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Segbefia SP, Asandem DA, Amoah LE, Kusi KA. Cytokine gene polymorphisms implicated in the pathogenesis of Plasmodium falciparum infection outcome. Front Immunol 2024; 15:1285411. [PMID: 38404582 PMCID: PMC10884311 DOI: 10.3389/fimmu.2024.1285411] [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: 08/29/2023] [Accepted: 01/24/2024] [Indexed: 02/27/2024] Open
Abstract
Cytokines play a critical role in the immune mechanisms involved in fighting infections including malaria. Polymorphisms in cytokine genes may affect immune responses during an infection with Plasmodium parasites and immunization outcomes during routine administration of malaria vaccines. These polymorphisms can increase or reduce susceptibility to this deadly infection, and this may affect the physiologically needed balance between anti-inflammatory and pro-inflammatory cytokines. The purpose of this review is to present an overview of the effect of selected cytokine gene polymorphisms on immune responses against malaria.
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Affiliation(s)
- Selorm Philip Segbefia
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- Department of Molecular Medicine, School of Medicine and Dentistry, College of Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Diana Asema Asandem
- Department of Virology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Kwadwo Asamoah Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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Cordeiro MCC, Tomé FD, Arruda FS, da Fonseca SG, Nagib PRA, Celes MRN. Curcumin as a Stabilizer of Macrophage Polarization during Plasmodium Infection. Pharmaceutics 2023; 15:2505. [PMID: 37896265 PMCID: PMC10610200 DOI: 10.3390/pharmaceutics15102505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
Malaria is a parasitic infection responsible for high morbidity and mortality rates worldwide. During the disease, phagocytosis of infected red blood cells by the macrophages induces the production of reactive oxygen (ROS) and nitrogen species (RNS), culminating in parasite death. Curcumin (CUR) is a bioactive compound that has been demonstrated to reduce the production of pro-inflammatory cytokines and chemokines produced by macrophages but to reduce parasitemia in infected mice. Hence, the main purpose of this study is to investigate whether curcumin may interfere with macrophage function and polarization after Plasmodium berghei infection in vitro. In our findings, non-polarized macrophage (M0), classically activated (M1), and alternatively activated (M2) phenotypes showed significantly increased phagocytosis of infected red blood cells (iRBCs) when compared to phagocytosis of uninfected red blood cells (RBCs) 3 h after infection. After 24 h, M1 macrophages exposed to RBCs + CUR showed greater elimination capacity when compared to macrophages exposed to iRBCs + CUR, suggesting the interference of curcumin with the microbicidal activity. Additionally, curcumin increased the phagocytic activity of macrophages when used in non-inflammatory conditions (M0) and reduced the inducible nitric oxide synthase (iNOS) and arginase activities in all macrophage phenotypes infected (M0, M1, and M2), suggesting interference in arginine availability by curcumin and balance promotion in macrophage polarization in neutral phenotype (M0). These results support the view of curcumin treatment in malaria as an adjuvant, promoting a balance between pro- and anti-inflammatory responses for a better clinical outcome.
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Affiliation(s)
- Maria Clara C. Cordeiro
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia 74605-050, GO, Brazil; (M.C.C.C.); (F.D.T.); (F.S.A.); (S.G.d.F.)
| | - Fernanda D. Tomé
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia 74605-050, GO, Brazil; (M.C.C.C.); (F.D.T.); (F.S.A.); (S.G.d.F.)
| | - Felipe S. Arruda
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia 74605-050, GO, Brazil; (M.C.C.C.); (F.D.T.); (F.S.A.); (S.G.d.F.)
| | - Simone Gonçalves da Fonseca
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia 74605-050, GO, Brazil; (M.C.C.C.); (F.D.T.); (F.S.A.); (S.G.d.F.)
| | - Patrícia R. A. Nagib
- Department of Microbiology, Immunology and Parasitology, Biological Science Institute, Federal University of Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil;
| | - Mara R. N. Celes
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia 74605-050, GO, Brazil; (M.C.C.C.); (F.D.T.); (F.S.A.); (S.G.d.F.)
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Tripathi H, Bhalerao P, Singh S, Arya H, Alotaibi BS, Rashid S, Hasan MR, Bhatt TK. Malaria therapeutics: are we close enough? Parasit Vectors 2023; 16:130. [PMID: 37060004 PMCID: PMC10103679 DOI: 10.1186/s13071-023-05755-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/22/2023] [Indexed: 04/16/2023] Open
Abstract
Malaria is a vector-borne parasitic disease caused by the apicomplexan protozoan parasite Plasmodium. Malaria is a significant health problem and the leading cause of socioeconomic losses in developing countries. WHO approved several antimalarials in the last 2 decades, but the growing resistance against the available drugs has worsened the scenario. Drug resistance and diversity among Plasmodium strains hinder the path of eradicating malaria leading to the use of new technologies and strategies to develop effective vaccines and drugs. A timely and accurate diagnosis is crucial for any disease, including malaria. The available diagnostic methods for malaria include microscopy, RDT, PCR, and non-invasive diagnosis. Recently, there have been several developments in detecting malaria, with improvements leading to achieving an accurate, quick, cost-effective, and non-invasive diagnostic tool for malaria. Several vaccine candidates with new methods and antigens are under investigation and moving forward to be considered for clinical trials. This article concisely reviews basic malaria biology, the parasite's life cycle, approved drugs, vaccine candidates, and available diagnostic approaches. It emphasizes new avenues of therapeutics for malaria.
