactions, to prevent the pathogens' maturation and transmission. Here we present an updated account of the antagonists and host factors that affect the development of Plasmodium, the parasite causing malaria, and mosquito-borne viruses, such as dengue virus and Zika virus, within their mosquito vectors, and we discuss the similarities and differences between Plasmodium and viral systems, looking toward the elucidation of new targets for disease control.
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Affiliation(s)
- Maria L Simões
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; These authors contributed equally
| | - Eric P Caragata
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; These authors contributed equally
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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A Knockout Screen of ApiAP2 Genes Reveals Networks of Interacting Transcriptional Regulators Controlling the Plasmodium Life Cycle. Cell Host Microbe 2017; 21:11-22. [PMID: 28081440 PMCID: PMC5241200 DOI: 10.1016/j.chom.2016.12.003] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 08/17/2016] [Accepted: 11/17/2016] [Indexed: 01/17/2023]
Abstract
A family of apicomplexa-specific proteins containing AP2 DNA-binding domains (ApiAP2s) was identified in malaria parasites. This family includes sequence-specific transcription factors that are key regulators of development. However, functions for the majority of ApiAP2 genes remain unknown. Here, a systematic knockout screen in Plasmodium berghei identified ten ApiAP2 genes that were essential for mosquito transmission: four were critical for the formation of infectious ookinetes, and three were required for sporogony. We describe non-essential functions for AP2-O and AP2-SP proteins in blood stages, and identify AP2-G2 as a repressor active in both asexual and sexual stages. Comparative transcriptomics across mutants and developmental stages revealed clusters of co-regulated genes with shared cis promoter elements, whose expression can be controlled positively or negatively by different ApiAP2 factors. We propose that stage-specific interactions between ApiAP2 proteins on partly overlapping sets of target genes generate the complex transcriptional network that controls the Plasmodium life cycle. Mutants in 11 of 26 apiAP2 genes reveal gene functions in mosquito transmission Co-expression clustering across mutants and stages reveals molecular phenotypes Multifunctional apiAP2 genes create complex regulatory networks in Plasmodium Ap2-g2 is a transcriptional repressor in both asexual and sexual blood stages
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Plasmodium berghei PIMMS2 Promotes Ookinete Invasion of the Anopheles gambiae Mosquito Midgut. Infect Immun 2017; 85:IAI.00139-17. [PMID: 28559405 PMCID: PMC5520436 DOI: 10.1128/iai.00139-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/11/2017] [Indexed: 12/21/2022] Open
Abstract
Mosquito midgut stages of the malaria parasite present an attractive biological system to study host-parasite interactions and develop interventions to block disease transmission. Mosquito infection ensues upon oocyst development that follows ookinete invasion and traversal of the mosquito midgut epithelium. Here, we report the characterization of PIMMS2 (Plasmodium invasion of mosquito midgut screen candidate 2), a Plasmodium berghei protein with structural similarities to subtilisin-like proteins. PIMMS2 orthologs are present in the genomes of all plasmodia and are mapped between the subtilisin-encoding genes SUB1 and SUB3. P. berghei PIMMS2 is specifically expressed in zygotes and ookinetes and is localized on the ookinete surface. Loss of PIMMS2 function through gene disruption by homologous recombination leads to normal development of motile ookinetes that exhibit a severely impaired capacity to traverse the mosquito midgut and transform to oocysts. Genetic complementation of the disrupted locus with a mutated PIMMS2 allele reveals that amino acid residues corresponding to the putative subtilisin-like catalytic triad are important but not essential for protein function. Our data demonstrate that PIMMS2 is a novel ookinete-specific protein that promotes parasite traversal of the mosquito midgut epithelium and establishment of mosquito infection.
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Rodgers FH, Gendrin M, Wyer CAS, Christophides GK. Microbiota-induced peritrophic matrix regulates midgut homeostasis and prevents systemic infection of malaria vector mosquitoes. PLoS Pathog 2017; 13:e1006391. [PMID: 28545061 PMCID: PMC5448818 DOI: 10.1371/journal.ppat.1006391] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/30/2017] [Accepted: 04/28/2017] [Indexed: 12/22/2022] Open
Abstract
Manipulation of the mosquito gut microbiota can lay the foundations for novel methods for disease transmission control. Mosquito blood feeding triggers a significant, transient increase of the gut microbiota, but little is known about the mechanisms by which the mosquito controls this bacterial growth whilst limiting inflammation of the gut epithelium. Here, we investigate the gut epithelial response to the changing microbiota load upon blood feeding in the malaria vector Anopheles coluzzii. We show that the synthesis and integrity of the peritrophic matrix, which physically separates the gut epithelium from its luminal contents, is microbiota dependent. We reveal that the peritrophic matrix limits the growth and persistence of Enterobacteriaceae within the gut, whilst preventing seeding of a systemic infection. Our results demonstrate that the peritrophic matrix is a key regulator of mosquito gut homeostasis and establish functional analogies between this and the mucus layers of the mammalian gastrointestinal tract. When a female mosquito takes a blood meal from a human, the bacteria residing within its gut grow significantly. Following a blood meal, female mosquitoes produce a barrier within their gut, known as the peritrophic matrix, which physically separates the blood meal from the cells of the epithelium. Here, we show that the presence of bacteria in the gut is required for the synthesis of the peritrophic matrix. By experimentally disrupting this barrier, we find that this structure plays a role in limiting the extent to which bacteria of one particular family are able to grow and persist in the mosquito gut. We also find that the peritrophic matrix ensures that bacteria remain within the gut, preventing them from invading the mosquito body cavity. These results will be useful in designing disease control strategies that depend on the ability of bacteria to colonize and persist in relevant tissues in the mosquito host.
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Affiliation(s)
- Faye H. Rodgers
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Mathilde Gendrin
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Claudia A. S. Wyer
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - George K. Christophides
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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15
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Santos JM, Egarter S, Zuzarte-Luís V, Kumar H, Moreau CA, Kehrer J, Pinto A, da Costa M, Franke-Fayard B, Janse CJ, Frischknecht F, Mair GR. Malaria parasite LIMP protein regulates sporozoite gliding motility and infectivity in mosquito and mammalian hosts. eLife 2017; 6:e24109. [PMID: 28525314 PMCID: PMC5438254 DOI: 10.7554/elife.24109] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/29/2017] [Indexed: 12/11/2022] Open
Abstract
Gliding motility allows malaria parasites to migrate and invade tissues and cells in different hosts. It requires parasite surface proteins to provide attachment to host cells and extracellular matrices. Here, we identify the Plasmodium protein LIMP (the name refers to a gliding phenotype in the sporozoite arising from epitope tagging of the endogenous protein) as a key regulator for adhesion during gliding motility in the rodent malaria model P. berghei. Transcribed in gametocytes, LIMP is translated in the ookinete from maternal mRNA, and later in the sporozoite. The absence of LIMP reduces initial mosquito infection by 50%, impedes salivary gland invasion 10-fold, and causes a complete absence of liver invasion as mutants fail to attach to host cells. GFP tagging of LIMP caused a limping defect during movement with reduced speed and transient curvature changes of the parasite. LIMP is an essential motility and invasion factor necessary for malaria transmission.
