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Diffendall G, Claes A, Barcons-Simon A, Nyarko P, Dingli F, Santos MM, Loew D, Claessens A, Scherf A. RNA polymerase III is involved in regulating Plasmodium falciparum virulence. eLife 2024; 13:RP95879. [PMID: 38921824 DOI: 10.7554/elife.95879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024] Open
Abstract
While often undetected and untreated, persistent seasonal asymptomatic malaria infections remain a global public health problem. Despite the presence of parasites in the peripheral blood, no symptoms develop. Disease severity is correlated with the levels of infected red blood cells (iRBCs) adhering within blood vessels. Changes in iRBC adhesion capacity have been linked to seasonal asymptomatic malaria infections, however how this is occurring is still unknown. Here, we present evidence that RNA polymerase III (RNA Pol III) transcription in Plasmodium falciparum is downregulated in field isolates obtained from asymptomatic individuals during the dry season. Through experiments with in vitro cultured parasites, we have uncovered an RNA Pol III-dependent mechanism that controls pathogen proliferation and expression of a major virulence factor in response to external stimuli. Our findings establish a connection between P. falciparum cytoadhesion and a non-coding RNA family transcribed by Pol III. Additionally, we have identified P. falciparum Maf1 as a pivotal regulator of Pol III transcription, both for maintaining cellular homeostasis and for responding adaptively to external signals. These results introduce a novel perspective that contributes to our understanding of P. falciparum virulence. Furthermore, they establish a connection between this regulatory process and the occurrence of seasonal asymptomatic malaria infections.
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Affiliation(s)
- Gretchen Diffendall
- Institut Pasteur, Universite Paris Cité, Paris, France
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du Vivant, Paris, France
| | - Aurelie Claes
- Institut Pasteur, Universite Paris Cité, Paris, France
| | - Anna Barcons-Simon
- Institut Pasteur, Universite Paris Cité, Paris, France
- Institut Pasteur, Sorbonne Université Ecole doctorale Complexité du Vivant, Paris, France
- Institut Pasteur, Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Prince Nyarko
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of Montpellier, Montpellier, France
| | - Florent Dingli
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Miguel M Santos
- Institut Pasteur, Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Damarys Loew
- Institut Pasteur, Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Antoine Claessens
- Institut Pasteur, Laboratory of Pathogen-Host Interaction (LPHI), CNRS, University of Montpellier, Montpellier, France
- Institut Pasteur, LPHI, MIVEGEC, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Artur Scherf
- Institut Pasteur, Universite Paris Cité, Paris, France
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Diffendall G, Scherf A. Deciphering the Plasmodium falciparum perinuclear var gene expression site. Trends Parasitol 2024:S1471-4922(24)00142-9. [PMID: 38910098 DOI: 10.1016/j.pt.2024.06.002] [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: 04/15/2024] [Revised: 06/03/2024] [Accepted: 06/03/2024] [Indexed: 06/25/2024]
Abstract
The protozoan parasite Plasmodium falciparum, responsible for the deadliest form of human malaria, employs antigenic variation via monoallelic expression as a key survival strategy. The selective activation of one out of the 60-member var gene family is key to understanding the parasite's ability to cause severe disease and evade the host immune response. var gene activation is initiated by its relocation to a specialized expression site. While the perinuclear expression site (PES) plays a crucial role in enabling the expression of a single allele, the characteristics of this PES remain largely obscure. Recent breakthroughs in genome editing tools and the discovery of regulatory noncoding RNAs have shed light on this intriguing biological feature, offering significant insights into the mechanisms of pathogen virulence.
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Affiliation(s)
- Gretchen Diffendall
- Institut Pasteur, Universite Paris Cité, INSERM U1201, CNRS EMR9195, Paris, France
| | - Artur Scherf
- Institut Pasteur, Universite Paris Cité, INSERM U1201, CNRS EMR9195, Paris, France.
