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Lee SM, Hickey JM, Miura K, Joshi SB, Volkin DB, King CR, Plieskatt JL. A C-terminal Pfs48/45 malaria transmission-blocking vaccine candidate produced in the baculovirus expression system. Sci Rep 2020; 10:395. [PMID: 31942034 PMCID: PMC6962329 DOI: 10.1038/s41598-019-57384-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/30/2019] [Indexed: 11/09/2022] Open
Abstract
The Plasmodium falciparum gametocyte surface protein, Pfs48/45, is a potential target for malaria transmission-blocking vaccines. However, due to its size and complexity, expression of the full-length protein has been difficult, leading to focus on the C-terminal six cysteine domain (6C) with the use of fusion proteins to facilitate expression and folding. In this study, we utilized the baculovirus system to evaluate the expression of three Pfs48/45 proteins including the full-length protein, the 6C domain fragment and the 6C domain mutant to prevent glycosylation. Expression of the recombinant Pfs48/45 proteins was conducted in super Sf9 cells combined with the use of tunicamycin to prevent N-glycosylation. The proteins were then evaluated as immunogens in mice to demonstrate the induction of functionally active polyclonal antibody responses as measured in the standard membrane feeding assay (SMFA). Only the 6C protein was found to exhibit significant transmission-reducing activity. Further characterization of the biologically active 6C protein demonstrated it was homogeneous in terms of size, charge, conformation, absence of glycosylation, and containing proper disulfide bond pairings. This study presents an alternative expression system, without the need of a fusion protein partner, for the Pfs48/45 6C protein fragment including further evaluation as a potential transmission-blocking vaccine candidate.
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Affiliation(s)
- Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA.
| | - John M Hickey
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Sangeeta B Joshi
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - David B Volkin
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - C Richter King
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - Jordan L Plieskatt
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
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de Jong RM, Tebeje SK, Meerstein‐Kessel L, Tadesse FG, Jore MM, Stone W, Bousema T. Immunity against sexual stage Plasmodium falciparum and Plasmodium vivax parasites. Immunol Rev 2020; 293:190-215. [PMID: 31840844 PMCID: PMC6973022 DOI: 10.1111/imr.12828] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 12/25/2022]
Abstract
The efficient spread of malaria from infected humans to mosquitoes is a major challenge for malaria elimination initiatives. Gametocytes are the only Plasmodium life stage infectious to mosquitoes. Here, we summarize evidence for naturally acquired anti-gametocyte immunity and the current state of transmission blocking vaccines (TBV). Although gametocytes are intra-erythrocytic when present in infected humans, developing Plasmodium falciparum gametocytes may express proteins on the surface of red blood cells that elicit immune responses in naturally exposed individuals. This immune response may reduce the burden of circulating gametocytes. For both P. falciparum and Plasmodium vivax, there is a solid evidence that antibodies against antigens present on the gametocyte surface, when co-ingested with gametocytes, can influence transmission to mosquitoes. Transmission reducing immunity, reducing the burden of infection in mosquitoes, is a well-acknowledged but poorly quantified phenomenon that forms the basis for the development of TBV. Transmission enhancing immunity, increasing the likelihood or intensity of transmission to mosquitoes, is more speculative in nature but is convincingly demonstrated for P. vivax. With the increased interest in malaria elimination, TBV and monoclonal antibodies have moved to the center stage of malaria vaccine development. Methodologies to prioritize and evaluate products are urgently needed.
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MESH Headings
- Antibodies, Blocking/immunology
- Antibodies, Protozoan/immunology
- Host-Parasite Interactions/immunology
- Humans
- Immunity
- Immunomodulation
- Life Cycle Stages
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Plasmodium vivax/growth & development
- Plasmodium vivax/immunology
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Affiliation(s)
- Roos M. de Jong
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Lisette Meerstein‐Kessel
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Centre for Molecular and Biomolecular InformaticsRadboud Institute for Molecular Life SciencesNijmegenThe Netherlands
| | - Fitsum G. Tadesse
- Armauer Hansen Research InstituteAddis AbabaEthiopia
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Matthijs M. Jore
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Will Stone
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
| | - Teun Bousema
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
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53
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Miura K, Tachibana M, Takashima E, Morita M, Kanoi BN, Nagaoka H, Baba M, Torii M, Ishino T, Tsuboi T. Malaria transmission-blocking vaccines: wheat germ cell-free technology can accelerate vaccine development. Expert Rev Vaccines 2019; 18:1017-1027. [PMID: 31566026 PMCID: PMC11000147 DOI: 10.1080/14760584.2019.1674145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 09/25/2019] [Indexed: 12/18/2022]
Abstract
Introduction: Highly effective malaria vaccines are essential component toward malaria elimination. Although the leading malaria vaccine, RTS,S/AS01, with modest efficacy is being evaluated in a pilot feasibility trial, development of a malaria transmission-blocking vaccine (TBV) could make a major contribution toward malaria elimination. Only a few TBV antigens have reached pre-clinical or clinical development but with several challenges including difficulties in the expression of malaria recombinant proteins and low immunogenicity in humans. Therefore, novel approaches to accelerate TBV research to preclinical development are critical to generate an efficacious TBV.Areas covered: PubMed was searched to review the progress and future prospects of malaria TBV research and development. We also reviewed registered trials at ClinicalTrials.gov as well as post-genome TBV candidate discovery research including our efforts.Expert opinion: Wheat germ cell-free protein synthesis technology can accelerate TBV development by overcoming some current challenges of TBV research.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Bernard N Kanoi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Minami Baba
