1
|
Ghosh A, Mishra A, Devi R, Narwal SK, Nirdosh, Srivastava PN, Mishra S. A Micronemal Protein, Scot1, Is Essential for Apicoplast Biogenesis and Liver Stage Development in Plasmodium berghei. ACS Infect Dis 2024; 10:3013-3025. [PMID: 39037752 DOI: 10.1021/acsinfecdis.4c00362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
Plasmodium sporozoites invade hepatocytes, transform into liver stages, and replicate into thousands of merozoites that infect erythrocytes and cause malaria. Proteins secreted from micronemes play an essential role in hepatocyte invasion, and unneeded micronemes are subsequently discarded for replication. The liver-stage parasites are potent immunogens that prevent malarial infection. Late liver stage-arresting genetically attenuated parasites (GAPs) exhibit greater protective efficacy than early GAP. However, the number of late liver-stage GAPs for generating GAPs with multiple gene deletions is limited. Here, we identified Scot1 (Sporozoite Conserved Orthologous Transcript 1), which was previously shown to be upregulated in sporozoites, and by endogenous tagging with mCherry, we demonstrated that it is expressed in the sporozoite and liver stages in micronemes. Using targeted gene deletion in Plasmodium berghei, we showed that Scot1 is essential for late liver-stage development. Scot1 KO sporozoites grew normally into liver stages but failed to initiate blood-stage infection in mice due to impaired apicoplast biogenesis and merozoite formation. Bioinformatic studies suggested that Scot1 is a metal-small-molecule carrier protein. Remarkably, supplementation with metals in the culture of infected Scot1 KO cells did not rescue their phenotype. Immunization with Scot1 KO sporozoites in C57BL/6 mice confers protection against malaria via infection. These proof-of-concept studies will enable the generation of P. falciparum Scot1 mutants that could be exploited to generate GAP malaria vaccines.
Collapse
Affiliation(s)
- Ankit Ghosh
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Akancha Mishra
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Raksha Devi
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sunil Kumar Narwal
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Nirdosh
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Pratik Narain Srivastava
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Satish Mishra
- Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
2
|
Sekar V, Rivero A, Pigeault R, Gandon S, Drews A, Ahren D, Hellgren O. Gene regulation of the avian malaria parasite Plasmodium relictum, during the different stages within the mosquito vector. Genomics 2021; 113:2327-2337. [PMID: 34023365 DOI: 10.1016/j.ygeno.2021.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/26/2021] [Accepted: 05/18/2021] [Indexed: 10/21/2022]
Abstract
The malaria parasite Plasmodium relictum is one of the most widespread species of avian malaria. As in the case of its human counterparts, bird Plasmodium undergoes a complex life cycle infecting two hosts: the arthropod vector and the vertebrate host. In this study, we examined transcriptomes of P. relictum (SGS1) during crucial timepoints within its vector, Culex pipiens quinquefasciatus. Differential gene-expression analyses identified genes linked to the parasites life-stages at: i) a few minutes after the blood meal is ingested, ii) during peak oocyst production phase, iii) during peak sporozoite phase and iv) during the late-stages of the infection. A large amount of genes coding for functions linked to host-immune invasion and multifunctional genes was active throughout the infection cycle. One gene associated with a conserved Plasmodium membrane protein with unknown function was upregulated throughout the parasite development in the vector, suggesting an important role in the successful completion of the sporogonic cycle. Gene expression analysis further identified genes, with unknown functions to be significantly differentially expressed during the infection in the vector as well as upregulation of reticulocyte-binding proteins, which raises the possibility of the multifunctionality of these RBPs. We establish the existence of highly stage-specific pathways being overexpressed during the infection. This first study of gene-expression of a non-human Plasmodium species in its vector provides a comprehensive insight into the molecular mechanisms of the common avian malaria parasite P. relictum and provides essential information on the evolutionary diversity in gene regulation of the Plasmodium's vector stages.
Collapse
Affiliation(s)
| | - Ana Rivero
- MIVEGEC (CNRS - Université de Montpellier - IRD), 34394 Montpellier, France; CREES (Centre de Recherche en Ecologie et Evolution de la Santé), 34394 Montpellier, France
| | - Romain Pigeault
- Department of Biology, Lund University, Sweden; Department of Ecology and Evolution, CH-1015 Lausanne, Switzerland
| | - Sylvain Gandon
- CEFE (CNRS - Université de Montpellier - Université Paul-Valéry - EPHE - IRD), Montpellier, France
| | - Anna Drews
- MEMEG, Department of Biology, Lund University, Sweden
| | - Dag Ahren
- National Bioinformatics Infrastructure Sweden (NBIS), SciLifeLab, Department of Biology, Lund, Sweden
| | - Olof Hellgren
- MEMEG, Department of Biology, Lund University, Sweden.
| |
Collapse
|
3
|
Bogale HN, Pascini TV, Kanatani S, Sá JM, Wellems TE, Sinnis P, Vega-Rodríguez J, Serre D. Transcriptional heterogeneity and tightly regulated changes in gene expression during Plasmodium berghei sporozoite development. Proc Natl Acad Sci U S A 2021; 118:e2023438118. [PMID: 33653959 PMCID: PMC7958459 DOI: 10.1073/pnas.2023438118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Despite the critical role of Plasmodium sporozoites in malaria transmission, we still know little about the mechanisms underlying their development in mosquitoes. Here, we use single-cell RNA sequencing to characterize the gene expression profiles of 16,038 Plasmodium berghei sporozoites isolated throughout their development from midgut oocysts to salivary glands, and from forced salivation experiments. Our results reveal a succession of tightly regulated changes in gene expression occurring during the maturation of sporozoites and highlight candidate genes that could play important roles in oocyst egress, sporozoite motility, and the mechanisms underlying the invasion of mosquito salivary glands and mammalian hepatocytes. In addition, the single-cell data reveal extensive transcriptional heterogeneity among parasites isolated from the same anatomical site, suggesting that Plasmodium development in mosquitoes is asynchronous and regulated by intrinsic as well as environmental factors. Finally, our analyses show a decrease in transcriptional activity preceding the translational repression observed in mature sporozoites and associated with their quiescent state in salivary glands, followed by a rapid reactivation of the transcriptional machinery immediately upon salivation.
Collapse
Affiliation(s)
- Haikel N Bogale
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Tales V Pascini
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Sachie Kanatani
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Juliana M Sá
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
| | - Photini Sinnis
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - Joel Vega-Rodríguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201;
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201
| |
Collapse
|
4
|
Briquet S, Marinach C, Silvie O, Vaquero C. Preparing for Transmission: Gene Regulation in Plasmodium Sporozoites. Front Cell Infect Microbiol 2021; 10:618430. [PMID: 33585284 PMCID: PMC7878544 DOI: 10.3389/fcimb.2020.618430] [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: 10/16/2020] [Accepted: 12/16/2020] [Indexed: 11/13/2022] Open
Abstract
Plasmodium sporozoites are transmitted to mammals by anopheline mosquitoes and first infect the liver, where they transform into replicative exoerythrocytic forms, which subsequently release thousands of merozoites that invade erythrocytes and initiate the malaria disease. In some species, sporozoites can transform into dormant hypnozoites in the liver, which cause malaria relapses upon reactivation. Transmission from the insect vector to a mammalian host is a critical step of the parasite life cycle, and requires tightly regulated gene expression. Sporozoites are formed inside oocysts in the mosquito midgut and become fully infectious after colonization of the insect salivary glands, where they remain quiescent until transmission. Parasite maturation into infectious sporozoites is associated with reprogramming of the sporozoite transcriptome and proteome, which depends on multiple layers of transcriptional and post-transcriptional regulatory mechanisms. An emerging scheme is that gene expression in Plasmodium sporozoites is controlled by alternating waves of transcription activity and translational repression, which shape the parasite RNA and protein repertoires for successful transition from the mosquito vector to the mammalian host.