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Affiliation(s)
- Jorge M Santos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, Lisbon, Portugal
| | - Saskia Egarter
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Vanessa Zuzarte-Luís
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, Lisbon, Portugal
| | - Hirdesh Kumar
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Catherine A Moreau
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Jessica Kehrer
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Andreia Pinto
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, Lisbon, Portugal
| | - Mário da Costa
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, Lisbon, Portugal
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Chris J Janse
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Friedrich Frischknecht
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Gunnar R Mair
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, Lisbon, Portugal
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
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Saraiva RG, Kang S, Simões ML, Angleró-Rodríguez YI, Dimopoulos G. Mosquito gut antiparasitic and antiviral immunity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 64:53-64. [PMID: 26827888 DOI: 10.1016/j.dci.2016.01.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/16/2016] [Accepted: 01/26/2016] [Indexed: 06/05/2023]
Abstract
Mosquitoes are responsible for the transmission of diseases with a serious impact on global human health, such as malaria and dengue. All mosquito-transmitted pathogens complete part of their life cycle in the insect gut, where they are exposed to mosquito-encoded barriers and active factors that can limit their development. Here we present the current understanding of mosquito gut immunity against malaria parasites, filarial worms, and viruses such as dengue, Chikungunya, and West Nile. The most recently proposed immune mediators involved in intestinal defenses are discussed, as well as the synergies identified between the recognition of gut microbiota and the mounting of the immune response.
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Affiliation(s)
- Raúl G Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Seokyoung Kang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Maria L Simões
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Yesseinia I Angleró-Rodríguez
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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Bennink S, Kiesow MJ, Pradel G. The development of malaria parasites in the mosquito midgut. Cell Microbiol 2016; 18:905-18. [PMID: 27111866 PMCID: PMC5089571 DOI: 10.1111/cmi.12604] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/13/2016] [Accepted: 04/20/2016] [Indexed: 01/01/2023]
Abstract
The mosquito midgut stages of malaria parasites are crucial for establishing an infection in the insect vector and to thus ensure further spread of the pathogen. Parasite development in the midgut starts with the activation of the intraerythrocytic gametocytes immediately after take-up and ends with traversal of the midgut epithelium by the invasive ookinetes less than 24 h later. During this time period, the plasmodia undergo two processes of stage conversion, from gametocytes to gametes and from zygotes to ookinetes, both accompanied by dramatic morphological changes. Further, gamete formation requires parasite egress from the enveloping erythrocytes, rendering them vulnerable to the aggressive factors of the insect gut, like components of the human blood meal. The mosquito midgut stages of malaria parasites are unprecedented objects to study a variety of cell biological aspects, including signal perception, cell conversion, parasite/host co-adaptation and immune evasion. This review highlights recent insights into the molecules involved in gametocyte activation and gamete formation as well as in zygote-to-ookinete conversion and ookinete midgut exit; it further discusses factors that can harm the extracellular midgut stages as well as the measures of the parasites to protect themselves from any damage.
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Affiliation(s)
- Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Meike J Kiesow
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
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Smith RC, Vega-Rodríguez J, Jacobs-Lorena M. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector. Mem Inst Oswaldo Cruz 2015. [PMID: 25185005 PMCID: PMC4156458 DOI: 10.1590/0074-0276130597] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.
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Affiliation(s)
- Ryan C Smith
- Department of Molecular Microbiology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health and Immunology, Baltimore, MD, USA
| | - Joel Vega-Rodríguez
- Department of Molecular Microbiology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health and Immunology, Baltimore, MD, USA
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health and Immunology, Baltimore, MD, USA
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19
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Ukegbu CV, Cho JS, Christophides GK, Vlachou D. Transcriptional silencing and activation of paternal DNA during Plasmodium berghei zygotic development and transformation to oocyst. Cell Microbiol 2015; 17:1230-40. [PMID: 25728487 PMCID: PMC4678591 DOI: 10.1111/cmi.12433] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 02/24/2015] [Accepted: 02/24/2015] [Indexed: 11/29/2022]
Abstract
The malaria parasite develops sexually in the mosquito midgut upon entry with the ingested blood meal before it can invade the midgut epithelium and embark on sporogony. Recent data have identified a number of distinct transcriptional programmes operating during this critical phase of the parasite life cycle. We aimed at characterizing the parental contribution to these transcriptional programmes and establish the genetic framework that would guide further studies of Plasmodium zygotic development and ookinete-to-oocyst transition. To achieve this we used in vitro and in vivo cross-fertilization experiments of various parasite lines expressing fluorescent reporters under the control of constitutive and stage-specific promoters. The results revealed that the zygote/ookinete stage exhibits a maternal phenotype with respect to constitutively expressed reporters, which is derived from either maternal mRNA inheritance or transcription of the maternal allele. The respective paternal alleles are silenced in the zygote/ookinete but reactivated after midgut invasion and transformation to oocyst. Transcripts specifically produced in the zygote/ookinete are synthesized de novo by both parental alleles. These findings highlight a putative role of epigenetic regulation of Plasmodium zygotic development and add substantially to the emerging picture of the molecular mechanisms regulating this important stage of malaria transmission.
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Affiliation(s)
| | - Jee-Sun Cho
- Department of Life Sciences, Imperial College London, London, UK
| | - George K Christophides
- Department of Life Sciences, Imperial College London, London, UK
- The Cyprus Institute, Nicosia, Cyprus
| | - Dina Vlachou
- Department of Life Sciences, Imperial College London, London, UK
- The Cyprus Institute, Nicosia, Cyprus
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20
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Borges-Veloso A, Saboia-Vahia L, Dias-Lopes G, Domont GB, Britto C, Cuervo P, De Jesus JB. In-depth characterization of trypsin-like serine peptidases in the midgut of the sugar fed Culex quinquefasciatus. Parasit Vectors 2015; 8:373. [PMID: 26174750 PMCID: PMC4502911 DOI: 10.1186/s13071-015-0985-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 07/03/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culex quinquefasciatus is a hematophagous insect from the Culicidae family that feeds on the blood of humans, dogs, birds and livestock. This species transmits a wide variety of pathogens between humans and animals. The midgut environment is the first location of pathogen-vector interactions for blood-feeding mosquitoes and the expression of specific peptidases in the early stages of feeding could influence the outcome of the infection. Trypsin-like serine peptidases belong to a multi-gene family that can be expressed in different isoforms under distinct physiological conditions. However, the confident assignment of the trypsin genes that are expressed under each condition is still a challenge due to the large number of trypsin-coding genes in the Culicidae family and most likely because they are low abundance proteins. METHODS We used zymography for the biochemical characterization of the peptidase profile of the midgut from C. quinquefasciatus females fed on sugar. Protein samples were also submitted to SDS-PAGE followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for peptidase identification. The peptidases sequences were analyzed with bioinformatics tools to assess their distinct features. RESULTS Zymography revealed that trypsin-like serine peptidases were responsible for the proteolytic activity in the midgut of females fed on sugar diet. After denaturation in SDS-PAGE, eight trypsin-like serine peptidases were identified by LC-MS/MS. These peptidases have structural features typical of invertebrate digestive trypsin peptidases but exhibited singularities at the protein sequence level such as: the presence of different amino acids at the autocatalytic motif and substrate binding regions as well as different number of disulfide bounds. Data mining revealed a group of trypsin-like serine peptidases that are specific to C. quinquefasciatus when compared to the culicids genomes sequenced so far. CONCLUSION We demonstrated that proteomics approaches combined with bioinformatics tools and zymographic analysis can lead to the functional annotation of trypsin-like serine peptidases coding genes and aid in the understanding of the complexity of peptidase expression in mosquitoes.