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Affiliation(s)
- Himani Tripathi
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, 305817, Rajasthan, India
| | - Preshita Bhalerao
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, 305817, Rajasthan, India
| | - Sujeet Singh
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, 305817, Rajasthan, India
| | - Hemant Arya
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, 305817, Rajasthan, India.
| | - Bader Saud Alotaibi
- Department of Clinical Laboratory Science, College of Applied Medical Sciences, Alquwayiyah, Shaqra University, Riyadh, 11971, Saudi Arabia
| | - Summya Rashid
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj, 11942, Saudi Arabia
| | - Mohammad Raghibul Hasan
- Department of Clinical Laboratory Science, College of Applied Medical Sciences, Alquwayiyah, Shaqra University, Riyadh, 11971, Saudi Arabia.
| | - Tarun Kumar Bhatt
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, 305817, Rajasthan, India.
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Thomas JJ, Harp KO, Bashi A, Hood JL, Botchway F, Wilson MD, Thompson WE, Stiles JK, Driss A. MiR-451a and let-7i-5p loaded extracellular vesicles attenuate heme-induced inflammation in hiPSC-derived endothelial cells. Front Immunol 2022; 13:1082414. [PMID: 36618355 PMCID: PMC9815029 DOI: 10.3389/fimmu.2022.1082414] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
Hemolysis is associated with many pathologies, including trauma, sepsis, hemorrhagic stroke, malaria, and genetic disorders such as sickle cell disease (SCD). When hemolysis occurs, free-heme drives vascular inflammation, resulting in oxidative tissue damage and cardiometabolic complications. A better understanding of heme clearance and detoxification is essential to preventing sustained tissue damage. Human induced pluripotent stem cell (hiPSC)-derived endothelial cells (hiPSC-ECs) provide a novel source of patient-specific cells and tissues for disease modeling, drug discovery, and regenerative therapeutics. Here we report the use of hiPSC-ECs to elucidate the role of miR-451a and let-7i-5p-loaded extracellular vesicles (EVs, such as exosomes) in the inflammatory response to free-heme as a model for heme-induced inflammation. We provide evidence of a significant correlation between miR-451a and let-7i-5p-loaded circulating exosomes in plasmodium-infected patients with reported clinical benchmarks of malaria-severity (e.g., Hemoglobin (Hb) levels, white blood cell counts). Additionally, we determined that exposure of Plasmodium falciparum (Pf) parasites to EVs, loaded with either miRNA, significantly reduces their counts in vitro. Using hiPSCs derived from individuals with wild-type Hb (HbAA) or homozygous sickle cell mutated Hb (HbSS) genotypes, we demonstrate that heme-treated hiPSC-ECs secreted inflammatory products (cytokines, chemokines and growth factors) into supporting media at concentrations that were similar to that reported in HbAA and HbSS serum. This inflammatory response was attenuated by exposure with miR-451a or let-7i-5p-loaded EVs. We also found a decrease in transcription of ICAM1 and P-Selectin, as well as the secretion of key inflammatory cytokines (e.g., CXCL10, TNF-α, and IFN-γ). Based on these findings, we propose a model in which increased levels of exosomal miR-451a and let-7i-5p in Plasmodium-infected individuals will attenuate inflammatory responses to free-heme and parasite-derived products. As a result, infected erythrocytes will less likely adhere to the endothelium, sequester in brain micro vessels, and reduce vaso-occlusive crises that exacerbate cerebral malaria.
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Affiliation(s)
- Justin J. Thomas
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Keri Oxendine Harp
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Alaijah Bashi
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Joshua L. Hood
- Department of Pharmacology and Toxicology, Brown Cancer Center, Hepatobiology and Toxicology COBRE, University of Louisville School of Medicine, Louisville, KY, United States
| | - Felix Botchway
- Department of Pathology, Korle-Bu Teaching Hospital, University of Ghana Medical School, Accra, Ghana
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Winston E. Thompson
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Jonathan K. Stiles
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Adel Driss
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA, United States,*Correspondence: Adel Driss,
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Kobia FM, Maiti K, Obimbo MM, Smith R, Gitaka J. Potential pharmacologic interventions targeting TLR signaling in placental malaria. Trends Parasitol 2022; 38:513-524. [DOI: 10.1016/j.pt.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 10/18/2022]
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Köllisch G, Solis FV, Obermann HL, Eckert J, Müller T, Vierbuchen T, Rickmeyer T, Muche S, Przyborski JM, Heine H, Kaufmann A, Baumeister S, Lingelbach K, Bauer S. TLR8 is activated by 5'-methylthioinosine, a Plasmodium falciparum-derived intermediate of the purine salvage pathway. Cell Rep 2022; 39:110691. [PMID: 35417716 DOI: 10.1016/j.celrep.2022.110691] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/02/2022] [Accepted: 03/25/2022] [Indexed: 12/31/2022] Open
Abstract
The innate immune recognition of the malaria-causing pathogen Plasmodium falciparum (P. falciparum) is not fully explored. Here, we identify the nucleoside 5'-methylthioinosine (MTI), a Plasmodium-specific intermediate of the purine salvage pathway, as a pathogen-derived Toll-like receptor 8 (TLR8) agonist. Co-incubation of MTI with the TLR8 enhancer poly(dT) as well as synthetic or P. falciparum-derived RNA strongly increase its stimulatory activity. Of note, MTI generated from methylthioadenosine (MTA) by P. falciparum lysates activates TLR8 when MTI metabolism is inhibited by immucillin targeting the purine nucleoside phosphorylase (PfPNP). Importantly, P. falciparum-infected red blood cells incubated with MTI or cultivated with MTA and immucillin lead to TLR8-dependent interleukin-6 (IL-6) production in human monocytes. Our data demonstrate that the nucleoside MTI is a natural human TLR8 ligand with possible in vivo relevance for innate sensing of P. falciparum.
