1
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Matos ADS, Soares IF, Rodrigues-da-Silva RN, Rodolphi CM, Albrecht L, Donassolo RA, Lopez-Camacho C, Ano Bom APD, Neves PCDC, Conte FDP, Pratt-Riccio LR, Daniel-Ribeiro CT, Totino PRR, Lima-Junior JDC. Immunogenicity of PvCyRPA, PvCelTOS and Pvs25 chimeric recombinant protein of Plasmodium vivax in murine model. Front Immunol 2024; 15:1392043. [PMID: 38962015 PMCID: PMC11219565 DOI: 10.3389/fimmu.2024.1392043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 06/03/2024] [Indexed: 07/05/2024] Open
Abstract
In the Americas, P. vivax is the predominant causative species of malaria, a debilitating and economically significant disease. Due to the complexity of the malaria parasite life cycle, a vaccine formulation with multiple antigens expressed in various parasite stages may represent an effective approach. Based on this, we previously designed and constructed a chimeric recombinant protein, PvRMC-1, composed by PvCyRPA, PvCelTOS, and Pvs25 epitopes. This chimeric protein was strongly recognized by naturally acquired antibodies from exposed population in the Brazilian Amazon. However, there was no investigation about the induced immune response of PvRMC-1. Therefore, in this work, we evaluated the immunogenicity of this chimeric antigen formulated in three distinct adjuvants: Stimune, AddaVax or Aluminum hydroxide (Al(OH)3) in BALB/c mice. Our results suggested that the chimeric protein PvRMC-1 were capable to generate humoral and cellular responses across all three formulations. Antibodies recognized full-length PvRMC-1 and linear B-cell epitopes from PvCyRPA, PvCelTOS, and Pvs25 individually. Moreover, mice's splenocytes were activated, producing IFN-γ in response to PvCelTOS and PvCyRPA peptide epitopes, affirming T-cell epitopes in the antigen. While aluminum hydroxide showed notable cellular response, Stimune and Addavax induced a more comprehensive immune response, encompassing both cellular and humoral components. Thus, our findings indicate that PvRMC-1 would be a promising multistage vaccine candidate that could advance to further preclinical studies.
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MESH Headings
- Animals
- Plasmodium vivax/immunology
- Plasmodium vivax/genetics
- Mice
- Antigens, Protozoan/immunology
- Antigens, Protozoan/genetics
- Malaria, Vivax/immunology
- Malaria, Vivax/prevention & control
- Antibodies, Protozoan/immunology
- Mice, Inbred BALB C
- Malaria Vaccines/immunology
- Female
- Protozoan Proteins/immunology
- Protozoan Proteins/genetics
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/genetics
- Disease Models, Animal
- Adjuvants, Immunologic
- Immunogenicity, Vaccine
- Antigens, Surface
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Affiliation(s)
- Ada da Silva Matos
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
| | - Isabela Ferreira Soares
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
| | | | | | - Letusa Albrecht
- Apicomplexa Research Laboratory, Carlos Chagas Institute, Curitiba, Brazil
| | | | - Cesar Lopez-Camacho
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Ana Paula Dinis Ano Bom
- Immunological Technology Laboratory, Immunobiological Technology Institute (Bio-Manguinhos/Fiocruz), Rio de Janeiro, Brazil
| | | | - Fernando de Paiva Conte
- Eukaryotic Pilot Laboratory, Immunobiological Technology Institute (Bio-Manguinhos/Fiocruz), Rio de Janeiro, Brazil
| | | | | | | | - Josué da Costa Lima-Junior
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
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2
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Oduoye MO, Haider MU, Marsool MDM, Kareem MO, Adedayo AE, Abdulkarim AS, Adegoke AA, Kaushik I, Irfan H, Yusuf HA, Shah HH, Karim KA. Unlocking the potential of novel RTS, S/AS01, and R21/Matrix-M™ malaria vaccines in African nations. Health Sci Rep 2024; 7:e1797. [PMID: 38186933 PMCID: PMC10766872 DOI: 10.1002/hsr2.1797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/25/2023] [Accepted: 12/14/2023] [Indexed: 01/09/2024] Open
Abstract
Introduction Mass malaria vaccination, rather than vaccinating only children below age 5, has been proven to have the potential to reduce morbidity and mortality among those vaccinated, both young and old. Addressing vaccine scepticism and misinformation is crucial in African nations to build public trust in malaria prevention. Therefore, including a wider range of demographics in vaccine trials is necessary for equitable representation and achieving herd immunity against malaria. Aim This present article aims to identify some of the obstacles that impede malaria vaccination usage and acceptability in African Nations in combating malaria in the region as it continues to pose a significant global public health problem. Methodology A literature search was done on the Malaria vaccine between 2000 and 2023. Past and present articles/studies on this topic were consulted on PubMed, Google Scholar, Scopus and Web of Science using the following keywords; "Malaria," "Vaccines," "African Nations," "Obstacles, Strategies," and "Public Health." Results The recently approved RTS, S/AS01, and R21/Matrix-M™ Malaria vaccines have the potential to prevent numerous deaths and cases of Malaria in Africa. These vaccines Malaria vaccines are cost-effective in African areas with moderate to high plasmodium falciparum and can be delivered through routine immunization. Conclusion To combat malaria effectively in African Nations, African leaders need to set up a comprehensive approach that involves; prevention, healthcare access, implementation research strategies towards adoption and acceptance of malaria vaccines in Africa as well as community engagement with the religious leaders, the market women, community heads, schools, as well as students' union towards the willingness and acceptability of the malaria vaccines among the African populations.
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Affiliation(s)
| | - Muhammad Usman Haider
- Department of Internal Medicine, Mayo Hospital LahoreKing Edward Medical University LahoreLahorePakistan
| | | | - Mayowa Odunayo Kareem
- Department of Internal MedicineBabcock University Teaching HospitalIlishan‐RemoOgun StateNigeria
| | | | | | | | - Ikshwaki Kaushik
- Department of MedicineDavid Tvildiani Medical UniversityTbilisiGeorgia
| | - Hamza Irfan
- Department of MedicineShaikh Khalifa Bin Zayed Al Nahyan Medical and Dental College LahoreLahorePakistan
| | - Hassan Abdullahi Yusuf
- Department of Medicine and Surgery, College of Health SciencesBayero UniversityKanoKano StateNigeria
| | | | - Karim Arif Karim
- Department of Research and EthicsKamuzu University of Health SciencesBlantyreMalawi
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3
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Nunu WN, Ndirangu J, Tsoka-Gwegweni J. Effects of COVID-19 on malaria elimination initiatives in sub-Saharan Africa: a scoping review protocol. BMJ Open 2023; 13:e076140. [PMID: 37821137 PMCID: PMC10582949 DOI: 10.1136/bmjopen-2023-076140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023] Open
Abstract
INTRODUCTION The occurrence of the COVID-19 pandemic significantly impacted health systems, resulting in varied outcomes of different variables in terms of health. Due to the nature of the causative organism that is spread mainly in the air, the disease rapidly spread to numerous countries, leading to a series of mitigation measures being proposed and implemented, including but not limited to travel restrictions, decongesting and in some instances closure of workplaces and schools and banning of social gatherings. This could have negatively impacted implementing strategies meant to ensure the effective management of malaria, hoping to eliminate it in different countries in sub-Saharan Africa (SSA). This review seeks to explore the effect of the COVID-19 pandemic on malaria elimination initiatives in SSA. METHODS AND ANALYSIS An exploratory scoping review will be conducted on literature (searched using keywords and a search strategy) sources published in English on Web of Science, Cochrane Library, PUBMED, Dimensions, ProQuest, Scopus and African Journals Online. These would then be imported to Rayyan Software for screening for possible inclusion. The JBI Guidelines on Reviews, Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist would guide the data collection, extraction and analysis from the accessed literature. Furthermore, charting, trends and developing themes would ensure the findings are presented comprehensively and yet understandable. The data collection and analysis process leading to the final submission of a review paper to a journal will be conducted from September 2023 to February 2024. ETHICS AND DISSEMINATION An application for ethical approval was lodged with the Health Sciences Research Ethics Committee at the University of the Free State in Bloemfontein, South Africa. This ethics committee granted ethics clearance (ethics number: UFS-HSD2022/1754). Results will be communicated through peer-reviewed publications, presentations, conferences, workshops and other means and forums to reach the critical stakeholders.
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Affiliation(s)
- Wilfred Njabulo Nunu
- Division of Public Health, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
- Office of the Executive Dean, Faculty of Environmental Science, National University of Science and Technology, Bulawayo, Zimbabwe
| | - James Ndirangu
- Division of Public Health, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
| | - Joyce Tsoka-Gwegweni
- Division of Public Health, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
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4
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Tsoumani ME, Voyiatzaki C, Efstathiou A. Malaria Vaccines: From the Past towards the mRNA Vaccine Era. Vaccines (Basel) 2023; 11:1452. [PMID: 37766129 PMCID: PMC10536368 DOI: 10.3390/vaccines11091452] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/29/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
Plasmodium spp. is the etiological agent of malaria, a life-threatening parasitic disease transmitted by infected mosquitoes. Malaria remains a major global health challenge, particularly in endemic regions. Over the years, various vaccine candidates targeting different stages of Plasmodium parasite life-cycle have been explored, including subunit vaccines, vectored vaccines, and whole organism vaccines with Mosquirix, a vaccine based on a recombinant protein, as the only currently approved vaccine for Plasmodium falciparum malaria. Despite the aforementioned notable progress, challenges such as antigenic diversity, limited efficacy, resistant parasites escaping protective immunity and the need for multiple doses have hindered the development of a highly efficacious malaria vaccine. The recent success of mRNA-based vaccines against SARS-CoV-2 has sparked renewed interest in mRNA vaccine platforms. The unique mRNA vaccine features, including their potential for rapid development, scalability, and flexibility in antigen design, make them a promising avenue for malaria vaccine development. This review provides an overview of the malaria vaccines' evolution from the past towards the mRNA vaccine era and highlights their advantages in overcoming the limitations of previous malaria vaccine candidates.
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Affiliation(s)
- Maria E. Tsoumani
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
| | - Chrysa Voyiatzaki
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
| | - Antonia Efstathiou
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
- Immunology of Infection Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece
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5
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El-Moamly AA, El-Sweify MA. Malaria vaccines: the 60-year journey of hope and final success-lessons learned and future prospects. Trop Med Health 2023; 51:29. [PMID: 37198702 DOI: 10.1186/s41182-023-00516-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND The world has made great strides towards beating malaria, although about half of the world population is still exposed to the risk of contracting malaria. Developing an effective malaria vaccine was a huge challenge for medical science. In 2021 the World Health Organization (WHO) approved the first malaria vaccine, RTS,S/AS01 vaccine (Mosquirix™), for widespread use. This review highlights the history of development, and the different approaches and types of malaria vaccines, and the literature to date. It covers the developmental stages of RTS,S/AS01 and recommends steps for its deployment. The review explores other potential vaccine candidates and their status, and suggests options for their further development. It also recommends future roles for vaccines in eradicating malaria. Questions remain on how RTS,S vaccine will work in widespread use and how it can best be utilized to benefit vulnerable communities. CONCLUSION Malaria vaccines have been in development for almost 60 years. The RTS,S/AS01 vaccine has now been approved, but cannot be a stand-alone solution. Development should continue on promising candidates such as R21, PfSPZ and P. vivax vaccines. Multi-component vaccines may be a useful addition to other malaria control techniques in achieving eradication of malaria.