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Affiliation(s)
- André Borges-Veloso
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
| | - Leonardo Saboia-Vahia
- Laboratorio de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Pav. Leônidas Deane, Sala 509, CEP: 21040-360, Rio de Janeiro, RJ, Brazil.
| | - Geovane Dias-Lopes
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
| | - Gilberto B Domont
- Unidade de Proteômica, Laboratório de Química de Proteínas, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Constança Britto
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
| | - Patricia Cuervo
- Laboratorio de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Pav. Leônidas Deane, Sala 509, CEP: 21040-360, Rio de Janeiro, RJ, Brazil.
| | - Jose B De Jesus
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil. .,Departamento de Medicina, Faculdade de Medicina, Universidade Federal de São João del Rei, São João del Rei, MG, Brasil.
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Wu Y, Sinden RE, Churcher TS, Tsuboi T, Yusibov V. Development of malaria transmission-blocking vaccines: from concept to product. ADVANCES IN PARASITOLOGY 2015; 89:109-52. [PMID: 26003037 DOI: 10.1016/bs.apar.2015.04.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Despite decades of effort battling against malaria, the disease is still a major cause of morbidity and mortality. Transmission-blocking vaccines (TBVs) that target sexual stage parasite development could be an integral part of measures for malaria elimination. In the 1950s, Huff et al. first demonstrated the induction of transmission-blocking immunity in chickens by repeated immunizations with Plasmodium gallinaceum-infected red blood cells. Since then, significant progress has been made in identification of parasite antigens responsible for transmission-blocking activity. Recombinant technologies accelerated evaluation of these antigens as vaccine candidates, and it is possible to induce effective transmission-blocking immunity in humans both by natural infection and now by immunization with recombinant vaccines. This chapter reviews the efforts to produce TBVs, summarizes the current status and advances and discusses the remaining challenges and approaches.
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Affiliation(s)
- Yimin Wu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, Rockville, MD, USA
| | | | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Takafumi Tsuboi
- Division of Malaria Research, Ehime University, Matsuyama, Ehime, Japan
| | - Vidadi Yusibov
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
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22
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Sinden RE. The cell biology of malaria infection of mosquito: advances and opportunities. Cell Microbiol 2015; 17:451-66. [PMID: 25557077 PMCID: PMC4409862 DOI: 10.1111/cmi.12413] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/12/2014] [Accepted: 12/24/2014] [Indexed: 01/01/2023]
Abstract
Recent reviews (Feachem et al.; Alonso et al.) have concluded that in order to have a sustainable impact on the global burden of malaria, it is essential that we knowingly reduce the global incidence of infected persons. To achieve this we must reduce the basic reproductive rate of the parasites to < 1 in diverse epidemiological settings. This can be achieved by impacting combinations of the following parameters: the number of mosquitoes relative to the number of persons, the mosquito/human biting rate, the proportion of mosquitoes carrying infectious sporozoites, the daily survival rate of the infectious mosquito and the ability of malaria-infected persons to infect mosquito vectors. This paper focuses on our understanding of parasite biology underpinning the last of these terms: infection of the mosquito. The article attempts to highlight central issues that require further study to assist in the discovery of useful transmission-blocking measures.
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Affiliation(s)
- R E Sinden
- Department of Life Sciences, Imperial College London and the Jenner Institute, The University of Oxford, Oxford, UK
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23
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Akinosoglou KA, Bushell ESC, Ukegbu CV, Schlegelmilch T, Cho JS, Redmond S, Sala K, Christophides GK, Vlachou D. Characterization of Plasmodium developmental transcriptomes in Anopheles gambiae midgut reveals novel regulators of malaria transmission. Cell Microbiol 2015; 17:254-68. [PMID: 25225164 PMCID: PMC4371638 DOI: 10.1111/cmi.12363] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 08/27/2014] [Accepted: 09/08/2014] [Indexed: 12/24/2022]
Abstract
The passage through the mosquito is a major bottleneck for malaria parasite populations and a target of interventions aiming to block disease transmission. Here, we used DNA microarrays to profile the developmental transcriptomes of the rodent malaria parasite Plasmodium berghei in vivo, in the midgut of Anopheles gambiae mosquitoes, from parasite stages in the midgut blood bolus to sporulating oocysts on the basal gut wall. Data analysis identified several distinct transcriptional programmes encompassing genes putatively involved in developmental processes or in interactions with the mosquito. At least two of these programmes are associated with the ookinete development that is linked to mosquito midgut invasion and establishment of infection. Targeted disruption by homologous recombination of two of these genes resulted in mutant parasites exhibiting notable infection phenotypes. GAMER encodes a short polypeptide with granular localization in the gametocyte cytoplasm and shows a highly penetrant loss-of-function phenotype manifested as greatly reduced ookinete numbers, linked to impaired male gamete release. HADO encodes a putative magnesium phosphatase with distinctive cortical localization along the concave ookinete periphery. Disruption of HADO compromises ookinete development leading to significant reduction of oocyst numbers. Our data provide important insights into the molecular framework underpinning Plasmodium development in the mosquito and identifies two genes with important functions at initial stages of parasite development in the mosquito midgut.
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Affiliation(s)
| | | | | | | | - Jee-Sun Cho
- Department of Life Sciences, Imperial College LondonLondon, UK
| | - Seth Redmond
- Department of Life Sciences, Imperial College LondonLondon, UK
| | - Katarzyna Sala
- Department of Life Sciences, Imperial College LondonLondon, UK
| | - George K Christophides
- Department of Life Sciences, Imperial College LondonLondon, UK
- The Cyprus InstituteNicosia, Cyprus
| | - Dina Vlachou
- Department of Life Sciences, Imperial College LondonLondon, UK
- The Cyprus InstituteNicosia, Cyprus
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24
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Nikolaeva D, Draper SJ, Biswas S. Toward the development of effective transmission-blocking vaccines for malaria. Expert Rev Vaccines 2015; 14:653-80. [PMID: 25597923 DOI: 10.1586/14760584.2015.993383] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The continued global burden of malaria can in part be attributed to a complex lifecycle, with both human hosts and mosquito vectors serving as transmission reservoirs. In preclinical models of vaccine-induced immunity, antibodies to parasite sexual-stage antigens, ingested in the mosquito blood meal, can inhibit parasite survival in the insect midgut as judged by ex vivo functional studies such as the membrane feeding assay. In an era of renewed political momentum for malaria elimination and eradication campaigns, such observations have fueled support for the development and implementation of so-called transmission-blocking vaccines. While leading candidates are being evaluated using a variety of promising vaccine platforms, the field is also beginning to capitalize on global '-omics' data for the rational genome-based selection and unbiased characterization of parasite and mosquito proteins to expand the candidate list. This review covers the progress and prospects of these recent developments.