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McLean FE, Azasi Y, Sutherland C, Toboh E, Ansong D, Agbenyega T, Awandare G, Rowe JA. Detection of naturally acquired, strain-transcending antibodies against rosetting Plasmodium falciparum strains in humans. Infect Immun 2024:e0001524. [PMID: 38842304 DOI: 10.1128/iai.00015-24] [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: 01/11/2024] [Accepted: 04/29/2024] [Indexed: 06/07/2024] Open
Abstract
Strain-transcending antibodies against virulence-associated subsets of P. falciparum-infected erythrocyte surface antigens could protect children from severe malaria. However, the evidence supporting the existence of such antibodies is incomplete and inconsistent. One subset of surface antigens associated with severe malaria, rosette-mediating Plasmodium falciparum Erythrocyte Membrane Protein one (PfEMP1) variants, cause infected erythrocytes to bind to uninfected erythrocytes to form clusters of cells (rosettes) that contribute to microvascular obstruction and pathology. Here, we tested plasma from 80 individuals living in malaria-endemic regions for IgG recognition of the surface of four P. falciparum rosetting strains using flow cytometry. Broadly reactive plasma samples were then used in antibody elution experiments in which intact IgG was eluted from the surface of infected erythrocytes and transferred to heterologous rosetting strains to look for strain-transcending antibodies. We found that seroprevalence (percentage of positive plasma samples) against allopatric rosetting strains was high in adults (63%-93%) but lower in children (13%-48%). Strain-transcending antibodies were present in nine out of eleven eluted antibody experiments, with six of these recognizing multiple heterologous rosetting parasite strains. One eluate had rosette-disrupting activity against heterologous strains, suggesting PfEMP1 as the likely target of the strain-transcending antibodies. Naturally acquired strain-transcending antibodies to rosetting P. falciparum strains in humans have not been directly demonstrated previously. Their existence suggests that such antibodies could play a role in clinical protection and raises the possibility that conserved epitopes recognized by strain-transcending antibodies could be targeted therapeutically by monoclonal antibodies or vaccines.
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Affiliation(s)
- Florence E McLean
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Yvonne Azasi
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Cameron Sutherland
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Daniel Ansong
- Kwame Nkrumah University of Science and Technology, School of Medical Sciences, Kumasi, Ghana
- Departments of Child Health and Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana
- Malaria Research Centre, Agogo, Ghana
| | - Tsiri Agbenyega
- Kwame Nkrumah University of Science and Technology, School of Medical Sciences, Kumasi, Ghana
- Departments of Child Health and Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana
- Malaria Research Centre, Agogo, Ghana
| | - Gordon Awandare
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - J Alexandra Rowe
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Bhalerao P, Singh S, Prajapati VK, Bhatt TK. Exploring malaria parasite surface proteins to devise highly immunogenic multi-epitope subunit vaccine for Plasmodium falciparum. J Genet Eng Biotechnol 2024; 22:100377. [PMID: 38797552 PMCID: PMC11089370 DOI: 10.1016/j.jgeb.2024.100377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/07/2024] [Accepted: 04/13/2024] [Indexed: 05/29/2024]
Abstract
BACKGROUND Malaria has remained a major health concern for decades among people living in tropical and sub-tropical countries. Plasmodium falciparum is one of the critical species that cause severe malaria and is responsible for major mortality. Moreover, the parasite has generated resistance against all WHO recommended drugs and therapies. Therefore, there is an urgent need for preventive measures in the form of reliable vaccines to achieve the target of a malaria-free world. Surface proteins are the preferable choice for subunit vaccine development because they are rapidly detected and engaged by host immune cells and vaccination-induced antibodies. Additionally, abundant surface or membrane proteins may contribute to the opsonization of pathogens by vaccine-induced antibodies. RESULTS In our study, we have listed all those surface proteins from the literature that could be functionally important and essential for infection and immune evasion of the malaria parasite. Eight Plasmodium surface and membrane proteins from the pre-erythrocyte and erythrocyte stages were shortlisted. Thirty-seven epitopes (B-cell, CTL, and HTL epitopes) from these proteins were predicted using immune-informatic tools and joined with suitable peptide linkers to design a vaccine construct. A TLR-4 agonist peptide adjuvant was added at the N-terminus of the multi-epitope series, followed by the PADRE sequence and EAAAK linker. The TLR-4 receptor was docked with the construct's anticipated model structure. The complex of vaccine and TLR-4, with the lowest energy -1514, was found to be stable under simulated physiological settings. CONCLUSION This study has provided a novel multi-epitope construct that may be exploited further for the development of an efficient vaccine for malaria.
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Affiliation(s)
- Preshita Bhalerao
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer 305817, Rajasthan, India
| | - Satyendra Singh
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer 305817, Rajasthan, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi 110021, India
| | - Tarun Kumar Bhatt
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer 305817, Rajasthan, India.
