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Sudhakaran G. Artemisinin herbal combo breakers: navigating malaria treatment's double-edged sword. Nat Prod Res 2024:1-3. [PMID: 38824677 DOI: 10.1080/14786419.2024.2358524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 05/16/2024] [Indexed: 06/04/2024]
Abstract
Artemisinin-based combination therapies (ACTs) have transformed malaria treatment, boasting high efficacy and tolerability. However, emerging resistance jeopardises their long-term effectiveness. ACTs' ability to target multiple parasite stages mitigates resistance risks, but severe malaria cases may require additional interventions. Research on combining ACTs with adjunctive therapies shows promise, but optimal regimens remain unclear. Vigilant resistance monitoring and innovative approaches are crucial to sustaining ACT efficacy. We highlight the ACTs' benefits, limitations, and potential synergies, emphasising the urgent need for comprehensive strategies to combat malaria's evolving challenges.
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Affiliation(s)
- Gokul Sudhakaran
- Center for Global Health Research, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Thandalam, Tamil Nadu, India
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2
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Chandley P, Ranjan R, Kumar S, Rohatgi S. Host-parasite interactions during Plasmodium infection: Implications for immunotherapies. Front Immunol 2023; 13:1091961. [PMID: 36685595 PMCID: PMC9845897 DOI: 10.3389/fimmu.2022.1091961] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/12/2022] [Indexed: 01/05/2023] Open
Abstract
Malaria is a global infectious disease that remains a leading cause of morbidity and mortality in the developing world. Multiple environmental and host and parasite factors govern the clinical outcomes of malaria. The host immune response against the Plasmodium parasite is heterogenous and stage-specific both in the human host and mosquito vector. The Plasmodium parasite virulence is predominantly associated with its ability to evade the host's immune response. Despite the availability of drug-based therapies, Plasmodium parasites can acquire drug resistance due to high antigenic variations and allelic polymorphisms. The lack of licensed vaccines against Plasmodium infection necessitates the development of effective, safe and successful therapeutics. To design an effective vaccine, it is important to study the immune evasion strategies and stage-specific Plasmodium proteins, which are targets of the host immune response. This review provides an overview of the host immune defense mechanisms and parasite immune evasion strategies during Plasmodium infection. Furthermore, we also summarize and discuss the current progress in various anti-malarial vaccine approaches, along with antibody-based therapy involving monoclonal antibodies, and research advancements in host-directed therapy, which can together open new avenues for developing novel immunotherapies against malaria infection and transmission.
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Affiliation(s)
- Pankaj Chandley
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ravikant Ranjan
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Sudhir Kumar
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Soma Rohatgi
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India,*Correspondence: Soma Rohatgi,
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3
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Müller K, Gibbins MP, Roberts M, Reyes‐Sandoval A, Hill AVS, Draper SJ, Matuschewski K, Silvie O, Hafalla JCR. Low immunogenicity of malaria pre-erythrocytic stages can be overcome by vaccination. EMBO Mol Med 2021; 13:e13390. [PMID: 33709544 PMCID: PMC8033512 DOI: 10.15252/emmm.202013390] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 11/09/2022] Open
Abstract
Immunogenicity is considered one important criterion for progression of candidate vaccines to further clinical evaluation. We tested this assumption in an infection and vaccination model for malaria pre-erythrocytic stages. We engineered Plasmodium berghei parasites that harbour a well-characterised epitope for stimulation of CD8+ T cells, either as an antigen in the sporozoite surface-expressed circumsporozoite protein or the parasitophorous vacuole membrane associated protein upregulated in sporozoites 4 (UIS4) expressed in exo-erythrocytic forms (EEFs). We show that the antigen origin results in profound differences in immunogenicity with a sporozoite antigen eliciting robust, superior antigen-specific CD8+ T-cell responses, whilst an EEF antigen evokes poor responses. Despite their contrasting immunogenic properties, both sporozoite and EEF antigens gain access to antigen presentation pathways in hepatocytes, as recognition and targeting by vaccine-induced effector CD8+ T cells results in high levels of protection when targeting either antigen. Our study is the first demonstration that poorly immunogenic EEF antigens do not preclude their susceptibility to antigen-specific CD8+ T-cell killing, which has wide-ranging implications on antigen prioritisation for next-generation pre-erythrocytic malaria vaccines.
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Affiliation(s)
- Katja Müller
- Parasitology UnitMax Planck Institute for Infection BiologyBerlinGermany
- Department of Molecular ParasitologyInstitute of BiologyHumboldt UniversityBerlinGermany
| | - Matthew P Gibbins
- Department of Infection BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
- Present address:
Wellcome Centre for Integrative ParasitologyInstitute of Infection, Immunity and InflammationUniversity of GlasgowGlasgowUK
| | - Mark Roberts
- Department of Infection BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
| | - Arturo Reyes‐Sandoval
- Jenner InstituteUniversity of OxfordOxfordUK
- Present address:
Instituto Politécnico NacionalIPN. Av. Luis Enrique Erro s/n, Unidad Adolfo López MateosMexico CityMexico
| | | | | | - Kai Matuschewski
- Parasitology UnitMax Planck Institute for Infection BiologyBerlinGermany
- Department of Molecular ParasitologyInstitute of BiologyHumboldt UniversityBerlinGermany
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies InfectieusesCIMI‐ParisParisFrance
| | - Julius Clemence R Hafalla
- Department of Infection BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
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4
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Kitowski A, Bernardes GJL. A Sweet Galactose Transfer: Metabolic Oligosaccharide Engineering as a Tool To Study Glycans in Plasmodium Infection. Chembiochem 2020; 21:2696-2700. [PMID: 32289201 PMCID: PMC7540713 DOI: 10.1002/cbic.202000226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Indexed: 12/13/2022]
Abstract
The introduction of chemical reporter groups into glycan structures through metabolic oligosaccharide engineering (MOE) followed by bio-orthogonal ligation is an important tool to study glycosylation. We show the incorporation of synthetic galactose derivatives that bear terminal alkene groups in hepatic cells, with and without infection by Plasmodium berghei parasites, the causative agent of malaria. Additionally, we demonstrated the contribution of GLUT1 to the transport of these galactose derivatives, and observed a consistent increase in the uptake of these compounds going from naïve to P. berghei-infected cells. Finally, we used MOE to study the interplay between Plasmodium parasites and their mosquito hosts, to reveal a possible transfer of galactose building blocks from the latter to the former. This strategy has the potential to provide new insights into Plasmodium glycobiology as well as for the identification and characterization of key glycan structures for further vaccine development.