Collapse
Affiliation(s)
- Sylvie Briquet
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Carine Marinach
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Olivier Silvie
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Catherine Vaquero
- Centre d'Immunologie et des Maladies Infectieuses, INSERM, CNRS, Sorbonne Université, Paris, France
| |
Collapse
|
5
|
Reeder SM, Reuschel EL, Bah MA, Yun K, Tursi NJ, Kim KY, Chu J, Zaidi FI, Yilmaz I, Hart RJ, Perrin B, Xu Z, Humeau L, Weiner DB, Aly ASI. Synthetic DNA Vaccines Adjuvanted with pIL-33 Drive Liver-Localized T Cells and Provide Protection from Plasmodium Challenge in a Mouse Model. Vaccines (Basel) 2020; 8:vaccines8010021. [PMID: 31936739 PMCID: PMC7157753 DOI: 10.3390/vaccines8010021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 12/11/2022] Open
Abstract
The need for a malaria vaccine is indisputable. A single vaccine for Plasmodium pre-erythrocytic stages targeting the major sporozoite antigen circumsporozoite protein (CSP) has had partial success. Additionally, CD8+ T cells targeting liver-stage (LS) antigens induced by live attenuated sporozoite vaccines were associated with protection in human challenge experiments. To further evaluate protection mediated by LS antigens, we focused on exported pre-erythrocytic proteins (exported protein 1 (EXP1), profilin (PFN), exported protein 2 (EXP2), inhibitor of cysteine proteases (ICP), transmembrane protein 21 (TMP21), and upregulated in infective sporozoites-3 (UIS3)) expressed in all Plasmodium species and designed optimized, synthetic DNA (synDNA) immunogens. SynDNA antigen cocktails were tested with and without the molecular adjuvant plasmid IL-33. Immunized animals developed robust T cell responses including induction of antigen-specific liver-localized CD8+ T cells, which were enhanced by the co-delivery of plasmid IL-33. In total, 100% of mice in adjuvanted groups and 71%–88% in non-adjuvanted groups were protected from blood-stage disease following Plasmodium yoelii sporozoite challenge. This study supports the potential of synDNA LS antigens as vaccine components for malaria parasite infection.
Collapse
Affiliation(s)
- Sophia M. Reeder
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emma L. Reuschel
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Mamadou A. Bah
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Kun Yun
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Kevin Y. Kim
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Jacqueline Chu
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Faraz I. Zaidi
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Ilknur Yilmaz
- Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul 34820, Turkey
| | - Robert J. Hart
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Benjamin Perrin
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Ziyang Xu
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laurent Humeau
- Inovio Pharmaceuticals, Inc., Plymouth Meeting, PA 19462, USA
| | - David B. Weiner
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Correspondence: (D.B.W.); (A.S.I.A.)
| | - Ahmed S. I. Aly
- Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul 34820, Turkey
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
- Correspondence: (D.B.W.); (A.S.I.A.)
| |
Collapse
|
6
|
Affiliation(s)
- Kelly T. Rios
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Scott E. Lindner
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
7
|
Bennink S, Pradel G. The molecular machinery of translational control in malaria parasites. Mol Microbiol 2019; 112:1658-1673. [PMID: 31531994 DOI: 10.1111/mmi.14388] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2019] [Indexed: 12/30/2022]
Abstract
Translational control regulates the levels of protein synthesized from its transcript and is key for the rapid adjustment of gene expression in response to environmental stimuli. The regulation of translation is of special importance for malaria parasites, which pass through a complex life cycle that includes various replication phases in the different organs of the human and mosquito hosts and a sexual reproduction phase in the mosquito midgut. In particular, the quiescent transmission stages rely on translational control to rapidly adapt to the new environment, once they switch over from the human to the mosquito and vice versa. Three control mechanisms are currently proposed in Plasmodium, (1) global regulation that acts on the translation initiation complex; (2) mRNA-specific regulation, involving cis control elements, mRNA-binding proteins and translational repressors; and (3) induced mRNA decay by the Ccr4-Not and the RNA exosome complex. The main molecules controlling translation are highly conserved in malaria parasites and an increasing number of studies shed light on the interwoven pathways leading to the up or downregulation of protein synthesis in the diverse plasmodial stages. We here highlight recent findings on translational control during life cycle progression of Plasmodium and discuss the molecules involved in regulating protein synthesis.
Collapse
Affiliation(s)
- Sandra Bennink
- 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
| |
Collapse
|
8
|
Muller I, Jex AR, Kappe SHI, Mikolajczak SA, Sattabongkot J, Patrapuvich R, Lindner S, Flannery EL, Koepfli C, Ansell B, Lerch A, Emery-Corbin SJ, Charnaud S, Smith J, Merrienne N, Swearingen KE, Moritz RL, Petter M, Duffy MF, Chuenchob V. Transcriptome and histone epigenome of Plasmodium vivax salivary-gland sporozoites point to tight regulatory control and mechanisms for liver-stage differentiation in relapsing malaria. Int J Parasitol 2019; 49:501-513. [PMID: 31071319 PMCID: PMC9973533 DOI: 10.1016/j.ijpara.2019.02.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/01/2019] [Accepted: 02/07/2019] [Indexed: 01/21/2023]
Abstract
Plasmodium vivax is the key obstacle to malaria elimination in Asia and Latin America, largely attributed to its ability to form resilient hypnozoites (sleeper cells) in the host liver that escape treatment and cause relapsing infections. The decision to form hypnozoites is made early in the liver infection and may already be set in sporozoites prior to invasion. To better understand these early stages of infection, we undertook a comprehensive transcriptomic and histone epigenetic characterization of P. vivax sporozoites. Through comparisons with recently published proteomic data for the P. vivax sporozoite, our study found that although highly transcribed, transcripts associated with functions needed for early infection of the vertebrate host are not detectable as proteins and may be regulated through translational repression. We identified differential transcription between the sporozoite and published transcriptomes of asexual blood stages and mixed versus hypnozoite-enriched liver stages. These comparisons point to multiple layers of transcriptional, post-transcriptional and post-translational control that appear active in sporozoites and to a lesser extent hypnozoites, but are largely absent in replicating liver schizonts or mixed blood stages. We also characterised histone epigenetic modifications in the P. vivax sporozoite and explored their role in regulating transcription. Collectively, these data support the hypothesis that the sporozoite is a tightly programmed stage to infect the human host and identify mechanisms for hypnozoite formation that may be further explored in liver stage models.
Collapse
Affiliation(s)
| | - Ivo Muller
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia,Malaria: Parasites & Hosts Unit, Institut Pasteur, 28
Rue de Dr. Roux, 75015, Paris, France,Department of Medical Biology, The University of Melbourne,
Victoria, 3010, Australia
| | - Aaron R. Jex
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia,Department of Medical Biology, The University of Melbourne,
Victoria, 3010, Australia,Faculty of Veterinary and Agricultural Sciences, The
University of Melbourne, Corner of Park and Flemington Road, Parkville, Victoria,
3010, Australia
| | - Stefan H. I. Kappe
- Seattle Children’s Research Institute, 307 Westlake
Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Sebastian A. Mikolajczak
- Seattle Children’s Research Institute, 307 Westlake
Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Center, Faculty of Tropical
Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | - Scott Lindner
- Department of Biochemistry and Molecular Biology, Center
for Malaria Research, Pennsylvania State University, University Park, PA 16802,
USA
| | - Erika L. Flannery
- Seattle Children’s Research Institute, 307 Westlake
Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Cristian Koepfli
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia
| | - Brendan Ansell
- Faculty of Veterinary and Agricultural Sciences, The
University of Melbourne, Corner of Park and Flemington Road, Parkville, Victoria,
3010, Australia
| | - Anita Lerch
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia
| | - Samantha J Emery-Corbin
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia
| | - Sarah Charnaud
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia
| | - Jeffrey Smith
- Population Health and Immunity Division, The Walter and
Eliza Hall Institute for Medical Research, 1G Royal Parade, Parkville, Victoria,
3052, Australia
| | - Nicolas Merrienne
- Malaria: Parasites & Hosts Unit, Institut Pasteur, 28
Rue de Dr. Roux, 75015, Paris, France
| | | | | | - Michaela Petter
- Department of Medicine Royal Melbourne Hospital, The Peter
Doherty Institute, The University of Melbourne, 792 Elizabeth Street, Melbourne,
Victoria 3000, Australia,Institute of Microbiology, University Hospital Erlangen,
Erlangen 91054, Germany
| | - Michael F. Duffy
- Department of Medicine Royal Melbourne Hospital, The Peter
Doherty Institute, The University of Melbourne, 792 Elizabeth Street, Melbourne,
Victoria 3000, Australia
| | - Vorada Chuenchob
- Seattle Children’s Research Institute, 307 Westlake
Avenue North, Suite 500, Seattle, WA 98109, USA
| |
Collapse
|
9
|
ApiAP2 Transcription Factors in Apicomplexan Parasites. Pathogens 2019; 8:pathogens8020047. [PMID: 30959972 PMCID: PMC6631176 DOI: 10.3390/pathogens8020047] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 12/26/2022] Open
Abstract
Apicomplexan parasites are protozoan organisms that are characterised by complex life cycles and they include medically important species, such as the malaria parasite Plasmodium and the causative agents of toxoplasmosis (Toxoplasma gondii) and cryptosporidiosis (Cryptosporidium spp.). Apicomplexan parasites can infect one or more hosts, in which they differentiate into several morphologically and metabolically distinct life cycle stages. These developmental transitions rely on changes in gene expression. In the last few years, the important roles of different members of the ApiAP2 transcription factor family in regulating life cycle transitions and other aspects of parasite biology have become apparent. Here, we review recent progress in our understanding of the different members of the ApiAP2 transcription factor family in apicomplexan parasites.