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Omoda A, Matsumoto K, Yoshino KI, Tachibana M, Tsuboi T, Torii M, Ishino T, Iriko H. Skeleton binding protein 1 localizes to the Maurer's cleft and interacts with PfHSP70-1 and PfHSP70-x in Plasmodium falciparum gametocyte-infected erythrocytes. Parasitol Int 2024; 100:102864. [PMID: 38331312 DOI: 10.1016/j.parint.2024.102864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/10/2024]
Abstract
Plasmodium falciparum accounts for the majority of malaria deaths, due to pathology provoked by the ability of infected erythrocytes to adhere to vascular endothelium within deep tissues. The parasite recognizes endothelium by trafficking and displaying protein ligands on the surface of asexual stage infected erythrocytes, such as members of the large family of pathogenic proteins, P. falciparum erythrocyte membrane protein 1 (PfEMP1). Parasite-encoded skeleton binding protein 1 (SBP1) plays an important role in the transport of these binding-related surface proteins, via cleft-like membranous structures termed Maurer's clefts, which are present within the cytoplasm of infected erythrocytes. Erythrocytes infected with gametocyte stages accumulate in the extravascular compartment of bone marrow; and it was suggested that their surface-expressed adhesion molecule profile and protein trafficking mechanisms might differ from those in asexual stage parasites. Protein trafficking mechanisms via Maurer's clefts have been well investigated in asexual stage parasite-infected erythrocytes; but little is known regarding the gametocyte stages. In this study, we characterized SBP1 during gametocyte maturation and demonstrated that SBP1 is expressed and localizes to dot-like Maurer's cleft structures in the cytoplasm of gametocyte-infected erythrocytes. Co-immunoprecipitation and mass spectrometry assays indicated that SBP1 interacts with the molecular chaperones PfHSP70-1 and PfHSP70-x. Localization analysis suggested that some PfHSP70-1 and/or PfHSP70-x localize in a dot-like pattern within the cytoplasm of immature gametocyte-infected erythrocytes. These findings suggest that SBP1 may interact with HSP70 chaperones in the infected erythrocyte cytoplasm during the immature gametocyte stages.
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Affiliation(s)
- Ayaka Omoda
- Division of Global Infectious Diseases, Department of Public Health, Graduate School of Health Sciences, Kobe University, Kobe, Hyogo, Japan
| | - Konomi Matsumoto
- Faculty of Health Sciences, Kobe University School of Medicine, Kobe, Hyogo, Japan
| | | | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Takafumi Tsuboi
- Division of Cell-Free Sciences, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Motomi Torii
- Division of Global Infectious Diseases, Department of Public Health, Graduate School of Health Sciences, Kobe University, Kobe, Hyogo, Japan; Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Tomoko Ishino
- Department of Parasitology and Tropical Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Hideyuki Iriko
- Division of Global Infectious Diseases, Department of Public Health, Graduate School of Health Sciences, Kobe University, Kobe, Hyogo, Japan; Faculty of Health Sciences, Kobe University School of Medicine, Kobe, Hyogo, Japan.
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Kong WZ, Zhang HY, Sun YF, Song J, Jiang J, Cui HY, Zhang Y, Han S, Cheng Y. Plasmodium vivax tryptophan-rich antigen reduces type I collagen secretion via the NF-κBp65 pathway in splenic fibroblasts. Parasit Vectors 2024; 17:239. [PMID: 38802961 PMCID: PMC11131192 DOI: 10.1186/s13071-024-06264-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 03/26/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND The spleen plays a critical role in the immune response against malaria parasite infection, where splenic fibroblasts (SFs) are abundantly present and contribute to immune function by secreting type I collagen (collagen I). The protein family is characterized by Plasmodium vivax tryptophan-rich antigens (PvTRAgs), comprising 40 members. PvTRAg23 has been reported to bind to human SFs (HSFs) and affect collagen I levels. Given the role of type I collagen in splenic immune function, it is important to investigate the functions of the other members within the PvTRAg protein family. METHODS Protein structural prediction was conducted utilizing bioinformatics analysis tools and software. A total of 23 PvTRAgs were successfully expressed and purified using an Escherichia coli prokaryotic expression system, and the purified proteins were used for co-culture with HSFs. The collagen I levels and collagen-related signaling pathway protein levels were detected by immunoblotting, and the relative expression levels of inflammatory factors were determined by quantitative real-time PCR. RESULTS In silico analysis showed that P. vivax has 40 genes encoding the TRAg family. The C-terminal region of all PvTRAgs is characterized by the presence of a domain rich in tryptophan residues. A total of 23 recombinant PvTRAgs were successfully expressed and purified. Only five PvTRAgs (PvTRAg5, PvTRAg16, PvTRAg23, PvTRAg30, and PvTRAg32) mediated the activation of the NF-κBp65 signaling pathway, which resulted in the production of inflammatory molecules and ultimately a significant reduction in collagen I levels in HSFs. CONCLUSIONS Our research contributes to the expansion of knowledge regarding the functional role of PvTRAgs, while it also enhances our understanding of the immune evasion mechanisms utilized by parasites.
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Affiliation(s)
- Wei-Zhong Kong
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China
| | - Hang-Ye Zhang
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China
- Case Room, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310016, China
| | - Yi-Fan Sun
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China
- Department of Laboratory Medicine, Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jing Song
- Department of Obstetrics and Gynecology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Jian Jiang
- Wuxi Red Cross Blood Center, Wuxi, 214000, China
| | - Heng-Yuan Cui
- Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China
| | - Yu Zhang
- Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China
| | - Su Han
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China.
| | - Yang Cheng
- Laboratory of Pathogen Infection and Immunity, Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214000, China.