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Affiliation(s)
- Amal A El-Moamly
- Department of Medical Parasitology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
| | - Mohamed A El-Sweify
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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6
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Quagliata M, Papini AM, Rovero P. Malaria vaccines. Expert Opin Ther Pat 2023; 33:169-178. [PMID: 36912026 DOI: 10.1080/13543776.2023.2190884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
INTRODUCTION : Eradication of malaria remains one of the main aims of medicine. Despite progress in malaria treatment, mortality rate remains high, especially in the poorest parts of the world. Therefore, prevention through vaccines is fundamental and recent approval of the first effective vaccine reinforced this assumption. However, since the parasite cycle is complex, being composed of three stages, different types of vaccine targeting stage-specific antigens shall be developed. Moreover, the beneficial effect on vaccinated subjects can be tuned using compositions targeting different disease stages. AREA COVERED : We analysed the malaria vaccine patent landscape describing the most significant patents published after 2016, classified according to the different parasite stages targeted focusing on selected protein antigens or epitopes. We searched "malaria vaccine" on Patentscope and Espacenet. EXPERT OPINION : Pre-erythrocytic vaccines were boosted by RTS,S approval, but its partial efficacy, limited to sporozoites, calls for compositions active against other disease stages. In particular, multi-antigens vaccines could be more effective than single-stage ones, as they would activate an immune response more similar to that acquired in endemic regions. Furthermore, vaccine storage is another factor to be taken into account given the climate of the areas where malaria is widespread. More advanced technologies can lead to more effective and safer vaccines.
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Affiliation(s)
- Michael Quagliata
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
| | - Anna Maria Papini
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
| | - Paolo Rovero
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of NeuroFarBa, University of Florence, Via Ugo Schiff 6, I-50019 Sesto Fiorentino, Italy
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7
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Tian C, Yan J, Tan X, Wang W. Reap success from persistence. J Glob Health 2022; 12:03077. [PMID: 36538475 PMCID: PMC9767391 DOI: 10.7189/jogh.12.03077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Cuihong Tian
- Clinical Research Centre, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
- Centre for Precision Health, Edith Cowan University, Perth, Australia
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Jingyi Yan
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Xuerui Tan
- Clinical Research Centre, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Wei Wang
- Clinical Research Centre, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
- Centre for Precision Health, Edith Cowan University, Perth, Australia
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8
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Lozano JM, Rodríguez Parra Z, Hernández-Martínez S, Yasnot-Acosta MF, Rojas AP, Marín-Waldo LS, Rincón JE. The Search of a Malaria Vaccine: The Time for Modified Immuno-Potentiating Probes. Vaccines (Basel) 2021; 9:vaccines9020115. [PMID: 33540947 PMCID: PMC7913233 DOI: 10.3390/vaccines9020115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 12/25/2022] Open
Abstract
Malaria is a deadly disease that takes the lives of more than 420,000 people a year and is responsible for more than 229 million clinical cases globally. In 2019, 95% of malaria morbidity occurred in African countries. The development of a highly protective vaccine is an urgent task that remains to be solved. Many vaccine candidates have been developed, from the use of the entire attenuated and irradiated pre-erythrocytic parasite forms (or recombinantly expressed antigens thereof) to synthetic candidates formulated in a variety of adjuvants and delivery systems, however these have unfortunately proven a limited efficacy. At present, some vaccine candidates are finishing safety and protective efficacy trials, such as the PfSPZ and the RTS,S/AS01 which are being introduced in Africa. We propose a strategy for introducing non-natural elements into target antigens representing key epitopes of Plasmodium spp. Accordingly, chemical strategies and knowledge of host immunity to Plasmodium spp. have served as the basis. Evidence is obtained after being tested in experimental rodent models for malaria infection and recognized for human sera from malaria-endemic regions. This encourages us to propose such an immune-potentiating strategy to be further considered in the search for new vaccine candidates.
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Affiliation(s)
- José Manuel Lozano
- Grupo de Investigación Mimetismo Molecular de los Agentes Infecciosos, Departamento de Farmacia, Universidad Nacional de Colombia—Sede Bogotá, 111321 Bogota, Colombia;
- Correspondence: ; Tel.: +57-3102-504-657
| | - Zully Rodríguez Parra
- Grupo de Investigación Mimetismo Molecular de los Agentes Infecciosos, Departamento de Farmacia, Universidad Nacional de Colombia—Sede Bogotá, 111321 Bogota, Colombia;
| | - Salvador Hernández-Martínez
- Dirección de Infección e Inmunidad, Centro de Investigaciones Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, 62508 Cuernavaca, Morelos, Mexico;
| | - Maria Fernanda Yasnot-Acosta
- Grupo de Investigaciones Microbiológicas y Biomédicas de Córdoba, Universidad de Córdoba, 230002 Monteria, Colombia;
| | - Angela Patricia Rojas
- Grupo de Investigación Biología Celular y Autoinmuniad, Departamento de Farmacia, Universidad Nacional de Colombia-Sede Bogotá, 111321 Bogota, Colombia;
| | | | - Juan Edilberto Rincón
- Departamento de Ingeniería y Mecatrónica, Universidad Nacional de Colombia-Sede Bogotá, 111321 Bogota, Colombia;
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9
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Pritam M, Singh G, Swaroop S, Singh AK, Pandey B, Singh SP. A cutting-edge immunoinformatics approach for design of multi-epitope oral vaccine against dreadful human malaria. Int J Biol Macromol 2020; 158:159-179. [PMID: 32360460 PMCID: PMC7189201 DOI: 10.1016/j.ijbiomac.2020.04.191] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/28/2020] [Accepted: 04/22/2020] [Indexed: 12/18/2022]
Abstract
Human malaria is a pathogenic disease mainly caused by Plasmodium falciparum, which was responsible for about 405,000 deaths globally in the year 2018. To date, several vaccine candidates have been evaluated for prevention, which failed to produce optimal output at various preclinical/clinical stages. This study is based on designing of polypeptide vaccines (PVs) against human malaria that cover almost all stages of life-cycle of Plasmodium and for the same 5 genome derived predicted antigenic proteins (GDPAP) have been used. For the development of a multi-immune inducer, 15 PVs were initially designed using T-cell epitope ensemble, which covered >99% human population as well as linear B-cell epitopes with or without adjuvants. The immune simulation of PVs showed higher levels of T-cell and B-cell activities compared to positive and negative vaccine controls. Furthermore, in silico cloning of PVs and codon optimization followed by enhanced expression within Lactococcus lactis host system was also explored. Although, the study has sound theoretical and in silico findings, the in vitro/in vivo evaluation seems imperative to warrant the immunogenicity and safety of PVs towards management of P. falciparum infection in the future.
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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
- Experimental & Public Health Lab, Department of Zoology, University of Lucknow, Lucknow 226007, India
| | - Akhilesh Kumar Singh
- Department of Biotechnology, Mahatma Gandhi Central University, Bihar 845401, India
| | - Brijesh Pandey
- Department of Biotechnology, Mahatma Gandhi Central University, Bihar 845401, India
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10
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Narula AK, Azad CS, Nainwal LM. New dimensions in the field of antimalarial research against malaria resurgence. Eur J Med Chem 2019; 181:111353. [DOI: 10.1016/j.ejmech.2019.05.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/16/2019] [Accepted: 05/15/2019] [Indexed: 12/20/2022]
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11
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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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12
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White SE, Harvey SA, Meza G, Llanos A, Guzman M, Gamboa D, Vinetz JM. Acceptability of a herd immunity-focused, transmission-blocking malaria vaccine in malaria-endemic communities in the Peruvian Amazon: an exploratory study. Malar J 2018; 17:179. [PMID: 29703192 PMCID: PMC5921293 DOI: 10.1186/s12936-018-2328-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/18/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND A transmission-blocking vaccine (TBV) to prevent malaria-infected humans from infecting mosquitoes has been increasingly considered as a tool for malaria control and elimination. This study tested the hypothesis that a malaria TBV would be acceptable among residents of a malaria-hypoendemic region. METHODS The study was carried out in six Spanish-speaking rural villages in the Department of Loreto in the Peruvian Amazon. These villages comprise a cohort of 430 households associated with the Peru-Brazil International Centre for Excellence in Malaria Research. Individuals from one-third (143) of enrolled households in an ongoing longitudinal, prospective cohort study in 6 communities in Loreto, Peru, were randomly selected to participate by answering a pre-validated questionnaire. RESULTS All 143 participants expressed desire for a malaria vaccine in general; only 1 (0.7%) expressed unwillingness to receive a transmission-blocking malaria vaccine. Injection was considered most acceptable for adults (97.2%); for children drops in the mouth were preferred (96.8%). Acceptability waned marginally with the prospect of multiple injections (83.8%) and different projected efficacies at 70 and 50% (90.1 and 71.8%, respectively). Respondents demonstrated clear understanding that the vaccine was for community, rather than personal, protection against malaria infection. DISCUSSION In this setting of the Peruvian Amazon, a transmission-blocking malaria vaccine was found to be almost universally acceptable. This study is the first to report that residents of a malaria-endemic region have been queried regarding a malaria vaccine strategy that policy-makers in the industrialized world often dismiss as altruistic.
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Affiliation(s)
- Sara E White
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive 0760, Biomedical Research Facility Room 4A16, La Jolla, CA, 92093-0760, USA
| | - Steven A Harvey
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St. E5030, Baltimore, MD, 21205, USA.
| | - Graciela Meza
- Facultad de Medicina Humana, Universidad Nacional de la Amazonia Peruana, Iquitos, Peru
| | - Alejandro Llanos
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Mitchel Guzman
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Dionicia Gamboa
- Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru.,Department of Cellular and Molecular Sciences, Faculty of Sciences and Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego School of Medicine, 9500 Gilman Drive 0760, Biomedical Research Facility Room 4A16, La Jolla, CA, 92093-0760, USA. .,Malaria and Leishmaniasis Division, Instituto de Medicina Tropical Alexander von Humboldt, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru. .,Department of Cellular and Molecular Sciences, Faculty of Sciences and Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.