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Tomoko Ishino
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
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54
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Kurtovic L, Boyle MJ, Opi DH, Kennedy AT, Tham WH, Reiling L, Chan JA, Beeson JG. Complement in malaria immunity and vaccines. Immunol Rev 2019; 293:38-56. [PMID: 31556468 PMCID: PMC6972673 DOI: 10.1111/imr.12802] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022]
Abstract
Developing efficacious vaccines for human malaria caused by Plasmodium falciparum is a major global health priority, although this has proven to be immensely challenging over the decades. One major hindrance is the incomplete understanding of specific immune responses that confer protection against disease and/or infection. While antibodies to play a crucial role in malaria immunity, the functional mechanisms of these antibodies remain unclear as most research has primarily focused on the direct inhibitory or neutralizing activity of antibodies. Recently, there is a growing body of evidence that antibodies can also mediate effector functions through activating the complement system against multiple developmental stages of the parasite life cycle. These antibody‐complement interactions can have detrimental consequences to parasite function and viability, and have been significantly associated with protection against clinical malaria in naturally acquired immunity, and emerging findings suggest these mechanisms could contribute to vaccine‐induced immunity. In order to develop highly efficacious vaccines, strategies are needed that prioritize the induction of antibodies with enhanced functional activity, including the ability to activate complement. Here we review the role of complement in acquired immunity to malaria, and provide insights into how this knowledge could be used to harness complement in malaria vaccine development.
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Affiliation(s)
- Liriye Kurtovic
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia
| | | | | | - Alexander T Kennedy
- Walter and Eliza Hall Institute, Melbourne, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Vic., Australia
| | - Wai-Hong Tham
- Walter and Eliza Hall Institute, Melbourne, Vic., Australia
| | | | - Jo-Anne Chan
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Microbiology, Monash University, Clayton, Vic., Australia.,Department of Medicine, The University of Melbourne, Parkville, Vic., Australia
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55
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Collins KA, Ouedraogo A, Guelbeogo WM, Awandu SS, Stone W, Soulama I, Ouattara MS, Nombre A, Diarra A, Bradley J, Selvaraj P, Gerardin J, Drakeley C, Bousema T, Tiono A. Investigating the impact of enhanced community case management and monthly screening and treatment on the transmissibility of malaria infections in Burkina Faso: study protocol for a cluster-randomised trial. BMJ Open 2019; 9:e030598. [PMID: 31519680 PMCID: PMC6747640 DOI: 10.1136/bmjopen-2019-030598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION A large proportion of malaria-infected individuals in endemic areas do not experience symptoms that prompt treatment-seeking. These asymptomatically infected individuals may retain their infections for many months during which sexual-stage parasites (gametocytes) are produced that may be transmissible to mosquitoes. Reductions in malaria transmission could be achieved by detecting and treating these infections early. This study assesses the impact of enhanced community case management (CCM) and monthly screening and treatment (MSAT) on the prevalence and transmissibility of malaria infections. METHODS AND ANALYSIS This cluster-randomised trial will take place in Sapone, an area of intense, highly seasonal malaria in Burkina Faso. In total, 180 compounds will be randomised to one of three interventions: arm 1 - current standard of care with passively monitored malaria infections; arm 2 - standard of care plus enhanced CCM, comprising active weekly screening for fever, and detection and treatment of infections in fever positive individuals using conventional rapid diagnostic tests (RDTs); or arm 3 - standard of care and enhanced CCM, plus MSAT using RDTs. The study will be conducted over approximately 18 months covering two high-transmission seasons and the intervening dry season. The recruitment strategy aims to ensure that overall transmission and force of infection is not affected so we are able to continuously evaluate the impact of interventions in the context of ongoing intense malaria transmission. The main objectives of the study are to determine the impact of enhanced CCM and MSAT on the prevalence and density of parasitaemia and gametocytaemia and the transmissibility of infections. This will be achieved by molecular detection of infections in all study participants during start and end season cross-sectional surveys and routine sampling of malaria-positive individuals to assess their infectiousness to mosquitoes. ETHICS AND DISSEMINATION The study has been reviewed and approved by the London School of Hygiene and Tropical Medicine (LSHTM) (Review number: 14724) and The Centre National de Recherche et de Formation sur le Paludisme institutional review board (IRB) (Deliberation N° 2018/000002/MS/SG/CNRFP/CIB) and Burkina Faso national medical ethics committees (Deliberation N° 2018-01-010).Findings of the study will be shared with the community via local opinion leaders and community meetings. Results may also be shared through conferences, seminars, reports, theses and peer-reviewed publications; disease occurrence data and study outcomes will be shared with the Ministry of Health. Data will be published in an online digital repository. TRIAL REGISTRATION NUMBER NCT03705624.