Collapse
|
10
|
Translational Control in the Latency of Apicomplexan Parasites. Trends Parasitol 2017; 33:947-960. [PMID: 28942109 DOI: 10.1016/j.pt.2017.08.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/08/2017] [Accepted: 08/14/2017] [Indexed: 01/07/2023]
Abstract
Apicomplexan parasites Toxoplasma gondii and Plasmodium spp. use latent stages to persist in the host, facilitate transmission, and thwart treatment of infected patients. Therefore, it is important to understand the processes driving parasite differentiation to and from quiescent stages. Here, we discuss how a family of protein kinases that phosphorylate the eukaryotic initiation factor-2 (eIF2) function in translational control and drive differentiation. This translational control culminates in reprogramming of the transcriptome to facilitate parasite transition towards latency. We also discuss how eIF2 phosphorylation contributes to the maintenance of latency and provides a crucial role in the timing of reactivation of latent parasites towards proliferative stages.
Collapse
|
11
|
Healer J, Cowman AF, Kaslow DC, Birkett AJ. Vaccines to Accelerate Malaria Elimination and Eventual Eradication. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025627. [PMID: 28490535 DOI: 10.1101/cshperspect.a025627] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.
Collapse
Affiliation(s)
- Julie Healer
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | - Alan F Cowman
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | | | | |
Collapse
|
12
|
Al-Nihmi FMA, Kolli SK, Reddy SR, Mastan BS, Togiri J, Maruthi M, Gupta R, Sijwali PS, Mishra S, Kumar KA. A Novel and Conserved Plasmodium Sporozoite Membrane Protein SPELD is Required for Maturation of Exo-erythrocytic Forms. Sci Rep 2017; 7:40407. [PMID: 28067322 PMCID: PMC5220379 DOI: 10.1038/srep40407] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 12/06/2016] [Indexed: 02/07/2023] Open
Abstract
Plasmodium sporozoites are the infective forms of malaria parasite to vertebrate host and undergo dramatic changes in their transcriptional repertoire during maturation in mosquito salivary glands. We report here the role of a novel and conserved Plasmodium berghei protein encoded by PBANKA_091090 in maturation of Exo-erythrocytic Forms (EEFs) and designate it as Sporozoite surface Protein Essential for Liver stage Development (PbSPELD). PBANKA_091090 was previously annotated as PB402615.00.0 and its transcript was recovered at maximal frequency in the Serial Analysis of the Gene Expression (SAGE) of Plasmodium berghei salivary gland sporozoites. An orthologue of this transcript was independently identified in Plasmodium vivax sporozoite microarrays and was designated as Sporozoite Conserved Orthologous Transcript-2 (scot-2). Functional characterization through reverse genetics revealed that PbSPELD is essential for Plasmodium liver stage maturation. mCherry transgenic of PbSPELD localized the protein to plasma membrane of sporozoites and early EEFs. Global microarray analysis of pbspeld ko revealed EEF attenuation being associated with down regulation of genes central to general transcription, cell cycle, proteosome and cadherin signaling. pbspeld mutant EEFs induced pre-erythrocytic immunity with 50% protective efficacy. Our studies have implications for attenuating the human Plasmodium liver stages by targeting SPELD locus.
Collapse
Affiliation(s)
| | - Surendra Kumar Kolli
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Segireddy Rameswara Reddy
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Babu S Mastan
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Jyothi Togiri
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Mulaka Maruthi
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Roshni Gupta
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Puran Singh Sijwali
- CSIR-Centre for Cellular and Molecular Biology, Habsiguda, Uppal Road, Hyderabad 500007, India
| | - Satish Mishra
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Kota Arun Kumar
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| |
Collapse
|
13
|
Speake C, Pichugin A, Sahu T, Malkov V, Morrison R, Pei Y, Juompan L, Milman N, Zarling S, Anderson C, Wong-Madden S, Wendler J, Ishizuka A, MacMillen ZW, Garcia V, Kappe SHI, Krzych U, Duffy PE. Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein. PLoS One 2016; 11:e0159449. [PMID: 27434123 PMCID: PMC4951032 DOI: 10.1371/journal.pone.0159449] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 07/01/2016] [Indexed: 12/17/2022] Open
Abstract
Malaria vaccine development has been hampered by the limited availability of antigens identified through conventional discovery approaches, and improvements are needed to enhance the efficacy of the leading vaccine candidate RTS,S that targets the circumsporozoite protein (CSP) of the infective sporozoite. Here we report a transcriptome-based approach to identify novel pre-erythrocytic vaccine antigens that could potentially be used in combination with CSP. We hypothesized that stage-specific upregulated genes would enrich for protective vaccine targets, and used tiling microarray to identify P. falciparum genes transcribed at higher levels during liver stage versus sporozoite or blood stages of development. We prepared DNA vaccines for 21 genes using the predicted orthologues in P. yoelii and P. berghei and tested their efficacy using different delivery methods against pre-erythrocytic malaria in rodent models. In our primary screen using P. yoelii in BALB/c mice, we found that 16 antigens significantly reduced liver stage parasite burden. In our confirmatory screen using P. berghei in C57Bl/6 mice, we confirmed 6 antigens that were protective in both models. Two antigens, when combined with CSP, provided significantly greater protection than CSP alone in both models. Based on the observations reported here, transcriptional patterns of Plasmodium genes can be useful in identifying novel pre-erythrocytic antigens that induce protective immunity alone or in combination with CSP.
Collapse
MESH Headings
- Animals
- Antibodies, Protozoan/immunology
- Antibodies, Protozoan/therapeutic use
- Antigens, Protozoan/immunology
- Female
- Humans
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/therapeutic use
- Malaria, Falciparum/drug therapy
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Mice
- Mice, Inbred C57BL
- Plasmodium falciparum/immunology
- Plasmodium falciparum/pathogenicity
- Plasmodium yoelii/immunology
- Protozoan Proteins/immunology
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vaccines, DNA/therapeutic use
Collapse
Affiliation(s)
- Cate Speake
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Alexander Pichugin
- Department of Cellular Immunology, Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Tejram Sahu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Vlad Malkov
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Robert Morrison
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ying Pei
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Laure Juompan
- Department of Cellular Immunology, Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Neta Milman
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Stasya Zarling
- Department of Cellular Immunology, Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sharon Wong-Madden
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jason Wendler
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Andrew Ishizuka
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Zachary W. MacMillen
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Valentino Garcia
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Stefan H. I. Kappe
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Urszula Krzych
- Department of Cellular Immunology, Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| |
Collapse
|
14
|
Vembar SS, Droll D, Scherf A. Translational regulation in blood stages of the malaria parasite Plasmodium spp.: systems-wide studies pave the way. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:772-792. [PMID: 27230797 PMCID: PMC5111744 DOI: 10.1002/wrna.1365] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 11/10/2022]
Abstract
The malaria parasite Plasmodium spp. varies the expression profile of its genes depending on the host it resides in and its developmental stage. Virtually all messenger RNA (mRNA) is expressed in a monocistronic manner, with transcriptional activation regulated at the epigenetic level and by specialized transcription factors. Furthermore, recent systems-wide studies have identified distinct mechanisms of post-transcriptional and translational control at various points of the parasite lifecycle. Taken together, it is evident that 'just-in-time' transcription and translation strategies coexist and coordinate protein expression during Plasmodium development, some of which we review here. In particular, we discuss global and specific mechanisms that control protein translation in blood stages of the human malaria parasite Plasmodium falciparum, once a cytoplasmic mRNA has been generated, and its crosstalk with mRNA decay and storage. We also focus on the widespread translational delay observed during the 48-hour blood stage lifecycle of P. falciparum-for over 30% of transcribed genes, including virulence factors required to invade erythrocytes-and its regulation by cis-elements in the mRNA, RNA-processing enzymes and RNA-binding proteins; the first-characterized amongst these are the DNA- and RNA-binding Alba proteins. More generally, we conclude that translational regulation is an emerging research field in malaria parasites and propose that its elucidation will not only shed light on the complex developmental program of this parasite, but may also reveal mechanisms contributing to drug resistance and define new targets for malaria intervention strategies. WIREs RNA 2016, 7:772-792. doi: 10.1002/wrna.1365 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Shruthi Sridhar Vembar
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France.