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13
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Mahmoudi S, Keshavarz H. Efficacy of phase 3 trial of RTS, S/AS01 malaria vaccine: The need for an alternative development plan. Hum Vaccin Immunother 2017; 13:2098-2101. [PMID: 28272979 DOI: 10.1080/21645515.2017.1295906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Although vaccines would be the ideal tool for control, prevention, elimination, and eradication of many infectious diseases, developing of parasites vaccines such as malaria vaccine is very complex. The most advanced malaria vaccine candidate RTS,S, a pre-erythrocytic vaccine, has been recommended for licensure by EMEA. The results of this phase III trial suggest that this candidate malaria vaccine has relatively little efficacy, and the vaccine apparently will not meet the goal of malaria eradication by itself. Since there are many vaccine candidates in the pipeline 1 that are being evaluated in vaccine trials, further study on using of alternative parasite targets and vaccination strategies are highly recommended.
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Affiliation(s)
- Shima Mahmoudi
- a Pediatric Infectious Disease Research Center , Tehran University of Medical Science , Tehran , Iran.,b Center for Research of Endemic Parasites of Iran (CREPI) , Tehran University of Medical Sciences , Tehran , Iran
| | - Hossein Keshavarz
- b Center for Research of Endemic Parasites of Iran (CREPI) , Tehran University of Medical Sciences , Tehran , Iran.,c Department of Medical Parasitology and Mycology , School of Public Heath, Tehran, University of Medical Science , Tehran , Iran
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14
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Mahmoudi S, Keshavarz H. Efficacy of Phase 3 Trial of RTS, S/AS01 Malaria Vaccine in infants: a systematic review and meta-analysis. Hum Vaccin Immunother 2017:0. [PMID: 28059665 DOI: 10.1080/21645515.2016.1271686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Although vaccines would be the ideal tool for control, prevention, elimination, and eradication of many infectious diseases, developing of parasites vaccines such as malaria vaccine is very complex. The most advanced malaria vaccine candidate is RTS,S, a pre-erythrocytic vaccine for which pivotal phase III trial design is underway. Few recent malaria vaccine review articles have attempted to outline of all clinical trials that have occurred globally and no meta-analysis was performed on efficacy of Phase 3 Trial of RTS, S/AS01 Malaria vaccine up to now in infants. Therefore, a systematic review and meta-analysis was carried out to review new and existing data on efficacy of Phase 3 Trial of RTS, S/AS01 Malaria Vaccine in infants. The electronic databases searched were Pubmed (1965-present) and Web of Science (1970-present) (Search date: May, 2016). After full-text review of the papers evaluating clinical/severe malaria in several well-designed phase III field efficacy trials, 5 were determined to meet the eligibility criteria for inclusion in the systematic review. Four out of the 5 publications dealing with efficacy of Phase 3 Trial of RTS, S/AS01 malaria vaccine were included in the qualitative analysis. Pooled estimate of vaccine efficacy in clinical and severe malaria in children aged 5-17 mo was 29% (95% CL: 19%-46%) and 39% (95% CI 20%-74%), while this estimate vaccine in clinical and severe malaria in children aged 6-12 mo was 19% (95% CI 14%-24%) and 21 (95% CI 19%-37%), respectively. On the other hand, higher VE was seen in both per- protocol and intention-to-treat population in children aged 5-17 than the children aged 6-12 mo. The results of this meta-analysis suggest that this candidate malaria vaccine has relatively little efficacy, and the vaccine apparently will not meet the goal of malaria eradication by itself.
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Affiliation(s)
- Shima Mahmoudi
- a Pediatric Infectious Disease Research Center, Tehran University of Medical Science , Tehran , Iran
- b Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences , Tehran , Iran
| | - Hossein Keshavarz
- b Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences , Tehran , Iran
- c Department of Medical Parasitology and Mycology , School of Public Heath, Tehran University of Medical Science , Tehran , Iran
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Mishra M, Mishra VK, Kashaw V, Iyer AK, Kashaw SK. Comprehensive review on various strategies for antimalarial drug discovery. Eur J Med Chem 2016; 125:1300-1320. [PMID: 27886547 DOI: 10.1016/j.ejmech.2016.11.025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 01/14/2023]
Abstract
The resistance of malaria parasites to existing drugs carries on growing and progressively limiting our ability to manage this severe disease and finally lead to a massive global health burden. Till now, malaria control has relied upon the traditional quinoline, antifolate and artemisinin compounds. Very few new antimalarials were developed in the past 50 years. Among recent approaches, identification of novel chemotherapeutic targets, exploration of natural products with medicinal significance, covalent bitherapy having a dual mode of action into a single hybrid molecule and malaria vaccine development are explored heavily. The proper execution of these approaches and proper investment from international agencies will accelerate the discovery of drugs that provide new hope for the control or eventual eradication of this global infectious disease. This review explores various strategies for assessment and development of new antimalarial drugs. Current status and scientific value of previous approaches are systematically reviewed and new approaches provide a pragmatic forecast for future developments are introduced as well.
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Affiliation(s)
- Mitali Mishra
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India
| | - Vikash K Mishra
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India
| | - Varsha Kashaw
- SVN Institute of Pharmaceutical Sciences, SVN University, Sagar, MP, India
| | - Arun K Iyer
- Use-inspired Biomaterials & Integrated Nano Delivery (U-BiND) Systems Laboratory, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, USA
| | - Sushil Kumar Kashaw
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India; Use-inspired Biomaterials & Integrated Nano Delivery (U-BiND) Systems Laboratory, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, USA.
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16
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Volz A, Sutter G. Modified Vaccinia Virus Ankara: History, Value in Basic Research, and Current Perspectives for Vaccine Development. Adv Virus Res 2016; 97:187-243. [PMID: 28057259 PMCID: PMC7112317 DOI: 10.1016/bs.aivir.2016.07.001] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Safety tested Modified Vaccinia virus Ankara (MVA) is licensed as third-generation vaccine against smallpox and serves as a potent vector system for development of new candidate vaccines against infectious diseases and cancer. Historically, MVA was developed by serial tissue culture passage in primary chicken cells of vaccinia virus strain Ankara, and clinically used to avoid the undesirable side effects of conventional smallpox vaccination. Adapted to growth in avian cells MVA lost the ability to replicate in mammalian hosts and lacks many of the genes orthopoxviruses use to conquer their host (cell) environment. As a biologically well-characterized mutant virus, MVA facilitates fundamental research to elucidate the functions of poxvirus host-interaction factors. As extremely safe viral vectors MVA vaccines have been found immunogenic and protective in various preclinical infection models. Multiple recombinant MVA currently undergo clinical testing for vaccination against human immunodeficiency viruses, Mycobacterium tuberculosis or Plasmodium falciparum. The versatility of the MVA vector vaccine platform is readily demonstrated by the swift development of experimental vaccines for immunization against emerging infections such as the Middle East Respiratory Syndrome. Recent advances include promising results from the clinical testing of recombinant MVA-producing antigens of highly pathogenic avian influenza virus H5N1 or Ebola virus. This review summarizes our current knowledge about MVA as a unique strain of vaccinia virus, and discusses the prospects of exploiting this virus as research tool in poxvirus biology or as safe viral vector vaccine to challenge existing and future bottlenecks in vaccinology.
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Affiliation(s)
- A Volz
- German Center for Infection Research (DZIF), Institute for Infectious Diseases and Zoonoses, LMU University of Munich, Munich, Germany
| | - G Sutter
- German Center for Infection Research (DZIF), Institute for Infectious Diseases and Zoonoses, LMU University of Munich, Munich, Germany.
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Vallejo AF, Rubiano K, Amado A, Krystosik AR, Herrera S, Arévalo-Herrera M. Optimization of a Membrane Feeding Assay for Plasmodium vivax Infection in Anopheles albimanus. PLoS Negl Trop Dis 2016; 10:e0004807. [PMID: 27355210 PMCID: PMC4927173 DOI: 10.1371/journal.pntd.0004807] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 06/06/2016] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Individuals exposed to malaria infections for a long time develop immune responses capable of blocking Plasmodium transmission to mosquito vectors, potentially limiting parasite spreading in nature. Development of a malaria TB vaccine requires a better understanding of the mechanisms and main effectors responsible for transmission blocking (TB) responses. The lack of an in vitro culture system for Plasmodium vivax has been an important drawback for development of a standardized method to assess TB responses to this parasite. This study evaluated host, vector, and parasite factors that may influence Anopheles mosquito infection in order to develop an efficient and reliable assay to assess the TB immunity. METHODS/PRINCIPAL FINDINGS A total of 94 P. vivax infected patients were enrolled as parasite donors or subjects of direct mosquito feeding in two malaria endemic regions of Colombia (Tierralta, and Buenaventura). Parasite infectiousness was assessed by membrane feeding assay or direct feeding assay using laboratory reared Anopheles mosquitoes. Infection was measured by qPCR and by microscopically examining mosquito midguts at day 7 for the presence of oocysts. Best infectivity was attained in four day old mosquitoes fed at a density of 100 mosquitos/cage. Membrane feeding assays produced statistically significant better infections than direct feeding assays in parasite donors; cytokine profiles showed increased IFN-γ, TNF and IL-1 levels in non-infectious individuals. Mosquito infections and parasite maturation were more reliably assessed by PCR compared to microscopy. CONCLUSIONS We evaluated mosquito, parasite and host factors that may affect the outcome of parasite transmission as measured by artificial membrane feeding assays. Results have led us to conclude that: 1) optimal mosquito infectivity occurs with mosquitoes four days after emergence at a cage density of 100; 2) mosquito infectivity is best quantified by PCR as it may be underestimated by microscopy; 3) host cellular immune response did not appear to significantly affect mosquito infectivity; and 4) no statistically significant difference was observed in transmission between mosquitoes directly feeding on humans and artificial membrane feeding assays.