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Affiliation(s)
| | - Alphonse Ouedraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Wamdaogo Moussa Guelbeogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Shehu S Awandu
- Department or Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Will Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Issiaka Soulama
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Maurice S Ouattara
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Apollinaire Nombre
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Teun Bousema
- Department or Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Alfred Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
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56
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Julien JP, Wardemann H. Antibodies against Plasmodium falciparum malaria at the molecular level. Nat Rev Immunol 2019; 19:761-775. [DOI: 10.1038/s41577-019-0209-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 12/11/2022]
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57
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Singh SK, Thrane S, Chourasia BK, Teelen K, Graumans W, Stoter R, van Gemert GJ, van de Vegte-Bolmer MG, Nielsen MA, Salanti A, Sander AF, Sauerwein RW, Jore MM, Theisen M. Pfs230 and Pfs48/45 Fusion Proteins Elicit Strong Transmission-Blocking Antibody Responses Against Plasmodium falciparum. Front Immunol 2019; 10:1256. [PMID: 31231386 PMCID: PMC6560166 DOI: 10.3389/fimmu.2019.01256] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/17/2019] [Indexed: 11/13/2022] Open
Abstract
The Plasmodium falciparum Pfs230 and Pfs48/45 proteins are expressed during transmission from man to mosquito and are leading candidates for a malaria transmission blocking vaccine. Individually they generate transmission blocking (TB) antibodies in rodent models. Whether the single protein vaccines are suitable to use in field settings will primarily depend on their potency to elicit functional antibodies. We hypothesized that a combination of both proteins will be more potent than each protein individually. Therefore we designed chimeric proteins composed of fragments of both Pfs230 and Pfs48/45 as well as single protein fragments, and expressed these in Lactoccus lactis. Both the individual Pfs230 and Pfs48/45 fragments and chimeras elicited high levels of functional antibodies in mice. Importantly, one of the chimeric proteins elicited over threefold higher transmission blocking antibody responses than the single antigens alone. Furthermore the immunogenicity of one of the chimeras could be enhanced through coupling to a virus-like particle (VLP). Altogether these data support further clinical development of these novel constructs.
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Affiliation(s)
- Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Susan Thrane
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Bishwanath K Chourasia
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Karina Teelen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Rianne Stoter
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Morten A Nielsen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ali Salanti
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Adam F Sander
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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58
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Abstract
In the progression of the life cycle of Plasmodium falciparum, a small proportion of asexual parasites differentiate into male or female sexual forms called gametocytes. Just like their asexual counterparts, gametocytes are contained within the infected host's erythrocytes (RBCs). However, unlike their asexual partners, they do not exit the RBC until they are taken up in a blood meal by a mosquito. In the mosquito midgut, they are stimulated to emerge from the RBC, undergo fertilization, and ultimately produce tens of thousands of sporozoites that are infectious to humans. This transmission cycle can be blocked by antibodies targeting proteins exposed on the parasite surface in the mosquito midgut, a process that has led to the development of candidate transmission-blocking vaccines (TBV), including some that are in clinical trials. Here we review the leading TBV antigens and highlight the ongoing search for additional gametocyte/gamete surface antigens, as well as antigens on the surfaces of gametocyte-infected erythrocytes, which can potentially become a new group of TBV candidates.
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59
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Venkatesh A, Jain A, Davies H, Periera L, Maki JN, Gomes E, Felgner PL, Srivastava S, Patankar S, Rathod PK. Hospital-derived antibody profiles of malaria patients in Southwest India. Malar J 2019; 18:138. [PMID: 30995911 PMCID: PMC6472095 DOI: 10.1186/s12936-019-2771-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 04/08/2019] [Indexed: 11/10/2022] Open
Abstract
Background Naturally acquired immunity to malaria across the globe varies in intensity and protective powers. Many of the studies on immunity are from hyperendemic regions of Africa. In Asia, particularly in India, there are unique opportunities for exploring and understanding malaria immunity relative to host age, co-occurrence of Plasmodium falciparum and Plasmodium vivax infections, varying travel history, and varying disease severity. Variation in immunity in hospital settings is particularly understudied. Methods A US NIH ICEMR (South Asia) team examined the level of immunity in an Indian malaria patient population visiting or admitted to Goa Medical College and Hospital in Goa, India. Sera from 200 patients of different ages, in different seasons, infected with P. falciparum or P. vivax or both species, and with different clinical severity were applied to an established protein array system with over 1000 P. falciparum and P. vivax antigens. Differential binding of patient IgG to different antigens was measured. Results Even though Goa itself has much more P. vivax than P. falciparum, IgG reactivity towards P. falciparum antigens was very strong and comparable to that seen in regions of the world with high P. falciparum endemicity. Of 248 seropositive P. falciparum antigens, the strongest were VAR, MSP10, HSP70, PTP5, AP2, AMA1, and SYN6. In P. vivax patients, ETRAMPs, MSPs, and ApiAP2, sexual stage antigen s16, RON3 were the strongest IgG binders. Both P. falciparum and P. vivax patients also revealed strong binding to new antigens with unknown functions. Seropositives showed antigens unique to the young (HSP40, ACS6, GCVH) or to non-severe malaria (MSP3.8 and PHIST). Conclusion Seroreactivity at a major hospital in Southwest India reveals antibody responses to P. falciparum and P. vivax in a low malaria transmission region with much migration. In addition to markers of transmission, the data points to specific leads for possible protective immunity against severe disease. Several, but not all, key antigens overlap with work from different settings around the globe and from other parts of India. Together, these studies confidently help define antigens with the greatest potential chance of universal application for surveillance and possibly for disease protection, in many different parts of India and the world. Electronic supplementary material The online version of this article (10.1186/s12936-019-2771-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Apoorva Venkatesh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Aarti Jain
- Vaccine R&D Center, University of California, Irvine, CA, 92697, USA
| | - Huw Davies
- Vaccine R&D Center, University of California, Irvine, CA, 92697, USA
| | - Ligia Periera
- Department of Chemistry and Department of Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Jennifer N Maki
- Department of Chemistry and Department of Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Edwin Gomes
- Department of Medicine, Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Philip L Felgner
- Vaccine R&D Center, University of California, Irvine, CA, 92697, USA
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Swati Patankar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Pradipsinh K Rathod
- Department of Chemistry and Department of Global Health, University of Washington, Seattle, WA, 98195, USA.