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Obeagu EI. Role of cytokines in immunomodulation during malaria clearance. Ann Med Surg (Lond) 2024; 86:2873-2882. [PMID: 38694310 PMCID: PMC11060309 DOI: 10.1097/ms9.0000000000002019] [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: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 05/04/2024] Open
Abstract
Malaria remains a significant global health challenge, demanding a deeper understanding of host immune responses for effective clearance of the parasitic infection. Cytokines, as crucial mediators of the immune system, orchestrate a complex interplay during the various stages of malaria infection. Throughout the course of the disease, an intricate balance of pro-inflammatory and anti-inflammatory cytokines dictate the immune response's outcome, influencing parasitic clearance and disease severity. During the initial stages, interleukins such as interleukin-12 (IL-12), interferon-gamma (IFN-γ), and tumour necrosis factor-alpha (TNF-α) play pivotal roles in activating innate immune cells, initiating the anti-parasitic response. Simultaneously, regulatory cytokines like interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β) modulate this immune activation, preventing excessive inflammation and tissue damage. As the infection progresses, a delicate shift occurs, characterized by a transition to adaptive immunity, guided by cytokines like interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-13 (IL-13), promoting antibody production and T-cell responses. Notably, the resolution of malaria infection crucially relies on a fine-tuned balance of cytokine networks. Dysregulation or imbalances in these mediators often result in immune hyperactivation, contributing to severe manifestations and prolonged infection. Understanding the multi-faceted roles of cytokines in malaria clearance offers promising avenues for therapeutic interventions. Targeting cytokine pathways to restore immune equilibrium or bolster protective responses could potentially enhance treatment strategies and vaccine development. In conclusion, the pivotal role of cytokines in immunomodulation during malaria clearance underscores their significance as potential targets for therapeutic interventions, offering promising prospects in the global fight against this infectious disease.
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Sacomboio ENM, Zua SD, Tchivango AT, Pululu AD, Caumba ACD, Paciência ABM, Sati DV, Agostinho SG, Agostinho YS, Mazanga FG, Ntambo NB, Sebastião CS, Paixão JP, Morais J. Blood count changes in malaria patients according to blood groups (ABO/Rh) and sickle cell trait. Malar J 2024; 23:126. [PMID: 38685081 PMCID: PMC11059660 DOI: 10.1186/s12936-024-04886-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 02/20/2024] [Indexed: 05/02/2024] Open
Abstract
INTRODUCTION Introduction: Malaria continues to be the leading cause of hospitalization and death in Angola, a country in sub- Saharan Africa. In 2023, in the first quarter, 2,744,682 cases were registered, and of these 2,673 patients died due to malaria disease. Previous studies have shown that the ABO blood group can affect the progression of malaria to severe conditions after P. falciparum infection, while the sickle cell gene offers relative protection. OBJECTIVE We investigated changes in the blood count according to blood groups (ABO/Rh) and sickle cell trait in patients with malaria in Luanda, capital of Angola. METHODOLOGY This was a longitudinal, prospective and observational study with 198 patients hospitalized for malaria. RESULTS Of the 198 patients studied, 13(6.6%) were ABRh(+), 4(2.0%) were ARh(-), 49(24.7%) were ARh(+), 42(21, 2%) were BRh (+), 5(2.5%) were ORh(-) and 85(42.9%) were ORh(+). For sickle cell trait, 145(73.2%) were AA, 37(18.7%) were AS and 16(8.1%) were SS. No statistical relationship was observed between age group, sex, parasitemia, clinical picture, hematocrit, MCV, HCM, MCHC, leukocytes, NEUT, LINF and PTL values with blood groups (p<0.05), but there was a relationship between values of hemoglobin and ABO/Rh blood groups (p>0.05). There was no relationship between age, parasitemia, clinical condition, MCV, HCM and MCHC values, leukocytes, NEUT and LINF with sickle cell trait (p<0.05), but there was a relationship between sex, hemoglobin and PTL and sickle cell values. sickle cell trait (p>0.05). CONCLUSION It is imperative to differentiate patients with malaria based on blood groups and sickle cell trait, taking into account mainly the blood count parameters that demonstrate that there are patients who, depending on blood group or sickle cell trait, may react weakly to malaria infection regardless of the degree of parasitemia and medical prognosis.
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Affiliation(s)
- Euclides N M Sacomboio
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola.
- Instituto Superior de Ciências de Saúde/Universidade Católica de Angola (ISCS/UCAN), Luanda, Angola.