| | - Dorothea Droll
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Artur Scherf
- Unité Biologie des Interactions Hôte-Parasite, Département de Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| |
Collapse
|
15
|
A Plasmodium yoelii Mei2-Like RNA Binding Protein Is Essential for Completion of Liver Stage Schizogony. Infect Immun 2016; 84:1336-1345. [PMID: 26883588 DOI: 10.1128/iai.01417-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/08/2016] [Indexed: 11/20/2022] Open
Abstract
Plasmodium parasites employ posttranscriptional regulatory mechanisms as their life cycle transitions between host cell invasion and replication within both the mosquito vector and mammalian host. RNA binding proteins (RBPs) provide one mechanism for modulation of RNA function. To explore the role of Plasmodium RBPs during parasite replication, we searched for RBPs that might play a role during liver stage development, the parasite stage that exhibits the most extensive growth and replication. We identified a parasite ortholog of the Mei2 (Meiosis inhibited 2) RBP that is conserved among Plasmodium species (PlasMei2) and exclusively transcribed in liver stage parasites. Epitope-tagged Plasmodium yoelii PlasMei2 was expressed only during liver stage schizogony and showed an apparent granular cytoplasmic location. Knockout of PlasMei2 (plasmei2(-)) in P. yoelii only affected late liver stage development. The P. yoelii plasmei2(-) liver stage size increased progressively until late in development, similar to wild-type parasite development. However, P. yoelii plasmei2(-) liver stage schizonts exhibited an abnormal DNA segregation phenotype and failed to form exoerythrocytic merozoites. Consequently the cellular integrity of P. yoelii plasmei2(-) liver stages became increasingly compromised late in development and the majority of P. yoelii plasmei2(-) underwent cell death by the time wild-type liver stages mature and release merozoites. This resulted in a complete block of P. yoelii plasmei2(-) transition from liver stage to blood stage infection in mice. Our results show for the first time the importance of a Plasmodium RBP in the coordinated progression of late liver stage schizogony and maturation of new invasive forms.
Collapse
|
16
|
Silva PAGC, Guerreiro A, Santos JM, Braks JAM, Janse CJ, Mair GR. Translational Control of UIS4 Protein of the Host-Parasite Interface Is Mediated by the RNA Binding Protein Puf2 in Plasmodium berghei Sporozoites. PLoS One 2016; 11:e0147940. [PMID: 26808677 PMCID: PMC4726560 DOI: 10.1371/journal.pone.0147940] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/11/2016] [Indexed: 11/19/2022] Open
Abstract
UIS4 is a key protein component of the host-parasite interface in the liver stage of the rodent malaria parasite Plasmodium berghei and required for parasite survival after invasion. In the infectious sporozoite, UIS4 protein has variably been shown to be translated but also been reported to be translationally repressed. Here we show that uis4 mRNA translation is regulated by the P. berghei RNA binding protein Pumilio-2 (PbPuf2 or Puf2 from here on forward) in infectious salivary gland sporozoites in the mosquito vector. Using RNA immunoprecipitation we show that uis4 mRNA is bound by Puf2 in salivary gland sporozoites. In the absence of Puf2, uis4 mRNA translation is de-regulated and UIS4 protein expression upregulated in salivary gland sporozoites. Here, using RNA immunoprecipitation, we reveal the first Puf2-regulated mRNA in this parasite.
Collapse
Affiliation(s)
- Patrícia A. G. C. Silva
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649–028, Lisbon, Portugal
| | - Ana Guerreiro
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649–028, Lisbon, Portugal
| | - Jorge M. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649–028, Lisbon, Portugal
| | | | | | - Gunnar R. Mair
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649–028, Lisbon, Portugal
- Parasitology, Department of Infectious Diseases, University of Heidelberg Medical School, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
- * E-mail:
| |
Collapse
|
17
|
Zhang M, Mishra S, Sakthivel R, Fontoura BMA, Nussenzweig V. UIS2: A Unique Phosphatase Required for the Development of Plasmodium Liver Stages. PLoS Pathog 2016; 12:e1005370. [PMID: 26735921 PMCID: PMC4712141 DOI: 10.1371/journal.ppat.1005370] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 12/07/2015] [Indexed: 12/28/2022] Open
Abstract
Plasmodium salivary sporozoites are the infectious form of the malaria parasite and are dormant inside salivary glands of Anopheles mosquitoes. During dormancy, protein translation is inhibited by the kinase UIS1 that phosphorylates serine 59 in the eukaryotic initiation factor 2α (eIF2α). De-phosphorylation of eIF2α-P is required for the transformation of sporozoites into the liver stage. In mammalian cells, the de-phosphorylation of eIF2α-P is mediated by the protein phosphatase 1 (PP1). Using a series of genetically knockout parasites we showed that in malaria sporozoites, contrary to mammalian cells, the eIF2α-P phosphatase is a member of the PP2C/PPM phosphatase family termed UIS2. We found that eIF2α was highly phosphorylated in uis2 conditional knockout sporozoites. These mutant sporozoites maintained the crescent shape after delivery into mammalian host and lost their infectivity. Both uis1 and uis2 were highly transcribed in the salivary gland sporozoites but uis2 expression was inhibited by the Pumilio protein Puf2. The repression of uis2 expression was alleviated when sporozoites developed into liver stage. While most eukaryotic phosphatases interact transiently with their substrates, UIS2 stably bound to phosphorylated eIF2α, raising the possibility that high-throughput searches may identify chemicals that disrupt this interaction and prevent malaria infection. Malaria is transmitted to humans by female mosquitoes as they take a blood meal. Plasmodium sporozoites are the infectious and quiescent forms of malaria parasites, which reside in the salivary glands of mosquitoes. Global protein synthesis is inhibited in sporozoites through phosphorylation of the translational factor eIF2α. However, the development of the parasites in the host liver requires de-phosphorylation of eIF2α-P. We find that a unique Plasmodium phosphatase termed UIS2 de-phosphorylates eIF2α-P in malaria. The eIF2α is highly phosphorylated in the uis2 mutant sporozoites. The uis2 mutant parasites did not change their morphology after delivery into the host and could not properly infect the host. We also showed that UIS2 expression was inhibited by the Pumilio protein Puf2. However, this repression was relieved when sporozoites developed into liver stage. In sum, our findings revealed a new mechanism that evolved to control eIF2α dephosphorylation and suggest that identification of UIS2 inhibitors may be useful in anti-malaria therapy.
Collapse
Affiliation(s)
- Min Zhang
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
- HIV and Malaria Vaccine Program, Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, New York, New York, United States of America
- * E-mail:
| | - Satish Mishra
- Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Ramanavelan Sakthivel
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Beatriz M. A. Fontoura
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Victor Nussenzweig
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| |
Collapse
|
18
|
Rijpma SR, van der Velden M, González-Pons M, Annoura T, van Schaijk BCL, van Gemert GJ, van den Heuvel JJMW, Ramesar J, Chevalley-Maurel S, Ploemen IH, Khan SM, Franetich JF, Mazier D, de Wilt JHW, Serrano AE, Russel FGM, Janse CJ, Sauerwein RW, Koenderink JB, Franke-Fayard BM. Multidrug ATP-binding cassette transporters are essential for hepatic development of Plasmodium sporozoites. Cell Microbiol 2015; 18:369-83. [PMID: 26332724 DOI: 10.1111/cmi.12517] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/11/2015] [Accepted: 08/24/2015] [Indexed: 12/23/2022]
Abstract
Multidrug resistance-associated proteins (MRPs) belong to the C-family of ATP-binding cassette (ABC) transport proteins and are known to transport a variety of physiologically important compounds and to be involved in the extrusion of pharmaceuticals. Rodent malaria parasites encode a single ABC transporter subfamily C protein, whereas human parasites encode two: MRP1 and MRP2. Although associated with drug resistance, their biological function and substrates remain unknown. To elucidate the role of MRP throughout the parasite life cycle, Plasmodium berghei and Plasmodium falciparum mutants lacking MRP expression were generated. P. berghei mutants lacking expression of the single MRP as well as P. falciparum mutants lacking MRP1, MRP2 or both proteins have similar blood stage growth kinetics and drug-sensitivity profiles as wild type parasites. We show that MRP1-deficient parasites readily invade primary human hepatocytes and develop into mature liver stages. In contrast, both P. falciparum MRP2-deficient parasites and P. berghei mutants lacking MRP protein expression abort in mid to late liver stage development, failing to produce mature liver stages. The combined P. berghei and P. falciparum data are the first demonstration of a critical role of an ABC transporter during Plasmodium liver stage development.