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60
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Case Definitions of Clinical Malaria in Children from Three Health Districts in the North Region of Cameroon. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9709013. [PMID: 31139663 PMCID: PMC6500661 DOI: 10.1155/2019/9709013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/26/2019] [Accepted: 03/20/2019] [Indexed: 12/05/2022]
Abstract
Malaria endemicity in Cameroon greatly varies according to ecological environment. In such conditions, parasitaemia, which is associated with fever, may not always suffice to define an episode of clinical malaria. The evaluation of malaria control intervention strategies mostly consists of identifying cases of clinical malaria and is crucial to promote better diagnosis for accurate measurement of the impact of the intervention. We sought out to define and quantify clinical malaria cases in children from three health districts in the Northern region of Cameroon. A cohort study of 6,195 children aged between 6 and 120 months was carried out during the raining season (July to October) between 2013 and 2014. Differential diagnosis of clinical malaria was performed using the parasite density and axillary temperature. At recruitment, patients with malaria-related symptoms (fever [axillary temperature ≥ 37.5°C], chills, severe malaise, headache, or vomiting) and a malaria positive blood smear were classified under clinical malaria group. The malaria attributable fraction was calculated using logistic regression models. Plasmodium falciparum was responsible for over 91% of infections. Children from Pitoa health district had the highest number of asymptomatic infections (45.60%) compared to those from Garoua and Mayo Oulo. The most suitable cut-off for the association between parasite densities and fever was found among children less than 24 months. Overall, parasite densities that ranged above 3,200 parasites per μl of blood could be used to define the malaria attributable fever cases. In groups of children aged between 24 and 59 months and 60 and 94 months, the optimum cut-off parasite density was 6,400 parasites per μl of blood, while children aged between 95 and 120 months had a cut-off of 800 parasites per μl of blood. In the same ecoepidemiological zone, clinical malaria case definitions are influenced by age and location (health district) and this could be considered when evaluating malaria intervention strategies in endemic areas.
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61
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Identification of domains within Pfs230 that elicit transmission blocking antibody responses. Vaccine 2019; 37:1799-1806. [PMID: 30824357 PMCID: PMC6708081 DOI: 10.1016/j.vaccine.2019.02.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/23/2019] [Accepted: 02/05/2019] [Indexed: 11/23/2022]
Abstract
A transmission-blocking vaccine (TBV) against Plasmodium falciparum is likely to be a valuable tool in a malaria eradication program. Pfs230 is one of the major TBV candidates, and multiple Pfs230-based vaccines induced antibodies, which prevented oocyst formation in mosquitoes as determined by a standard membrane-feeding assay (SMFA). Pfs230 is a >300 kDa protein consisting of 14 cysteine motif (CM) domains, and the size and cysteine-rich nature of the molecule have hampered its production as an intact protein. Except for one early study with maltose-binding protein fusion Pfs230 constructs expressed in Esherichia coli, all other studies have focused on only the first four CM domains in the Pfs230 molecule. To identify all possible TBV candidate domains, we systematically produced either single-CM-domain (a total of 14), 2-CM-domain (7), or 4-CM-domain (6) recombinant protein fragments using a eukaryotic wheat germ cell-free expression system (WGCFS). In addition, two more constructs which covered previously published regions, and an N-terminal prodomain construct spanning the natural cleavage site of Pfs230 were produced. Antisera against each fragment were generated in mice and we evaluated the reactivity to native Pfs230 protein by Western blots and immunofluorescence assay (IFA), and functionality by SMFA. All 30 WGCFS-produced Pfs230 constructs were immunogenic in mice. Approximately half of the mouse antibodies specifically recognized native Pfs230 by Western blots with variable band intensities. Among them, seven antibodies showed higher reactivities against native Pfs230 determined by IFA. Interestingly, antibodies against all protein fragments containing CM domain 1 displayed strong inhibitions in SMFA, while antibodies generated using constructs without CM domain 1 showed no inhibition. The results strongly support the concept that future Pfs230-based vaccine development should focus on the Pfs230 CM domain 1.