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Affiliation(s)
- Daria Nikolaeva
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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Garcia-Longoria L, Hellgren O, Bensch S. Molecular identification of the chitinase genes in Plasmodium relictum. Malar J 2014; 13:239. [PMID: 24943514 PMCID: PMC4072489 DOI: 10.1186/1475-2875-13-239] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/07/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria parasites need to synthesize chitinase in order to go through the peritrophic membrane, which is created around the mosquito midgut, to complete its life cycle. In mammalian malaria species, the chitinase gene comprises either a large or a short copy. In the avian malaria parasites Plasmodium gallinaceum both copies are present, suggesting that a gene duplication in the ancestor to these extant species preceded the loss of either the long or the short copy in Plasmodium parasites of mammals. Plasmodium gallinaceum is not the most widespread and harmful parasite of birds. This study is the first to search for and identify the chitinase gene in one of the most prevalent avian malaria parasites, Plasmodium relictum. METHODS Both copies of P. gallinaceum chitinase were used as reference sequences for primer design. Different sequences of Plasmodium spp. were used to build the phylogenetic tree of chitinase gene. RESULTS The gene encoding for chitinase was identified in isolates of two mitochondrial lineages of P. relictum (SGS1 and GRW4). The chitinase found in these two lineages consists both of the long (PrCHT1) and the short (PrCHT2) copy. The genetic differences found in the long copy of the chitinase gene between SGS1 and GRW4 were higher than the difference observed for the cytochrome b gene. CONCLUSION The identification of both copies in P. relictum sheds light on the phylogenetic relationship of the chitinase gene in the genus Plasmodium. Due to its high variability, the chitinase gene could be used to study the genetic population structure in isolates from different host species and geographic regions.
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Affiliation(s)
- Luz Garcia-Longoria
- Departamento de Biología Animal, Universidad de Extremadura, E-06071 Badajoz, Spain.
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Multiple pathways for Plasmodium ookinete invasion of the mosquito midgut. Proc Natl Acad Sci U S A 2014; 111:E492-500. [PMID: 24474798 DOI: 10.1073/pnas.1315517111] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plasmodium ookinete invasion of the mosquito midgut is a crucial step of the parasite life cycle but little is known about the molecular mechanisms involved. Previously, a phage display peptide library screen identified SM1, a peptide that binds to the mosquito midgut epithelium and inhibits ookinete invasion. SM1 was characterized as a mimotope of an ookinete surface enolase and SM1 presumably competes with enolase, the presumed ligand, for binding to a putative midgut receptor. Here we identify a mosquito midgut receptor that binds both SM1 and ookinete surface enolase, termed "enolase-binding protein" (EBP). Moreover, we determined that Plasmodium berghei parasites are heterogeneous for midgut invasion, as some parasite clones are strongly inhibited by SM1 whereas others are not. The SM1-sensitive parasites required the mosquito EBP receptor for midgut invasion whereas the SM1-resistant parasites invaded the mosquito midgut independently of EBP. These experiments provide evidence that Plasmodium ookinetes can invade the mosquito midgut by alternate pathways. Furthermore, another peptide from the original phage display screen, midgut peptide 2 (MP2), strongly inhibited midgut invasion by P. berghei (SM1-sensitive and SM1-resistant) and Plasmodium falciparum ookinetes, suggesting that MP2 binds to a separate, universal receptor for midgut invasion.
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Basseri HR, Mohamadzadeh Hajipirloo H, Mohammadi Bavani M, Whitten MMA. Comparative susceptibility of different biological forms of Anopheles stephensi to Plasmodium berghei ANKA strain. PLoS One 2013; 8:e75413. [PMID: 24086525 PMCID: PMC3781038 DOI: 10.1371/journal.pone.0075413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 08/16/2013] [Indexed: 11/22/2022] Open
Abstract
Background There are varying degrees of compatibility between malaria parasite-mosquito species, and understanding this compatibility may be crucial for developing effective transmission-blocking vaccines. This study investigates the compatibility of different biological forms of a malaria vector, Anopheles stephensi, to Plasmodium berghei ANKA strain. Methods Several biologically different and allopatric forms of A. stephensi were studied. Three forms were isolated from different regions of southern Iran: the variety mysorensis, the intermediate form and the native type form, and an additional type form originated from India (Beech strain).The mosquitoes were experimentally infected with P. berghei to compare their susceptibility to parasitism. Anti-mosquito midgut antiserum was then raised in BALB/cs mice immunized against gut antigens from the most susceptible form of A. stephensi (Beech strain), and the efficacy of the antiserum was assessed in transmission-blocking assays conducted on the least susceptible mosquito biological form. Results The susceptibility of different biological forms of A. stephensi mosquito to P. berghei was specifically inter-type varied. The Beech strain and the intermediate form were both highly susceptible to infection, with higher oocyst and sporozoite infection rates than intermediate and mysorensis forms. The oocyst infection, and particularly sporozite infection, was lowest in the mysorensis strain. Antiserum raised against midgut proteins of the Indian Beech type form blocked infection in this mosquito population, but it was ineffective at blocking both oocyst and sporozoite development in the permissive but geographically distant intermediate form mosquitoes. This suggests that a strong degree of incompatibility exists between the mosquito strains in terms of midgut protein(s) acting as putative ookinete receptors. Conclusions The incompatibility in the midgut protein profiles between two biological forms of A. stephensi demonstrates a well-differentiated population structure according to geographical origin. Therefore, the design of potential transmission-blocking strategies should incorporate a more thorough understanding of intra-species variations in host-parasite interactions.
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Affiliation(s)
- Hamid R. Basseri
- Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Habib Mohamadzadeh Hajipirloo
- Department of Parasitology and Mycology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
- * E-mail:
| | - Mulood Mohammadi Bavani
- Department of Parasitology and Mycology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Miranda M. A. Whitten
- Institute of Life Science, College of Medicine, Swansea University, Singleton Park, Swansea, United Kingdom
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Tremp AZ, Carter V, Saeed S, Dessens JT. Morphogenesis of Plasmodium zoites is uncoupled from tensile strength. Mol Microbiol 2013; 89:552-64. [PMID: 23773015 PMCID: PMC3912903 DOI: 10.1111/mmi.12297] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 12/17/2022]
Abstract
A shared feature of the motile stages (zoites) of malaria parasites is a cortical cytoskeletal structure termed subpellicular network (SPN), thought to define and maintain cell shape. Plasmodium alveolins comprise structural components of the SPN, and alveolin gene knockout causes morphological abnormalities that coincide with markedly reduced tensile strength of the affected zoites, indicating the alveolins are prime cell shape determinants. Here, we characterize a novel SPN protein of Plasmodium berghei ookinetes and sporozoites named G2 (glycine at position 2), which is structurally unrelated to alveolins. G2 knockout abolishes parasite transmission and causes zoite malformations and motility defects similar to those observed in alveolin null mutants. Unlike alveolins, however, G2 contributes little to tensile strength, arguing against a cause-effect relationship between tensile strength and cell shape. We also show that G2 null mutant sporozoites display an abnormal arrangement of their subpellicular microtubules. These results provide important new understanding of the factors that determine zoite morphogenesis, as well as the potential roles of the cortical cytoskeleton in gliding motility.