- Centro de Formação em Saúde (CFS) da Clinica Multiperfil, Luanda, Angola.
| | - Santo D Zua
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Adelino T Tchivango
- Instituto Politécnico de Malanje da Universidade Rainha Njinga A Mbande (IPM/URNM), Malanje, Angola
| | - António D Pululu
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Adilson C D Caumba
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Adelina B M Paciência
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Danilson V Sati
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Sabina G Agostinho
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Yolanda S Agostinho
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Fernando G Mazanga
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Neusa B Ntambo
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
| | - Cruz S Sebastião
- Instituto de Ciências de Saúde da Universidade Agostinho Neto (ICISA/UAN), Luanda, Angola
- Instituto Nacional de Investigação em Saúde (INIS), Luanda, Angola
- Centro de Investigação em Saúde de Angola (CISA), Caxito, Angola
| | - Joana P Paixão
- Instituto Nacional de Investigação em Saúde (INIS), Luanda, Angola
- Centro de Investigação em Saúde de Angola (CISA), Caxito, Angola
| | - Joana Morais
- Instituto Nacional de Investigação em Saúde (INIS), Luanda, Angola
- Faculdade de Medicina, Universidade Agostinho Neto, Luanda, Angola
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9
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Letcher B, Maciuca S, Iqbal Z. Role for gene conversion in the evolution of cell-surface antigens of the malaria parasite Plasmodium falciparum. PLoS Biol 2024; 22:e3002507. [PMID: 38451924 PMCID: PMC10919680 DOI: 10.1371/journal.pbio.3002507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024] Open
Abstract
While the malaria parasite Plasmodium falciparum has low average genome-wide diversity levels, likely due to its recent introduction from a gorilla-infecting ancestor (approximately 10,000 to 50,000 years ago), some genes display extremely high diversity levels. In particular, certain proteins expressed on the surface of human red blood cell-infecting merozoites (merozoite surface proteins (MSPs)) possess exactly 2 deeply diverged lineages that have seemingly not recombined. While of considerable interest, the evolutionary origin of this phenomenon remains unknown. In this study, we analysed the genetic diversity of 2 of the most variable MSPs, DBLMSP and DBLMSP2, which are paralogs (descended from an ancestral duplication). Despite thousands of available Illumina WGS datasets from malaria-endemic countries, diversity in these genes has been hard to characterise as reads containing highly diverged alleles completely fail to align to the reference genome. To solve this, we developed a pipeline leveraging genome graphs, enabling us to genotype them at high accuracy and completeness. Using our newly- resolved sequences, we found that both genes exhibit 2 deeply diverged lineages in a specific protein domain (DBL) and that one of the 2 lineages is shared across the genes. We identified clear evidence of nonallelic gene conversion between the 2 genes as the likely mechanism behind sharing, leading us to propose that gene conversion between diverged paralogs, and not recombination suppression, can generate this surprising genealogy; a model that is furthermore consistent with high diversity levels in these 2 genes despite the strong historical P. falciparum transmission bottleneck.
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Affiliation(s)
- Brice Letcher
- EMBL-EBI, Hinxton, United Kingdom
- Laboratory of Biology and Modelling of the Cell, CNRS UMR 5239, Ecole Normale Supérieure de Lyon, Lyon, France
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10
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Deb B, Das A, Vilvadrinath R, Jangra A, Shukla MS, Akhouri RR, Goel S. Glycophorin B-PfEMP1 interaction mediates robust rosetting in Plasmodium falciparum. Int J Biol Macromol 2024; 262:129868. [PMID: 38309398 DOI: 10.1016/j.ijbiomac.2024.129868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/15/2024] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
P. falciparumerythrocyte membrane protein 1 (PfEMP1) is the major parasite protein responsible for rosetting by binding to host receptors such as heparan sulfate, CR1 on RBC surface. Usually monomeric protein-carbohydrate interactions are weak [1], therefore PfEMP1 binds to plasma proteins like IgM or α2-macroglobulin that facilitate its clustering on parasitized RBC surface and augment rosetting [2,3]. We show that 3D7A expresses PfEMP1, PF3D7_0412900, and employs its CIDRγ2 domain to interact with glycophorin B on uninfected RBC to form large rosettes but more importantly even in the absence of plasma proteins. Overall, we established the role of PF3D7_0412900 in rosetting as antibodies against CIDRγ2 domain reduced rosetting and also identified its receptor, glycophorin B which could provide clue why glycophorin B null phenotype, S-s-U- RBCs prevalent in malaria endemic areas is protective against severe malaria.
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Affiliation(s)
- Bijayeeta Deb
- Indian Institute of Science Education and Research (IISER) Tirupati, India
| | - Adrita Das
- Indian Institute of Science Education and Research (IISER) Tirupati, India
| | - Ramya Vilvadrinath
- Indian Institute of Science Education and Research (IISER) Tirupati, India
| | - Arvind Jangra
- Indian Institute of Science Education and Research (IISER) Tirupati, India
| | | | | | - Suchi Goel
- Indian Institute of Science Education and Research (IISER) Tirupati, India.