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Affiliation(s)
- Annabel Kitowski
- Instituto de Medicina Molecular João Lobo AntunesFaculdade de MedicinaUniversidade de LisboaAvenida Professor Egas Moniz1649-028LisboaPortugal
| | - Gonçalo J. L. Bernardes
- Instituto de Medicina Molecular João Lobo AntunesFaculdade de MedicinaUniversidade de LisboaAvenida Professor Egas Moniz1649-028LisboaPortugal
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
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5
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Skwarczynski M, Chandrudu S, Rigau-Planella B, Islam MT, Cheong YS, Liu G, Wang X, Toth I, Hussein WM. Progress in the Development of Subunit Vaccines against Malaria. Vaccines (Basel) 2020; 8:vaccines8030373. [PMID: 32664421 PMCID: PMC7563759 DOI: 10.3390/vaccines8030373] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 12/02/2022] Open
Abstract
Malaria is a life-threatening disease and one of the main causes of morbidity and mortality in the human population. The disease also results in a major socio-economic burden. The rapid spread of malaria epidemics in developing countries is exacerbated by the rise in drug-resistant parasites and insecticide-resistant mosquitoes. At present, malaria research is focused mainly on the development of drugs with increased therapeutic effects against Plasmodium parasites. However, a vaccine against the disease is preferable over treatment to achieve long-term control. Trials to develop a safe and effective immunization protocol for the control of malaria have been occurring for decades, and continue on today; still, no effective vaccines are available on the market. Recently, peptide-based vaccines have become an attractive alternative approach. These vaccines utilize short protein fragments to induce immune responses against malaria parasites. Peptide-based vaccines are safer than traditional vaccines, relatively inexpensive to produce, and can be composed of multiple T- and B-cell epitopes integrated into one antigenic formulation. Various combinations, based on antigen choice, peptide epitope modification and delivery mechanism, have resulted in numerous potential malaria vaccines candidates; these are presently being studied in both preclinical and clinical trials. This review describes the current landscape of peptide-based vaccines, and addresses obstacles and opportunities in the production of malaria vaccines.
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Affiliation(s)
- Mariusz Skwarczynski
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Saranya Chandrudu
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Berta Rigau-Planella
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Md. Tanjir Islam
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Yee S. Cheong
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Genan Liu
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Xiumin Wang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
- Correspondence: (I.T.); (W.M.H.)
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- Correspondence: (I.T.); (W.M.H.)
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6
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Leitner WW, Haraway M, Pierson T, Bergmann-Leitner ES. Role of Opsonophagocytosis in Immune Protection against Malaria. Vaccines (Basel) 2020; 8:E264. [PMID: 32486320 PMCID: PMC7350021 DOI: 10.3390/vaccines8020264] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/15/2022] Open
Abstract
The quest for immune correlates of protection continues to slow vaccine development. To date, only vaccine-induced antibodies have been confirmed as direct immune correlates of protection against a plethora of pathogens. Vaccine immunologists, however, have learned through extensive characterizations of humoral responses that the quantitative assessment of antibody responses alone often fails to correlate with protective immunity or vaccine efficacy. Despite these limitations, the simple measurement of post-vaccination antibody titers remains the most widely used approaches for vaccine evaluation. Developing and performing functional assays to assess the biological activity of pathogen-specific responses continues to gain momentum; integrating serological assessments with functional data will ultimately result in the identification of mechanisms that contribute to protective immunity and will guide vaccine development. One of these functional readouts is phagocytosis of antigenic material tagged by immune molecules such as antibodies and/or complement components. This review summarizes our current understanding of how phagocytosis contributes to immune defense against pathogens, the pathways involved, and defense mechanisms that pathogens have evolved to deal with the threat of phagocytic removal and destruction of pathogens.
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Affiliation(s)
- Wolfgang W. Leitner
- Basic Immunology Branch, Division of Allergy, Immunology, and Transplantation/National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852, USA;
| | - Megan Haraway
- Immunology Core/Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (M.H.); (T.P.)
| | - Tony Pierson
- Immunology Core/Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (M.H.); (T.P.)
| | - Elke S. Bergmann-Leitner
- Immunology Core/Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (M.H.); (T.P.)
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7
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Abstract
Parasitic diseases, such as sleeping sickness, Chagas disease and malaria, remain a major cause of morbidity and mortality worldwide, but particularly in tropical, developing countries. Controlling these diseases requires a better understanding of host-parasite interactions, including a deep appreciation of parasite distribution in the host. The preferred accumulation of parasites in some tissues of the host has been known for many years, but recent technical advances have allowed a more systematic analysis and quantifications of such tissue tropisms. The functional consequences of tissue tropism remain poorly studied, although it has been associated with important aspects of disease, including transmission enhancement, treatment failure, relapse and clinical outcome. Here, we discuss current knowledge of tissue tropism in Trypanosoma infections in mammals, describe potential mechanisms of tissue entry, comparatively discuss relevant findings from other parasitology fields where tissue tropism has been extensively investigated, and reflect on new questions raised by recent discoveries and their potential impact on clinical treatment and disease control strategies.