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Affiliation(s)
- Annie Z Tremp
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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Sumitani M, Kasashima K, Yamamoto DS, Yagi K, Yuda M, Matsuoka H, Yoshida S. Reduction of malaria transmission by transgenic mosquitoes expressing an antisporozoite antibody in their salivary glands. INSECT MOLECULAR BIOLOGY 2013; 22:41-51. [PMID: 23176559 DOI: 10.1111/j.1365-2583.2012.01168.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We have previously developed a robust salivary gland-specific expression system in transgenic Anopheles stephensi mosquitoes. To establish transgenic mosquito lines refractory to Plasmodium falciparum using this system, we generated a transgenic mosquito harbouring the gene encoding an anti-P. falciparum circumsporozoite protein (PfCSP) single-chain antibody (scFv) fused to DsRed in a secretory form (mDsRed-2A10 scFv). Fluorescence microscopy showed that the mDsRed-2A10 scFv was localized in the secretory cavities and ducts of the salivary glands in a secreted form. To evaluate P. falciparum transmission-blocking in a rodent malaria model, a transgenic Plasmodium berghei line expressing PfCSP in place of PbCSP (PfCSP/Pb) was constructed. The PfCSP/Pb parasites were able to bind to the mDsRed-2A10 scFv in the salivary glands of the transgenic mosquitoes. Importantly, the infectivity of the transgenic mosquitoes to mice was strongly impaired, indicating that the parasites had been inactivated. These results suggest that salivary gland-specific expression of antisporozoite molecules could be a promising strategy for blocking malaria transmission to humans.
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Affiliation(s)
- M Sumitani
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences, Owashi, Tsukuba, Ibaraki, Japan
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Insect-Derived Chitinases. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 136:19-50. [DOI: 10.1007/10_2013_207] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Zhang X, Zhang J, Park Y, Zhu KY. Identification and characterization of two chitin synthase genes in African malaria mosquito, Anopheles gambiae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:674-82. [PMID: 22683441 PMCID: PMC3489263 DOI: 10.1016/j.ibmb.2012.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 05/07/2012] [Accepted: 05/13/2012] [Indexed: 05/25/2023]
Abstract
Chitin synthase (CHS) represents an attractive target site for combating insect pests as insect growth and development are strictly dependent on precisely tuned chitin biosynthesis and this pathway is absent in humans and other vertebrates. Current knowledge on CHS in insects, especially their structures, functions, and regulations is still very limited. We report the identification and characterization of two chitin synthase genes, AgCHS1 and AgCHS2, in African malaria mosquito, Anopheles gambiae. AgCHS1 and AgCHS2 were predicted to encode proteins of 1,578 and 1,586 amino acid residues, respectively. Their deduced amino acid sequences show high similarities to other insect chitin synthases. Transcriptional analysis indicated that AgCHS1 was expressed in egg, larval, pupal and adult stages whereas AgCHS2 appeared to be expressed at relatively low levels, particularly during the larval stages as examined by reverse transcription (RT)-PCR and real-time quantitative PCR. Relatively high expression was detected in the carcass followed by the foregut and hindgut for AgCHS1, and the foregut (cardia included) followed by the midgut for AgCHS2. Fluorescence in situ hybridization (FISH) and immunohistochemical analysis revealed new information including the localization of the two enzymes in the ommatidia of the compound eyes, and AgCHS2 in the thoracic and abdominal inter-segmental regions of pupal integument.
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Affiliation(s)
- Xin Zhang
- Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA
| | - Jianzhen Zhang
- Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Yoonseong Park
- Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA
| | - Kun Yan Zhu
- Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA
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Angrisano F, Tan YH, Sturm A, McFadden GI, Baum J. Malaria parasite colonisation of the mosquito midgut – Placing the Plasmodium ookinete centre stage. Int J Parasitol 2012; 42:519-27. [DOI: 10.1016/j.ijpara.2012.02.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/03/2012] [Accepted: 02/04/2012] [Indexed: 11/28/2022]
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Lee CG, Da Silva CA, Dela Cruz CS, Ahangari F, Ma B, Kang MJ, He CH, Takyar S, Elias JA. Role of chitin and chitinase/chitinase-like proteins in inflammation, tissue remodeling, and injury. Annu Rev Physiol 2011; 73:479-501. [PMID: 21054166 DOI: 10.1146/annurev-physiol-012110-142250] [Citation(s) in RCA: 609] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The 18 glycosyl hydrolase family of chitinases is an ancient gene family that is widely expressed from prokaryotes to eukaryotes. In mammals, despite the absence of endogenous chitin, a number of chitinases and chitinase-like proteins (C/CLPs) have been identified. However, their roles have only recently begun to be elucidated. Acidic mammalian chitinase (AMCase) inhibits chitin-induced innate inflammation; augments chitin-free, allergen-induced Th2 inflammation; and mediates effector functions of IL-13. The CLPs BRP-39/YKL-40 (also termed chitinase 3-like 1) inhibit oxidant-induced lung injury, augments adaptive Th2 immunity, regulates apoptosis, stimulates alternative macrophage activation, and contributes to fibrosis and wound healing. In accord with these findings, levels of YKL-40 in the lung and serum are increased in asthma and other inflammatory and remodeling disorders and often correlate with disease severity. Our understanding of the roles of C/CLPs in inflammation, tissue remodeling, and tissue injury in health and disease is reviewed below.
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Affiliation(s)
- Chun Geun Lee
- Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8057, USA
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Apidianakis Y, Rahme LG. Drosophila melanogaster as a model for human intestinal infection and pathology. Dis Model Mech 2011; 4:21-30. [PMID: 21183483 PMCID: PMC3014343 DOI: 10.1242/dmm.003970] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Recent findings concerning Drosophila melanogaster intestinal pathology suggest that this model is well suited for the study of intestinal stem cell physiology during aging, stress and infection. Despite the physiological divergence between vertebrates and insects, the modeling of human intestinal diseases is possible in Drosophila because of the high degree of conservation between Drosophila and mammals with respect to the signaling pathways that control intestinal development, regeneration and disease. Furthermore, the genetic amenability of Drosophila makes it an advantageous model species. The well-studied intestinal stem cell lineage, as well as the tools available for its manipulation in vivo, provide a promising framework that can be used to elucidate many aspects of human intestinal pathology. In this Perspective, we discuss recent advances in the study of Drosophila intestinal infection and pathology, and briefly review the parallels and differences between human and Drosophila intestinal regeneration and disease.
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Affiliation(s)
- Yiorgos Apidianakis
- Department of Surgery, Massachusetts General Hospital, 50 Blossom Street, Their 340, Boston, MA 02114, USA
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Plata G, Hsiao TL, Olszewski KL, Llinás M, Vitkup D. Reconstruction and flux-balance analysis of the Plasmodium falciparum metabolic network. Mol Syst Biol 2010; 6:408. [PMID: 20823846 PMCID: PMC2964117 DOI: 10.1038/msb.2010.60] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 07/09/2010] [Indexed: 12/18/2022] Open
Abstract
Genome-scale metabolic reconstructions can serve as important tools for hypothesis generation and high-throughput data integration. Here, we present a metabolic network reconstruction and flux-balance analysis (FBA) of Plasmodium falciparum, the primary agent of malaria. The compartmentalized metabolic network accounts for 1001 reactions and 616 metabolites. Enzyme-gene associations were established for 366 genes and 75% of all enzymatic reactions. Compared with other microbes, the P. falciparum metabolic network contains a relatively high number of essential genes, suggesting little redundancy of the parasite metabolism. The model was able to reproduce phenotypes of experimental gene knockout and drug inhibition assays with up to 90% accuracy. Moreover, using constraints based on gene-expression data, the model was able to predict the direction of concentration changes for external metabolites with 70% accuracy. Using FBA of the reconstructed network, we identified 40 enzymatic drug targets (i.e. in silico essential genes), with no or very low sequence identity to human proteins. To demonstrate that the model can be used to make clinically relevant predictions, we experimentally tested one of the identified drug targets, nicotinate mononucleotide adenylyltransferase, using a recently discovered small-molecule inhibitor.