Collapse
Affiliation(s)
- Sanna R Rijpma
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Maarten van der Velden
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Maria González-Pons
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, PR 00936-5067, San Juan, Puerto Rico, USA
| | - Takeshi Annoura
- Department of Tropical Medicine, The Jikei University School of Medicine, Post code 105-8461, Nishi-shinbashi 3-25-8, Minato-ku, Tokyo, Japan
| | - Ben C L van Schaijk
- Department of Medical Microbiology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Jeroen J M W van den Heuvel
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Jai Ramesar
- Department of Parasitology, Center of Infectious Diseases, Leiden Malaria Research Group, Leiden, The Netherlands
| | - Severine Chevalley-Maurel
- Department of Parasitology, Center of Infectious Diseases, Leiden Malaria Research Group, Leiden, The Netherlands
| | - Ivo H Ploemen
- Department of Medical Microbiology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Shahid M Khan
- Department of Tropical Medicine, The Jikei University School of Medicine, Post code 105-8461, Nishi-shinbashi 3-25-8, Minato-ku, Tokyo, Japan
| | - Jean-Francois Franetich
- AP-HP, Groupe hospitalier Pitié-Salpêtrière, Service Parasitologie-Mycologie, 47-83 Boulevard de l'Hôpital, 75651, Paris, France
| | - Dominique Mazier
- AP-HP, Groupe hospitalier Pitié-Salpêtrière, Service Parasitologie-Mycologie, 47-83 Boulevard de l'Hôpital, 75651, Paris, France.,CIMI-Paris (UPMC UMRS CR7 - Inserm U1135 - CNRS ERL 8255), Paris, France
| | - Johannes H W de Wilt
- Department of Surgery, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Adelfa E Serrano
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, PR 00936-5067, San Juan, Puerto Rico, USA
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Chris J Janse
- Department of Parasitology, Center of Infectious Diseases, Leiden Malaria Research Group, Leiden, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Jan B Koenderink
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Blandine M Franke-Fayard
- Department of Parasitology, Center of Infectious Diseases, Leiden Malaria Research Group, Leiden, The Netherlands
| |
Collapse
|
19
|
Bijker EM, Borrmann S, Kappe SH, Mordmüller B, Sack BK, Khan SM. Novel approaches to whole sporozoite vaccination against malaria. Vaccine 2015; 33:7462-8. [PMID: 26469716 PMCID: PMC6858867 DOI: 10.1016/j.vaccine.2015.09.095] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 08/22/2015] [Accepted: 09/22/2015] [Indexed: 12/15/2022]
Abstract
The parasitic disease malaria threatens more than 3 billion people worldwide, resulting in more than 200 million clinical cases and almost 600,000 deaths annually. Vaccines remain crucial for prevention and ultimately eradication of infectious diseases and, for malaria, whole sporozoite based immunization has been shown to be the most effective in experimental settings. In addition to immunization with radiation-attenuated sporozoites, chemoprophylaxis and sporozoites (CPS) is a highly efficient strategy to induce sterile protection in humans. Genetically attenuated parasites (GAP) have demonstrated significant protection in rodent studies, and are now being advanced into clinical testing. This review describes the existing pre-clinical and clinical data on CPS and GAP, discusses recent developments and examines how to transform these immunization approaches into vaccine candidates for clinical development.
Collapse
Affiliation(s)
- Else M Bijker
- Radboud University Medical Center, Department of Medical Microbiology, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stefan H Kappe
- Seattle Biomedical Research Institute, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA
| | - Benjamin Mordmüller
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales de Lambaréné, Alberts Schweitzer Hospital, BP 118 Lambaréné, Gabon
| | | | - Shahid M Khan
- Leiden University Medical Center, Department of Parasitology, PO Box 9600, 2300 RC Leiden, The Netherlands
| |
Collapse
|
20
|
Groat-Carmona AM, Kain H, Brownell J, Douglass AN, Aly ASI, Kappe SHI. A Plasmodium α/β-hydrolase modulates the development of invasive stages. Cell Microbiol 2015; 17:1848-67. [PMID: 26118838 DOI: 10.1111/cmi.12477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 06/19/2015] [Accepted: 06/23/2015] [Indexed: 11/26/2022]
Abstract
The bud emergence (BEM)46 proteins are evolutionarily conserved members of the α/β-hydrolase superfamily, which includes enzymes with diverse functions and a wide range of substrates. Here, we identified a Plasmodium BEM46-like protein (PBLP) and characterized it throughout the life cycle of the rodent malaria parasite Plasmodium yoelii. The Plasmodium BEM46-like protein is shown to be closely associated with the parasite plasma membrane of asexual erythrocytic stage schizonts and exo-erythrocytic schizonts; however, PBLP localizes to unique intracellular structures in sporozoites. Generation and analysis of P. yoelii knockout (Δpblp) parasite lines showed that PBLP has an important role in erythrocytic stage merozoite development with Δpblp parasites forming fewer merozoites during schizogony, which results in decreased parasitemia when compared with wild-type (WT) parasites. Δpblp parasites showed no defects in gametogenesis or transmission to mosquitoes; however, because they formed fewer oocysts there was a reduction in the number of developed sporozoites in infected mosquitoes when compared with WT. Although Δpblp sporozoites showed no apparent defect in mosquito salivary gland infection, they showed decreased infectivity in hepatocytes in vitro. Similarly, mice infected with Δpblp sporozoites exhibited a delay in the onset of blood-stage patency, which is likely caused by reduced sporozoite infectivity and a discernible delay in exo-erythrocytic merozoite formation. These data are consistent with the model that PBLP has an important role in parasite invasive-stage morphogenesis throughout the parasite life cycle.
Collapse
Affiliation(s)
- Anna M Groat-Carmona
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Heather Kain
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Jessica Brownell
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Alyse N Douglass
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA
| | - Ahmed S I Aly
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Stefan H I Kappe
- Center for Infectious Disease Research, formerly Seattle BioMedical Research Institute, Seattle, WA, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
| |
Collapse
|
21
|
Cyclic GMP balance is critical for malaria parasite transmission from the mosquito to the mammalian host. mBio 2015; 6:e02330. [PMID: 25784701 PMCID: PMC4453516 DOI: 10.1128/mbio.02330-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Transmission of malaria occurs during Anopheles mosquito vector blood meals, when Plasmodium sporozoites that have invaded the mosquito salivary glands are delivered to the mammalian host. Sporozoites display a unique form of motility that is essential for their movement across cellular host barriers and invasion of hepatocytes. While the molecular machinery powering motility and invasion is increasingly well defined, the signaling events that control these essential parasite activities have not been clearly delineated. Here, we identify a phosphodiesterase (PDEγ) in Plasmodium, a regulator of signaling through cyclic nucleotide second messengers. Reverse transcriptase PCR (RT-PCR) analysis and epitope tagging of endogenous PDEγ detected its expression in blood stages and sporozoites of Plasmodium yoelii. Deletion of PDEγ (pdeγ−) rendered sporozoites nonmotile, and they failed to invade the mosquito salivary glands. Consequently, PDEγ deletion completely blocked parasite transmission by mosquito bite. Strikingly, pdeγ− sporozoites showed dramatically elevated levels of cyclic GMP (cGMP), indicating that a perturbation in cyclic nucleotide balance is involved in the observed phenotypic defects. Transcriptome sequencing (RNA-Seq) analysis of pdeγ− sporozoites revealed reduced transcript abundance of genes that encode key components of the motility and invasion apparatus. Our data reveal a crucial role for PDEγ in maintaining the cyclic nucleotide balance in the malaria parasite sporozoite stage, which in turn is essential for parasite transmission from mosquito to mammal. Malaria is a formidable threat to human health worldwide, and there is an urgent need to identify novel drug targets for this parasitic disease. The parasite is transmitted by mosquito bite, inoculating the host with infectious sporozoite stages. We show that cellular signaling by cyclic nucleotides is critical for transmission of the parasite from the mosquito vector to the mammalian host. Parasite phosphodiesterase γ is essential for maintaining cyclic nucleotide balance, and its deletion blocks transmission of sporozoites. A deeper understanding of the signaling mechanisms involved in transmission might inform the discovery of novel drugs that interrupt this essential step in the parasite life cycle.