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Affiliation(s)
- Sara Silva Pereira
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa , Lisbon , Portugal
| | - Sandra Trindade
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa , Lisbon , Portugal
| | - Mariana De Niz
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa , Lisbon , Portugal
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa , Lisbon , Portugal
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8
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Abstract
The liver is an immunologically tolerant organ that is uniquely equipped to limit hypersensitivity to food-derived antigens and bacterial products through the portal vein and can feasibly accept liver allografts. The adaptive immune response is a major branch of the immune system that induces organ/tissue-localized and systematic responses against pathogens and tumors while promoting self-tolerance. Persistent infection of the liver with a virus or other pathogen typically results in tolerance, which is a key feature of the liver. The liver's immunosuppressive microenvironment means that hepatic adaptive immune cells become readily tolerogenic, promoting the death of effector cells and the “education” of regulatory cells. The above mechanisms may result in the clonal deletion, exhaustion, or inhibition of peripheral T cells, which are key players in the adaptive immune response. These tolerance mechanisms are believed to be responsible for almost all liver diseases. However, optimal protective adaptive immune responses may be achieved through checkpoint immunotherapy and the modulation of hepatic innate immune cells in the host. In this review, we focus on the mechanisms involved in hepatic adaptive immune tolerance, the liver diseases caused thereby, and the therapeutic strategies needed to overcome this tolerance.
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Affiliation(s)
- Meijuan Zheng
- Department of Clinical Laboratory, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zhigang Tian
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Molecular Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, China.,Institute of Immunology, University of Science and Technology of China, Hefei, China
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9
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Kumar A, Ghosh DK, Ali J, Ranjan A. Characterization of Lipid Binding Properties of Plasmodium falciparum Acyl-Coenzyme A Binding Proteins and Their Competitive Inhibition by Mefloquine. ACS Chem Biol 2019; 14:901-915. [PMID: 30986346 DOI: 10.1021/acschembio.9b00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Malaria remains a worldwide concern in terms of morbidity and mortality. Limited understanding of the Plasmodium proteome makes it challenging to control malaria. Understanding of the expression and functions of different Plasmodium proteins will help in knowing this organism's virulence properties, besides facilitating the drug development process. In this study, we characterize the lipid binding and biophysical properties of the putative Plasmodium falciparum acyl-CoA binding proteins (PfACBPs), which may have intriguing functions in different stages of P. falciparum life cycle. While the PfACBPs can bind to long-chain fatty acyl-CoAs with high affinity, their affinity for short-chain fatty acyl-CoAs is weak. Base-stacking, electrostatic, and hydrophobic interactions between the aromatic rings, charged groups or residues, and hydrophobic chains or residues are responsible for acyl-CoA binding to PfACBPs. PfACBPs can also bind to phospholipids. PfACBPs cannot bind to the fatty acids and unphosphorylated fatty acid esters. PfACBPs are globular-helical proteins that contain a conserved acyl-CoA binding region. They exist in folded or unfolded conformations without attaining any intermediate state. In a systematic high-throughput in silico screening, mefloquine is identified as a potential ligand of PfACBPs. Binding affinities of mefloquine are much higher than those of fatty acyl-CoAs for all PfACBPs. Mefloquine binds to the acyl-CoA binding pocket of PfACBPs, thereby engaging many of the critical residues. Thus, mefloquine acts as a competitive inhibitor against fatty acyl-CoA binding to PfACBPs, leading to the prevention of P. falciparum growth and proliferation. Taken together, our study characterizes the functions of annotated PfACBPs and highlights the mechanistic details of their inactivation by mefloquine.
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Affiliation(s)
- Abhishek Kumar
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Debasish Kumar Ghosh
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Jamshaid Ali
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
- Graduate studies, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
- Rajiv Gandhi Centre for Biotechnology Thiruvananthapuram, Kerala 695014, India
| | - Akash Ranjan
- Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Uppal, Hyderabad, Telangana 500039, India
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10
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Gowda DC, Wu X. Parasite Recognition and Signaling Mechanisms in Innate Immune Responses to Malaria. Front Immunol 2018; 9:3006. [PMID: 30619355 PMCID: PMC6305727 DOI: 10.3389/fimmu.2018.03006] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/05/2018] [Indexed: 12/20/2022] Open
Abstract
Malaria caused by the Plasmodium family of parasites, especially P.falciparum and P. vivax, is a major health problem in many countries in the tropical and subtropical regions of the world. The disease presents a wide array of systemic clinical conditions and several life-threatening organ pathologies, including the dreaded cerebral malaria. Like many other infectious diseases, malaria is an inflammatory response-driven disease, and positive outcomes to infection depend on finely tuned regulation of immune responses that efficiently clear parasites and allow protective immunity to develop. Immune responses initiated by the innate immune system in response to parasites play key roles both in protective immunity development and pathogenesis. Initial pro-inflammatory responses are essential for clearing infection by promoting appropriate cell-mediated and humoral immunity. However, elevated and prolonged pro-inflammatory responses owing to inappropriate cellular programming contribute to disease conditions. A comprehensive knowledge of the molecular and cellular mechanisms that initiate immune responses and how these responses contribute to protective immunity development or pathogenesis is important for developing effective therapeutics and/or a vaccine. Historically, in efforts to develop a vaccine, immunity to malaria was extensively studied in the context of identifying protective humoral responses, targeting proteins involved in parasite invasion or clearance. The innate immune response was thought to be non-specific. However, during the past two decades, there has been a significant progress in understanding the molecular and cellular mechanisms of host-parasite interactions and the associated signaling in immune responses to malaria. Malaria infection occurs at two stages, initially in the liver through the bite of a mosquito, carrying sporozoites, and subsequently, in the blood through the invasion of red blood cells by merozoites released from the infected hepatocytes. Soon after infection, both the liver and blood stage parasites are sensed by various receptors of the host innate immune system resulting in the activation of signaling pathways and production of cytokines and chemokines. These immune responses play crucial roles in clearing parasites and regulating adaptive immunity. Here, we summarize the knowledge on molecular mechanisms that underlie the innate immune responses to malaria infection.