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Affiliation(s)
- Germán Plata
- Center for Computational Biology and Bioinformatics, Columbia University, New York City, NY 10032, USA
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36
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Tremp AZ, Dessens JT. Malaria IMC1 membrane skeleton proteins operate autonomously and participate in motility independently of cell shape. J Biol Chem 2010; 286:5383-91. [PMID: 21098480 PMCID: PMC3037651 DOI: 10.1074/jbc.m110.187195] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Plasmodium IMC1 (inner membrane complex 1) proteins comprise components of the subpellicular network, a lattice of intermediate filaments that form a structural part of the pellicle in the zoite stages of malaria parasites. Family members IMC1a and IMC1b are differentially expressed in sporozoites and ookinetes, respectively, but have functionally equivalent roles affecting cell morphology, strength, motility, and infectivity. Because of the coincident effects of previous imc1 gene disruptions on both zoite shape and locomotion, it has been impossible to ascribe a direct involvement in motility to these proteins. We show here that a third family member, IMC1h, has a distinct differential expression pattern and localizes to the pellicle of both ookinetes and sporozoites. Knock-out of IMC1h mimics the loss-of-function phenotypes of IMC1a and IMC1b in their respective life stages, indicating that IMC1 proteins could be operating co-dependently. By generating double null mutant parasites for IMC1h and IMC1b, we tested this hypothesis: double knock-out exacerbated the phenotypes of the single knock-outs in terms of ookinete strength, motility, and infectivity but did not further affect ookinete morphology. These findings provide the first genetic evidence that IMC1 proteins can function independently of each other and contribute to gliding motility independently of cell shape.
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Affiliation(s)
- Annie Z Tremp
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
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Production of chitooligosaccharides and their potential applications in medicine. Mar Drugs 2010; 8:1482-517. [PMID: 20559485 PMCID: PMC2885077 DOI: 10.3390/md8051482] [Citation(s) in RCA: 439] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 04/14/2010] [Accepted: 04/23/2010] [Indexed: 01/17/2023] Open
Abstract
Chitooligosaccharides (CHOS) are homo- or heterooligomers of N-acetylglucosamine and D-glucosamine. CHOS can be produced using chitin or chitosan as a starting material, using enzymatic conversions, chemical methods or combinations thereof. Production of well-defined CHOS-mixtures, or even pure CHOS, is of great interest since these oligosaccharides are thought to have several interesting bioactivities. Understanding the mechanisms underlying these bioactivities is of major importance. However, so far in-depth knowledge on the mode-of-action of CHOS is scarce, one major reason being that most published studies are done with badly characterized heterogeneous mixtures of CHOS. Production of CHOS that are well-defined in terms of length, degree of N-acetylation, and sequence is not straightforward. Here we provide an overview of techniques that may be used to produce and characterize reasonably well-defined CHOS fractions. We also present possible medical applications of CHOS, including tumor growth inhibition and inhibition of T(H)2-induced inflammation in asthma, as well as use as a bone-strengthener in osteoporosis, a vector for gene delivery, an antibacterial agent, an antifungal agent, an anti-malaria agent, or a hemostatic agent in wound-dressings. By using well-defined CHOS-mixtures it will become possible to obtain a better understanding of the mechanisms underlying these bioactivities.
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Smith RC, Jacobs-Lorena M. Plasmodium-Mosquito Interactions: A Tale of Roadblocks and Detours. ADVANCES IN INSECT PHYSIOLOGY 2010; 39:119-149. [PMID: 23729903 PMCID: PMC3666160 DOI: 10.1016/b978-0-12-381387-9.00004-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- Ryan C Smith
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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Aly ASI, Vaughan AM, Kappe SHI. Malaria parasite development in the mosquito and infection of the mammalian host. Annu Rev Microbiol 2009; 63:195-221. [PMID: 19575563 DOI: 10.1146/annurev.micro.091208.073403] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Plasmodium sporozoites are the product of a complex developmental process in the mosquito vector and are destined to infect the mammalian liver. Attention has been drawn to the mosquito stages and pre-erythrocytic stages owing to recognition that these are bottlenecks in the parasite life cycle and that intervention at these stages can block transmission and prevent infection. Parasite progression in the Anopheles mosquito, sporozoite transmission to the mammalian host by mosquito bite, and subsequent infection of the liver are characterized by extensive migration of invasive stages, cell invasion, and developmental changes. Preparation for the liver phase in the mammalian host begins in the mosquito with an extensive reprogramming of the sporozoite to support efficient infection and survival. Here, we discuss what is known about the molecular and cellular basis of the developmental progression of parasites and their interactions with host tissues in the mosquito and during the early phase of mammalian infection.
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Affiliation(s)
- Ahmed S I Aly
- Seattle Biomedical Research Institute, Seattle, Washington 98109, USA.
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Bushell ESC, Ecker A, Schlegelmilch T, Goulding D, Dougan G, Sinden RE, Christophides GK, Kafatos FC, Vlachou D. Paternal effect of the nuclear formin-like protein MISFIT on Plasmodium development in the mosquito vector. PLoS Pathog 2009; 5:e1000539. [PMID: 19662167 PMCID: PMC2715856 DOI: 10.1371/journal.ppat.1000539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 07/14/2009] [Indexed: 12/27/2022] Open
Abstract
Malaria parasites must undergo sexual and sporogonic development in mosquitoes before they can infect their vertebrate hosts. We report the discovery and characterization of MISFIT, the first protein with paternal effect on the development of the rodent malaria parasite Plasmodium berghei in Anopheles mosquitoes. MISFIT is expressed in male gametocytes and localizes to the nuclei of male gametocytes, zygotes and ookinetes. Gene disruption results in mutant ookinetes with reduced genome content, microneme defects and altered transcriptional profiles of putative cell cycle regulators, which yet successfully invade the mosquito midgut. However, developmental arrest ensues during the ookinete transformation to oocysts leading to malaria transmission blockade. Genetic crosses between misfit mutant parasites and parasites that are either male or female gamete deficient reveal a strict requirement for a male misfit allele. MISFIT belongs to the family of formin-like proteins, which are known regulators of the dynamic remodeling of actin and microtubule networks. Our data identify the ookinete-to-oocyst transition as a critical cell cycle checkpoint in Plasmodium development and lead us to hypothesize that MISFIT may be a regulator of cell cycle progression. This study offers a new perspective for understanding the male contribution to malaria parasite development in the mosquito vector. The unicellular protozoan parasites that cause malaria must undergo sexual development and subsequent proliferation in mosquitoes before they can infect humans and cause malaria. We characterized the first protein with paternal effect on the development of malaria parasites in the mosquito. This protein, which we named MISFIT, is produced in the progenitor cells of male gametes and found in the nuclei of these cells as well as in the nuclei of zygotes and their invasive forms, termed ookinetes. Disruption of the gene that encodes MISFIT leads to ookinetes with reduced DNA content, a defective secretory machinery and altered expression of various regulators of DNA replication and cell division. These mutant parasites stop developing immediately after traversing the mosquito gut, leading to malaria transmission blockage. Our study offers a new perspective for understanding the sexual development of malaria parasites in the mosquito vector, which leads to transmission of one of the most devastating diseases of mankind.
