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Cao Y, Hayashi CTH, Kumar N. A Novel Ex Vivo Assay to Evaluate Functional Effectiveness of Plasmodium vivax Transmission-Blocking Vaccine Using Pvs25 Transgenic Plasmodium berghei. J Infect Dis 2024; 229:1894-1903. [PMID: 38408353 PMCID: PMC11175679 DOI: 10.1093/infdis/jiae102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/20/2024] [Accepted: 02/22/2024] [Indexed: 02/28/2024] Open
Abstract
BACKGROUND Plasmodium falciparum and Plasmodium vivax account for >90% global malaria burden. Transmission intervention strategies encompassing transmission-blocking vaccines (TBV) and drugs represent ideal public health tools to eliminate malaria at the population level. The availability of mature P. falciparum gametocytes through in vitro culture has facilitated development of a standard membrane feeding assay to assess efficacy of transmission interventions against P. falciparum. The lack of in vitro culture for P. vivax has significantly hampered similar progress on P. vivax and limited studies have been possible using blood from infected patients in endemic areas. The ethical and logistical limitations of on-time access to blood from patients have impeded the development of P. vivax TBVs. METHODS Transgenic murine malaria parasites (Plasmodium berghei) expressing TBV candidates offer a promising alternative for evaluation of P. vivax TBVs through in vivo studies in mice, and ex vivo membrane feeding assay (MFA). RESULTS We describe the development of transmission-competent transgenic TgPbvs25 parasites and optimization of parameters to establish an ex vivo MFA to evaluate P. vivax TBV based on Pvs25 antigen. CONCLUSIONS The MFA is expected to expedite Pvs25-based TBV development without dependence on blood from P. vivax-infected patients in endemic areas for evaluation.
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Affiliation(s)
- Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, District of Columbia, USA
| | - Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, District of Columbia, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, District of Columbia, USA
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Miura K, Flores-Garcia Y, Long CA, Zavala F. Vaccines and monoclonal antibodies: new tools for malaria control. Clin Microbiol Rev 2024; 37:e0007123. [PMID: 38656211 PMCID: PMC11237600 DOI: 10.1128/cmr.00071-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
SUMMARYMalaria remains one of the biggest health problems in the world. While significant reductions in malaria morbidity and mortality had been achieved from 2000 to 2015, the favorable trend has stalled, rather significant increases in malaria cases are seen in multiple areas. In 2022, there were 249 million estimated cases, and 608,000 malaria-related deaths, mostly in infants and children aged under 5 years, globally. Therefore, in addition to the expansion of existing anti-malarial control measures, it is critical to develop new tools, such as vaccines and monoclonal antibodies (mAbs), to fight malaria. In the last 2 years, the first and second malaria vaccines, both targeting Plasmodium falciparum circumsporozoite proteins (PfCSP), have been recommended by the World Health Organization to prevent P. falciparum malaria in children living in moderate to high transmission areas. While the approval of the two malaria vaccines is a considerable milestone in vaccine development, they have much room for improvement in efficacy and durability. In addition to the two approved vaccines, recent clinical trials with mAbs against PfCSP, blood-stage vaccines against P. falciparum or P. vivax, and transmission-blocking vaccine or mAb against P. falciparum have shown promising results. This review summarizes the development of the anti-PfCSP vaccines and mAbs, and recent topics in the blood- and transmission-blocking-stage vaccine candidates and mAbs. We further discuss issues of the current vaccines and the directions for the development of next-generation vaccines.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Malaria Research Institute, Baltimore, Maryland, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Fidel Zavala
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Malaria Research Institute, Baltimore, Maryland, USA
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Kisakov DN, Belyakov IM, Kisakova LA, Yakovlev VA, Tigeeva EV, Karpenko LI. The use of electroporation to deliver DNA-based vaccines. Expert Rev Vaccines 2024; 23:102-123. [PMID: 38063059 DOI: 10.1080/14760584.2023.2292772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023]
Abstract
INTRODUCTION Nucleic acids represent a promising platform for creating vaccines. One disadvantage of this approach is its relatively low immunogenicity. Electroporation (EP) is an effective way to increase the DNA vaccines immunogenicity. However, due to the different configurations of devices used for EP, EP protocols optimization is required not only to enhance immunogenicity, but also to ensure greater safety and tolerability of the EP procedure. AREA COVERED An data analysis for recent years on the DNA vaccines delivery against viral and parasitic infections using EP was carried out. The study of various EP physical characteristics, such as frequency, pulse duration, pulse interval, should be considered along with the immunogenic construct design and the site of delivery of the vaccine, through the study of the immunogenic and protective characteristics of the latter. EXPERT OPINION Future research should focus on regulating the humoral and cellular response required for protection against infectious agents by modifying the EP protocol. Significant efforts will be directed to establishing the possibility of redirecting the immune response toward the Th1 or Th2 response by changing the EP physical parameters. It will allow for an individual selective approach during EP, depending on the pathogen type of an infectious disease.