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Affiliation(s)
- Andrés F. Vallejo
- Malaria Vaccine and Drug Development Center (MVDC), Cali, Valle de Cauca, Colombia
| | - Kelly Rubiano
- Caucaseco Scientific Research Center, Cali, Cali, Valle de Cauca, Colombia
| | - Andres Amado
- Caucaseco Scientific Research Center, Cali, Cali, Valle de Cauca, Colombia
| | - Amy R. Krystosik
- Kent State University College of Public Health, Kent, Ohio, United States of America
| | - Sócrates Herrera
- Caucaseco Scientific Research Center, Cali, Cali, Valle de Cauca, Colombia
- * E-mail:
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18
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Favuzza P, Blaser S, Dreyer AM, Riccio G, Tamborrini M, Thoma R, Matile H, Pluschke G. Generation of Plasmodium falciparum parasite-inhibitory antibodies by immunization with recombinantly-expressed CyRPA. Malar J 2016; 15:161. [PMID: 26979066 PMCID: PMC4791974 DOI: 10.1186/s12936-016-1213-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/05/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The pathogenesis of malaria is primarily associated with blood-stage infection and there is strong evidence that antibodies specific for parasite blood-stage antigens can control parasitaemia. This provides a strong rationale for incorporation of asexual blood-stage antigen components into an effective multivalent malaria subunit vaccine. On the basis of available genome-wide transcriptomic and proteomic data, previously uncharacterized Plasmodium falciparum open reading frames were screened for new blood stage vaccine candidates. This has led to the identification of the cysteine-rich protective antigen (PfCyRPA), which forms together with PfRH5 and PfRipr a multiprotein complex that is crucial for erythrocyte invasion. METHODS Glycosylated and non-glycosylated variants of recombinant PfCyRPA were expressed and produced as secreted protein in mammalian cells. Adjuvanted formulations of purified PfCyRPA were tested to assess whether they can effectively elicit parasite inhibitory antibodies, and to investigate whether or not the glycosylation status affects antibody binding. For this purpose, two sets of PfCyRPA-specific mouse monoclonal antibodies (mAbs) have been raised and evaluated for functional activity. RESULTS Generated PfCyRPA-specific mAbs, irrespective of the immunogen's glycosylation status, showed substantial parasite in vitro growth-inhibitory activity due to inhibition of erythrocyte invasion by merozoites. Furthermore, passive immunization experiments in P. falciparum infected NOD-scid IL2Rγ (null) mice engrafted with human erythrocytes demonstrated potent in vivo growth-inhibitory activity of generated mAbs. CONCLUSIONS Recombinantly expressed PfCyRPA tested as adjuvanted vaccine formulations in mice elicited antibodies that significantly inhibit P. falciparum asexual blood stage parasite growth both in vitro and in vivo. These findings render PfCyRPA a promising blood-stage candidate antigen for inclusion into a multicomponent malaria subunit vaccine.
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Affiliation(s)
- Paola Favuzza
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Simon Blaser
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Anita M Dreyer
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Guy Riccio
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Marco Tamborrini
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Ralf Thoma
- Roche Pharmaceutical Research & Early Development, Small Molecule Research, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Hugues Matile
- Roche Pharmaceutical Research & Early Development, Small Molecule Research, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Gerd Pluschke
- Medical Parasitology and Infection Biology Department, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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Cha SJ, Park K, Srinivasan P, Schindler CW, van Rooijen N, Stins M, Jacobs-Lorena M. CD68 acts as a major gateway for malaria sporozoite liver infection. ACTA ACUST UNITED AC 2015. [PMID: 26216124 PMCID: PMC4548058 DOI: 10.1084/jem.20110575] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cha et al. use a phage display library screen to identify a peptide, P39, that binds to CD68 on the surface of Kupffer cells to inhibit malaria sporozoite cell entry. Thus, P39 may represent a therapeutic strategy for malaria by limiting hepatic infection. After being delivered by the bite from an infected mosquito, Plasmodium sporozoites enter the blood circulation and infect the liver. Previous evidence suggests that Kupffer cells, a macrophage-like component of the liver blood vessel lining, are traversed by sporozoites to initiate liver invasion. However, the molecular determinants of sporozoite–Kupffer cell interactions are unknown. Understanding the molecular basis for this specific recognition may lead to novel therapeutic strategies to control malaria. Using a phage display library screen, we identified a peptide, P39, that strongly binds to the Kupffer cell surface and, importantly, inhibits sporozoite Kupffer cell entry. Furthermore, we determined that P39 binds to CD68, a putative receptor for sporozoite invasion of Kupffer cells that acts as a gateway for malaria infection of the liver.
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Affiliation(s)
- Sung-Jae Cha
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205 W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Kiwon Park
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205 W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Christian W Schindler
- Department of Microbiology and Immunology and Department of Medicine, Columbia University, New York, NY 10032 Department of Microbiology and Immunology and Department of Medicine, Columbia University, New York, NY 10032
| | - Nico van Rooijen
- Department of Molecular Cell Biology and Immunology, VUmc, 1081 BT Amsterdam, Netherlands
| | - Monique Stins
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Marcelo Jacobs-Lorena
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205 W. Harry Feinstone Department of Molecular Microbiology and Immunology and Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health; and Department of Neurology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205
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20
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Chia WN, Goh YS, Rénia L. Novel approaches to identify protective malaria vaccine candidates. Front Microbiol 2014; 5:586. [PMID: 25452745 PMCID: PMC4233905 DOI: 10.3389/fmicb.2014.00586] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/17/2014] [Indexed: 12/17/2022] Open
Abstract
Efforts to develop vaccines against malaria have been the focus of substantial research activities for decades. Several categories of candidate vaccines are currently being developed for protection against malaria, based on antigens corresponding to the pre-erythrocytic, blood stage, or sexual stages of the parasite. Long lasting sterile protection from Plasmodium falciparum sporozoite challenge has been observed in human following vaccination with whole parasite formulations, clearly demonstrating that a protective immune response targeting predominantly the pre-erythrocytic stages can develop against malaria. However, most of vaccine candidates currently being investigated, which are mostly subunits vaccines, have not been able to induce substantial (>50%) protection thus far. This is due to the fact that the antigens responsible for protection against the different parasite stages are still yet to be known and relevant correlates of protection have remained elusive. For a vaccine to be developed in a timely manner, novel approaches are required. In this article, we review the novel approaches that have been developed to identify the antigens for the development of an effective malaria vaccine.
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Affiliation(s)
- Wan Ni Chia
- Singapore Immunology Network, Agency for Science, Technology and Research Singapore, Singapore ; Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
| | - Yun Shan Goh
- Singapore Immunology Network, Agency for Science, Technology and Research Singapore, Singapore
| | - Laurent Rénia
- Singapore Immunology Network, Agency for Science, Technology and Research Singapore, Singapore ; Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
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21
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Doderer-Lang C, Atchade PS, Meckert L, Haar E, Perrotey S, Filisetti D, Aboubacar A, Pfaff AW, Brunet J, Chabi NW, Akpovi CD, Anani L, Bigot A, Sanni A, Candolfi E. The ears of the African elephant: unexpected high seroprevalence of Plasmodium ovale and Plasmodium malariae in healthy populations in Western Africa. Malar J 2014; 13:240. [PMID: 24946685 PMCID: PMC4071337 DOI: 10.1186/1475-2875-13-240] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/29/2014] [Indexed: 11/25/2022] Open
Abstract
Background Malaria Is A Life-Threatening Pathology In Africa. Plasmodium Falciparum And Plasmodium Vivax Attract The Most Focus Because Of Their High Prevalence And Mortality. Knowledge About The Prevalence Of The Cryptic Pathogens Plasmodium Ovale And Plasmodium Malariae Is Limited. Thanks To Recombinant Tools, Their Seroprevalence Was Measured For The First Time, As Well As The Prevalence Of Mixed Infections In A Malaria-Asymptomatic Population In Benin, A Malaria-Endemic Country. Methods A Panel Of 1,235 Blood Donations Collected Over Ten Months In Benin Was Used For Validation Of The Recombinant Tools. Recombinant P. Falciparum, P. Malariae, P. Ovale MSP1, And P. Falciparum AMA1 Were Engineered And Validated On A Biobank With Malaria-Infected Patients (N = 144) Using A Species-Speific ELISA Test (Recelisa). Results Were Compared To An ELISA Using A Native P. Falciparum Antigen (NatELISA). Results Among Microscopically Negative African Blood Donors, 85% (1,050/1,235) Present Antibodies Directed To Native P. Falciparum, 94.4% (1,166/1,235) To rPfMSP1 And rPfAMA1, 56.8% (702/1,235) To rPoMSP1, 67.5% (834/1235) To rPmMSP1 And 45.3% Of The Malaria Seropositive Population Had Antibodies Recognizing The Three Species. Conclusion A High Rate Of Antibodies Against P. Ovale And P. Malariae Was Found In Asymptomatic Blood Donors. The Proportion Of Mixed Infections Involving Three Species Was Also Unexpected. These Data Suggest That Determining Seroprevalence For These Cryptic Species Is An Appropriate Tool To Estimate Their Incidence, At The Eve Of Upcoming Anti-P. Falciparum Vaccination Campaigns.
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Affiliation(s)
- Cécile Doderer-Lang
- Institut de Parasitologie et de Pathologie Tropicale Université de Strasbourg, 3, Rue Koeberlé, F67000 Strasbourg, France.
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Abstract
Malaria is a life-threatening disease caused by parasites of the Plasmodium genus. In many parts of the world, the parasites have developed resistance to a number of antimalarial agents. Key interventions to control malaria include prompt and effective treatment with artemisinin-based combination therapies, use of insecticidal nets by individuals at risk and active research into malaria vaccines. Protection against malaria through vaccination was demonstrated more than 30 years ago when individuals were vaccinated via repeated bites by Plasmodium falciparum-infected and irradiated but still metabolically active mosquitoes. However, vaccination with high doses of irradiated sporozoites injected into humans has long been considered impractical. Yet, following recent success using whole-organism vaccines, the approach has received renewed interest; it was recently reported that repeated injections of irradiated sporozoites increased protection in 80 vaccinated individuals. Other approaches include subunit malaria vaccines, such as the current leading candidate RTS,S (consisting of fusion between a portion of the P. falciparum-derived circumsporozoite protein and the hepatitis B surface antigen), which has been demonstrated to induce reasonably good protection. Although results have been encouraging, the level of protection is generally considered to be too low to achieve eradication of malaria. There is great interest in developing new and better formulations and stable delivery systems to improve immunogenicity. In this review, we will discuss recent strategies to develop efficient malaria vaccines.
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Affiliation(s)
- C Arama
- Malaria Research and Training Center, University of Sciences Techniques and Technologies of Bamako (USTTB), Bamako, Mali; Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Brooker S, Bethony JM, Rodrigues LC, Alexander N, Geiger SM, Hotez PJ. Epidemiologic, immunologic and practical considerations in developing and evaluating a human hookworm vaccine. Expert Rev Vaccines 2014. [DOI: 10.1586/14760584.4.1.35] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Possible relationship between Plasmodium falciparum ring-infected erythrocyte surface antigen (RESA) and host cell resistance to destruction by chemicals. Parasitol Res 2013; 112:4043-51. [PMID: 24005477 DOI: 10.1007/s00436-013-3595-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 08/25/2013] [Indexed: 10/26/2022]
Abstract
Repeated incubation of Plasmodium falciparum culture in 0.015% saponin solution for a total of 35 min destroys most of the uninfected cells, leaving only the ring-infected erythrocytes (RIEs). Parasites concentrated by this method can subsequently complete the asexual cycle and infect other erythrocytes. It is possible that resistance to saponin is mediated by one or more of the numerous parasite proteins present in the host erythrocyte membrane. We have found that schizonts are as susceptible as uninfected erythrocytes to saponin, indicating that the protective protein is parasite stage specific. Studies with cultured parasites have shown that ring-infected erythrocyte surface antigen (RESA) strengthens host erythrocyte membrane and protects against destruction. Therefore, we hypothesize that RESA could be involved in resistance to saponin. Here, we have carried out PCR test on RESA gene, using three different primers. One of them showed that P. falciparum isolates collected directly from infected humans and cultured only for a few days, or not at all, have amplicon sizes ranging from 372 to 510 bp. However, the amplicon size changed to 873 bp when in vitro growth was continued for one or more weeks. This genetic transformation precedes acquisition of the ability to confer saponin resistance to RIEs.