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Affiliation(s)
- Gabriele Köllisch
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | | | - Hannah-Lena Obermann
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany
| | - Jeannine Eckert
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Thomas Müller
- Institute for Medical Microbiology, Immunology und Hygiene, Technical University Munich, Munich, Germany
| | - Tim Vierbuchen
- Division of Innate Immunity, Research Center Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
| | - Thomas Rickmeyer
- Institute for Pharmaceutical Chemistry, Philipps University Marburg, 35043 Marburg, Germany
| | - Simon Muche
- Department of Chemistry, Philipps University Marburg, 35043 Marburg, Germany
| | - Jude M Przyborski
- Department of Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Holger Heine
- Division of Innate Immunity, Research Center Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
| | - Andreas Kaufmann
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany
| | - Stefan Baumeister
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Klaus Lingelbach
- Department of Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | - Stefan Bauer
- Institute for Immunology, Philipps University Marburg, BMFZ, 35043 Marburg, Germany.
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Tintó-Font E, Cortés A. Malaria parasites do respond to heat. Trends Parasitol 2022; 38:435-449. [PMID: 35301987 DOI: 10.1016/j.pt.2022.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 01/09/2023]
Abstract
The capacity of malaria parasites to respond to changes in their environment at the transcriptional level has been the subject of debate, but recent evidence has unambiguously demonstrated that Plasmodium spp. can produce adaptive transcriptional responses when exposed to some specific types of stress. These include metabolic conditions and febrile temperature. The Plasmodium falciparum protective response to thermal stress is similar to the response in other organisms, but it is regulated by a transcription factor evolutionarily unrelated to the conserved transcription factor that drives the heat shock (HS) response in most eukaryotes. Of the many genes that change expression during HS, only a subset constitutes an authentic response that contributes to parasite survival.
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Affiliation(s)
- Elisabet Tintó-Font
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona 08036, Catalonia, Spain
| | - Alfred Cortés
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona 08036, Catalonia, Spain; ICREA, Barcelona 08010, Catalonia, Spain.
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Recent Advances in Understanding the Inflammatory Response in Malaria: A Review of the Dual Role of Cytokines. J Immunol Res 2021; 2021:7785180. [PMID: 34790829 PMCID: PMC8592744 DOI: 10.1155/2021/7785180] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/01/2021] [Accepted: 10/15/2021] [Indexed: 11/25/2022] Open
Abstract
Malaria is a serious and, in some unfortunate cases, fatal disease caused by a parasite of the Plasmodium genus. It predominantly occurs in tropical areas where it is transmitted through the bite of an infected Anopheles mosquito. The pathogenesis of malaria is complex and incompletely elucidated. During blood-stage infection, in response to the presence of the parasite, the host's immune system produces proinflammatory cytokines including IL-6, IL-8, IFN-γ, and TNF, cytokines which play a pivotal role in controlling the growth of the parasite and its elimination. Regulatory cytokines such as transforming growth factor- (TGF-) β and IL-10 maintain the balance between the proinflammatory and anti-inflammatory responses. However, in many cases, cytokines have a double role. On the one hand, they contribute to parasitic clearance, and on the other, they are responsible for pathological changes encountered in malaria. Cytokine-modulating strategies may represent a promising modern approach in disease management. In this review, we discuss the host immune response in malaria, analyzing the latest studies on the roles of pro- and anti-inflammatory cytokines.
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Immunosuppression in Malaria: Do Plasmodium falciparum Parasites Hijack the Host? Pathogens 2021; 10:pathogens10101277. [PMID: 34684226 PMCID: PMC8536967 DOI: 10.3390/pathogens10101277] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/13/2022] Open
Abstract
Malaria reflects not only a state of immune activation, but also a state of general immune defect or immunosuppression, of complex etiology that can last longer than the actual episode. Inhabitants of malaria-endemic regions with lifelong exposure to the parasite show an exhausted or immune regulatory profile compared to non- or minimally exposed subjects. Several studies and experiments to identify and characterize the cause of this malaria-related immunosuppression have shown that malaria suppresses humoral and cellular responses to both homologous (Plasmodium) and heterologous antigens (e.g., vaccines). However, neither the underlying mechanisms nor the relative involvement of different types of immune cells in immunosuppression during malaria is well understood. Moreover, the implication of the parasite during the different stages of the modulation of immunity has not been addressed in detail. There is growing evidence of a role of immune regulators and cellular components in malaria that may lead to immunosuppression that needs further research. In this review, we summarize the current evidence on how malaria parasites may directly and indirectly induce immunosuppression and investigate the potential role of specific cell types, effector molecules and other immunoregulatory factors.