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Affiliation(s)
- D Channe Gowda
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Xianzhu Wu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
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11
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Immune Response and Evasion Mechanisms of Plasmodium falciparum Parasites. J Immunol Res 2018; 2018:6529681. [PMID: 29765991 PMCID: PMC5889876 DOI: 10.1155/2018/6529681] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 01/17/2018] [Accepted: 02/21/2018] [Indexed: 02/07/2023] Open
Abstract
Malaria causes approximately 212 million cases and 429 thousand deaths annually. Plasmodium falciparum is responsible for the vast majority of deaths (99%) than others. The virulence of P. falciparum is mostly associated with immune response-evading ability. It has different mechanisms to evade both Anopheles mosquito and human host immune responses. Immune-evading mechanisms in mosquito depend mainly on the Pfs47 gene that inhibits Janus kinase-mediated activation. Host complement factor also protects human complement immune attack of extracellular gametes in Anopheles mosquito midgut. In the human host, evasion largely results from antigenic variation, polymorphism, and sequestration. They also induce Kupffer cell apoptosis at the preerythrocytic stage and interfere with phagocytic functions of macrophage by hemozoin in the erythrocytic stage. Lack of major histocompatibility complex-I molecule expression on the surface red blood cells also avoids recognition by CD8+ T cells. Complement proteins could allow for the entry of parasite into the red blood cell. Intracellular survival also assists the escape of malarial parasite. Invading, evading, and immune response mechanisms both in malaria vector and human host are critical to design appropriate vaccine. As a result, the receptors and ligands involved in different stages of malaria parasites should be elucidated.
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12
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Mahanta A, Ganguli P, Barah P, Sarkar RR, Sarmah N, Phukan S, Bora M, Baruah S. Integrative Approaches to Understand the Mastery in Manipulation of Host Cytokine Networks by Protozoan Parasites with Emphasis on Plasmodium and Leishmania Species. Front Immunol 2018. [PMID: 29527208 PMCID: PMC5829655 DOI: 10.3389/fimmu.2018.00296] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Diseases by protozoan pathogens pose a significant public health concern, particularly in tropical and subtropical countries, where these are responsible for significant morbidity and mortality. Protozoan pathogens tend to establish chronic infections underscoring their competence at subversion of host immune processes, an important component of disease pathogenesis and of their virulence. Modulation of cytokine and chemokine levels, their crosstalks and downstream signaling pathways, and thereby influencing recruitment and activation of immune cells is crucial to immune evasion and subversion. Many protozoans are now known to secrete effector molecules that actively modulate host immune transcriptome and bring about alterations in host epigenome to alter cytokine levels and signaling. The complexity of multi-dimensional events during interaction of hosts and protozoan parasites ranges from microscopic molecular levels to macroscopic ecological and epidemiological levels that includes disrupting metabolic pathways, cell cycle (Toxoplasma and Theileria sp.), respiratory burst, and antigen presentation (Leishmania spp.) to manipulation of signaling hubs. This requires an integrative systems biology approach to combine the knowledge from all these levels to identify the complex mechanisms of protozoan evolution via immune escape during host-parasite coevolution. Considering the diversity of protozoan parasites, in this review, we have focused on Leishmania and Plasmodium infections. Along with the biological understanding, we further elucidate the current efforts in generating, integrating, and modeling of multi-dimensional data to explain the modulation of cytokine networks by these two protozoan parasites to achieve their persistence in host via immune escape during host-parasite coevolution.
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Affiliation(s)
- Anusree Mahanta
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India.,Institute of Stem Cell Biology and Regenerative Medicine, Bengaluru, India
| | - Piyali Ganguli
- Chemical Engineering and Process Development, CSIR- National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune, India
| | - Pankaj Barah
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Ram Rup Sarkar
- Chemical Engineering and Process Development, CSIR- National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune, India
| | - Neelanjana Sarmah
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Saurav Phukan
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Mayuri Bora
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
| | - Shashi Baruah
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, India
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13
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Moris P, Jongert E, van der Most RG. Characterization of T-cell immune responses in clinical trials of the candidate RTS,S malaria vaccine. Hum Vaccin Immunother 2017; 14:17-27. [PMID: 28934066 PMCID: PMC5791571 DOI: 10.1080/21645515.2017.1381809] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The candidate malaria vaccine RTS,S has demonstrated 45.7% efficacy over 18 months against all clinical disease in a phase-III field study of African children. RTS,S targets the circumsporozoite protein (CSP), which is expressed on the Plasmodium sporozoite during the pre-erythrocyte stage of its life-cycle; the stage between mosquito bite and liver infection. Early in the development of RTS,S, it was recognized that CSP-specific cell-mediated immunity (CMI) was required to complement CSP-specific antibody-mediated immunity. In reviewing RTS,S clinical studies, associations between protection and various types of CMI (CSP-specific CD4+ T cells and INF-γ ELISPOTs) have been identified, but not consistently. It is plausible that certain CD4+ T cells support antibody responses or co-operate with other immune-cell types to potentially elicit protection. However, the identities of vaccine correlates of protection, implicating either CSP-specific antibodies or T cells remain elusive, suggesting that RTS,S clinical trials may benefit from additional immunogenicity analyses that can be informed by the results of controlled human malaria infection studies.