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Kengne-Ouafo JA, Sutherland CJ, Binka FN, Awandare GA, Urban BC, Dinko B. Immune Responses to the Sexual Stages of Plasmodium falciparum Parasites. Front Immunol 2019; 10:136. [PMID: 30804940 PMCID: PMC6378314 DOI: 10.3389/fimmu.2019.00136] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/16/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria infections remain a serious global health problem in the world, particularly among children and pregnant women in Sub-Saharan Africa. Moreover, malaria control and elimination is hampered by rapid development of resistance by the parasite and the vector to commonly used antimalarial drugs and insecticides, respectively. Therefore, vaccine-based strategies are sorely needed, including those designed to interrupt disease transmission. However, a prerequisite for such a vaccine strategy is the understanding of both the human and vector immune responses to parasite developmental stages involved in parasite transmission in both man and mosquito. Here, we review the naturally acquired humoral and cellular responses to sexual stages of the parasite while in the human host and the Anopheles vector. In addition, updates on current anti-gametocyte, anti-gamete, and anti-mosquito transmission blocking vaccines are given. We conclude with our views on some important future directions of research into P. falciparum sexual stage immunity relevant to the search for the most appropriate transmission-blocking vaccine.
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Affiliation(s)
- Jonas A Kengne-Ouafo
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Colin J Sutherland
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fred N Binka
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho, Ghana
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Britta C Urban
- Faculty of Biological Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
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63
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Abstract
The development of highly effective and durable vaccines against the human malaria parasites Plasmodium falciparum and P. vivax remains a key priority. Decades of endeavor have taught that achieving this goal will be challenging; however, recent innovation in malaria vaccine research and a diverse pipeline of novel vaccine candidates for clinical assessment provides optimism. With first-generation pre-erythrocytic vaccines aiming for licensure in the coming years, it is important to reflect on how next-generation approaches can improve on their success. Here we review the latest vaccine approaches that seek to prevent malaria infection, disease, and transmission and highlight some of the major underlying immunological and molecular mechanisms of protection. The synthesis of rational antigen selection, immunogen design, and immunization strategies to induce quantitatively and qualitatively improved immune effector mechanisms offers promise for achieving sustained high-level protection.
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64
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Pritam M, Singh G, Swaroop S, Singh AK, Singh SP. Exploitation of reverse vaccinology and immunoinformatics as promising platform for genome-wide screening of new effective vaccine candidates against Plasmodium falciparum. BMC Bioinformatics 2019; 19:468. [PMID: 30717656 PMCID: PMC7394322 DOI: 10.1186/s12859-018-2482-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 11/09/2018] [Indexed: 12/14/2022] Open
Abstract
Background In the current scenario, designing of world-wide effective malaria vaccine against Plasmodium falciparum remain challenging despite the significant progress has been made in last few decades. Conventional vaccinology (isolate, inactivate and inject) approaches are time consuming, laborious and expensive; therefore, the use of computational vaccinology tools are imperative, which can facilitate the design of new and promising vaccine candidates. Results In current investigation, initially 5548 proteins of P. falciparum genome were carefully chosen for the incidence of signal peptide/ anchor using SignalP4.0 tool that resulted into 640 surface linked proteins (SLP). Out of these SLP, only 17 were predicted to contain GPI-anchors using PredGPI tool in which further 5 proteins were considered as malarial antigenic adhesins by MAAP and VaxiJen programs, respectively. In the subsequent step, T cell epitopes of 5 genome derived predicted antigenic adhesins (GDPAA) and 5 randomly selected known malarial adhesins (RSKMA) were analysed employing MHC class I and II tools of IEDB analysis resource. Finally, VaxiJen scored T cell epitopes from each antigen were considered for prediction of population coverage (PPC) analysis in the world-wide population including malaria endemic regions. The validation of the present in silico strategy was carried out by comparing the PPC of combined (MHC class I and II) predicted epitope ensemble among GDPAA (99.97%), RSKMA (99.90%) and experimentally known epitopes (EKE) of P. falciparum (97.72%) pertaining to world-wide human population. Conclusions The present study systematically screened 5 potential protective antigens from P. falciparum genome using bioinformatics tools. Interestingly, these GDPAA, RSKMA and EKE of P. falciparum epitope ensembles forecasted to contain highly promiscuous T cell epitopes, which are potentially effective for most of the world-wide human population with malaria endemic regions. Therefore, these epitope ensembles could be considered in near future for novel and significantly effective vaccine candidate against malaria. Electronic supplementary material The online version of this article (10.1186/s12859-018-2482-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Manisha Pritam
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, 226028, India
| | - Garima Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, 226028, India
| | - Suchit Swaroop
- Department of Zoology, University of Lucknow, Lucknow, 226007, India
| | - Akhilesh Kumar Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, 226028, India
| | - Satarudra Prakash Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, 226028, India.