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Affiliation(s)
- Ellen S. C. Bushell
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Andrea Ecker
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Timm Schlegelmilch
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - David Goulding
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Gordon Dougan
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Robert E. Sinden
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Fotis C. Kafatos
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Dina Vlachou
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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Takeo S, Hisamori D, Matsuda S, Vinetz J, Sattabongkot J, Tsuboi T. Enzymatic characterization of the Plasmodium vivax chitinase, a potential malaria transmission-blocking target. Parasitol Int 2009; 58:243-8. [PMID: 19427918 DOI: 10.1016/j.parint.2009.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 04/29/2009] [Accepted: 05/02/2009] [Indexed: 11/16/2022]
Abstract
The chitinase (EC 3.2.1.14) of the human malaria parasite Plasmodium falciparum, PfCHT1, has been validated as a malaria transmission-blocking vaccine (TBV). The present study aimed to delineate functional characteristics of the P. vivax chitinase PvCHT1, whose primary structure differs from that of PfCHT1 by having proenzyme and chitin-binding domains. The recombinant protein rPvCHT1 expressed with a wheat germ cell-free system hydrolyzed 4-methylumbelliferone (4MU) derivatives of chitin oligosaccharides (beta-1,4-poly-N-acetyl glucosamine (GlcNAc)). An anti-rPvCHT1 polyclonal antiserum reacted with in vitro-obtained P. vivax ookinetes in anterior cytoplasm, showing uneven patchy distribution. Enzymatic activity of rPvCHT1 shared the exclusive endochitinase property with parallelly expressed rPfCHT1 as demonstrated by a marked substrate preference for 4MU-GlcNAc(3) compared to shorter GlcNAc substrates. While rPvCHT1 was found to be sensitive to the general family-18 chitinase inhibitor, allosamidin, its pH (maximal in neutral environment) and temperature (max. at approximately 25 degrees C) activity profiles and sensitivity to allosamidin (IC50=6 microM) were different from rPfCHT1. The results in this first report of functional rPvCHT1 synthesis indicate that the P. vivax chitinase is enzymatically close to long form Plasmodium chitinases represented by P. gallinaceum PgCHT1.
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Affiliation(s)
- Satoru Takeo
- Cell-Free Science and Technology Research Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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Sutherland TE, Maizels RM, Allen JE. Chitinases and chitinase-like proteins: potential therapeutic targets for the treatment of T-helper type 2 allergies. Clin Exp Allergy 2009; 39:943-55. [PMID: 19400900 DOI: 10.1111/j.1365-2222.2009.03243.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mammalian chitinase and chitinase-like proteins (CLPs) are a family of mediators increasingly associated with infection, T cell-mediated inflammation, wound healing, allergy and asthma. Although our current knowledge of the function of mammalian chitinases and CLPs is very limited, important information can be deduced from research carried out in lower organisms, and in different immunopathological conditions. Enzymatically active mammalian chitinase proteins may have evolved to degrade the copious amounts of chitin mammals are exposed to on a daily basis, and to form an innate barrier to chitin-containing organisms. CLPs are homologous to chitinases but lack the ability to degrade chitin. It is most striking that both chitinases and CLPs are up-regulated in T-helper type 2 (Th2)-driven conditions, and the first evidence is now emerging that these proteins may accentuate Th2 reactivity, and possibly contribute to the repair process that follows inflammation. Following studies demonstrating that chitinase inhibition leads to an attenuated allergic response, several strategies are being used to develop enzyme inhibitors for therapeutic use in human diseases. In this review, we will summarize recent insights into the effects of chitinases and CLPs in the context of Th2-dominated pathology with particular focus on allergy and asthma, discussing whether chitinase enzyme inhibitors may be of therapeutic value.
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Affiliation(s)
- T E Sutherland
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK.
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Ecker A, Bushell ESC, Tewari R, Sinden RE. Reverse genetics screen identifies six proteins important for malaria development in the mosquito. Mol Microbiol 2008; 70:209-20. [PMID: 18761621 PMCID: PMC2658712 DOI: 10.1111/j.1365-2958.2008.06407.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Transmission from the vertebrate host to the mosquito vector represents a major population bottleneck in the malaria life cycle that can successfully be targeted by intervention strategies. However, to date only about 25 parasite proteins expressed during this critical phase have been functionally analysed by gene disruption. We describe the first systematic, larger scale generation and phenotypic analysis of Plasmodium berghei knockout (KO) lines, characterizing 20 genes encoding putatively secreted proteins expressed by the ookinete, the parasite stage responsible for invasion of the mosquito midgut. Of 12 KO lines that were generated, six showed significant reductions in parasite numbers during development in the mosquito, resulting in a block in transmission of five KOs. While expression data, time point of essential function and mutant phenotype correlate well in three KOs defective in midgut invasion, in three KOs that fail at sporulation, maternal inheritance of the mutant phenotype suggests that essential function occurs during ookinete formation and thus precedes morphological abnormalities by several days.
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Affiliation(s)
- Andrea Ecker
- Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.
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Tremp AZ, Khater EI, Dessens JT. IMC1b is a putative membrane skeleton protein involved in cell shape, mechanical strength, motility, and infectivity of malaria ookinetes. J Biol Chem 2008; 283:27604-27611. [PMID: 18650444 PMCID: PMC2562075 DOI: 10.1074/jbc.m801302200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Membrane skeletons are cytoskeletal elements that have important roles in
cell development, shape, and structural integrity. Malaria parasites encode a
conserved family of putative membrane skeleton proteins related to articulins.
One member, IMC1a, is expressed in sporozoites and localizes to the pellicle,
a unique membrane complex believed to form a scaffold onto which the ligands
and glideosome are arranged to mediate parasite motility and invasion. IMC1b
is a closely related structural paralogue of IMC1a, fostering speculation that
it could be functionally homologous but in a different invasive life stage.
Here we have generated genetically modified parasites that express IMC1b
tagged with green fluorescent protein, and we show that it is targeted
exclusively to the pellicle of ookinetes. We also show that IMC1b-deficient
ookinetes display abnormal cell shape, reduced gliding motility, decreased
mechanical strength, and reduced infectivity. These findings are consistent
with a membrane skeletal role of IMC1b and provide strong experimental support
for the view that membrane skeletons form an integral part of the pellicle of
apicomplexan zoites and function to provide rigidity to the pellicular
membrane complex. The similarities observed between the loss-of-function
phenotypes of IMC1a and IMC1b show that membrane skeletons of ookinetes and
sporozoites function in an overall similar way. However, the fact that
ookinetes and sporozoites do not use the same IMC1 protein implies that
different mechanical properties are required of their respective membrane
skeletons, likely reflecting the distinct environments in which these life
stages must operate.