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14
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van Wolfswinkel ME, Langenberg MCC, Wammes LJ, Sauerwein RW, Koelewijn R, Hermsen CC, van Hellemond JJ, van Genderen PJ. Changes in total and differential leukocyte counts during the clinically silent liver phase in a controlled human malaria infection in malaria-naïve Dutch volunteers. Malar J 2017; 16:457. [PMID: 29126422 PMCID: PMC5681833 DOI: 10.1186/s12936-017-2108-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/04/2017] [Indexed: 11/25/2022] Open
Abstract
Background Both in endemic countries and in imported malaria, changes in total and differential leukocyte count during Plasmodium falciparum infection have been described. To study the exact dynamics of differential leukocyte counts and their ratios, they were monitored in a group of healthy non-immune volunteers in two separate Controlled Human Malaria Infection (CHMI) studies. Methods In two CHMI trials, CHMI-a and CHMI-b, 15 and 24 healthy malaria-naïve volunteers, respectively, were exposed to bites of infected mosquitoes, using the P. falciparum research strain NF54 and the novel clones NF135.C10 and NF166.C8. After mosquito bite exposure, twice-daily blood draws were taken to detect parasitaemia and to monitor the total and differential leukocyte counts. All subjects received a course of atovaquone–proguanil when meeting the treatment criteria. Results A total of 39 volunteers participated in the two trials. Thirty-five participants, all 15 participants in CHMI-a and 20 of the 24 volunteers in CHMI-b, developed parasitaemia. During liver stage development of the parasite, the median total leukocyte count increased from 5.5 to 6.1 × 109 leukocytes/L (p = 0.005), the median lymphocyte count from 1.9 to 2.2 (p = 0.001) and the monocyte count from 0.50 to 0.54 (p = 0.038). During the subsequent blood stage infection, significant changes in total and differential leukocyte counts lead to a leukocytopenia (nadir median 3.3 × 109 leukocytes/L, p = 0.0001), lymphocytopenia (nadir median 0.7 × 109 lymphocytes/L, p = 0.0001) and a borderline neutropenia (nadir median 1.5 × 109 neutrophils/L, p = 0.0001). The neutrophil to lymphocyte count ratio (NLCR) reached a maximum of 4.0. Significant correlations were found between parasite load and absolute lymphocyte count (p < 0.001, correlation coefficient − 0.46) and between parasite load and NLCR (p < 0.001, correlation coefficient 0.50). All parameters normalized after parasite clearance. Conclusions During the clinically silent liver phase of malaria, an increase of peripheral total leukocyte count and differential lymphocytes and monocytes occurs. This finding has not been described previously. This increase is followed by the appearance of parasites in the peripheral blood after 2–3 days, accompanied by a marked decrease in total leukocyte count, lymphocyte count and the neutrophil count and a rise of the NLCR. Electronic supplementary material The online version of this article (10.1186/s12936-017-2108-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marlies E van Wolfswinkel
- Institute for Tropical Diseases, Harbour Hospital, Rotterdam, The Netherlands. .,Department of Medical Microbiology and Infectious Diseases, Erasmus MC and Harbour Hospital, Rotterdam, The Netherlands.
| | - Marijke C C Langenberg
- Institute for Tropical Diseases, Harbour Hospital, Rotterdam, The Netherlands.,Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Linda J Wammes
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC and Harbour Hospital, Rotterdam, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob Koelewijn
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC and Harbour Hospital, Rotterdam, The Netherlands
| | - Cornelus C Hermsen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jaap J van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC and Harbour Hospital, Rotterdam, The Netherlands
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15
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Delayed fractional dose regimen of the RTS,S/AS01 malaria vaccine candidate enhances an IgG4 response that inhibits serum opsonophagocytosis. Sci Rep 2017; 7:7998. [PMID: 28801554 PMCID: PMC5554171 DOI: 10.1038/s41598-017-08526-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/10/2017] [Indexed: 01/19/2023] Open
Abstract
A recent study of the RTS,S malaria vaccine, which is based on the circumsporozoite protein (CSP), demonstrated an increase in efficacy from 50–60% to 80% when using a delayed fractional dose regimen, in which the standard 0–1–2 month immunization schedule was modified to a 0–1–7 month schedule and the third immunization was delivered at 20% of the full dose. Given the role that antibodies can play in RTS,S-induced protection, we sought to determine how the modified regimen alters IgG subclasses and serum opsonophagocytic activity (OPA). Previously, we showed that lower CSP-mediated OPA was associated with protection in an RTS,S study. Here we report that the delayed fractional dose regimen resulted in decreased CSP-mediated OPA and an enhanced CSP-specific IgG4 response. Linear regression modeling predicted that CSP-specific IgG1 promote OPA, and that CSP-specific IgG4 interferes with OPA, which we subsequently confirmed by IgG subclass depletion. Although the role of IgG4 antibodies and OPA in protection is still unclear, our findings, combined with previous results that the delayed fractional dose increases CSP-specific antibody avidity and somatic hypermutation frequency in CSP-specific B cells, demonstrate how changes in vaccine regimen alone can significantly alter the quality of antibody responses to improve vaccine efficacy.
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16
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Abstract
Complications arising from malaria are a concern for public health authorities worldwide, since the annual caseload in humans usually exceeds millions. Of more than 160 species of Plasmodium, only 4 infect humans, with the most severe cases ascribed to Plasmodium falciparum and the most prevalent to Plasmodium vivax. Over the past 70 years, since World War II, when the first antimalarial drugs were widely used, many efforts have been made to combat this disease, including vectorial control, new drug discoveries and genetic and molecular approaches. Molecular approaches, such as glycobiology, may lead to new therapeutic targets (both in the host and the parasites), since all interactions are mediated by carbohydrates or glycan moieties decorating both cellular surfaces from parasite and host cells. In this review, we address the carbohydrate-mediated glycobiology that directly affects Plasmodium survival or host resistance.