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65
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Chan JA, Drew DR, Reiling L, Lisboa-Pinto A, Dinko B, Sutherland CJ, Dent AE, Chelimo K, Kazura JW, Boyle MJ, Beeson JG. Low Levels of Human Antibodies to Gametocyte-Infected Erythrocytes Contrasts the PfEMP1-Dominant Response to Asexual Stages in P. falciparum Malaria. Front Immunol 2019; 9:3126. [PMID: 30692996 PMCID: PMC6340286 DOI: 10.3389/fimmu.2018.03126] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 12/18/2018] [Indexed: 11/13/2022] Open
Abstract
Vaccines that target Plasmodium falciparum gametocytes have the potential to reduce malaria transmission and are thus attractive targets for malaria control. However, very little is known about human immune responses to gametocytes present in human hosts. We evaluated naturally-acquired antibodies to gametocyte-infected erythrocytes (gametocyte-IEs) of different developmental stages compared to other asexual parasite stages among naturally-exposed Kenyan residents. We found that acquired antibodies strongly recognized the surface of mature asexual-IEs, but there was limited reactivity to the surface of gametocyte-IEs of different stages. We used genetically-modified P. falciparum with suppressed expression of PfEMP1, the major surface antigen of asexual-stage IEs, to demonstrate that PfEMP1 is a dominant target of antibodies to asexual-IEs, in contrast to gametocyte-IEs. Antibody reactivity to gametocyte-IEs was similar to asexual-IEs lacking PfEMP1. Significant antibody reactivity to the surface of gametocytes was observed when outside of the host erythrocyte, including recognition of the major gametocyte antigen, Pfs230. This indicates that there is a deficiency of acquired antibodies to gametocyte-IEs despite the acquisition of antibodies to gametocyte antigens and asexual IEs. Our findings suggest that the acquisition of substantial immunity to the surface of gametocyte-IEs is limited, which may facilitate immune evasion to enable malaria transmission even in the face of substantial host immunity to malaria. Further studies are needed to understand the basis for the limited acquisition of antibodies to gametocytes and whether vaccine strategies can generate substantial immunity.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Ashley Lisboa-Pinto
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Colin J Sutherland
- Department of Immunology and InfectionLondon School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Arlene E Dent
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, United States
| | - Kiprotich Chelimo
- Department of Biomedical Science and Technology Maseno University, Kisumu, Kenya
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, United States
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne Parkville, VIC, Australia.,Department of Microbiology and Central Clinical School, Monash University Melbourne, VIC, Australia
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66
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Tan J, Piccoli L, Lanzavecchia A. The Antibody Response to Plasmodium falciparum: Cues for Vaccine Design and the Discovery of Receptor-Based Antibodies. Annu Rev Immunol 2018; 37:225-246. [PMID: 30566366 DOI: 10.1146/annurev-immunol-042617-053301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plasmodium falciparum remains a serious public health problem and a continuous challenge for the immune system due to the complexity and diversity of the pathogen. Recent advances from several laboratories in the characterization of the antibody response to the parasite have led to the identification of critical targets for protection and revealed a new mechanism of diversification based on the insertion of host receptors into immunoglobulin genes, leading to the production of receptor-based antibodies. These advances have opened new possibilities for vaccine design and passive antibody therapies to provide sterilizing immunity and control blood-stage parasites.
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Affiliation(s)
- Joshua Tan
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom.,Current affiliation: National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852, USA
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland;
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,VIR Biotechnology, San Francisco, California 94158, USA
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67
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Stone W, Bousema T, Sauerwein R, Drakeley C. Two-Faced Immunity? The Evidence for Antibody Enhancement of Malaria Transmission. Trends Parasitol 2018; 35:140-153. [PMID: 30573175 DOI: 10.1016/j.pt.2018.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 10/27/2022]
Abstract
Plasmodium gametocytes can induce an immune response in humans that interferes with the development of sexual-stage parasites in the mosquito gut. Many early studies of the sexual-stage immune response noted that mosquito infection could be enhanced as well as reduced by immune sera. For Plasmodium falciparum, these reports are scarce, and the phenomenon is generally regarded as a methodological artefact. Plasmodium transmission enhancement (TE) remains contentious, but the clinical development of transmission-blocking vaccines based on sexual-stage antigens requires that it is further studied. In this essay, we review the early literature on the sexual-stage immune response and transmission-modulating immunity. We discuss hypotheses for the mechanism of TE, suggest experiments to prove or disprove its existence, and discuss its possible implications.
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Affiliation(s)
- Will Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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68
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Oakes RS, Jewell CM. A plug-and-play approach for malaria vaccination. NATURE NANOTECHNOLOGY 2018; 13:1096-1097. [PMID: 30297817 DOI: 10.1038/s41565-018-0291-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Robert S Oakes
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
| | - Christopher M Jewell
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
- Robert E. Fischell Institute for Biomedical Devices, College Park, MD, USA.
- Department of Veterans Affairs, Baltimore VA Medical Center, Baltimore, MD, USA.
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69
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Structural delineation of potent transmission-blocking epitope I on malaria antigen Pfs48/45. Nat Commun 2018; 9:4458. [PMID: 30367064 PMCID: PMC6203815 DOI: 10.1038/s41467-018-06742-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/17/2018] [Indexed: 12/28/2022] Open
Abstract
Interventions that can block the transmission of malaria-causing Plasmodium falciparum (Pf) between the human host and Anopheles vector have the potential to reduce the incidence of malaria. Pfs48/45 is a gametocyte surface protein critical for parasite development and transmission, and its targeting by monoclonal antibody (mAb) 85RF45.1 leads to the potent reduction of parasite transmission. Here, we reveal how the Pfs48/45 6C domain adopts a (SAG1)-related-sequence (SRS) fold. We structurally delineate potent epitope I and show how mAb 85RF45.1 recognizes an electronegative surface with nanomolar affinity. Analysis of Pfs48/45 sequences reveals that polymorphisms are rare for residues involved at the binding interface. Humanization of rat-derived mAb 85RF45.1 conserved the mode of recognition and activity of the parental antibody, while also improving its thermostability. Our work has implications for the development of transmission-blocking interventions, both through improving vaccine designs and the testing of passive delivery of mAbs in humans. Malaria protein Pfs48/45 is a promising transmission-blocking antigen targeted by antibodies. Here, the authors determine the structure of its transmission-blocking epitope I, and generate a humanized monoclonal antibody that binds Pfs48/45 with high affinity.