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11
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Govindaraju G, Rajavelu A. Reading the epitranscriptome of the human malaria parasite. Biomed J 2024:100703. [PMID: 38316392 DOI: 10.1016/j.bj.2024.100703] [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: 09/27/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/07/2024] Open
Abstract
Epigenetic machinery has emerged as a central player in gene regulation and chromatin organization in Plasmodium spp. Epigenetic modifications on histones and their role in antigenic variation in P. falciparum are widely studied. Recent discoveries on nucleic acid methylome are exciting and provide a new dimension to the apicomplexan protozoan parasite's gene regulatory process. Reports have confirmed that N6-methyl adenosine (m6A) methylation plays a crucial role in the translational plasticity of the human malaria parasite during its development in RBC. The YTH domain (YT521-B Homology) protein in P. falciparum binds to m6A epitranscriptome modifications on the mRNA and regulates protein translation. The binding of the PfYTH domain protein to the m6A-modified mRNA is mediated through a binding pocket formed by aromatic amino acids. The P. falciparum genome encodes two members of YTH domain proteins, i.e., YTH1 and YTH2, and both have distinct roles in dictating the epitranscriptome in human malaria parasites. This review highlights recent advancements in the functions and mechanisms of YTH domain protein's role in translational plasticity in the various developmental stages of the parasite.
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Affiliation(s)
- Gayathri Govindaraju
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Chennai, India
| | - Arumugam Rajavelu
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Chennai, India.
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12
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Fraering J, Salnot V, Gautier EF, Ezinmegnon S, Argy N, Peoc'h K, Manceau H, Alao J, Guillonneau F, Migot-Nabias F, Bertin GI, Kamaliddin C. Infected erythrocytes and plasma proteomics reveal a specific protein signature of severe malaria. EMBO Mol Med 2024; 16:319-333. [PMID: 38297098 PMCID: PMC10897182 DOI: 10.1038/s44321-023-00010-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 02/02/2024] Open
Abstract
Cerebral malaria (CM), the most lethal complication of Plasmodium falciparum severe malaria (SM), remains fatal for 15-25% of affected children despite the availability of treatment. P. falciparum infects and multiplies in erythrocytes, contributing to anemia, parasite sequestration, and inflammation. An unbiased proteomic assessment of infected erythrocytes and plasma samples from 24 Beninese children was performed to study the complex mechanisms underlying CM. A significant down-regulation of proteins from the ubiquitin-proteasome pathway and an up-regulation of the erythroid precursor marker transferrin receptor protein 1 (TFRC) were associated with infected erythrocytes from CM patients. At the plasma level, the samples clustered according to clinical presentation. Significantly, increased levels of the 20S proteasome components were associated with SM. Targeted quantification assays confirmed these findings on a larger cohort (n = 340). These findings suggest that parasites causing CM preferentially infect reticulocytes or erythroblasts and alter their maturation. Importantly, the host plasma proteome serves as a specific signature of SM and presents a remarkable opportunity for developing innovative diagnostic and prognostic biomarkers.
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Affiliation(s)
- Jeremy Fraering
- UMR261 MERIT, Université Paris Cité, IRD, F-75006, Paris, France
- Plateforme Proteom'IC, Institut Cochin, Université Paris Cité, INSERM U-1016, CNRS UMR8104, Paris, France
| | - Virginie Salnot
- Plateforme Proteom'IC, Institut Cochin, Université Paris Cité, INSERM U-1016, CNRS UMR8104, Paris, France
| | - Emilie-Fleur Gautier
- Plateforme Proteom'IC, Institut Cochin, Université Paris Cité, INSERM U-1016, CNRS UMR8104, Paris, France
- Institut Imagine-INSERM U1163, Hôpital Necker, Université Paris Cité, F-75015, Paris, France
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - Sem Ezinmegnon
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Nicolas Argy
- UMR261 MERIT, Université Paris Cité, IRD, F-75006, Paris, France
- Laboratoire de parasitologie, Hôpital Bichat-Claude Bernard, APHP, Paris, France
| | - Katell Peoc'h
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
- Biochimie Métabolique et Cellulaire, Hôpital Bichat-Claude Bernard, APHP, Paris, France
- Centre de Recherche sur l'Inflammation, UFR de Médecine Xavier Bichat, Université Paris Cité, INSERM UMR1149, Paris, France
| | - Hana Manceau
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
- Biochimie Métabolique et Cellulaire, Hôpital Bichat-Claude Bernard, APHP, Paris, France
- Département de Biochimie, Hôpital Universitaire Beaujon, APHP, Clichy, France
| | - Jules Alao
- Service de Pédiatrie, Centre Hospitalier Universitaire de la Mère et de l'Enfant-Lagune de Cotonou, Cotonou, Benin
| | - François Guillonneau
- Plateforme Proteom'IC, Institut Cochin, Université Paris Cité, INSERM U-1016, CNRS UMR8104, Paris, France
- Unité OncoProtéomique, Institut de Cancérologie de l'Ouest, F-49055, Angers, France
- Université d'Angers, Inserm UMR 1307, CNRS UMR 6075, Nantes Université, CRCI2NA, F-49000, Angers, France
| | | | - Gwladys I Bertin
- UMR261 MERIT, Université Paris Cité, IRD, F-75006, Paris, France.
| | - Claire Kamaliddin
- UMR261 MERIT, Université Paris Cité, IRD, F-75006, Paris, France.