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Duffy PE, Sahu T, Akue A, Milman N, Anderson C. Pre-erythrocytic malaria vaccines: identifying the targets. Expert Rev Vaccines 2013; 11:1261-80. [PMID: 23176657 DOI: 10.1586/erv.12.92] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pre-erythrocytic malaria vaccines target Plasmodium during its sporozoite and liver stages, and can prevent progression to blood-stage disease, which causes a million deaths each year. Whole organism sporozoite vaccines induce sterile immunity in animals and humans and guide subunit vaccine development. A recombinant protein-in-adjuvant pre-erythrocytic vaccine called RTS,S reduces clinical malaria without preventing infection in field studies and additional antigens may be required to achieve sterile immunity. Although few vaccine antigens have progressed to human testing, new insights into parasite biology, expression profiles and immunobiology have offered new targets for intervention. Future advances require human trials of additional antigens, as well as platforms to induce the durable antibody and cellular responses including CD8(+) T cells that contribute to sterile protection.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology & Vaccinology, Division of Intramural Research, NIAID, NIH, Rockville, MD, USA.
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Kajumbula H, Byarugaba W, Wayengera M. Targeting wild-type Erythrocyte receptors for Plasmodium falciparum and vivax Merozoites by Zinc Finger Nucleases In- silico: Towards a Genetic Vaccine against Malaria. GENETIC VACCINES AND THERAPY 2012; 10:8. [PMID: 22938508 PMCID: PMC3500210 DOI: 10.1186/1479-0556-10-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 08/29/2012] [Indexed: 11/10/2022]
Abstract
UNLABELLED BACKGROUND Malaria causes immense human morbidity and mortality globally. The plasmodium species vivax and falciparum cause over 75 % clinical malaria cases. Until now, gene-based strategies against malaria have only been applied to plasmodium species and their mosquito-vector. Merozoites of these two respective plasmodium species target and invade red blood cells (RBCs) by using the duffy antigen receptor for chemokines (DARC), and Sialic Acid (SLC4A1) residues of the O-linked glycans of Glycophorin A. RBCs of naturally selected duffy-negative blacks are resistant to P.vivax tropism. We hypothesized that artificial aberration of the host-pathway by target mutagenesis of either RBC -receptors, may abolish or reduce susceptibility of the host to malaria. As a first step towards the experimental actualization of these concepts, we aimed to identify zinc finger arrays (ZFAs) for constructing ZFNs that target genes of either wild-type host-RBC- receptors. METHODS In-Silico Gene & Genome Informatics RESULTS Using the genomic contextual nucleotide-sequences of homo-sapiens darc and glycophorin-a, and the ZFN-consortia software- CoDA-ZiFiT-ZFA and CoDA-ZiFiT-ZFN: we identified 163 and over 1,000 single zinc finger arrays (sZFAs) that bind sequences within the genes for the two respective RBC-receptors. Second, 2 and 18 paired zinc finger arrays (pZFAs) that are precursors for zinc finger nucleases (ZFNs) capable of cleaving the genes for darc and glycophorin-a were respectively assembled. Third, a mega-BLAST evaluation of the genome-wide cleavage specificity of this set of ZFNs was done, revealing alternate homologous nucleotide targets in the human genome other than darc or glycophorin A. CONCLUSIONS ZFNs engineered with these ZFA-precursors--with further optimization to enhance their specificity to only darc and glycophorin-a, could be used in constructing an experimental gene-based-malaria vaccine. Alternatively, meganucleases and transcription activator-like (TAL) nucleases that target conserved stretches of darc and glycophorin-a DNA may serve the purpose of abrogating invasion of RBCs by falciparam and vivax plasmodia species.
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Affiliation(s)
- Henry Kajumbula
- Dept of Medical Microbiology, School of Biomedical Science, College of Health Sciences, Makerere University, P O Box 7072, Kampala, Uganda.
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Kynast-Wolf G, Wakilzadeh W, Coulibaly B, Schnitzler P, Traoré C, Becher H, Müller O. ITN protection, MSP1 antibody levels and malaria episodes in young children of rural Burkina Faso. Acta Trop 2012; 123:117-22. [PMID: 22569564 DOI: 10.1016/j.actatropica.2012.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/29/2012] [Accepted: 04/22/2012] [Indexed: 10/28/2022]
Abstract
Malaria blood-stage vaccines are in an early phase of clinical development with MSP1 being a major antigen candidate. There are limited data on the protective efficacy of antibodies against subunits of MSP1 in the malaria endemic areas of sub-Saharan Africa. This prospective cohort study was nested into a large insecticide-treated mosquito net (ITN) trial during which neonates were individually randomised to ITN protection from birth vs. protection from month six onwards in rural Burkina Faso. A sub sample of 120 children from three villages was followed for 10 months with six measurements of MSP1(42) antibodies (ELISA based on recombinant 42kDa fragment) and daily assessment of malaria episodes. Time to the next malaria episode was determined in relation to MSP1(42) antibody titres. MSP1(42) antibody titres were dependent on age, season, ITN-group, number of previous malaria episodes and parasitaemia. There were no significant differences in time until the next malaria episode in children with low compared to children with high MSP1(42) antibody titres at any point in time (101 vs. 97 days in May, p=0.6; 58 vs. 84 days in September, p=0.3; 144 vs. 161 days in March, p=0.5). The findings of this study support the short-lived nature of the humoral immune response in infants of malaria endemic areas. The study provides no evidence for antibodies against a subunit of MSP1 being protective against new malaria episodes in infants.
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Affiliation(s)
- Gisela Kynast-Wolf
- Institute of Public Health, Ruprecht-Karls-University Heidelberg, Germany.
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Schlarman MS, Roberts RN, Kariuki MM, LaCrue AN, Ou R, Beerntsen BT. Transcript and protein expression profile of PF11_0394, a Plasmodium falciparum protein expressed in salivary gland sporozoites. Malar J 2012; 11:80. [PMID: 22443220 PMCID: PMC3355004 DOI: 10.1186/1475-2875-11-80] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 03/23/2012] [Indexed: 11/12/2022] Open
Abstract
Background Plasmodium falciparum malaria is a significant problem around the world today, thus there is still a need for new control methods to be developed. Because the sporozoite displays dual infectivity for both the mosquito salivary glands and vertebrate host tissue, it is a good target for vaccine development. Methods The P. falciparum gene, PF11_0394, was chosen as a candidate for study due to its potential role in the invasion of host tissues. This gene, which was selected using a data mining approach from PlasmoDB, is expressed both at the transcriptional and protein levels in sporozoites and likely encodes a putative surface protein. Using reverse transcription-polymerase chain reaction (RT-PCR) and green fluorescent protein (GFP)-trafficking studies, a transcript and protein expression profile of PF11_0394 was determined. Results The PF11_0394 protein has orthologs in other Plasmodium species and Apicomplexans, but none outside of the group Apicomplexa. PF11_0394 transcript was found to be present during both the sporozoite and erythrocytic stages of the parasite life cycle, but no transcript was detected during axenic exoerythrocytic stages. Despite the presence of transcript throughout several life cycle stages, the PF11_0394 protein was only detected in salivary gland sporozoites. Conclusions PF11_0394 appears to be a protein uniquely detected in salivary gland sporozoites. Even though a specific function of PF11_0394 has not been determined in P. falciparum biology, it could be another candidate for a new vaccine.
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Affiliation(s)
- Maggie S Schlarman
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
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Abstract
In the twentieth century vaccine development has moved from the use of attenuated or killed micro-organisms to protein sub-unit vaccines, with vaccine immunogenicity assessed by measuring antibodies induced by vaccination. However, for many infectious diseases T cells are an important part of naturally acquired protective immune responses, and inducing these by vaccination has been the aim of much research. The progress that has been made in developing effective T-cell-inducing vaccines against viral and parasitic diseases such as HIV and malaria is discussed, along with recent developments in therapeutic vaccine development for chronic viral infections and cancer. Although many ways of inducing T cells by vaccination have been assessed, the majority result in low level, non-protective responses. Sufficient clinical research has now been conducted to establish that replication-deficient viral vectored vaccines lead the field in inducing strong and broad responses, and efficacy studies of T-cell-inducing vaccines against a number of diseases are finally demonstrating that this is a valid approach to filling the gaps in our defence against not only infectious disease, but some forms of cancer.
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Amiruddin N, Lee XW, Blake DP, Suzuki Y, Tay YL, Lim LS, Tomley FM, Watanabe J, Sugimoto C, Wan KL. Characterisation of full-length cDNA sequences provides insights into the Eimeria tenella transcriptome. BMC Genomics 2012; 13:21. [PMID: 22244352 PMCID: PMC3315734 DOI: 10.1186/1471-2164-13-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 01/13/2012] [Indexed: 11/12/2022] Open
Abstract
Background Eimeria tenella is an apicomplexan parasite that causes coccidiosis in the domestic fowl. Infection with this parasite is diagnosed frequently in intensively reared poultry and its control is usually accorded a high priority, especially in chickens raised for meat. Prophylactic chemotherapy has been the primary method used for the control of coccidiosis. However, drug efficacy can be compromised by drug-resistant parasites and the lack of new drugs highlights demands for alternative control strategies including vaccination. In the long term, sustainable control of coccidiosis will most likely be achieved through integrated drug and vaccination programmes. Characterisation of the E. tenella transcriptome may provide a better understanding of the biology of the parasite and aid in the development of a more effective control for coccidiosis. Results More than 15,000 partial sequences were generated from the 5' and 3' ends of clones randomly selected from an E. tenella second generation merozoite full-length cDNA library. Clustering of these sequences produced 1,529 unique transcripts (UTs). Based on the transcript assembly and subsequently primer walking, 433 full-length cDNA sequences were successfully generated. These sequences varied in length, ranging from 441 bp to 3,083 bp, with an average size of 1,647 bp. Simple sequence repeat (SSR) analysis identified CAG as the most abundant trinucleotide motif, while codon usage analysis revealed that the ten most infrequently used codons in E. tenella are UAU, UGU, GUA, CAU, AUA, CGA, UUA, CUA, CGU and AGU. Subsequent analysis of the E. tenella complete coding sequences identified 25 putative secretory and 60 putative surface proteins, all of which are now rational candidates for development as recombinant vaccines or drug targets in the effort to control avian coccidiosis. Conclusions This paper describes the generation and characterisation of full-length cDNA sequences from E. tenella second generation merozoites and provides new insights into the E. tenella transcriptome. The data generated will be useful for the development and validation of diagnostic and control strategies for coccidiosis and will be of value in annotation of the E. tenella genome sequence.