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Bonam SR, Rénia L, Tadepalli G, Bayry J, Kumar HMS. Plasmodium falciparum Malaria Vaccines and Vaccine Adjuvants. Vaccines (Basel) 2021; 9:1072. [PMID: 34696180 PMCID: PMC8541031 DOI: 10.3390/vaccines9101072] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 12/02/2022] Open
Abstract
Malaria-a parasite vector-borne disease-is a global health problem, and Plasmodium falciparum has proven to be the deadliest among Plasmodium spp., which causes malaria in humans. Symptoms of the disease range from mild fever and shivering to hemolytic anemia and neurological dysfunctions. The spread of drug resistance and the absence of effective vaccines has made malaria disease an ever-emerging problem. Although progress has been made in understanding the host response to the parasite, various aspects of its biology in its mammalian host are still unclear. In this context, there is a pressing demand for the development of effective preventive and therapeutic strategies, including new drugs and novel adjuvanted vaccines that elicit protective immunity. The present article provides an overview of the current knowledge of anti-malarial immunity against P. falciparum and different options of vaccine candidates in development. A special emphasis has been made on the mechanism of action of clinically used vaccine adjuvants.
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Affiliation(s)
- Srinivasa Reddy Bonam
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, 8A Biomedical Grove, Singapore 138648, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Ganesh Tadepalli
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
| | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
- Biological Sciences & Engineering, Indian Institute of Technology Palakkad, Palakkad 678623, India
| | - Halmuthur Mahabalarao Sampath Kumar
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
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Pham TT, Lamb TJ, Deroost K, Opdenakker G, Van den Steen PE. Hemozoin in Malarial Complications: More Questions Than Answers. Trends Parasitol 2020; 37:226-239. [PMID: 33223096 DOI: 10.1016/j.pt.2020.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/29/2020] [Accepted: 09/29/2020] [Indexed: 02/07/2023]
Abstract
Plasmodium parasites contain various virulence factors that modulate the host immune response. Malarial pigment, or hemozoin (Hz), is an undegradable crystalline product of the hemoglobin degradation pathway in the parasite and possesses immunomodulatory properties. An association has been found between Hz accumulation and severe malaria, suggesting that the effects of Hz on the host immune response may contribute to the development of malarial complications. Although the immunomodulatory roles of Hz have been widely investigated, many conflicting data exist, likely due to the variability between experimental set-ups and technical limitations of Hz generation and isolation methods. Here, we critically assess the potential immunomodulatory effects of Hz, its role in malarial complications, and its potential effects after parasite clearance.
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Affiliation(s)
- Thao-Thy Pham
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium
| | - Tracey J Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Katrien Deroost
- Malaria Immunology Laboratory, The Francis Crick Institute, London, UK
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium.
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12
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Gao W, Sun X, Li D, Sun L, He Y, Wei H, Jin F, Cao Y. Toll-like receptor 4, Toll-like receptor 7 and Toll-like receptor 9 agonists enhance immune responses against blood-stage Plasmodium chabaudi infection in BALB/c mice. Int Immunopharmacol 2020; 89:107096. [PMID: 33091818 DOI: 10.1016/j.intimp.2020.107096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/09/2020] [Accepted: 10/09/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Toll-like receptor (TLR) signals play vital roles during the blood-stage of malaria infections. However, the roles of TLR agonists in the regulation of immune responses and the development of protective immunity to malaria remain poorly understood. METHOD BALB/c mice were pre-treated with TLR4, TLR7 and TLR9 agonists, followed by infection with Plasmodium chabaudi. After infection, splenic dendritic cells (DCs), Th1 cells and programmed death-1 (PD-1) expressed on Th1 cells, as well as regulatory T cells (Tregs) were analyzed by flow cytometry. The levels of IFN-γ, TNF-α, TGF-β and IL-10 in splenocytes and IgG1 and IgG2a in serum were measured by ELISA. RESULT Administration of TLR4, TLR7 and TLR9 agonists prior to infection improved disease outcomes. All TLR agonists promoted DC activation, and the proportions of Th1 cells increased. In TLR4, TLR7 and TLR9 agonist treated groups the levels of pro-inflammatory cytokines IFN-γ and TNF-α were elevated, and IgG1 and IgG2a serum levels were also significantly increased. TLR4, TLR7 and TLR9 agonists diminished the activation of Tregs and down-regulated the anti-inflammatory cytokines TGF-β and IL-10. Finally, PD-1 expressed on Th1 cells were decreased in TLR4, TLR7 and TLR9 agonist treated groups compared with control groups. CONCLUSION TLR4, TLR7 and TLR9 agonists activated DC-mediated innate immune responses and adaptive immune response, which against the blood-stage of Plasmodium and might be applied to malaria protection and treatment.
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Affiliation(s)
- Wenyan Gao
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China; Department of Obstetrics, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning, China.
| | - Xiaodan Sun
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China
| | - Danni Li
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China
| | - Lin Sun
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China
| | - Yang He
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China
| | - Huanping Wei
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China.
| | - Feng Jin
- Department of Breast Surgery, The First Hospital of China Medical University, Shenyang 110001, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, Basic Medicine College of China Medical University, Shenyang 110122, Liaoning, China.