- Cumming School of Medicine, The University of Calgary, Calgary, AB, Canada.
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13
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Andradi-Brown C, Wichers-Misterek JS, von Thien H, Höppner YD, Scholz JAM, Hansson H, Filtenborg Hocke E, Gilberger TW, Duffy MF, Lavstsen T, Baum J, Otto TD, Cunnington AJ, Bachmann A. A novel computational pipeline for var gene expression augments the discovery of changes in the Plasmodium falciparum transcriptome during transition from in vivo to short-term in vitro culture. eLife 2024; 12:RP87726. [PMID: 38270586 PMCID: PMC10945709 DOI: 10.7554/elife.87726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
The pathogenesis of severe Plasmodium falciparum malaria involves cytoadhesive microvascular sequestration of infected erythrocytes, mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1). PfEMP1 variants are encoded by the highly polymorphic family of var genes, the sequences of which are largely unknown in clinical samples. Previously, we published new approaches for var gene profiling and classification of predicted binding phenotypes in clinical P. falciparum isolates (Wichers et al., 2021), which represented a major technical advance. Building on this, we report here a novel method for var gene assembly and multidimensional quantification from RNA-sequencing that outperforms the earlier approach of Wichers et al., 2021, on both laboratory and clinical isolates across a combination of metrics. Importantly, the tool can interrogate the var transcriptome in context with the rest of the transcriptome and can be applied to enhance our understanding of the role of var genes in malaria pathogenesis. We applied this new method to investigate changes in var gene expression through early transition of parasite isolates to in vitro culture, using paired sets of ex vivo samples from our previous study, cultured for up to three generations. In parallel, changes in non-polymorphic core gene expression were investigated. Modest but unpredictable var gene switching and convergence towards var2csa were observed in culture, along with differential expression of 19% of the core transcriptome between paired ex vivo and generation 1 samples. Our results cast doubt on the validity of the common practice of using short-term cultured parasites to make inferences about in vivo phenotype and behaviour.
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Affiliation(s)
- Clare Andradi-Brown
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College LondonLondonUnited Kingdom
- Department of Life Sciences, Imperial College London, South KensingtonLondonUnited Kingdom
- Centre for Paediatrics and Child Health, Imperial College LondonLondonUnited Kingdom
| | - Jan Stephan Wichers-Misterek
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Heidrun von Thien
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Yannick D Höppner
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Judith AM Scholz
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
| | - Helle Hansson
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Emma Filtenborg Hocke
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Tim Wolf Gilberger
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
| | - Michael F Duffy
- Department of Microbiology and Immunology, University of MelbourneMelbourneAustralia
| | - Thomas Lavstsen
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Diseases, Copenhagen University HospitalCopenhagenDenmark
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South KensingtonLondonUnited Kingdom
- School of Biomedical Sciences, Faculty of Medicine & Health, UNSW, KensingtonSydneyUnited Kingdom
| | - Thomas D Otto
- School of Infection & Immunity, MVLS, University of GlasgowGlasgowUnited Kingdom
| | - Aubrey J Cunnington
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College LondonLondonUnited Kingdom
- Centre for Paediatrics and Child Health, Imperial College LondonLondonUnited Kingdom
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-StrasseHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Biology Department, University of HamburgHamburgGermany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-RiemsHamburgGermany
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14
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Pitman EL, Counihan NA, Modak JK, Chowdury M, Gilson PR, Webb CT, de Koning-Ward TF. Dissecting EXP2 sequence requirements for protein export in malaria parasites. Front Cell Infect Microbiol 2024; 13:1332146. [PMID: 38282616 PMCID: PMC10811066 DOI: 10.3389/fcimb.2023.1332146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/19/2023] [Indexed: 01/30/2024] Open
Abstract
Apicomplexan parasites that reside within a parasitophorous vacuole harbor a conserved pore-forming protein that enables small-molecule transfer across the parasitophorous vacuole membrane (PVM). In Plasmodium parasites that cause malaria, this nutrient pore is formed by EXP2 which can complement the function of GRA17, an orthologous protein in Toxoplasma gondii. EXP2, however, has an additional function in Plasmodium parasites, serving also as the pore-forming component of the protein export machinery PTEX. To examine how EXP2 can play this additional role, transgenes that encoded truncations of EXP2, GRA17, hybrid GRA17-EXP2, or EXP2 under the transcriptional control of different promoters were expressed in EXP2 knockdown parasites to determine which could complement EXP2 function. This revealed that EXP2 is a unique pore-forming protein, and its protein export role in P. falciparum cannot be complemented by T. gondii GRA17. This was despite the addition of the EXP2 assembly strand and part of the linker helix to GRA17, which are regions necessary for the interaction of EXP2 with the other core PTEX components. This indicates that the body region of EXP2 plays a critical role in PTEX assembly and/or that the absence of other T. gondii GRA proteins in P. falciparum leads to its reduced efficiency of insertion into the PVM and complementation potential. Altering the timing and abundance of EXP2 expression did not affect protein export but affected parasite viability, indicating that the unique transcriptional profile of EXP2 when compared to other PTEX components enables it to serve an additional role in nutrient exchange.