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70
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Lennartz F, Brod F, Dabbs R, Miura K, Mekhaiel D, Marini A, Jore MM, Søgaard MM, Jørgensen T, de Jongh WA, Sauerwein RW, Long CA, Biswas S, Higgins MK. Structural basis for recognition of the malaria vaccine candidate Pfs48/45 by a transmission blocking antibody. Nat Commun 2018; 9:3822. [PMID: 30237518 PMCID: PMC6148045 DOI: 10.1038/s41467-018-06340-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022] Open
Abstract
The quest to develop an effective malaria vaccine remains a major priority in the fight against global infectious disease. An approach with great potential is a transmission-blocking vaccine which induces antibodies that prevent establishment of a productive infection in mosquitos that feed on infected humans, thereby stopping the transmission cycle. One of the most promising targets for such a vaccine is the gamete surface protein, Pfs48/45. Here we establish a system for production of full-length Pfs48/45 and use this to raise a panel of monoclonal antibodies. We map the binding regions of these antibodies on Pfs48/45 and correlate the location of their epitopes with their transmission-blocking activity. Finally, we present the structure of the C-terminal domain of Pfs48/45 bound to the most potent transmission-blocking antibody, and provide key molecular information for future structure-guided immunogen design. Pfs48/45 is a promising component for a transmission-blocking malaria vaccine. Here, the authors develop a system to produce full-length Pfs48/45 for immunisation, characterise a panel of monoclonal antibodies and determine the structure of a potent transmission-blocking epitope.
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Florian Brod
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Rebecca Dabbs
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - David Mekhaiel
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Arianna Marini
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Max M Søgaard
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Thomas Jørgensen
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Willem A de Jongh
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Carole A Long
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - Sumi Biswas
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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71
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Agrawal A, Bisharyan Y, Papoyan A, Bednenko J, Cardarelli J, Yao M, Clark T, Berkmen M, Ke N, Colussi P. Fusion to Tetrahymena thermophila granule lattice protein 1 confers solubility to sexual stage malaria antigens in Escherichia coli. Protein Expr Purif 2018; 153:7-17. [PMID: 30081196 PMCID: PMC6189453 DOI: 10.1016/j.pep.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 11/30/2022]
Abstract
A transmission-blocking vaccine targeting the sexual stages of Plasmodium species could play a key role in eradicating malaria. Multiple studies have identified the P. falciparum proteins Pfs25 and Pfs48/45 as prime targets for transmission-blocking vaccines. Although significant advances have been made in recombinant expression of these antigens, they remain difficult to produce at large scale and lack strong immunogenicity as subunit antigens. We linked a self-assembling protein, granule lattice protein 1 (Grl1p), from the ciliated protozoan, Tetrahymena thermophila, to regions of the ectodomains of either Pfs25 or Pfs48/45. We found that resulting protein chimera could be produced in E. coli as nanoparticles that could be readily purified in soluble form. When produced in the E. coli SHuffle strain, fusion to Grl1p dramatically increased solubility of target antigens while at the same time directing the formation of particles with diameters centering on 38 and 25 nm depending on the antigen. In a number of instances, co-expression with chaperone proteins and induction at a lower temperature further increased expression and solubility. Based on Western blotting and ELISA analysis, Pfs25 and Pfs48/45 retained their transmission-blocking epitopes within E. coli-derived particles, and the particles themselves elicited strong antibody responses in rabbits when given with an aluminum-based adjuvant. Antibodies against Pfs25-containing nanoparticles blocked parasite transmission in standard membrane-feeding assays. In conclusion, fusion to Grl1p can act as a solubility enhancer for proteins with limited solubility while retaining correct folding, which may be useful for applications such as the production of vaccines and other biologics.