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Affiliation(s)
- Nadzirah Amiruddin
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor DE, Malaysia
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Cherif MS, Shuaibu MN, Kurosaki T, Helegbe GK, Kikuchi M, Yanagi T, Tsuboi T, Sasaki H, Hirayama K. Immunogenicity of novel nanoparticle-coated MSP-1 C-terminus malaria DNA vaccine using different routes of administration. Vaccine 2011; 29:9038-50. [PMID: 21939717 DOI: 10.1016/j.vaccine.2011.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 08/31/2011] [Accepted: 09/09/2011] [Indexed: 01/08/2023]
Abstract
An important aspect in optimizing DNA vaccination is antigen delivery to the site of action. In this way, any alternative delivery system having higher transfection efficiency and eventual superior antibody production needs to be further explored. The novel nanoparticle, pDNA/PEI/γ-PGA complex, is one of a promising delivery system, which is taken up by cells and is shown to have high transfection efficiency. The immunostimulatory effect of this novel nanoparticle (NP) coated plasmid encoding Plasmodium yoelii MSP1-C-terminus was examined. Groups of C57BL/6 mice were immunized either with NP-coated MSP-1 plasmid, naked plasmid or NP-coated blank plasmid, by three different routes of administration; intravenous (i.v.), intraperitoneal (i.p.) and subcutaneous (s.c). Mice were primed and boosted twice at 3-week intervals, then challenged 2 weeks after; and 100%, 100% and 50% mean of survival was observed in immunized mice with coated DNA vaccine by i.p., i.v. and s.c., respectively. Coated DNA vaccine showed significant immunogenicity and elicited protective levels of antigen specific IgG and its subclass antibody, an increased proportion of CD4(+) and CD8(+) T cells and INF-γ and IL-12 levels in the serum and cultured splenocyte supernatant, as well as INF-γ producing cells in the spleen. We demonstrate that, NP-coated MSP-1 DNA-based vaccine confers protection against lethal P. yoelii challenge in murine model across the various route of administration and may therefore, be considered a promising delivery system for vaccination.
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Affiliation(s)
- Mahamoud Sama Cherif
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University 1-12-4 Sakamoto, 852-8523, Japan
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Germann A, Schulz JC, Kemp-Kamke B, Zimmermann H, von Briesen H. Standardized Serum-Free Cryomedia Maintain Peripheral Blood Mononuclear Cell Viability, Recovery, and Antigen-Specific T-Cell Response Compared to Fetal Calf Serum-Based Medium. Biopreserv Biobank 2011; 9:229-236. [PMID: 21977240 DOI: 10.1089/bio.2010.0033] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/26/2011] [Indexed: 10/17/2022] Open
Abstract
The ability to analyze cryopreserved peripheral blood mononuclear cells (PBMCs) from biobanks for antigen-specific T-cell immunity is necessary to evaluate responses to immune-based therapies. Comprehensive studies have demonstrated that the quality of frozen PBMCs is critical and the maintenance of cell viability and functionality by using appropriate cryopreservation techniques is a key to the successful outcome of assays using PBMCs. Different cryomedia additives affect cell viability. The most common additive is fetal calf serum (FCS), although it is widely known that each FCS lot has to be tested before usage to prevent nonspecific stimulation of T-cells. Also, shipping of samples containing FCS is critical because of many import restrictions. Often, dimethyl sulfoxide (DMSO) is added as a cryoprotectant. However, DMSO concentration has to be reduced significantly because of its toxic effect on cells at room temperature. Therefore, we have developed freezing approaches to minimize cytotoxicity of cryoprotectants and maintain T-cell functionality. We compared different additives to the widely used FCS and found bovine serum albumin fraction V to be an appropriate substitute for the potentially immune-modulating FCS. We also found that DMSO concentration can be reduced by the addition of hydroxyethyl starch. Using our serum-free cryomedia, the PBMC recovery was more than 83% and the PBMC viability was more than 98%. Also, the T-cell functionality measured by enzyme-linked immunospot (ELISpot) was optimal after cryopreservation with our new cryomedia. On the basis of our experimental results, we could finally design 2 different, fully working cryomedia that are standardized, serum free, and manufactured under GMP conditions.
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Arévalo-Herrera M, Solarte Y, Marin C, Santos M, Castellanos J, Beier JC, Valencia SH. Malaria transmission blocking immunity and sexual stage vaccines for interrupting malaria transmission in Latin America. Mem Inst Oswaldo Cruz 2011; 106 Suppl 1:202-11. [PMID: 21881775 PMCID: PMC4830685 DOI: 10.1590/s0074-02762011000900025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 07/13/2011] [Indexed: 11/22/2022] Open
Abstract
Malaria is a vector-borne disease that is considered to be one of the most serious public health problems due to its high global mortality and morbidity rates. Although multiple strategies for controlling malaria have been used, many have had limited impact due to the appearance and rapid dissemination of mosquito resistance to insecticides, parasite resistance to multiple antimalarial drug, and the lack of sustainability. Individuals in endemic areas that have been permanently exposed to the parasite develop specific immune responses capable of diminishing parasite burden and the clinical manifestations of the disease, including blocking of parasite transmission to the mosquito vector. This is referred to as transmission blocking (TB) immunity (TBI) and is mediated by specific antibodies and other factors ingested during the blood meal that inhibit parasite development in the mosquito. These antibodies recognize proteins expressed on either gametocytes or parasite stages that develop in the mosquito midgut and are considered to be potential malaria vaccine candidates. Although these candidates, collectively called TB vaccines (TBV), would not directly stop malaria from infecting individuals, but would stop transmission from infected person to non-infected person. Here, we review the progress that has been achieved in TBI studies and the development of TBV and we highlight their potential usefulness in areas of low endemicity such as Latin America.
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Identification of a highly antigenic linear B cell epitope within Plasmodium vivax apical membrane antigen 1 (AMA-1). PLoS One 2011; 6:e21289. [PMID: 21713006 PMCID: PMC3119695 DOI: 10.1371/journal.pone.0021289] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/25/2011] [Indexed: 12/21/2022] Open
Abstract
Apical membrane antigen 1 (AMA-1) is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1) have shown a higher prevalence of specific antibodies to domain II (DII) of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs). The B cell epitope comprising the amino acid sequence 290–307 of PvAMA-1 (SASDQPTQYEEEMTDYQK), with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both), respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.
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Murine immune responses to a Plasmodium vivax-derived chimeric recombinant protein expressed in Brassica napus. Malar J 2011; 10:106. [PMID: 21529346 PMCID: PMC3098821 DOI: 10.1186/1475-2875-10-106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 04/29/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To develop a plant-based vaccine against Plasmodium vivax, two P. vivax candidate proteins were chosen. First, the merozoite surface protein-1 (MSP-1), a major asexual blood stage antigen that is currently considered a strong vaccine candidate. Second, the circumsporozoite protein (CSP), a component of sporozoites that contains a B-cell epitope. METHODS A synthetic chimeric recombinant 516 bp gene encoding containing PvMSP-1, a Pro-Gly linker motif, and PvCSP was synthesized; the gene, named MLC, encoded a total of 172 amino acids. The recombinant gene was modified with regard to codon usage to optimize gene expression in Brassica napus. The Ti plasmid inducible gene transfer system was used for MLC chimeric recombinant gene expression in B. napus. Gene expression was confirmed by polymerase chain reaction (PCR), beta-glucuronidase reporter gene (GUS) assay, and Western blot. RESULTS The MLC chimeric recombinant protein expressed in B. napus had a molecular weight of approximately 25 kDa. It exhibited a clinical sensitivity of 84.21% (n=38) and a clinical specificity of 100% (n=24) as assessed by enzyme-linked immunosorbent assay (ELISA). Oral immunization of BALB/c mice with MLC chimeric recombinant protein successfully induced antigen-specific IgG1 production. Additionally, the Th1-related cytokines IL-12 (p40), TNF, and IFN-γ were significantly increased in the spleens of the BALB/c mice. CONCLUSIONS The chimeric MLC recombinant protein produced in B. napus has potential as both as an antigen for diagnosis and as a valuable vaccine candidate for oral immunization against vivax malaria.
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Suwancharoen C, Putaporntip C, Rungruang T, Jongwutiwes S. Naturally acquired IgG antibodies against the C-terminal part of Plasmodium falciparum sporozoite threonine–asparagine-rich protein in a low endemic area. Parasitol Res 2011; 109:315-20. [DOI: 10.1007/s00436-011-2257-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 01/14/2011] [Indexed: 10/18/2022]
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Shuaibu MN, Kikuchi M, Cherif MS, Helegbe GK, Yanagi T, Hirayama K. Selection and identification of malaria vaccine target molecule using bioinformatics and DNA vaccination. Vaccine 2010; 28:6868-75. [PMID: 20709002 DOI: 10.1016/j.vaccine.2010.08.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 07/21/2010] [Accepted: 08/02/2010] [Indexed: 11/24/2022]
Abstract
Following a genome-wide search for a blood stage malaria DNA-based vaccine using web-based bioinformatic tools, 29 genes from the annotated Plasmodium yoelii genome sequence (www.PlasmoDB.org and www.tigr.org) were identified as encoding GPI-anchored proteins. Target genes were those with orthologues in P. falciparum, containing an N-terminal signal sequence containing hydrophobic amino acid stretch and signal P criteria, a transmembrane-like domain and GPI anchor motif. Focusing on the blood stage, we extracted mRNA from pRBCs, PCR-amplified 22 out of the 29 selected genes, and eventually cloned nine of these into a DNA vaccine plasmid, pVAX 200-DEST. Biojector-mediated delivery of the nine DNA vaccines was conducted using ShimaJET to C57BL/6 mice at a dose of 4 μg/mouse three times at an interval of 3 weeks. Two weeks after the second booster, immunized mice were challenged with P. y. yoelii 17XL-parasitized RBCs and the level of parasitaemia, protection and survival was assessed. Immunization with one gene (PY03470) resulted in 2-4 days of delayed onset and level of parasitaemia and was associated with increased survival compared to non-immunized mice. Antibody production was, however, low following DNA vaccination, as determined by immunofluorescence assay. Recombinant protein from this gene, GPI8p transamidase-related protein (rPyTAM) in PBS or emulsified with GERBU adjuvant was also used to immunize another set of C57BL/6 mice with 10-20 μg/mouse three times at 3-week interval. Higher antibody response was obtained as determined by ELISA with similar protective effects as observed after DNA vaccination.