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Yaman Y, Aymaz R, Keleş M, Bay V, Özüiçli M, Şenlik B. Association between ovine Toll-like receptor 4 ( TLR4) gene coding variants and presence of Eimeria spp. in naturally infected adult Turkish native sheep. Anim Biotechnol 2020; 32:375-380. [PMID: 32967565 DOI: 10.1080/10495398.2020.1824921] [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: 10/23/2022]
Abstract
Coccidiosis caused by Eimeria spp. is a protozoan disease prevalent in farm animals, and it is responsible for serious economic losses especially in young animals. It has been popular to breed disease-resistant animals due to the concern about food safety, animal welfare, and public health. Toll-like receptor (TLR) gene family plays a key role in the innate immune system participating in host-antigen interaction, therefore, they are candidate genes for breeding disease-resistant animals. In the present study, possible genetic associations between TLR4 gene coding variants and the presence of Eimeria spp. in adult Turkish sheep were investigated. For this purpose, the presence of Eimeria spp. in fecal samples from six native Turkish sheep were determined, and approximately 1450 bp region in the 3rd exon of the ovine TLR4 gene was sequenced. Ten nonsynonymous and four synonymous single nucleotide polymorphisms (SNPs) were detected in the targeted region. Statistical analyses revealed that the SNP at the codon at 356th position encoding Leucine instead of Phenylalanine (F356L) was significantly associated with the presence of Eimeria spp. It was found that the individuals carrying at least one Leucine amino acid sequence at this position have 2.3-fold more risk for the presence of Eimeria spp.
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Affiliation(s)
- Yalçın Yaman
- Department of Biometry and Genetics, Sheep Breeding and Research Institute, Bandirma, Turkey
| | - Ramazan Aymaz
- Department of Biometry and Genetics, Sheep Breeding and Research Institute, Bandirma, Turkey
| | - Murat Keleş
- Department of Biometry and Genetics, Sheep Breeding and Research Institute, Bandirma, Turkey
| | - Veysel Bay
- Department of Biometry and Genetics, Sheep Breeding and Research Institute, Bandirma, Turkey
| | - Mehmet Özüiçli
- Veterinary Faculty, Department of Parasitology, Uludag University, Bursa, Turkey
| | - Bayram Şenlik
- Veterinary Faculty, Department of Parasitology, Uludag University, Bursa, Turkey
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14
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Żeromski J, Kierepa A, Brzezicha B, Kowala-Piaskowska A, Mozer-Lisewska I. Pattern Recognition Receptors: Significance of Expression in the Liver. Arch Immunol Ther Exp (Warsz) 2020; 68:29. [PMID: 32944845 PMCID: PMC7498499 DOI: 10.1007/s00005-020-00595-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 09/02/2020] [Indexed: 02/07/2023]
Abstract
Pattern recognition receptors (PRRs) are a pivotal part of the immune system. They are distributed in almost every site of higher organisms, able to recognize foreign pathogens or unwanted remnants of metabolism and mount innate immune response. Moreover, PRRs create bridging signaling to initiate adaptive immunity. The liver being the largest organ of the body, exposed to myriads of foreign substances often being immunogenic, is well equipped with PRRs. They act as sentinels of the organ, both in health and disease. In viral hepatitis C at least two of them, RIG-1 and TLR3 sense HCV, induce protective interferon production and create proinflammatory status. The hepatitis B virus is apparently invisible to PRRs, which has recently been denied. Besides, they are active in the course of infection. In liver injury and hepatic fibrogenesis Toll-like receptors (TLRs), predominantly TLR4, TLR3 and TLR9 are associated with gut microflora-related products and DNA from dying hepatocytes, lead to the activation of hepatic stellate cells. The latter initiate production of fibrillar collagens, the main agents forming hepatic fibrosis. Tumor cells of primary liver cancer also express PRRs, mainly TLRs. In concert with non-resolving liver inflammation, they are considered pivotal factors leading to carcinogenesis.
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Affiliation(s)
- Jan Żeromski
- Chair of Pathomorphology and Clinical Immunology, Karol Marcinkowski University of Medical Sciences, Poznan, Poland.
| | - Agata Kierepa
- Chair and Department of Infectious Diseases, Hepatology and Acquired Immunodeficiencies, Karol Marcinkowski University of Medical Sciences, Poznan, Poland
| | - Bartosz Brzezicha
- Chair of Pathomorphology and Clinical Immunology, Karol Marcinkowski University of Medical Sciences, Poznan, Poland
| | - Arleta Kowala-Piaskowska
- Chair and Department of Infectious Diseases, Hepatology and Acquired Immunodeficiencies, Karol Marcinkowski University of Medical Sciences, Poznan, Poland
| | - Iwona Mozer-Lisewska
- Chair and Department of Infectious Diseases, Hepatology and Acquired Immunodeficiencies, Karol Marcinkowski University of Medical Sciences, Poznan, Poland
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15
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Federico S, Pozzetti L, Papa A, Carullo G, Gemma S, Butini S, Campiani G, Relitti N. Modulation of the Innate Immune Response by Targeting Toll-like Receptors: A Perspective on Their Agonists and Antagonists. J Med Chem 2020; 63:13466-13513. [PMID: 32845153 DOI: 10.1021/acs.jmedchem.0c01049] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Toll-like receptors (TLRs) are a class of proteins that recognize pathogen-associated molecular patterns (PAMPs) and damaged-associated molecular patterns (DAMPs), and they are involved in the regulation of innate immune system. These transmembrane receptors, localized at the cellular or endosomal membrane, trigger inflammatory processes through either myeloid differentiation primary response 88 (MyD88) or TIR-domain-containing adapter-inducing interferon-β (TRIF) signaling pathways. In the last decades, extensive research has been performed on TLR modulators and their therapeutic implication under several pathological conditions, spanning from infections to cancer, from metabolic disorders to neurodegeneration and autoimmune diseases. This Perspective will highlight the recent discoveries in this field, emphasizing the role of TLRs in different diseases and the therapeutic effect of their natural and synthetic modulators, and it will discuss insights for the future exploitation of TLR modulators in human health.