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Affiliation(s)
- Denis N Kisakov
- Department of bioengineering, State Research Center of Virology and Biotechnology VECTOR, Rospotrebnadzor, Novosibirsk region, Russia
| | - Igor M Belyakov
- Department of medico-biological disciplines, Moscow University for Industry and Finance "Synergy", Moscow, Russia
| | - Lubov A Kisakova
- Department of bioengineering, State Research Center of Virology and Biotechnology VECTOR, Rospotrebnadzor, Novosibirsk region, Russia
| | - Vladimir A Yakovlev
- Department of bioengineering, State Research Center of Virology and Biotechnology VECTOR, Rospotrebnadzor, Novosibirsk region, Russia
| | - Elena V Tigeeva
- Department of bioengineering, State Research Center of Virology and Biotechnology VECTOR, Rospotrebnadzor, Novosibirsk region, Russia
| | - Larisa I Karpenko
- Department of bioengineering, State Research Center of Virology and Biotechnology VECTOR, Rospotrebnadzor, Novosibirsk region, Russia
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Bansal GP, Kumar N. Immune mechanisms targeting malaria transmission: opportunities for vaccine development. Expert Rev Vaccines 2024; 23:645-654. [PMID: 38888098 DOI: 10.1080/14760584.2024.2369583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 06/14/2024] [Indexed: 06/20/2024]
Abstract
INTRODUCTION Malaria continues to remain a major global health problem with nearly a quarter of a billion clinical cases and more than 600,000 deaths in 2022. There has been significant progress toward vaccine development, however, poor efficacy of approved vaccines requiring multiple immunizing doses emphasizes the need for continued efforts toward improved vaccines. Progress to date, nonetheless, has provided impetus for malaria elimination. AREAS COVERED In this review we will focus on diverse immune mechanisms targeting gametocytes in the human host and gametocyte-mediated malaria transmission via the mosquito vector. EXPERT OPINION To march toward the goal of malaria elimination it will be critical to target the process of malaria transmission by mosquitoes, mediated exclusively by the sexual stages, i.e. male, and female gametocytes, ingested from infected vertebrate host. Studies over several decades have established antigens in the parasite sexual stages developing in the mosquito midgut as attractive targets for the development of transmission blocking vaccines (TBVs). Immune clearance of gametocytes in the vertebrate host can synergize with TBVs and directly aid in maintaining effective transmission reducing immune potential.
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Affiliation(s)
- Geetha P Bansal
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Nirbhay Kumar
- Department of Global Health, The Milken Institute School of Public Health, George Washington University, Washington, DC, USA
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Hayashi CTH, Cao Y, Zavala F, Simonyan H, Young CN, Kumar N. Antibodies elicited by Plasmodium falciparum circumsporozoite proteins lacking sequentially deleted C-terminal amino acids reveal mouse strain and epitopes specific differences. Vaccine 2023; 41:6824-6833. [PMID: 37827967 PMCID: PMC11004087 DOI: 10.1016/j.vaccine.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/14/2023]
Abstract
Malaria affects ∼ ¼ billion people globally and requires the development of additional tools to aid in elimination efforts. The recently approved RTS,S/AS01 vaccine represents a positive step, however, the moderate efficacy necessitates the development of more efficacious vaccines. PfCSP is a key target antigen for pre-erythrocytic vaccines aimed at preventing Plasmodium falciparum malaria infections. Epitopes within the central repeat region and at the junction of the repeat and N-terminal domain are well documented as major protective B cell epitopes. On the other hand, a majority of antibodies against the epitopes in the C-terminal domain, have been shown to be non-protective against sporozoite challenge. The C-terminal domain, however, contains CD4+ and CD8+ T cell epitopes previously shown to be important for regulating immune responses. The present study was designed to further explore the immunomodulatory potential of the C-terminal domain using DNA vaccines encoding PfCSP with sequential C-terminal truncations following known T cell epitopes. Five DNA vaccines encoding different truncations of PfCSP within the C-terminal domain were administered via intramuscular route and in vivo electroporation for effective immunogenicity. Protection in mice was evaluated by challenge with transgenic P. berghei expressing PfCSP. In Balb/c mice, antibody responses and protective efficacy were both affected progressively with sequential deletion of C-terminal amino acid residues. Similar studies in C57Bl/6 mice revealed that immunizations with plasmids encoding truncated PfCSP showed partial protection from sporozoite challenge with no significant differences in antibody titers observed compared to full-length PfCSP DNA immunized mice. Further analysis revealed murine strain-specific differences in the recognition of specific epitopes.