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Affiliation(s)
- Annie Z Tremp
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Emad I Khater
- Department of Entomology, Ain Shams University, Abbassia 11566, Cairo, Egypt
| | - Johannes T Dessens
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom.
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Weedall GD, Polley SD, Conway DJ. Gene-specific signatures of elevated non-synonymous substitution rates correlate poorly across the Plasmodium genus. PLoS One 2008; 3:e2281. [PMID: 18509456 PMCID: PMC2384006 DOI: 10.1371/journal.pone.0002281] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 04/13/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Comparative genome analyses of parasites allow large scale investigation of selective pressures shaping their evolution. An acute limitation to such analysis of Plasmodium falciparum is that there is only very partial low-coverage genome sequence of the most closely related species, the chimpanzee parasite P. reichenowi. However, if orthologous genes have been under similar selective pressures throughout the Plasmodium genus then positive selection on the P. falciparum lineage might be predicted to some extent by analysis of other lineages. PRINCIPAL FINDINGS Here, three independent pairs of closely related species in different sub-generic clades (P. falciparum and P. reichenowi; P. vivax and P. knowlesi; P. yoelii and P. berghei) were compared for a set of 43 candidate ligand genes considered likely to be under positive directional selection and a set of 102 control genes for which there was no selective hypothesis. The ratios of non-synonymous to synonymous substitutions (dN/dS) were significantly elevated in the candidate ligand genes compared to control genes in each of the three clades. However, the rank order correlation of dN/dS ratios for individual candidate genes was very low, less than the correlation for the control genes. SIGNIFICANCE The inability to predict positive selection on a gene in one lineage by identifying elevated dN/dS ratios in the orthologue within another lineage needs to be noted, as it reflects that adaptive mutations are generally rare events that lead to fixation in individual lineages. Thus it is essential to complete the genome sequences of particular species of phylogenetic importance, such as P. reichenowi.
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Affiliation(s)
- Gareth D Weedall
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
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Hot, sweet and sticky: the glycobiology of Plasmodium falciparum. Trends Parasitol 2008; 24:210-8. [DOI: 10.1016/j.pt.2008.02.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 02/02/2008] [Accepted: 02/05/2008] [Indexed: 11/22/2022]
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Carter V, Shimizu S, Arai M, Dessens JT. PbSR is synthesized in macrogametocytes and involved in formation of the malaria crystalloids. Mol Microbiol 2008; 68:1560-9. [PMID: 18452513 PMCID: PMC2615194 DOI: 10.1111/j.1365-2958.2008.06254.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Crystalloids are transient organelles that form in developing malaria ookinetes and disappear after ookinete-to-oocyst transition. Their origins and functions remain poorly understood. The Plasmodium berghei scavenger receptor-like protein PbSR is essential for mosquito-to-host transmission of the parasite: PbSR knockout parasites produce normal numbers of oocysts that fail to form sporozoites, pointing to a role for PbSR in the oocyst during sporogony. Here, using fluorescent protein tagging and targeted gene disruption, we show that PbSR is synthesized in macrogametocytes, gets targeted to the crystalloids of developing ookinetes and is involved in crystalloid formation. While oocyst sporulation rates of PbSR knockout parasites are highly reduced in parasite-infected mosquitoes, sporulation rates in vitro are not adversely affected, supporting the view that mosquito factors could be involved in the PbSR loss-of-function phenotype. These findings are the first to identify a parasite protein involved with the crystalloid organelle, and suggest a novel protein-trafficking mechanism to deliver PbSR to the oocysts.
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Affiliation(s)
- Victoria Carter
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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Rogers ME, Hajmová M, Joshi MB, Sadlova J, Dwyer DM, Volf P, Bates PA. Leishmania chitinase facilitates colonization of sand fly vectors and enhances transmission to mice. Cell Microbiol 2008; 10:1363-72. [PMID: 18284631 PMCID: PMC2408650 DOI: 10.1111/j.1462-5822.2008.01132.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Chitinases of trypanosomatid parasites have been proposed to fulfil various roles in their blood-feeding arthropod vectors but so far none have been directly tested using a molecular approach. We characterized the ability of Leishmania mexicana episomally transfected with LmexCht1 (the L. mexicana chitinase gene) to survive and grow within the permissive sand fly vector, Lutzomyia longipalpis. Compared with control plasmid transfectants, the overexpression of chitinase was found to increase the average number of parasites per sand fly and accelerate the escape of parasites from the peritrophic matrix-enclosed blood meal as revealed by earlier arrival at the stomodeal valve. Such flies also exhibited increased damage to the structure of the stomodeal valve, which may facilitate transmission by regurgitation. When exposed individually to BALB/c mice, those flies with chitinase-overexpressing parasites spent on average 2.4–2.5 times longer in contact with their host during feeding, compared with flies with control infections. Furthermore, the lesions that resulted from these single fly bite infections were both significantly larger and with higher final parasite burdens than controls. These data show that chitinase is a multifunctional virulence factor for L. mexicana which assists its survival in Lu. longipalpis. Specifically, this enzyme enables the parasites to colonize the anterior midgut of the sand fly more quickly, modify the sand fly stomodeal valve and affect its blood feeding, all of which combine to enhance transmission.
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Affiliation(s)
- Matthew E Rogers
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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Garcia CRS, de Azevedo MF, Wunderlich G, Budu A, Young JA, Bannister L. Plasmodium in the postgenomic era: new insights into the molecular cell biology of malaria parasites. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 266:85-156. [PMID: 18544493 DOI: 10.1016/s1937-6448(07)66003-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this review, we bring together some of the approaches toward understanding the cellular and molecular biology of Plasmodium species and their interaction with their host red blood cells. Considerable impetus has come from the development of new methods of molecular genetics and bioinformatics, and it is important to evaluate the wealth of these novel data in the context of basic cell biology. We describe how these approaches are gaining valuable insights into the parasite-host cell interaction, including (1) the multistep process of red blood cell invasion by the merozoite; (2) the mechanisms by which the intracellular parasite feeds on the red blood cell and exports parasite proteins to modify its cytoadherent properties; (3) the modulation of the cell cycle by sensing the environmental tryptophan-related molecules; (4) the mechanism used to survive in a low Ca(2+) concentration inside red blood cells; (5) the activation of signal transduction machinery and the regulation of intracellular calcium; (6) transfection technology; and (7) transcriptional regulation and genome-wide mRNA studies in Plasmodium falciparum.
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Affiliation(s)
- Celia R S Garcia
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, CEP 05508-900, São Paulo, SP, Brazil
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Abstract
PURPOSE OF REVIEW This review highlights progress made in the development of vaccines aimed at the stages of malaria parasites found in mosquitoes that block the transmission of malaria within a community. RECENT FINDINGS Substantial progress has been made on the production and characterization of the leading candidates P25 and P28 from Plasmodium falciparum and P. vivax. Immunogenicity data have been obtained for P25 in humans that showed significant transmission blocking activity and further advances in formulation should boost this activity. The completion of the malaria genome and ongoing proteomics identified further candidate antigens now entering development. SUMMARY Recent advances increase confidence that a mosquito stage transmission blocking malaria vaccine will be feasible.
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Affiliation(s)
- Allan Saul
- Laboratory of Malaria and Vector Biology, NIAID, NIH, Rockville, Maryland 20852, USA.
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