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Affiliation(s)
| | | | | | | | | | | | - Theodore Clark
- TetraGenetics Inc, Arlington, MA, USA; Department of Immunology and Microbiology, Cornell University, Ithaca, NY, USA
| | | | - Na Ke
- New England Biolabs, Ipswich, MA, USA
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72
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Bradley J, Stone W, Da DF, Morlais I, Dicko A, Cohuet A, Guelbeogo WM, Mahamar A, Nsango S, Soumaré HM, Diawara H, Lanke K, Graumans W, Siebelink-Stoter R, van de Vegte-Bolmer M, Chen I, Tiono A, Gonçalves BP, Gosling R, Sauerwein RW, Drakeley C, Churcher TS, Bousema T. Predicting the likelihood and intensity of mosquito infection from sex specific Plasmodium falciparum gametocyte density. eLife 2018; 7:34463. [PMID: 29848446 PMCID: PMC6013255 DOI: 10.7554/elife.34463] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/26/2018] [Indexed: 12/02/2022] Open
Abstract
Understanding the importance of gametocyte density on human-to-mosquito transmission is of immediate relevance to malaria control. Previous work (Churcher et al., 2013) indicated a complex relationship between gametocyte density and mosquito infection. Here we use data from 148 feeding experiments on naturally infected gametocyte carriers to show that the relationship is much simpler and depends on both female and male parasite density. The proportion of mosquitoes infected is primarily determined by the density of female gametocytes though transmission from low gametocyte densities may be impeded by a lack of male parasites. Improved precision of gametocyte quantification simplifies the shape of the relationship with infection increasing rapidly before plateauing at higher densities. The mean number of oocysts per mosquito rises quickly with gametocyte density but continues to increase across densities examined. The work highlights the importance of measuring both female and male gametocyte density when estimating the human reservoir of infection.
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Affiliation(s)
- John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Will Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Direction, Bobo Dioulasso, Burkina Faso
| | - Isabelle Morlais
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Anna Cohuet
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Wamdaogo M Guelbeogo
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Almahamoudou Mahamar
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Sandrine Nsango
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon
| | - Harouna M Soumaré
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Halimatou Diawara
- Institut de recherche pour le développement, MIVEGEC (UM-CNRS 5290-IRD 224), Montpellier, France
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Wouter Graumans
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Rianne Siebelink-Stoter
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, United States
| | - Alfred Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner Pamplona Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Roland Gosling
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, United States
| | - Robert W Sauerwein
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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73
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Ouédraogo AL, Eckhoff PA, Luty AJF, Roeffen W, Sauerwein RW, Bousema T, Wenger EA. Modeling the impact of Plasmodium falciparum sexual stage immunity on the composition and dynamics of the human infectious reservoir for malaria in natural settings. PLoS Pathog 2018; 14:e1007034. [PMID: 29742161 PMCID: PMC5962096 DOI: 10.1371/journal.ppat.1007034] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/21/2018] [Accepted: 04/16/2018] [Indexed: 12/22/2022] Open
Abstract
Malaria transmission remains high in Sub-Saharan Africa despite large-scale implementation of malaria control interventions. A comprehensive understanding of the transmissibility of infections to mosquitoes may guide the design of more effective transmission reducing strategies. The impact of P. falciparum sexual stage immunity on the infectious reservoir for malaria has never been studied in natural settings. Repeated measurements were carried out at start-wet, peak-wet and dry season, and provided data on antibody responses against gametocyte/gamete antigens Pfs48/45 and Pfs230 as anti-gametocyte immunity. Data on high and low-density infections and their infectiousness to anopheline mosquitoes were obtained using quantitative molecular methods and mosquito feeding assays, respectively. An event-driven model for P. falciparum sexual stage immunity was developed and fit to data using an agent based malaria model infrastructure. We found that Pfs48/45 and Pfs230 antibody densities increased with increasing concurrent gametocyte densities; associated with 55–70% reduction in oocyst intensity and achieved up to 44% reduction in proportions of infected mosquitoes. We showed that P. falciparum sexual stage immunity significantly reduces transmission of microscopic (p < 0.001) but not submicroscopic (p = 0.937) gametocyte infections to mosquitoes and that incorporating sexual stage immunity into mathematical models had a considerable impact on the contribution of different age groups to the infectious reservoir of malaria. Human antibody responses to gametocyte antigens are likely to be dependent on recent and concurrent high-density gametocyte exposure and have a pronounced impact on the likelihood of onward transmission of microscopic gametocyte densities compared to low density infections. Our mathematical simulations indicate that anti-gametocyte immunity is an important factor for predicting and understanding the composition and dynamics of the human infectious reservoir for malaria. Submicroscopic gametocyte infections are efficiently transmitted from humans to mosquitoes in settings with efficient malaria vectors and may pose challenges for malaria control and elimination efforts. Our understanding of what mechanisms contribute to submicroscopic gametocytes infectiousness remains limited. Here we assess the impact of naturally acquired anti-gametocyte antibodies on malaria transmission to mosquitoes and on the age-dependent composition of the infectious reservoir and seasonal dynamics. Anti-gametocyte immunity significantly reduces the infectiousness of high gametocyte density infections, contributes to explain the age-related profiles of the infectious reservoir in the study area, whilst submicroscopic gametocyte infections that present with lower anti-Pfs48/45 and anti-Pfs230 antibody responses commonly remain transmissible to mosquitoes. Our findings indicate that sexual stage immunity needs to be incorporated in transmission models to better understand transmission dynamics. Furthermore, tools that boost sexual stage immunity may reduce transmission to mosquitoes and thus aid elimination strategies.
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Affiliation(s)
- André Lin Ouédraogo
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
- Département de Sciences Biomédicales, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
- * E-mail:
| | - Philip A. Eckhoff
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
| | - Adrian J. F. Luty
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
- MERIT UMR 216/CERPAGE, Institut de Recherche pour le Développement, Cotonou, Bénin
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le Développement, Paris, France
| | - Will Roeffen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Edward A. Wenger
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
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