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Affiliation(s)
- Stefano Federico
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Luca Pozzetti
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Alessandro Papa
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Gabriele Carullo
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Sandra Gemma
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Stefania Butini
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Giuseppe Campiani
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
| | - Nicola Relitti
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, via Aldo Moro 2, 53100, Siena, Italy
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16
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Ghartey-Kwansah G, Adu-Nti F, Aboagye B, Ankobil A, Essuman EE, Opoku YK, Abokyi S, Abu EK, Boampong JN. Autophagy in the control and pathogenesis of parasitic infections. Cell Biosci 2020; 10:101. [PMID: 32944216 PMCID: PMC7487832 DOI: 10.1186/s13578-020-00464-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/25/2020] [Indexed: 12/11/2022] Open
Abstract
Background Autophagy has a crucial role in the defense against parasites. The interplay existing between host autophagy and parasites has varied outcomes due to the kind of host cell and microorganism. The presence of autophagic compartments disrupt a significant number of pathogens and are further cleared by xenophagy in an autolysosome. Another section of pathogens have the capacity to outwit the autophagic pathway to their own advantage. Result To comprehend the interaction between pathogens and the host cells, it is significant to distinguish between starvation-induced autophagy and other autophagic pathways. Subversion of host autophagy by parasites is likely due to differences in cellular pathways from those of ‘classical’ autophagy and that they are controlled by parasites in a peculiar way. In xenophagy clearance at the intracellular level, the pathogens are first ubiquitinated before autophagy receptors acknowledgement, followed by labeling with light chain 3 (LC3) protein. The LC3 in LC3-associated phagocytosis (LAP) is added directly into vacuole membrane and functions regardless of the ULK, an initiation complex. The activation of the ULK complex composed of ATG13, FIP200 and ATG101causes the initiation of host autophagic response. Again, the recognition of PAMPs by conserved PRRs marks the first line of defense against pathogens, involving Toll-like receptors (TLRs). These all important immune-related receptors have been reported recently to regulate autophagy. Conclusion In this review, we sum up recent advances in autophagy to acknowledge and understand the interplay between host and parasites, focusing on target proteins for the design of therapeutic drugs. The target host proteins on the initiation of the ULK complex and PRRs-mediated recognition of PAMPs may provide strong potential for the design of therapeutic drugs against parasitic infections.
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Affiliation(s)
- George Ghartey-Kwansah
- Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Frank Adu-Nti
- Department of Medical Laboratory Science, Radford University College, Accra, Ghana
| | - Benjamin Aboagye
- Department of Forensic Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Amandus Ankobil
- School of Nursing and Midwifery, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.,Department of Epidemiology and Biostatistics, State University of New York at Albany, New York, USA
| | - Edward Eyipe Essuman
- US Food and Drugs Administration CBER, OBRR, DETTD 10903 New Hampshire Avenue, White Oak, USA
| | - Yeboah Kwaku Opoku
- Department of Biology Education, Faculty of Science, University of Education, Winneba, Ghana
| | - Samuel Abokyi
- Department of Optometry and Vision Science, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.,School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Emmanuel Kwasi Abu
- Department of Optometry and Vision Science, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Johnson Nyarko Boampong
- Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
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17
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Troye-Blomberg M, Arama C, Quin J, Bujila I, Östlund Farrants AK. What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria? Scand J Immunol 2020; 92:e12932. [PMID: 32652609 PMCID: PMC7583377 DOI: 10.1111/sji.12932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/18/2020] [Accepted: 07/06/2020] [Indexed: 12/27/2022]
Abstract
There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub‐Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide‐treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.