Collapse
|
22
|
van Schaijk BCL, Ploemen IHJ, Annoura T, Vos MW, Foquet L, van Gemert GJ, Chevalley-Maurel S, van de Vegte-Bolmer M, Sajid M, Franetich JF, Lorthiois A, Leroux-Roels G, Meuleman P, Hermsen CC, Mazier D, Hoffman SL, Janse CJ, Khan SM, Sauerwein RW. A genetically attenuated malaria vaccine candidate based on P. falciparum b9/slarp gene-deficient sporozoites. eLife 2014; 3. [PMID: 25407681 PMCID: PMC4273440 DOI: 10.7554/elife.03582] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 11/19/2014] [Indexed: 12/16/2022] Open
Abstract
A highly efficacious pre-erythrocytic stage vaccine would be an important tool for the control and elimination of malaria but is currently unavailable. High-level protection in humans can be achieved by experimental immunization with Plasmodium falciparum sporozoites attenuated by radiation or under anti-malarial drug coverage. Immunization with genetically attenuated parasites (GAP) would be an attractive alternative approach. In this study, we present data on safety and protective efficacy using sporozoites with deletions of two genes, that is the newly identified b9 and slarp, which govern independent and critical processes for successful liver-stage development. In the rodent malaria model, PbΔb9ΔslarpGAP was completely attenuated showing no breakthrough infections while efficiently inducing high-level protection. The human PfΔb9ΔslarpGAP generated without drug resistance markers were infective to human hepatocytes in vitro and to humanized mice engrafted with human hepatocytes in vivo but completely aborted development after infection. These findings support the clinical development of a PfΔb9ΔslarpSPZ vaccine. DOI:http://dx.doi.org/10.7554/eLife.03582.001 Vaccines commonly contain a weakened or dead version of a disease-causing microorganism, or its toxins, or surface proteins. These prime the immune system to rapidly recognize, respond to, and eliminate the actual infectious pathogen if later encountered. While vaccines are currently available to help prevent a large number of diseases, vaccines for many deadly diseases, including malaria, do not yet exist. Malaria is caused by a group of parasites called Plasmodium, which are transferred to humans by mosquitoes. While measures to control mosquito populations and prevent mosquito bites have helped to reduce the incidence of malaria in some countries, the number of people—and especially children—that die of malaria every year remains very high. When a mosquito carrying Plasmodium in its salivary glands bites a human, the parasite is injected into the human's bloodstream and travels to the liver. The parasite reproduces in the liver cells until there are so many of them that the cells rupture, and the parasites are released back into the bloodstream. Any mosquito that then feeds on the blood of the infected individual may also suck up the parasite. The parasite then goes through a further stage of development in the mosquito, eventually migrating to the salivary glands, from where the parasite can be transmitted into a new human host. Recent work in rodents suggests that genetically altered or weakened Plasmodium falciparum sporozoites—the form of the parasite found in mosquito saliva—could be used to vaccinate humans against malaria caused by this parasite species. Now, van Schaijk, Ploemen et al. evaluate whether a safe and effective vaccine could be made from sporozoites that lack two genes, called b9 and slarp, which are critical for the parasites to develop inside liver cells. When mice were injected with the modified sporozoites, their immune cells were able to detect the parasites and respond against them. The mice subsequently did not develop malaria when they were infected with normal, unmodified parasites. Furthermore, none of the mice contracted malaria from the modified sporozoites. The modified sporozoites behaved similarly in human liver cells: after invading these cells, the parasites were unable to develop. Clinical testing and further development are now needed to see if a successful malaria vaccine can be made from these sporozoites. DOI:http://dx.doi.org/10.7554/eLife.03582.002
Collapse
Affiliation(s)
- Ben C L van Schaijk
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Ivo H J Ploemen
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Takeshi Annoura
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Martijn W Vos
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Lander Foquet
- Center for Vaccinology, Ghent University and University Hospital, Ghent, Belgium
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | | | - Marga van de Vegte-Bolmer
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Mohammed Sajid
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Jean-Francois Franetich
- Centre d'Immunologie et des Maladies Infectieuses, Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Audrey Lorthiois
- Centre d'Immunologie et des Maladies Infectieuses, Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Geert Leroux-Roels
- Center for Vaccinology, Ghent University and University Hospital, Ghent, Belgium
| | - Philip Meuleman
- Center for Vaccinology, Ghent University and University Hospital, Ghent, Belgium
| | - Cornelius C Hermsen
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| | - Dominique Mazier
- Centre d'Immunologie et des Maladies Infectieuses, Université Pierre et Marie Curie-Paris 6, Paris, France
| | | | - Chris J Janse
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Shahid M Khan
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands
| |
Collapse
|
23
|
Krzych U, Zarling S, Pichugin A. Memory T cells maintain protracted protection against malaria. Immunol Lett 2014; 161:189-95. [PMID: 24709142 PMCID: PMC6499475 DOI: 10.1016/j.imlet.2014.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/25/2014] [Accepted: 03/27/2014] [Indexed: 10/25/2022]
Abstract
Immunologic memory is one of the cardinal features of antigen-specific immune responses, and the persistence of memory cells contributes to prophylactic immunizations against infectious agents. Adequately maintained memory T and B cell pools assure a fast, effective and specific response against re-infections. However, many aspects of immunologic memory are still poorly understood, particularly immunologic memory inducible by parasites, for example, Plasmodium spp., the causative agents of malaria. For example, memory responses to Plasmodium antigens amongst residents of malaria endemic areas appear to be either inadequately developed or maintained, because persons who survive episodes of childhood malaria remain vulnerable to intermittent malaria infections. By contrast, multiple exposures of humans and laboratory rodents to radiation-attenuated Plasmodium sporozoites (γ-spz) induce sterile and long-lasting protection against experimental sporozoite challenge. Multifactorial immune mechanisms maintain this protracted and sterile protection. While the presence of memory CD4 T cell subsets has been associated with lasting protection in humans exposed to multiple bites from Anopheles mosquitoes infected with attenuated Plasmodium falciparum, memory CD8 T cells maintain protection induced with Plasmodium yoelii and Plasmodium berghei γ-spz in murine models. In this review, we discuss our observations that show memory CD8 T cells specific for antigens expressed by P. berghei liver stage parasites as an indispensable component for the maintenance of protracted protective immunity against experimental malaria infection; moreover, the provision of an Ag-depot assures a quick recall of memory T cells as IFN-γ-producing effector CD8 T cells and IL-4- producing CD4 T cells that collaborate with B cells for an effective antibody response.
Collapse
Affiliation(s)
- Urszula Krzych
- Department of Cellular Immunology, Branch of Malaria Vaccine Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States.
| | - Stasya Zarling
- Department of Cellular Immunology, Branch of Malaria Vaccine Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States
| | - Alexander Pichugin
- Department of Cellular Immunology, Branch of Malaria Vaccine Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States
| |
Collapse
|
24
|
A next-generation genetically attenuated Plasmodium falciparum parasite created by triple gene deletion. Mol Ther 2014; 22:1707-15. [PMID: 24827907 DOI: 10.1038/mt.2014.85] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/29/2014] [Indexed: 12/14/2022] Open
Abstract
Immunization with live-attenuated Plasmodium sporozoites completely protects against malaria infection. Genetic engineering offers a versatile platform to create live-attenuated sporozoite vaccine candidates. We previously generated a genetically attenuated parasite (GAP) by deleting the P52 and P36 genes in the NF54 wild-type (WT) strain of Plasmodium falciparum (Pf p52(-)/p36(-) GAP). Preclinical assessment of p52(-)/p36(-) GAP in a humanized mouse model indicated an early and severe liver stage growth defect. However, human exposure to >200 Pf p52(-)/p36(-) GAP-infected mosquito bites in a safety trial resulted in peripheral parasitemia in one of six volunteers, revealing that this GAP was incompletely attenuated. We have now created a triple gene deleted GAP by additionally removing the SAP1 gene (Pf p52(-)/p36(-)/sap1(-) GAP) and employed flippase (FLP)/flippase recognition target (FRT) recombination for drug selectable marker cassette removal. This next-generation GAP was indistinguishable from WT parasites in blood stage and mosquito stage development. Using an improved humanized mouse model transplanted with human hepatocytes and human red blood cells, we show that despite a high-dose sporozoite challenge, Pf p52(-)/p36(-)/sap1(-) GAP did not transition to blood stage infection and appeared to be completely attenuated. Thus, clinical testing of Pf p52(-)/p36(-)/sap1(-) GAP assessing safety, immunogenicity, and efficacy against sporozoite challenge is warranted.
Collapse
|
25
|
Silvie O, Briquet S, Müller K, Manzoni G, Matuschewski K. Post-transcriptional silencing of UIS4 in Plasmodium berghei sporozoites is important for host switch. Mol Microbiol 2014; 91:1200-13. [PMID: 24446886 DOI: 10.1111/mmi.12528] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2014] [Indexed: 01/15/2023]
Abstract
Plasmodium sporozoites are transmitted by mosquitoes and first infect hepatocytes of their mammalian host, wherein they develop as liver stages, surrounded by the parasitophorous vacuole membrane (PVM). The parasite must rapidly adapt to its changing environment after switching host. Shortly after invasion, the PVM is remodelled by insertion of essential parasite proteins of the early transcribed membrane protein family such as UIS4. Here, using the rodent malaria model Plasmodium berghei, we show that transcripts encoding UIS4 are stored in a translationally repressed state in sporozoites, allowing UIS4 protein synthesis only after host cell invasion. Using a series of reporter transgenic parasite lines we could demonstrate that the open reading frame of UIS4 mRNA is critical for gene silencing, whereas the 5' and 3' untranslated regions are dispensable. Our data further indicate that the UIS4 translational repression machinery is present only in mature sporozoites in the mosquito salivary glands, and that premature expression of UIS4 protein results in a loss of parasite infectivity. Our findings reveal the importance of specific post-transcriptional control in sporozoites, and establish that host switch requires high levels of translationally silent UIS4 RNA, which permits stage conversion, yet avoids premature expression of this liver stage-specific protein.