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MESH Headings
- Animals
- Protozoan Proteins/immunology
- Protozoan Proteins/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/genetics
- Mice
- Plasmodium falciparum/immunology
- Plasmodium falciparum/genetics
- Antibodies, Protozoan/immunology
- Vaccines, DNA/immunology
- Vaccines, DNA/genetics
- Vaccines, DNA/administration & dosage
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/genetics
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/immunology
- Mice, Inbred BALB C
- Female
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/genetics
- Epitopes/immunology
- Epitopes/genetics
- Sporozoites/immunology
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Affiliation(s)
- Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA
| | - Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21215, USA
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA.
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Malyško-Ptašinskė V, Staigvila G, Novickij V. Invasive and non-invasive electrodes for successful drug and gene delivery in electroporation-based treatments. Front Bioeng Biotechnol 2023; 10:1094968. [PMID: 36727038 PMCID: PMC9885012 DOI: 10.3389/fbioe.2022.1094968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/28/2022] [Indexed: 01/17/2023] Open
Abstract
Electroporation is an effective physical method for irreversible or reversible permeabilization of plasma membranes of biological cells and is typically used for tissue ablation or targeted drug/DNA delivery into living cells. In the context of cancer treatment, full recovery from an electroporation-based procedure is frequently dependent on the spatial distribution/homogeneity of the electric field in the tissue; therefore, the structure of electrodes/applicators plays an important role. This review focuses on the analysis of electrodes and in silico models used for electroporation in cancer treatment and gene therapy. We have reviewed various invasive and non-invasive electrodes; analyzed the spatial electric field distribution using finite element method analysis; evaluated parametric compatibility, and the pros and cons of application; and summarized options for improvement. Additionally, this review highlights the importance of tissue bioimpedance for accurate treatment planning using numerical modeling and the effects of pulse frequency on tissue conductivity and relative permittivity values.
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Affiliation(s)
| | - Gediminas Staigvila
- Faculty of Electronics, Vilnius Gediminas Technical University, Vilnius, Lithuania
| | - Vitalij Novickij
- Faculty of Electronics, Vilnius Gediminas Technical University, Vilnius, Lithuania
- Department of Immunology, State Research Institute Centre of Innovative Medicine, Vilnius, Lithuania
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Hayashi CTH, Cao Y, Clark LC, Tripathi AK, Zavala F, Dwivedi G, Knox J, Alameh MG, Lin PJC, Tam YK, Weissman D, Kumar N. mRNA-LNP expressing PfCSP and Pfs25 vaccine candidates targeting infection and transmission of Plasmodium falciparum. NPJ Vaccines 2022; 7:155. [PMID: 36456563 PMCID: PMC9715627 DOI: 10.1038/s41541-022-00577-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
Malaria is a deadly disease responsible for between 550,000 and 627,000 deaths annually. There is a pressing need to develop vaccines focused on malaria elimination. The complex lifecycle of Plasmodium falciparum provides opportunities not only to target the infectious sporozoite stage, introduced by anopheline mosquitoes, but also the sexual stages, which are ingested by mosquitoes during blood feeding, leading to parasite transmission. It is widely recognized that a vaccine targeting multiple stages would induce efficacious transmission reducing immunity. Technological advancements offer new vaccine platforms, such as mRNA-LNPs, which can be used to develop highly effective malarial vaccines. We evaluated the immunogenicity of two leading P. falciparum vaccine candidates, Pfs25 and PfCSP, delivered as mRNA-LNP vaccines. Both vaccines induced extremely potent immune responses when administered alone or in combination, which were superior to Pfs25 and PfCSP DNA vaccine formulations. Purified IgGs from Pfs25 mRNA-LNPs immunized mice were highly potent in reducing malaria transmission to mosquitoes. Additionally, mice after three and four immunizations with PfCSP mRNA-LNP provided evidence for varying degrees of protection against sporozoite challenge. The comparison of immune responses and stage-specific functional activity induced by each mRNA-LNP vaccine, administered alone or in combination, also supports the development of an effective combination vaccine without any risk of immune interference for targeting malaria parasites at various life cycle stages. A combination of vaccines targeting both the infective stage and sexual/midgut stages is expected to interrupt malaria transmission, which is critical for achieving elimination goals.
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Affiliation(s)
- Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Leor C Clark
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Abhai K Tripathi
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21215, USA
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21215, USA
| | - Garima Dwivedi
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - James Knox
- Department of Pathology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | | | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC, Canada
| | - Drew Weissman
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA.
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