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Affiliation(s)
- M N Shuaibu
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
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Min-Oo G, Ayi K, Bongfen SE, Tam M, Radovanovic I, Gauthier S, Santiago H, Rothfuchs AG, Roffê E, Sher A, Mullick A, Fortin A, Stevenson MM, Kain KC, Gros P. Cysteamine, the natural metabolite of pantetheinase, shows specific activity against Plasmodium. Exp Parasitol 2010; 125:315-24. [PMID: 20219464 DOI: 10.1016/j.exppara.2010.02.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 01/21/2010] [Accepted: 02/22/2010] [Indexed: 11/26/2022]
Abstract
In mice, loss of pantetheinase activity causes susceptibility to infection with Plasmodium chabaudi AS. Treatment of mice with the pantetheinase metabolite cysteamine reduces blood-stage replication of P. chabaudi and significantly increases survival. Similarly, a short exposure of Plasmodium to cysteamine ex vivo is sufficient to suppress parasite infectivity in vivo. This effect of cysteamine is specific and not observed with a related thiol (dimercaptosuccinic acid) or with the pantethine precursor of cysteamine. Also, cysteamine does not protect against infection with the parasite Trypanosoma cruzi or the fungal pathogen Candida albicans, suggesting cysteamine acts directly against the parasite and does not modulate host inflammatory response. Cysteamine exposure also blocks replication of P. falciparum in vitro; moreover, these treated parasites show higher levels of intact hemoglobin. This study highlights the in vivo action of cysteamine against Plasmodium and provides further evidence for the involvement of pantetheinase in host response to this infection.
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Affiliation(s)
- Gundula Min-Oo
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, Canada
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Furuta T, Kimura M, Watanabe N. Elevated levels of vascular endothelial growth factor (VEGF) and soluble vascular endothelial growth factor receptor (VEGFR)-2 in human malaria. Am J Trop Med Hyg 2010; 82:136-9. [PMID: 20065009 DOI: 10.4269/ajtmh.2010.09-0203] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In cerebral malaria, the binding of parasitized erythrocytes to the cerebral endothelium and the consequent angiogenic dysregulation play a key role in pathogenesis. Because vascular endothelial growth factor (VEGF) is widely regarded as a potent stimulator of angiogenesis, edema, inflammation, and vascular remodeling, the plasma levels of VEGF and the soluble form of the VEGF receptor (sVEGFR)-1 and -2 in uncomplicated malaria patients and healthy adults were measured by enzyme-linked immunosorbent assay (ELISA) to examine their roles in malaria. The results showed that VEGF and sVEGFR-2 levels were significantly elevated in malaria patients compared with healthy adults. Moreover, it was confirmed that malarial parasite antigens induced VEGF secretion from the human mast cell lines HMC-1 or KU812 cell. This is the first report to suggest that the interaction of VEGF and sVEGFR-2 is involved in the host immune response to malarial infection and that malarial parasites induce VEGF secretion from human mast cells.
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Affiliation(s)
- Takahisa Furuta
- Division of Infectious Genetics, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.
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Nguyen TV, Sacci JB, de la Vega P, John CC, James AA, Kang AS. Characterization of immunoglobulin G antibodies to Plasmodium falciparum sporozoite surface antigen MB2 in malaria exposed individuals. Malar J 2009; 8:235. [PMID: 19852802 PMCID: PMC2772840 DOI: 10.1186/1475-2875-8-235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 10/23/2009] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND MB2 protein is a sporozoite surface antigen on the human malaria parasite Plasmodium falciparum. MB2 was identified by screening a P. falciparum sporozoite cDNA expression library using immune sera from a protected donor immunized via the bites of P. falciparum-infected irradiated mosquitoes. It is not known whether natural exposure to P. falciparum also induces the anti-MB2 response and if this response differs from that in protected individuals immunized via the bites of P. falciparum infected irradiated mosquitoes. The anti-MB2 antibody response may be part of a robust protective response against the sporozoite. METHODS Fragments of polypeptide regions of MB2 were constructed as recombinant fusions sandwiched between glutathione S-transferase and a hexa histidine tag for bacterial expression. The hexa histidine tag affinity purified proteins were used to immunize rabbits and the polyclonal sera evaluated in an in vitro inhibition of sporozoite invasion assay. The proteins were also used in immunoblots with sera from a limited number of donors immunized via the bites of P. falciparum infected irradiated mosquitoes and plasma and serum obtained from naturally exposed individuals in Kenya. RESULTS Rabbit polyclonal antibodies targeting the non-repeat region of the basic domain of MB2 inhibited sporozoites entry into HepG2-A16 cells in vitro. Analysis of serum from five human volunteers that were immunized via the bites of P. falciparum infected irradiated mosquitoes that developed immunity and were completely protected against subsequent challenge with non-irradiated parasite also had detectable levels of antibody against MB2 basic domain. In contrast, in three volunteers not protected, anti-MB2 antibodies were below the level of detection. Sera from protected volunteers preferentially recognized a non-repeat region of the basic domain of MB2, whereas plasma from naturally-infected individuals also had antibodies that recognize regions of MB2 that contain a repeat motif in immunoblots. Sequence analysis of eleven field isolates and four laboratory strains showed that these antigenic regions of the basic domain of the MB2 gene are highly conserved in parasites obtained from different parts of the world. Moreover, anti-MB2 antibodies also were detected in the plasma of 83% of the individuals living in a malaria endemic area of Kenya (n = 41). CONCLUSION A preliminary analysis of the human humoral response against MB2 indicates that it may be an additional highly conserved target for immune intervention at the pre-erythrocytic stage of P. falciparum life cycle.
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Affiliation(s)
- Thanh V Nguyen
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- NeoGenomics California, 6 Morgan, Suite 150, Irvine, CA 92618, USA
| | - John B Sacci
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Room 324 660 W Redwood Street, Baltimore, MD 21201, USA
| | - Patricia de la Vega
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Room 324 660 W Redwood Street, Baltimore, MD 21201, USA
- Department of Cell Mediated Immunity, Division of Malaria Vaccine Development, US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, USA
| | - Chandy C John
- Global Pediatrics Program and Division of Pediatric Infectious Diseases, University of MN Medical School, 420 Delaware Street, SE, MMC #296, 850-Mayo, Minneapolis, MN 55455, USA
| | - Anthony A James
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697-3900, USA
| | - Angray S Kang
- The School of Life Sciences, Department of Molecular and Applied Biosciences, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK
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Abstract
Naturally acquired immunity to malaria requires repeat infections yet does not engender sterile immunity or long-lasting protective immunologic memory. This renders infants and young children the most susceptible to malaria-induced morbidity and mortality, and the ultimate target for a malaria vaccine. The prevailing paradigm is that infants initially garner protection due to transplacentally transferred anti-malarial antibodies and other intrinsic factors such as foetal haemoglobin. As these wane infants have an insufficient immune repertoire to prevent genetically diverse Plasmodium infections and an inability to control malaria-induced immunopathology. This Review discusses humoral, cell-mediated and innate immune responses to malaria and how each contributes to protection – focusing on how deficiencies in infant and paediatric immune responses might influence malaria vaccine efficacy in this population. In addition, burgeoning evidence suggests a role for inhibitory receptors that limit immunopathology and guide the development of long-lived immunity. Precisely how age or malaria infections influence the function of these regulators is unknown. Therefore the possibility that infants may not have the immune-dexterity to balance effective parasite clearance with timely immune-regulation leading to protective immunologic memory is considered. And thus, malaria vaccines tested in adults and older children may not be predictive for trials conducted in infants.
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Affiliation(s)
- A M Moormann
- Case Western Reserve University, Center for Global Health and Diseases, 2103 Cornell Road, WRB 4-130, Cleveland, OH 44106-7286, USA.
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Bueno LL, Morais CG, da Silva Soares I, Bouillet LEM, Bruna-Romero O, Fontes CJ, Fujiwara RT, Braga ÉM. Plasmodium vivax recombinant vaccine candidate AMA-1 plays an important role in adaptive immune response eliciting differentiation of dendritic cells. Vaccine 2009; 27:5581-8. [DOI: 10.1016/j.vaccine.2009.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/06/2009] [Accepted: 07/14/2009] [Indexed: 11/16/2022]
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Patil DP, Atanur S, Dhotre DP, Anantharam D, Mahajan VS, Walujkar SA, Chandode RK, Kulkarni GJ, Ghate PS, Srivastav A, Dayananda KM, Gupta N, Bhagwat B, Joshi RR, Mourya DT, Patole MS, Shouche YS. Generation, annotation, and analysis of ESTs from midgut tissue of adult female Anopheles stephensi mosquitoes. BMC Genomics 2009; 10:386. [PMID: 19695102 PMCID: PMC2743715 DOI: 10.1186/1471-2164-10-386] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 08/20/2009] [Indexed: 11/23/2022] Open
Abstract
Background Malaria is a tropical disease caused by protozoan parasite, Plasmodium, which is transmitted to humans by various species of female anopheline mosquitoes. Anopheles stephensi is one such major malaria vector in urban parts of the Indian subcontinent. Unlike Anopheles gambiae, an African malaria vector, transcriptome of A. stephensi midgut tissue is less explored. We have therefore carried out generation, annotation, and analysis of expressed sequence tags from sugar-fed and Plasmodium yoelii infected blood-fed (post 24 h) adult female A. stephensi midgut tissue. Results We obtained 7061 and 8306 ESTs from the sugar-fed and P. yoelii infected mosquito midgut tissue libraries, respectively. ESTs from the combined dataset formed 1319 contigs and 2627 singlets, totaling to 3946 unique transcripts. Putative functions were assigned to 1615 (40.9%) transcripts using BLASTX against UniProtKB database. Amongst unannotated transcripts, we identified 1513 putative novel transcripts and 818 potential untranslated regions (UTRs). Statistical comparison of annotated and unannotated ESTs from the two libraries identified 119 differentially regulated genes. Out of 3946 unique transcripts, only 1387 transcripts were mapped on the A. gambiae genome. These also included 189 novel transcripts, which were mapped to the unannotated regions of the genome. The EST data is available as ESTDB at . Conclusion 3946 unique transcripts were successfully identified from the adult female A. stephensi midgut tissue. These data can be used for microarray development for better understanding of vector-parasite relationship and to study differences or similarities with other malaria vectors. Mapping of putative novel transcripts from A. stephensi on the A. gambiae genome proved fruitful in identification and annotation of several genes. Failure of some novel transcripts to map on the A. gambiae genome indicates existence of substantial genomic dissimilarities between these two potent malaria vectors.
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Affiliation(s)
- Deepak P Patil
- Lab 3, National Center for Cell Science, Pune - 411007, India.