Collapse
Affiliation(s)
- Olivier Silvie
- Sorbonne Universités, UPMC Univ Paris 06, CR7, 75013, Paris, France; INSERM, U1135, 75013, Paris, France; CNRS, ERL 8255, 75013, Paris, France
| | | | | | | | | |
Collapse
|
26
|
Villarino N, Schmidt NW. CD8 + T Cell Responses to Plasmodium and Intracellular Parasites. ACTA ACUST UNITED AC 2014; 9:169-178. [PMID: 24741372 PMCID: PMC3983867 DOI: 10.2174/1573395509666131126232327] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 12/29/2022]
Abstract
Parasitic protozoa are major threats to human health affecting millions of people around the world. Control of these infections by the host immune system relies on a myriad of immunological mechanisms that includes both humoral and cellular immunity. CD8+ T cells contribute to the control of these parasitic infections in both animals and humans. Here, we will focus on the CD8+ T cell response against a subset of these protozoa: Plasmodium, Toxoplasma gondii, Leishmania and Trypanosoma cruzi, with an emphasis on experimental rodent systems. It is evident a complex interaction occurs between CD8+ T cells and the invading protozoa. A detailed understanding of how CD8+ T cells mediate protection should provide the basis for the development of effective vaccines that prevent and control infections by these parasites.
Collapse
Affiliation(s)
- Nicolas Villarino
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
| | - Nathan W Schmidt
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
| |
Collapse
|
27
|
Kramer S. RNA in development: how ribonucleoprotein granules regulate the life cycles of pathogenic protozoa. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:263-84. [PMID: 24339376 DOI: 10.1002/wrna.1207] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/22/2013] [Accepted: 10/29/2013] [Indexed: 12/11/2022]
Abstract
Ribonucleoprotein (RNP) granules are important posttranscriptional regulators of messenger RNA (mRNA) fate. Several types of RNP granules specifically regulate gene expression during development of multicellular organisms and are commonly referred to as germ granules. The function of germ granules is not entirely understood and probably diverse, but it is generally agreed that one main function is posttranscriptional regulation of gene expression during early development, when transcription is silent. One example is the translational repression of maternally derived mRNAs in oocytes. Here, I hope to show that the need for regulation of gene expression by RNP granules is not restricted to animal development, but plays an equally important role during the development of pathogenic protozoa. Apicomplexa and Trypanosomatidae have complex life cycles with frequent host changes. The need to quickly adapt gene expression to a new environment as well as the ability to suppress translation to survive latencies is critical for successful completion of life cycles. Posttranscriptional gene regulation is not necessarily simpler in protozoa. Apicomplexa surprise with the presence of micro RNA (miRNAs) and upstream open reading frames (µORFs). Trypanosomes have an unusually large repertoire of different RNP granule types. A better understanding of RNP granules in protozoa may help to gain insight into the evolutionary origin of RNP granules: Trypanosomes for example have two types of granules with interesting similarities to animal germ granules.
Collapse
Affiliation(s)
- Susanne Kramer
- Lehrstuhl für Zell- und Entwicklungsbiologie, Biozentrum, Universität Würzburg, Würzburg, Germany
| |
Collapse
|
28
|
Model for in vivo assessment of humoral protection against malaria sporozoite challenge by passive transfer of monoclonal antibodies and immune serum. Infect Immun 2013; 82:808-17. [PMID: 24478094 DOI: 10.1128/iai.01249-13] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evidence from clinical trials of malaria vaccine candidates suggests that both cell-mediated and humoral immunity to pre-erythrocytic parasite stages can provide protection against infection. Novel pre-erythrocytic antibody (Ab) targets could be key to improving vaccine formulations, which are currently based on targeting antigens such as the circumsporozoite protein (CSP). However, methods to assess the effects of sporozoite-specific Abs on pre-erythrocytic infection in vivo remain underdeveloped. Here, we combined passive transfer of monoclonal Abs (MAbs) or immune serum with a luciferase-expressing Plasmodium yoelii sporozoite challenge to assess Ab-mediated inhibition of liver infection in mice. Passive transfer of a P. yoelii CSP MAb showed inhibition of liver infection when mice were challenged with sporozoites either intravenously or by infectious mosquito bite. However, inhibition was most potent for the mosquito bite challenge, leading to a more significant reduction of liver-stage burden and even a lack of progression to blood-stage parasitemia. This suggests that Abs provide effective protection against a natural infection. Inhibition of liver infection was also achieved by passive transfer of immune serum from whole-parasite-immunized mice. Furthermore, we demonstrated that passive transfer of a MAb against P. falciparum CSP inhibited liver-stage infection in a humanized mouse/P. falciparum challenge model. Together, these models constitute unique and sensitive in vivo methods to assess serum-transferable protection against Plasmodium sporozoite challenge.
Collapse
|
29
|
Nganou-Makamdop K, Sauerwein RW. Liver or blood-stage arrest during malaria sporozoite immunization: the later the better? Trends Parasitol 2013; 29:304-10. [PMID: 23608185 DOI: 10.1016/j.pt.2013.03.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 03/01/2013] [Accepted: 03/18/2013] [Indexed: 10/26/2022]
Abstract
So far, the best immunization strategies to achieve high levels of protection against malaria are based on whole parasites. Complete sterile protection can be obtained in rodent models after immunization with sporozoites and chemoprophylaxis, or with sporozoites attenuated either genetically or by radiation. These approaches target specific stages, with arrests occurring at different time-points of the parasite life cycle. Here, we review these different approaches in relation to their capacity to induce protection in both Plasmodium berghei and Plasmodium yoelii models. The combined data suggest that maximal liver-stage exposure without further development into blood stages may induce the most efficient protection in mice.
Collapse
Affiliation(s)
- Krystelle Nganou-Makamdop
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | | |
Collapse
|
30
|
Lindner SE, Mikolajczak SA, Vaughan AM, Moon W, Joyce BR, Sullivan WJ, Kappe SHI. Perturbations of Plasmodium Puf2 expression and RNA-seq of Puf2-deficient sporozoites reveal a critical role in maintaining RNA homeostasis and parasite transmissibility. Cell Microbiol 2013; 15:1266-83. [PMID: 23356439 DOI: 10.1111/cmi.12116] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 01/18/2013] [Accepted: 01/22/2013] [Indexed: 12/30/2022]
Abstract
Malaria's cycle of infection requires parasite transmission between a mosquito vector and a mammalian host. We here demonstrate that the Plasmodium yoelii Pumilio-FBF family member Puf2 allows the sporozoite to remain infectious in the mosquito salivary glands while awaiting transmission. Puf2 mediates this solely through its RNA-binding domain (RBD) likely by stabilizing or hastening the degradation of specific mRNAs. Puf2 traffics to sporozoite cytosolic granules, which are negative for several markers of stress granules and P-bodies, and disappear rapidly after infection of hepatocytes. In contrast to previously described Plasmodium berghei pbpuf2(-) parasites, pypuf2(-) sporozoites have no apparent defect in host infection when tested early in salivary gland residence, but become progressively non-infectious and prematurely transform into EEFs during prolonged salivary gland residence. The premature overexpression of Puf2 in oocysts causes striking deregulation of sporozoite maturation and infectivity while extension of Puf2 expression in liverstages causes no defect, suggesting that the presence of Puf2 alone is not sufficient for its functions. Finally, by conducting the first comparative RNA-seq analysis of Plasmodium sporozoites, we find that Puf2 may play a role in directly or indirectly maintaining the homeostasis of specific transcripts. These findings uncover requirements for maintaining a window of opportunity for the malaria parasite to accommodate the unpredictable moment of transmission from mosquito to mammalian host.
Collapse
Affiliation(s)
- Scott E Lindner
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Zhao J, Deng S, Liang J, Cao Y, Liu J, Du F, Shang H, Cui L, Luo E. Immunogenicity, protective efficacy and safety of a recombinant DNA vaccine encoding truncated Plasmodium yoelii sporozoite asparagine-rich protein 1 (PySAP1). Hum Vaccin Immunother 2013; 9:1104-11. [PMID: 23357857 DOI: 10.4161/hv.23688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although great efforts have been undertaken for the development of malaria vaccines, no completely effective malaria vaccines are available yet. Despite being clinically silent, the pre-erythrocytic stage is considered an ideal target for the development of malaria vaccines. Sporozoite asparagine-rich protein 1 (SAP1) is a sporozoite-localized protein that regulates the expression of UIS (upregulated in infectious sporozoites) genes, which are essential for the infectivity of sporozoites. In this study, a recombinant DNA vaccine encoding a predicted antigenic determinant region of Plasmodium yoelii SAP1 (PySAP1) was constructed. Immunization of mice with this DNA vaccine construct resulted in significant elevation of cytokines such as IFN-γ, IL-2, IL-4 and IL-10, and total IgG as compared with control groups immunized with either the empty DNA vector or saline. After challenge with sporozoites, the group receiving the DNA vaccine showed delayed development of parasitemia and prolonged survival time compared with the control group. The DNA vaccine provided partial protection against P. yoelii 17XL infection, with an overall protection rate of 20%. In addition, the DNA vaccine did not show integration into the host genome. Further studies of SAP1 are needed to test whether it can be used as subunit vaccine candidate.