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Affiliation(s)
- Pollyanna S Gomes
- Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Daniel F Feijó
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz)Salvador, Brazil
| | - Alexandre Morrot
- Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil.,Instituto Oswaldo CruzFiocruz, Rio de Janeiro, Brazil
| | - Celio G Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
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17
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Fonseca JA, McCaffery JN, Kashentseva E, Singh B, Dmitriev IP, Curiel DT, Moreno A. A prime-boost immunization regimen based on a simian adenovirus 36 vectored multi-stage malaria vaccine induces protective immunity in mice. Vaccine 2017; 35:3239-3248. [PMID: 28483199 PMCID: PMC5522619 DOI: 10.1016/j.vaccine.2017.04.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/22/2022]
Abstract
Malaria remains a considerable burden on public health. In 2015, the WHO estimates there were 212 million malaria cases causing nearly 429,000 deaths globally. A highly effective malaria vaccine is needed to reduce the burden of this disease. We have developed an experimental vaccine candidate (PyCMP) based on pre-erythrocytic (CSP) and erythrocytic (MSP1) stage antigens derived from the rodent malaria parasite P. yoelii. Our protein-based vaccine construct induces protective antibodies and CD4+ T cell responses. Based on evidence that viral vectors increase CD8+ T cell-mediated immunity, we also have tested heterologous prime-boost immunization regimens that included human adenovirus serotype 5 vector (Ad5), obtaining protective CD8+ T cell responses. While Ad5 is commonly used for vaccine studies, the high prevalence of pre-existing immunity to Ad5 severely compromises its utility. Here, we report the use of the novel simian adenovirus 36 (SAd36) as a candidate for a vectored malaria vaccine since this virus is not known to infect humans, and it is not neutralized by anti-Ad5 antibodies. Our study shows that the recombinant SAd36PyCMP can enhance specific CD8+ T cell response and elicit similar antibody titers when compared to an immunization regimen including the recombinant Ad5PyCMP. The robust immune responses induced by SAd36PyCMP are translated into a lower parasite load following P. yoelii infectious challenge when compared to mice immunized with Ad5PyCMP.
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Affiliation(s)
- Jairo A Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307, United States
| | - Jessica N McCaffery
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States
| | - Elena Kashentseva
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States
| | - Igor P Dmitriev
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - David T Curiel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307, United States.
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18
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Silva-Barrios S, Stäger S. Protozoan Parasites and Type I IFNs. Front Immunol 2017; 8:14. [PMID: 28154565 PMCID: PMC5243830 DOI: 10.3389/fimmu.2017.00014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 01/05/2017] [Indexed: 12/16/2022] Open
Abstract
For many years, the role of interferon (IFN)-I has been characterized primarily in the context of viral infections. However, regulatory functions mediated by IFN-I have also been described against bacterial infections and in tumor immunology. Only recently, the interest in understanding the immune functions mediated by IFN-I has dramatically increased in the field of protozoan infections. In this review, we discuss the discrete role of IFN-I in the immune response against major protozoan infections: Plasmodium, Leishmania, Trypanosoma, and Toxoplasma.
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Affiliation(s)
- Sasha Silva-Barrios
- INRS-Institut Armand Frappier, Center for Host-Parasite Interactions , Laval, QC , Canada
| | - Simona Stäger
- INRS-Institut Armand Frappier, Center for Host-Parasite Interactions , Laval, QC , Canada
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19
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Spencer AJ, Longley RJ, Gola A, Ulaszewska M, Lambe T, Hill AVS. The Threshold of Protection from Liver-Stage Malaria Relies on a Fine Balance between the Number of Infected Hepatocytes and Effector CD8 + T Cells Present in the Liver. THE JOURNAL OF IMMUNOLOGY 2017; 198:2006-2016. [PMID: 28087668 PMCID: PMC5318841 DOI: 10.4049/jimmunol.1601209] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/16/2016] [Indexed: 12/20/2022]
Abstract
Since the demonstration of sterile protection afforded by injection of irradiated sporozoites, CD8+ T cells have been shown to play a significant role in protection from liver-stage malaria. This is, however, dependent on the presence of an extremely high number of circulating effector cells, thought to be necessary to scan, locate, and kill infected hepatocytes in the short time that parasites are present in the liver. We used an adoptive transfer model to elucidate the kinetics of the effector CD8+ T cell response in the liver following Plasmodium berghei sporozoite challenge. Although effector CD8+ T cells require <24 h to find, locate, and kill infected hepatocytes, active migration of Ag-specific CD8+ T cells into the liver was not observed during the 2-d liver stage of infection, as divided cells were only detected from day 3 postchallenge. However, the percentage of donor cells recruited into division was shown to indicate the level of Ag presentation from infected hepatocytes. By titrating the number of transferred Ag-specific effector CD8+ T cells and sporozoites, we demonstrate that achieving protection toward liver-stage malaria is reliant on CD8+ T cells being able to locate infected hepatocytes, resulting in a protection threshold dependent on a fine balance between the number of infected hepatocytes and CD8+ T cells present in the liver. With such a fine balance determining protection, achieving a high number of CD8+ T cells will be critical to the success of a cell-mediated vaccine against liver-stage malaria.