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Affiliation(s)
- Marita Troye-Blomberg
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Charles Arama
- Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, Malaria Research and Training Centre, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Jaclyn Quin
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.,CEITEC Masaryk University, Brno, Czech Republic
| | - Ioana Bujila
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.,Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden
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18
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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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19
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Goodier MR, Wolf AS, Riley EM. Differentiation and adaptation of natural killer cells for anti-malarial immunity. Immunol Rev 2019; 293:25-37. [PMID: 31762040 DOI: 10.1111/imr.12798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/07/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022]
Abstract
Natural killer cells employ a diverse arsenal of effector mechanisms to target intracellular pathogens. Differentiation of natural killer (NK) cell activation pathways occurs along a continuum from reliance on innate pro-inflammatory cytokines and stress-induced host ligands through to interaction with signals derived from acquired immune responses. Importantly, the degree of functional differentiation of the NK cell lineage influences the magnitude and specificity of interactions with host cells infected with viruses, bacteria, fungi, and parasites. Individual humans possess a vast diversity of distinct NK cell clones, each with the capacity to vary along this functional differentiation pathway, which - when combined - results in unique individual responses to different infections. Here we summarize these NK cell differentiation events, review evidence for direct interaction of malaria-infected host cells with NK cells and assess how innate inflammatory signals induced by malaria parasite-associated molecular patterns influence the indirect activation and function of NK cells. Finally, we discuss evidence that anti-malarial immunity develops in parallel with advancing NK differentiation, coincident with a loss of reliance on inflammatory signals, and a refined capacity of NK cells to target malaria parasites more precisely, particularly through antibody-dependent mechanisms.
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Affiliation(s)
- Martin R Goodier
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Asia-Sophia Wolf
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.,Department of Infection and Immunity, University College London, London, UK
| | - Eleanor M Riley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.,The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
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20
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Humoral immunity prevents clinical malaria during Plasmodium relapses without eliminating gametocytes. PLoS Pathog 2019; 15:e1007974. [PMID: 31536608 PMCID: PMC6752766 DOI: 10.1371/journal.ppat.1007974] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 07/10/2019] [Indexed: 12/19/2022] Open
Abstract
Plasmodium relapses are attributed to the activation of dormant liver-stage parasites and are responsible for a significant number of recurring malaria blood-stage infections. While characteristic of human infections caused by P. vivax and P. ovale, their relative contribution to malaria disease burden and transmission remains poorly understood. This is largely because it is difficult to identify ‘bona fide’ relapse infections due to ongoing transmission in most endemic areas. Here, we use the P. cynomolgi–rhesus macaque model of relapsing malaria to demonstrate that clinical immunity can form after a single sporozoite-initiated blood-stage infection and prevent illness during relapses and homologous reinfections. By integrating data from whole blood RNA-sequencing, flow cytometry, P. cynomolgi-specific ELISAs, and opsonic phagocytosis assays, we demonstrate that this immunity is associated with a rapid recall response by memory B cells that expand and produce anti-parasite IgG1 that can mediate parasite clearance of relapsing parasites. The reduction in parasitemia during relapses was mirrored by a reduction in the total number of circulating gametocytes, but importantly, the cumulative proportion of gametocytes increased during relapses. Overall, this study reveals that P. cynomolgi relapse infections can be clinically silent in macaques due to rapid memory B cell responses that help to clear asexual-stage parasites but still carry gametocytes. Plasmodium vivax contributes significantly to global malaria morbidity and remains a major obstacle for malaria elimination due to its ability to form dormant stages in the liver. These forms can become activated to cause relapsing blood-stage infections. Relapses remain poorly understood because it is difficult to verify whether P. vivax blood-stage infections in patients are due to new infections or relapses in most cases. Here, we use a nonhuman primate model of Plasmodium vivax malaria in concert with state-of-the-art immunological and molecular techniques to assess pathogenesis, host responses, and circulating gametocyte levels during relapses. We found that relapses were clinically silent compared to initial infections, and they were associated with a robust memory B cell response. This response resulted in the production of antibodies that were able to mediate clearance of asexual parasites. Despite this rapid immune protection, the sexual-stage gametocytes continued to circulate. Our study provides mechanistic insights into the host-parasite interface during Plasmodium relapse infections and demonstrates that clinically silent relapses can harbor gametocytes that may be infectious to mosquitoes.
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21
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Gut Microbiota Disorder, Gut Epithelial and Blood-Brain Barrier Dysfunctions in Etiopathogenesis of Dementia: Molecular Mechanisms and Signaling Pathways. Neuromolecular Med 2019; 21:205-226. [PMID: 31115795 DOI: 10.1007/s12017-019-08547-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 05/17/2019] [Indexed: 12/12/2022]
Abstract
Emerging evidences indicate a critical role of the gut microbiota in etiopathogenesis of dementia, a debilitating multifactorial disorder characterized by progressive deterioration of cognition and behavior that interferes with the social and professional functions of the sufferer. Available data suggest that gut microbiota disorder that triggers development of dementia is characterized by substantial reduction in specific species belonging to the Firmicutes and Bacteroidetes phyla and presence of pathogenic species, predominantly, pro-inflammatory bacteria of the Proteobacteria phylum. These changes in gut microbiota microecology promote the production of toxic metabolites and pro-inflammatory cytokines, and reduction in beneficial substances such as short chain fatty acids and other anti-inflammatory factors, thereby, enhancing destruction of the gut epithelial barrier with concomitant activation of local and distant immune cells as well as dysregulation of enteric neurons and glia. This subsequently leads to blood-brain barrier dysfunctions that trigger neuroinflammatory reactions and predisposes to apoptotic neuronal and glial cell death, particularly in the hippocampus and cerebral cortex, which underlie the development of dementia. However, the molecular switches that control these processes in the histo-hematic barriers of the gut and brain are not exactly known. This review integrates very recent data on the molecular mechanisms that link gut microbiota disorder to gut epithelial and blood-brain barrier dysfunctions, underlying the development of dementia. The signaling pathways that link gut microbiota disorder with impairment in cognition and behavior are also discussed. The review also highlights potential therapeutic options for dementia.