Collapse
Affiliation(s)
- Jia Zhao
- Department of Pathogen Biology; College of Basic Medical Sciences; China Medical University; Shenyang, Liaoning P.R. China
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Lindner SE, Swearingen KE, Harupa A, Vaughan AM, Sinnis P, Moritz RL, Kappe SHI. Total and putative surface proteomics of malaria parasite salivary gland sporozoites. Mol Cell Proteomics 2013; 12:1127-43. [PMID: 23325771 DOI: 10.1074/mcp.m112.024505] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Malaria infections of mammals are initiated by the transmission of Plasmodium salivary gland sporozoites during an Anopheles mosquito vector bite. Sporozoites make their way through the skin and eventually to the liver, where they infect hepatocytes. Blocking this initial stage of infection is a promising malaria vaccine strategy. Therefore, comprehensively elucidating the protein composition of sporozoites will be invaluable in identifying novel targets for blocking infection. Previous efforts to identify the proteins expressed in Plasmodium mosquito stages were hampered by the technical difficulty of separating the parasite from its vector; without effective purifications, the large majority of proteins identified were of vector origin. Here we describe the proteomic profiling of highly purified salivary gland sporozoites from two Plasmodium species: human-infective Plasmodium falciparum and rodent-infective Plasmodium yoelii. The combination of improved sample purification and high mass accuracy mass spectrometry has facilitated the most complete proteome coverage to date for a pre-erythrocytic stage of the parasite. A total of 1991 P. falciparum sporozoite proteins and 1876 P. yoelii sporozoite proteins were identified, with >86% identified with high sequence coverage. The proteomic data were used to confirm the presence of components of three features critical for sporozoite infection of the mammalian host: the sporozoite motility and invasion apparatus (glideosome), sporozoite signaling pathways, and the contents of the apical secretory organelles. Furthermore, chemical labeling and identification of proteins on live sporozoites revealed previously uncharacterized complexity of the putative sporozoite surface-exposed proteome. Taken together, the data constitute the most comprehensive analysis to date of the protein expression of salivary gland sporozoites and reveal novel potential surface-exposed proteins that might be valuable targets for antibody blockage of infection.
Collapse
Affiliation(s)
- Scott E Lindner
- Malaria Program, Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Krzych U, Dalai S, Zarling S, Pichugin A. Memory CD8 T cells specific for plasmodia liver-stage antigens maintain protracted protection against malaria. Front Immunol 2012; 3:370. [PMID: 23233854 PMCID: PMC3517952 DOI: 10.3389/fimmu.2012.00370] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 11/20/2012] [Indexed: 01/15/2023] Open
Abstract
Immunologic memory induced by pathogenic agents or vaccinations is inextricably linked to long-lasting protection. Adequately maintained memory T and B cell pools assure a fast, effective, and specific response against re-infections. Studies of immune responses amongst residents of malaria endemic areas suggest that memory responses to Plasmodia antigens appear to be neither adequately developed nor maintained, because persons who survive episodes of childhood malaria remain vulnerable to persistent or intermittent malaria infections. By contrast, multiple exposures of humans and laboratory rodents to radiation-attenuated Plasmodia sporozoites (γ-spz) induces sterile and long-lasting protection against experimental sporozoite challenge. Protection is associated with MHC-class I-dependent CD8 T cells, the key effectors against pre-erythrocytic stage infection. We have adopted the P. berghei γ-spz mouse model to study memory CD8 T cells that are specific for antigens expressed by Pb liver-stage (LS) parasites and are found predominantly in the liver. On the basis of phenotypic and functional characteristics, we have demonstrated that liver CD8 T cells form two subsets: CD44hiCD62LloKLRG-1+CD107+CD127−CD122loCD8 T effector/effector memory (TE/EM) cells that are the dominant IFN-γ producers and CD44hiCD62LhiKLRG-1−CD107−CD127+CD122hiCD8 T central memory (TCM) cells. In this review, we discuss our observations concerning the role of CD8 TE/EM and CD8 TCM cells in the maintenance of protracted protective immunity against experimental malaria infection. Finally, we present a hypothesis consistent with a model whereby intrahepatic CD8 TCM cells, that are maintained in part by LS-Ag depot and by IL-15-mediated survival and homeostatic proliferation, form a reservoir of cells ready for conscription to CD8 TE/EM cells needed to prevent re-infections.
Collapse
Affiliation(s)
- Urszula Krzych
- Department of Cellular Immunology, Branch of Military Malaria Vaccine Development, Walter Reed Army Institute of Research Silver Spring, MD, USA
| | | | | | | |
Collapse
|
34
|
Identification of an AP2-family protein that is critical for malaria liver stage development. PLoS One 2012; 7:e47557. [PMID: 23144823 PMCID: PMC3492389 DOI: 10.1371/journal.pone.0047557] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 09/18/2012] [Indexed: 11/23/2022] Open
Abstract
Liver-stage malaria parasites are a promising target for drugs and vaccines against malaria infection. However, little is currently known about gene regulation in this stage. In this study, we used the rodent malaria parasite Plasmodium berghei and showed that an AP2-family transcription factor, designated AP2-L, plays a critical role in the liver-stage development of the parasite. AP2-L-depleted parasites proliferated normally in blood and in mosquitoes. However, the ability of these parasites to infect the liver was approximately 10,000 times lower than that of wild-type parasites. In vitro assays showed that the sporozoites of these parasites invaded hepatocytes normally but that their development stopped in the middle of the liver schizont stage. Expression profiling using transgenic P. berghei showed that fluorescent protein-tagged AP2-L increased rapidly during the liver schizont stage but suddenly disappeared with the formation of the mature liver schizont. DNA microarray analysis showed that the expression of several genes, including those of parasitophorous vacuole membrane proteins, was significantly decreased in the early liver stage of AP2-L-depleted parasites. Investigation of the targets of this transcription factor should greatly promote the exploration of liver-stage antigens and the elucidation of the mechanisms of hepatocyte infection by malaria parasites.
Collapse
|
35
|
Annoura T, Ploemen IHJ, van Schaijk BCL, Sajid M, Vos MW, van Gemert GJ, Chevalley-Maurel S, Franke-Fayard BMD, Hermsen CC, Gego A, Franetich JF, Mazier D, Hoffman SL, Janse CJ, Sauerwein RW, Khan SM. Assessing the adequacy of attenuation of genetically modified malaria parasite vaccine candidates. Vaccine 2012; 30:2662-70. [PMID: 22342550 DOI: 10.1016/j.vaccine.2012.02.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 11/30/2022]
Abstract
The critical first step in the clinical development of a malaria vaccine, based on live-attenuated Plasmodium falciparum sporozoites, is the guarantee of complete arrest in the liver. We report on an approach for assessing adequacy of attenuation of genetically attenuated sporozoites in vivo using the Plasmodium berghei model of malaria and P. falciparum sporozoites cultured in primary human hepatocytes. We show that two genetically attenuated sporozoite vaccine candidates, Δp52+p36 and Δfabb/f, are not adequately attenuated. Sporozoites infection of mice with both P. berghei candidates can result in blood infections. We also provide evidence that P. falciparum sporozoites of the leading vaccine candidate that is similarly attenuated through the deletion of the genes encoding the proteins P52 and P36, can develop into replicating liver stages. Therefore, we propose a minimal set of screening criteria to assess adequacy of sporozoite attenuation necessary before advancing into further clinical development and studies in humans.
Collapse
Affiliation(s)
- Takeshi Annoura
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Lindner SE, Miller JL, Kappe SHI. Malaria parasite pre-erythrocytic infection: preparation meets opportunity. Cell Microbiol 2012; 14:316-24. [PMID: 22151703 DOI: 10.1111/j.1462-5822.2011.01734.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
For those stricken with malaria, the classic clinical symptoms are caused by the parasite's cyclic infection of red blood cells. However, this erythrocytic phase of the parasite's life cycle initiates from an asymptomatic pre-erythrocytic phase: the injection of sporozoites via the bite of a parasite-carrying Anopheline mosquito, and the ensuing infection of the liver. With the increased capabilities of studying liver stages in mice, much progress has been made elucidating the cellular and molecular basis of the parasite's progression through this bottleneck of its life cycle. Here we review relevant findings on how sporozoites prepare for infection of the liver and factors crucial to liver stage development as well as key host/parasite interactions.
Collapse
Affiliation(s)
- Scott E Lindner
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
| | | | | |
Collapse
|