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Affiliation(s)
| | - Rhea J Longley
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Anita Gola
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Marta Ulaszewska
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Teresa Lambe
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Adrian V S Hill
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
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21
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A Proteomic Investigation of Hepatic Resistance to Ascaris in a Murine Model. PLoS Negl Trop Dis 2016; 10:e0004837. [PMID: 27490109 PMCID: PMC4974003 DOI: 10.1371/journal.pntd.0004837] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/20/2016] [Indexed: 12/15/2022] Open
Abstract
The helminth Ascaris causes ascariasis in both humans and pigs. Humans, especially children, experience significant morbidity including respiratory complications, growth deficits and intestinal obstruction. Given that 800 million people worldwide are infected by Ascaris, this represents a significant global public health concern. The severity of the symptoms and associated morbidity are related to the parasite burden and not all hosts are infected equally. While the pathology of the disease has been extensively examined, our understanding of the molecular mechanisms underlying resistance and susceptibility to this nematode infection is poor. In order to investigate host differences associated with heavy and light parasite burden, an experimental murine model was developed utilising Ascaris-susceptible and -resistant mice strains, C57BL/6J and CBA/Ca, respectively, which experience differential burdens of migratory Ascaris larvae in the host lungs. Previous studies identified the liver as the site where this difference in susceptibility occurs. Using a label free quantitative proteomic approach, we analysed the hepatic proteomes of day four post infection C57BL/6J and CBA/Ca mice with and without Ascaris infection to identify proteins changes potentially linked to both resistance and susceptibility amongst the two strains, respectively. Over 3000 proteins were identified in total and clear intrinsic differences were elucidated between the two strains. These included a higher abundance of mitochondrial proteins, particularly those associated with the oxidative phosphorylation pathway and reactive oxygen species (ROS) production in the relatively resistant CBA/Ca mice. We hypothesise that the increased ROS levels associated with higher levels of mitochondrial activity results in a highly oxidative cellular environment that has a dramatic effect on the nematode’s ability to successfully sustain a parasitic association with its resistant host. Under infection, both strains had increased abundances in proteins associated with the oxidative phosphorylation pathway, as well as the tricarboxylic acid cycle, with respect to their controls, indicating a general stress response to Ascaris infection. Despite the early stage of infection, some immune-associated proteins were identified to be differentially abundant, providing a novel insight into the host response to Ascaris. In general, the susceptible C57BL/6J mice displayed higher abundances in immune-associated proteins, most likely signifying a more active nematode cohort with respect to their CBA/Ca counterparts. The complement component C8a and S100 proteins, S100a8 and S100a9, were highly differentially abundant in both infected strains, signifying a potential innate immune response and the importance of the complement pathway in defence against macroparasite infection. In addition, the signatures of an early adaptive immune response were observed through the presence of proteins, such as plastin-2 and dipeptidyl peptidase 1. A marked decrease in proteins associated with translation was also observed in both C57BL/6J and CBA/Ca mice under infection, indicative of either a general response to Ascaris or a modulatory effect by the nematode itself. Our research provides novel insights into the in vivo host-Ascaris relationship on the molecular level and provides new research perspectives in the development of Ascaris control and treatment strategies. Ascaris infection is a significant burden on the people who live in developing countries with infection being linked to poor hygiene and low socio-economic status. The parasite causes a range of symptoms, especially in children, which include both chronic morbidity, such as growth retardation, and acute outcomes, such as intestinal obstruction. Certain people tend to be more heavily infected than others, with those individuals experiencing worse morbidity. The understanding of the difference between susceptible and resistant people is an essential first step in the development of new therapies in order to eliminate this neglected parasitic disease. Using an established mouse model involving a susceptible and resistant strain, we aimed to gain insight into the host-Ascaris interaction at the hepatic interface and elucidate some of the molecular mechanisms potentially involved in resistance. A number of key intrinsic differences were determined between both strains including major differences in mitochondrial and ROS associated processes which may present the nematodes with differing oxidative conditions and explain the failure of the nematode to establish a successful parasitism in the resistant strain. In addition, we resolved signatures of the innate and early adaptive immune response and a major reduction in the proteins associated with translation in both strains under infection. Our findings need to be further explored, but could be the foundation for a better understanding of the mechanisms behind the differential parasite burden and in the future, potential new therapies for control.
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22
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Al-Quraishy SA, Dkhil MA, Abdel-Baki AAA, Delic D, Wunderlich F. Protective Vaccination against Blood-Stage Malaria of Plasmodium chabaudi: Differential Gene Expression in the Liver of Balb/c Mice toward the End of Crisis Phase. Front Microbiol 2016; 7:1087. [PMID: 27471498 PMCID: PMC4943960 DOI: 10.3389/fmicb.2016.01087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/29/2016] [Indexed: 01/16/2023] Open
Abstract
Protective vaccination induces self-healing of otherwise fatal blood-stage malaria of Plasmodium chabaudi in female Balb/c mice. To trace processes critically involved in self-healing, the liver, an effector against blood-stage malaria, is analyzed for possible changes of its transcriptome in vaccination-protected in comparison to non-protected mice toward the end of the crisis phase. Gene expression microarray analyses reveal that vaccination does not affect constitutive expression of mRNA and lincRNA. However, malaria induces significant (p < 0.01) differences in hepatic gene and lincRNA expression in vaccination-protected vs. non-vaccinated mice toward the end of crisis phase. In vaccination-protected mice, infections induce up-regulations of 276 genes and 40 lincRNAs and down-regulations of 200 genes and 43 lincRNAs, respectively, by >3-fold as compared to the corresponding constitutive expressions. Massive up-regulations, partly by >100-fold, are found for genes as RhD, Add2, Ank1, Ermap, and Slc4a, which encode proteins of erythrocytic surface membranes, and as Gata1 and Gfi1b, which encode transcription factors involved in erythrocytic development. Also, Cldn13 previously predicted to be expressed on erythroblast surfaces is up-regulated by >200-fold, though claudins are known as main constituents of tight junctions acting as paracellular barriers between epithelial cells. Other genes are up-regulated by <100- and >10-fold, which can be subgrouped in genes encoding proteins known to be involved in mitosis, in cell cycle regulation, and in DNA repair. Our data suggest that protective vaccination enables the liver to respond to P. chabaudi infections with accelerated regeneration and extramedullary erythropoiesis during crisis, which contributes to survival of otherwise lethal blood-stage malaria.