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Plasmodium falciparum-specific cellular immune responses after immunization with the RTS,S/AS02D candidate malaria vaccine in infants living in an area of high endemicity in Mozambique. Infect Immun 2009; 77:4502-9. [PMID: 19651872 DOI: 10.1128/iai.00442-09] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Results from clinical trials in areas where malaria is endemic have shown that immunization with RTS,S/AS02A malaria vaccine candidate induces partial protection in adults and children and cellular effector and memory responses in adults. For the first time in a malaria vaccine trial, we sought to assess the cell-mediated immune responses to RTS,S antigen components in infants under 1 year of age participating in a clinical phase I/IIb trial of RTS,S/AS02D in Mozambique. Circumsporozoite protein (CSP)-specific responses were detected in approximately half of RTS,S-immunized infants and included gamma interferon (IFN-gamma), interleukin-2 (IL-2), and combined IL-2/IL-4 responses. The median stimulation indices of cytokine-producing CD4(+) and CD8(+) cells were very low but significantly higher in RTS,S-immunized infants than in infants that received the comparator vaccine. Protection against subsequent malarial infection tended to be associated with a higher percentage of individuals with CSP-specific IL-2 in the supernatant (P = 0.053) and with higher CSP-specific IFN-gamma-producing CD8(+) T-cell responses (P = 0.07). These results report for the first time the detection of malaria-specific cellular immune responses after vaccination of infants less than 1 year of age and pave the way for future field studies of cellular immunity to malaria vaccine candidates.
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Toward the rational design of a malaria vaccine construct using the MSP3 family as an example: contribution of immunogenicity studies in models. Infect Immun 2009; 78:477-85. [PMID: 19581391 DOI: 10.1128/iai.00941-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum merozoite surface protein 3 (MSP3), the target of antibodies that mediate parasite killing in cooperation with blood monocytes and are associated with protection in exposed populations, is a vaccine candidate under development. It belongs to a family of six structurally related genes. To optimize immunogenicity, we attempted to improve its design based on knowledge of antigenicity of various regions from the conserved C terminus of the six proteins and an analysis of the immunogenicity of "tailored" constructs. The immunogenicity studies were conducted in BALB/c and C57BL/6J mice, using MSP3 (referred to here as MSP3-1) as a model. Four constructs were designed in order to assess the effect of sequences flanking the 69-amino-acid region of MSP3-1 previously shown to be the target of biologically active antibodies. The results indicate major beneficial effects of removing (i) the subregion downstream from the 69-amino-acid sequence, since antibody titers increased by 2 orders of magnitude, and (ii) the upstream subregion which, although it defines a T-helper cell epitope, is not the target of antibodies. The construct, excluding both flanking sequences, was able to induce Th1-like responses, with a dominance of cytophilic antibodies. This led to design a multigenic construct based on these results, combining the six members of the MSP3 family. This new construction was immunogenic in mice, induced antibodies that recognized the parasite native proteins, and inhibited parasite growth in the functional antibody-dependent cellular inhibition assay, thus satisfying the preclinical criteria for a valuable vaccine candidate.
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Villa S, Compagni A, Reich MR. Orphan drug legislation: lessons for neglected tropical diseases. Int J Health Plann Manage 2009; 24:27-42. [PMID: 18435430 DOI: 10.1002/hpm.930] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the last 20 years, orphan drug legislation (ODL) has been adopted in several countries around the world (USA, Japan, Australia, and the European Union) and has successfully promoted R&D investments to develop new pharmaceutical products for the treatment of rare diseases. Without these incentives, many life-saving new drugs would have not been developed and produced. For economic reasons, the development of medicines for the treatment of diseases prevalent in the developing world (or tropical diseases) is lagging behind. Among several factors, the low average per-capita income makes pharmaceutical markets in developing countries appear relatively unprofitable and therefore unattractive for R&D-oriented companies. The case of ODL may offer some useful insights and perspectives for the fight against neglected tropical diseases. First, the measures used in ODL may also be effective in boosting R&D for neglected tropical diseases, if appropriately adapted to this market. Second, small-sized companies, which have played a successful role in the development of orphan drugs for rare diseases, may also represent a good business strategy for the case of tropical diseases.
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Affiliation(s)
- Stefano Villa
- Centre for Research on Health and Social Care Management (CERGAS), Università Bocconi, Milan, Italy.
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Spring MD, Cummings JF, Ockenhouse CF, Dutta S, Reidler R, Angov E, Bergmann-Leitner E, Stewart VA, Bittner S, Juompan L, Kortepeter MG, Nielsen R, Krzych U, Tierney E, Ware LA, Dowler M, Hermsen CC, Sauerwein RW, de Vlas SJ, Ofori-Anyinam O, Lanar DE, Williams JL, Kester KE, Tucker K, Shi M, Malkin E, Long C, Diggs CL, Soisson L, Dubois MC, Ballou WR, Cohen J, Heppner DG. Phase 1/2a study of the malaria vaccine candidate apical membrane antigen-1 (AMA-1) administered in adjuvant system AS01B or AS02A. PLoS One 2009; 4:e5254. [PMID: 19390585 PMCID: PMC2669163 DOI: 10.1371/journal.pone.0005254] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 03/23/2009] [Indexed: 11/19/2022] Open
Abstract
Background This Phase 1/2a study evaluated the safety, immunogenicity, and efficacy of an experimental malaria vaccine comprised of the recombinant Plasmodium falciparum protein apical membrane antigen-1 (AMA-1) representing the 3D7 allele formulated with either the AS01B or AS02A Adjuvant Systems. Methodology/Principal Findings After a preliminary safety evaluation of low dose AMA-1/AS01B (10 µg/0.5 mL) in 5 adults, 30 malaria-naïve adults were randomly allocated to receive full dose (50 µg/0.5 mL) of AMA-1/AS01B (n = 15) or AMA-1/AS02A (n = 15), followed by a malaria challenge. All vaccinations were administered intramuscularly on a 0-, 1-, 2-month schedule. All volunteers experienced transient injection site erythema, swelling and pain. Two weeks post-third vaccination, anti-AMA-1 Geometric Mean Antibody Concentrations (GMCs) with 95% Confidence Intervals (CIs) were high: low dose AMA-1/AS01B 196 µg/mL (103–371 µg/mL), full dose AMA-1/AS01B 279 µg/mL (210–369 µg/mL) and full dose AMA-1/AS02A 216 µg/mL (169–276 µg/mL) with no significant difference among the 3 groups. The three vaccine formulations elicited equivalent functional antibody responses, as measured by growth inhibition assay (GIA), against homologous but not against heterologous (FVO) parasites as well as demonstrable interferon-gamma (IFN-γ) responses. To assess efficacy, volunteers were challenged with P. falciparum-infected mosquitoes, and all became parasitemic, with no significant difference in the prepatent period by either light microscopy or quantitative polymerase chain reaction (qPCR). However, a small but significant reduction of parasitemia in the AMA-1/AS02A group was seen with a statistical model employing qPCR measurements. Significance All three vaccine formulations were found to be safe and highly immunogenic. These immune responses did not translate into significant vaccine efficacy in malaria-naïve adults employing a primary sporozoite challenge model, but encouragingly, estimation of parasite growth rates from qPCR data may suggest a partial biological effect of the vaccine. Further evaluation of the immunogenicity and efficacy of the AMA-1/AS02A formulation is ongoing in a malaria-experienced pediatric population in Mali. Trial Registration www.clinicaltrials.govNCT00385047
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Affiliation(s)
- Michele D Spring
- United States Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.
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[Vaccines for the future]. ANNALES PHARMACEUTIQUES FRANÇAISES 2009; 67:203-12. [PMID: 19446671 DOI: 10.1016/j.pharma.2009.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/19/2008] [Accepted: 02/06/2009] [Indexed: 12/27/2022]
Abstract
The field of vaccines and vaccinology has seen remarkable progress during the past 20 years. Many vaccines, however, still need to be improved, either because the protection they provide is relatively short-lived and would greatly benefit from the development of booster formulations (as is the case for tuberculosis), or because they only cover part of the many serotypes of the pathogen that causes the disease (rotaviruses, papillomaviruses, or Streptococcus pneumoniae). In addition, still many diseases lack a proper preventive vaccine, such as AIDS, hepatitis C, malaria, viral pneumonias, croup and bronchiolitis, dengue fever, leishmaniasis, Staphylococcus aureus, groups A and B Streptococcus, Shigellas and enterotoxigenic Escherichia coli, to only name a few. These are the current targets of vaccines under development, a great many of which will hopefully reach the market within the coming 10 years. The development of preventive vaccines against chronic diseases such as AIDS and hepatitis C will probably require more time, due to basic science complexities to be overcome first. It is likely that the future will also see an emphasis on therapeutic vaccines targeted against noninfectious diseases such as cancers (lung, skin, prostate, etc) and metabolic or neurologic diseases (atherosclerosis, Alzheimer's disease). This review will focus on examples of preventive vaccines under development that target infectious diseases with a heavy global burden on public health.
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Reed ZH, Kieny MP, Engers H, Friede M, Chang S, Longacre S, Malhotra P, Pan W, Long C. Comparison of immunogenicity of five MSP1-based malaria vaccine candidate antigens in rabbits. Vaccine 2009; 27:1651-60. [DOI: 10.1016/j.vaccine.2008.10.093] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 10/21/2008] [Accepted: 10/27/2008] [Indexed: 10/21/2022]
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Lategan CA, Campbell WE, Seaman T, Smith PJ. The bioactivity of novel furanoterpenoids isolated from Siphonochilus aethiopicus. JOURNAL OF ETHNOPHARMACOLOGY 2009; 121:92-97. [PMID: 18996179 DOI: 10.1016/j.jep.2008.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 09/12/2008] [Accepted: 10/03/2008] [Indexed: 05/27/2023]
Abstract
AIM OF THE STUDY This study investigated the medicinal plant Siphonochilus aethiopicus (Zingiberaceae) for antiplasmodial activity. MATERIALS AND METHODS The ethyl acetate extract of Siphonochilus aethiopicus rhizomes was fractionated using solid phase extraction (SPE) and purified by high performance liquid chromatography. Structure elucidation was performed with nuclear magnetic resonance and mass spectrometry. The in vitro cytotoxicity and antiplasmodial activity was determined. In vivo schizontocidal activity was performed in a malaria mouse-model. Additional in vitro testing was done against Staphylococcus aureus, Klebsiella pneumoniae and Mycobacterium tuberculosis. RESULTS AND DISCUSSION The ethyl acetate extract showed in vitro activity against the chloroquine-sensitive (CQS) and chloroquine-resistant (CQR) strains of Plasmodium falciparum with IC(50)-values of 2.9 microg/ml and 1.4 microg/ml, respectively. Bioassay-guided fractionation led to the isolation of three novel furanoterpenoids with moderate in vitro antiplasmodial activity. The crude extract showed very good in vivo activity. The compounds and crude extract were more active against the CQR strain than the CQS strain of Plasmodium falciparum. The SPE fractions were more active than the isolated compounds. The compounds did not show good activity against the micro-organisms tested. No in vitro cytotoxicity was observed. CONCLUSION This study provides evidence of antiplasmodial compounds present in Siphonochilus aethiopicus.
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Affiliation(s)
- Carmen A Lategan
- Division of Pharmacology, Department of Medicine, University of Cape Town, K-45 OMB GSH, Observatory 7925, South Africa
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