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22
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Coch C, Hommertgen B, Zillinger T, Daßler-Plenker J, Putschli B, Nastaly M, Kümmerer BM, Scheunemann JF, Schumak B, Specht S, Schlee M, Barchet W, Hoerauf A, Bartok E, Hartmann G. Human TLR8 Senses RNA From Plasmodium falciparum-Infected Red Blood Cells Which Is Uniquely Required for the IFN-γ Response in NK Cells. Front Immunol 2019; 10:371. [PMID: 30972055 PMCID: PMC6445952 DOI: 10.3389/fimmu.2019.00371] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 02/14/2019] [Indexed: 01/03/2023] Open
Abstract
During blood-stage malaria, the innate immune system initiates the production of pro-inflammatory cytokines, including IFN-γ, that are critical to host defense and responsible for severe disease. Nonetheless, the innate immune pathways activated during this process in human malaria remain poorly understood. Here, we identify TLR8 as an essential sensor of Plasmodium falciparum-infected red blood cells (iRBC). In human immune cells, iRBC and RNA purified from iRBC were detected by TLR8 but not TLR7 leading to IFN-γ induction in NK cells. While TLR7 and 9 have been shown to lead to IFN-γ in mice, our data demonstrate that TLR8 was the only TLR capable of inducing IFN-γ release in human immune cells. This unique capacity was mediated by the release of IL-12p70 and bioactive IL-18 from monocytes, the latter via a hitherto undescribed pathway. Altogether, our data are the first reported activation of TLR8 by protozoan RNA and demonstrate both the critical role of TLR8 in human blood-stage malaria and its unique functionality in the human immune system. Moreover, our study offers important evidence that mouse models alone may not be sufficient to describe the human innate immune response to malaria.
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Affiliation(s)
- Christoph Coch
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Benjamin Hommertgen
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Thomas Zillinger
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Juliane Daßler-Plenker
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Bastian Putschli
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Maximilian Nastaly
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | | | - Johanna F Scheunemann
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Beatrix Schumak
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Martin Schlee
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Winfried Barchet
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Achim Hoerauf
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.,Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Eva Bartok
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Gunther Hartmann
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
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23
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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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24
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Welcome MO. Current Perspectives and Mechanisms of Relationship between Intestinal Microbiota Dysfunction and Dementia: A Review. Dement Geriatr Cogn Dis Extra 2018; 8:360-381. [PMID: 30483303 PMCID: PMC6244112 DOI: 10.1159/000492491] [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: 05/04/2018] [Accepted: 07/26/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Accumulating data suggest a crucial role of the intestinal microbiota in the development and progression of neurodegenerative diseases. More recently, emerging reports have revealed an association between intestinal microbiota dysfunctions and dementia, a debilitating multifactorial disorder, characterized by progressive deterioration of cognition and behavior that interferes with the social and professional life of the sufferer. However, the mechanisms of this association are not fully understood. SUMMARY In this review, I discuss recent data that suggest mechanisms of cross-talk between intestinal microbiota dysfunction and the brain that underlie the development of dementia. Potential therapeutic options for dementia are also discussed. The pleiotropic signaling of the metabolic products of the intestinal microbiota together with their specific roles in the maintenance of both the intestinal and blood-brain barriers as well as regulation of local, distant, and circulating immunocytes, and enteric, visceral, and central neural functions are integral to a healthy gut and brain. KEY MESSAGES Research investigating the effect of intestinal microbiota dysfunctions on brain health should focus on multiple interrelated systems involving local and central neuroendocrine, immunocyte, and neural signaling of microbial products and transmitters and neurohumoral cells that not only maintain intestinal, but also blood brain-barrier integrity. The change in intestinal microbiome/dysbiome repertoire is crucial to the development of dementia.
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Affiliation(s)
- Menizibeya O. Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria
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Arama C, Quin JE, Kouriba B, Östlund Farrants AK, Troye-Blomberg M, Doumbo OK. Epigenetics and Malaria Susceptibility/Protection: A Missing Piece of the Puzzle. Front Immunol 2018; 9:1733. [PMID: 30158923 PMCID: PMC6104485 DOI: 10.3389/fimmu.2018.01733] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/12/2018] [Indexed: 12/22/2022] Open
Abstract
A better understanding of stable changes in regulation of gene expression that result from epigenetic events is of great relevance in the development of strategies to prevent and treat infectious diseases. Histone modification and DNA methylation are key epigenetic mechanisms that can be regarded as marks, which ensure an accurate transmission of the chromatin states and gene expression profiles over generations of cells. There is an increasing list of these modifications, and the complexity of their action is just beginning to be understood. It is clear that the epigenetic landscape plays a fundamental role in most biological processes that involve the manipulation and expression of DNA. Although the molecular mechanism of gene regulation is relatively well understood, the hierarchical order of events and dependencies that lead to protection against infection remain largely unknown. In this review, we propose that host epigenetics is an essential, though relatively under studied, factor in the protection or susceptibility to malaria.
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Affiliation(s)
- Charles Arama
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Jaclyn E Quin
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Bourèma Kouriba
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Marita Troye-Blomberg
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Ogobara K Doumbo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
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