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Affiliation(s)
- Saleh A Al-Quraishy
- Department of Zoology, College of Science, King Saud University Riyadh, Saudi Arabia
| | - Mohamed A Dkhil
- Department of Zoology, College of Science, King Saud UniversityRiyadh, Saudi Arabia; Department of Zoology and Entomology, Faculty of Science, Helwan UniversityCairo, Egypt
| | - Abdel-Azeem A Abdel-Baki
- Department of Zoology, College of Science, King Saud UniversityRiyadh, Saudi Arabia; Department of Zoology, Faculty of Science, Beni-Suef UniversityBeni-Suef, Egypt
| | - Denis Delic
- Boehringer-Ingelheim Pharma Biberach, Germany
| | - Frank Wunderlich
- Department of Biology, Heinrich-Heine-University Duesseldorf, Germany
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23
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Fonseca JA, Cabrera-Mora M, Kashentseva EA, Villegas JP, Fernandez A, Van Pelt A, Dmitriev IP, Curiel DT, Moreno A. A Plasmodium Promiscuous T Cell Epitope Delivered within the Ad5 Hexon Protein Enhances the Protective Efficacy of a Protein Based Malaria Vaccine. PLoS One 2016; 11:e0154819. [PMID: 27128437 PMCID: PMC4851317 DOI: 10.1371/journal.pone.0154819] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/19/2016] [Indexed: 12/20/2022] Open
Abstract
A malaria vaccine is a public health priority. In order to produce an effective vaccine, a multistage approach targeting both the blood and the liver stage infection is desirable. The vaccine candidates also need to induce balanced immune responses including antibodies, CD4+ and CD8+ T cells. Protein-based subunit vaccines like RTS,S are able to induce strong antibody response but poor cellular reactivity. Adenoviral vectors have been effective inducing protective CD8+ T cell responses in several models including malaria; nonetheless this vaccine platform exhibits a limited induction of humoral immune responses. Two approaches have been used to improve the humoral immunogenicity of recombinant adenovirus vectors, the use of heterologous prime-boost regimens with recombinant proteins or the genetic modification of the hypervariable regions (HVR) of the capsid protein hexon to express B cell epitopes of interest. In this study, we describe the development of capsid modified Ad5 vectors that express a promiscuous Plasmodium yoelii T helper epitope denominated PyT53 within the hexon HVR2 region. Several regimens were tested in mice to determine the relevance of the hexon modification in enhancing protective immune responses induced by the previously described protein-based multi-stage experimental vaccine PyCMP. A heterologous prime-boost immunization regime that combines a hexon modified vector with transgenic expression of PyCMP followed by protein immunizations resulted in the induction of robust antibody and cellular immune responses in comparison to a similar regimen that includes a vector with unmodified hexon. These differences in immunogenicity translated into a better protective efficacy against both the hepatic and red blood cell stages of P. yoelii. To our knowledge, this is the first time that a hexon modification is used to deliver a promiscuous T cell epitope. Our data support the use of such modification to enhance the immunogenicity and protective efficacy of adenoviral based malaria vaccines.
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Affiliation(s)
- Jairo Andres Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Elena A. Kashentseva
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - John Paul Villegas
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Alejandra Fernandez
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Amelia Van Pelt
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Igor P. Dmitriev
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - David T. Curiel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
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Frevert U, Krzych U, Richie TL. Editorial: Breaking the cycle: attacking the malaria parasite in the liver. Front Microbiol 2015; 6:810. [PMID: 26300873 PMCID: PMC4528169 DOI: 10.3389/fmicb.2015.00810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 07/22/2015] [Indexed: 01/29/2023] Open
Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine New York, NY, USA
| | - Urszula Krzych
- Cellular Immunology, Walter Reed Army Institute of Research Silver Spring, MD, USA
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25
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Frevert U, Krzych U. Plasmodium cellular effector mechanisms and the hepatic microenvironment. Front Microbiol 2015; 6:482. [PMID: 26074888 PMCID: PMC4445044 DOI: 10.3389/fmicb.2015.00482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/01/2015] [Indexed: 12/23/2022] Open
Abstract
Plasmodium falciparum malaria remains one of the most serious health problems globally. Immunization with attenuated parasites elicits multiple cellular effector mechanisms capable of eliminating Plasmodium liver stages. However, malaria liver stage (LS) immunity is complex and the mechanisms effector T cells use to locate the few infected hepatocytes in the large liver in order to kill the intracellular LS parasites remain a mystery to date. Here, we review our current knowledge on the behavior of CD8 effector T cells in the hepatic microvasculature, in malaria and other hepatic infections. Taking into account the unique immunological and lymphogenic properties of the liver, we discuss whether classical granule-mediated cytotoxicity might eliminate infected hepatocytes via direct cell contact or whether cytokines might operate without cell–cell contact and kill Plasmodium LSs at a distance. A thorough understanding of the cellular effector mechanisms that lead to parasite death hence sterile protection is a prerequisite for the development of a successful malaria vaccine to protect the 40% of the world’s population currently at risk of Plasmodium infection.
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Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine , New York, NY, USA
| | - Urszula Krzych
- Division of Malaria Vaccine Development, Department of Cellular Immunology, Walter Reed Army Institute of Research , Silver Spring, MD, USA
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