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Affiliation(s)
- Ethan L. Pitman
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Natalie A. Counihan
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Joyanta K. Modak
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Mrittika Chowdury
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Paul R. Gilson
- Burnet Institute, Melbourne, VIC, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia
| | - Chaille T. Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
- Centre to Impact AMR, Monash University, Clayton, VIC, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
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15
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Roessner R, Michelarakis N, Gräter F, Aponte-Santamaría C. Mechanical forces control the valency of the malaria adhesin VAR2CSA by exposing cryptic glycan binding sites. PLoS Comput Biol 2023; 19:e1011726. [PMID: 38117828 PMCID: PMC10786402 DOI: 10.1371/journal.pcbi.1011726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 01/12/2024] [Accepted: 12/02/2023] [Indexed: 12/22/2023] Open
Abstract
Plasmodium falciparum (Pf) is responsible for the most lethal form of malaria. VAR2CSA is an adhesin protein expressed by this parasite at the membrane of infected erythrocytes for attachment to the placenta, leading to pregnancy-associated malaria. VAR2CSA is a large 355 kDa multidomain protein composed of nine extracellular domains, a transmembrane helix, and an intracellular domain. VAR2CSA binds to Chondroitin Sulphate A (CSA) of the proteoglycan matrix of the placenta. Shear flow, as the one occurring in blood, has been shown to enhance the (VAR2CSA-mediated) adhesion of Pf-infected erythrocytes on the CSA-matrix. However, the underlying molecular mechanism governing this enhancement has remained elusive. Here, we address this question by using equilibrium, force-probe, and docking-based molecular dynamics simulations. We subjected the VAR2CSA protein-CSA sugar complex to a force mimicking the tensile force exerted on this system due to the shear of the flowing blood. We show that upon this force exertion, VAR2CSA undergoes a large opening conformational transition before the CSA sugar chain dissociates from its main binding site. This preferential order of events is caused by the orientation of the molecule during elongation, as well as the strong electrostatic attraction of the sugar to the main protein binding site. Upon opening, two additional cryptic CSA binding sites get exposed and a functional dodecameric CSA molecule can be stably accommodated at these force-exposed positions. Thus, our results suggest that mechanical forces increase the avidity of VAR2CSA by turning it from a monovalent to a multivalent state. We propose this to be the molecular cause of the observed shear-enhanced adherence. Mechanical control of the valency of VAR2CSA is an intriguing hypothesis that can be tested experimentally and which is of relevance for the understanding of the malaria infection and for the development of anti placental-malaria vaccines targeting VAR2CSA.
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Affiliation(s)
- Rita Roessner
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Nicholas Michelarakis
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany
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16
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Hadjilaou A, Brandi J, Riehn M, Friese MA, Jacobs T. Pathogenetic mechanisms and treatment targets in cerebral malaria. Nat Rev Neurol 2023; 19:688-709. [PMID: 37857843 DOI: 10.1038/s41582-023-00881-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 10/21/2023]
Abstract
Malaria, the most prevalent mosquito-borne infectious disease worldwide, has accompanied humanity for millennia and remains an important public health issue despite advances in its prevention and treatment. Most infections are asymptomatic, but a small percentage of individuals with a heavy parasite burden develop severe malaria, a group of clinical syndromes attributable to organ dysfunction. Cerebral malaria is an infrequent but life-threatening complication of severe malaria that presents as an acute cerebrovascular encephalopathy characterized by unarousable coma. Despite effective antiparasite drug treatment, 20% of patients with cerebral malaria die from this disease, and many survivors of cerebral malaria have neurocognitive impairment. Thus, an important unmet clinical need is to rapidly identify people with malaria who are at risk of developing cerebral malaria and to develop preventive, adjunctive and neuroprotective treatments for cerebral malaria. This Review describes important advances in the understanding of cerebral malaria over the past two decades and discusses how these mechanistic insights could be translated into new therapies.
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Affiliation(s)
- Alexandros Hadjilaou
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany.
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
| | - Johannes Brandi
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
| | - Mathias Riehn
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
| | - Manuel A Friese
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Jacobs
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
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17
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Akhouri RR, Goel S, Skoglund U. Cryo-electron microscopy of IgM-VAR2CSA complex reveals IgM inhibits binding of Plasmodium falciparum to Chondroitin Sulfate A. Nat Commun 2023; 14:6391. [PMID: 37828011 PMCID: PMC10570280 DOI: 10.1038/s41467-023-41838-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 09/20/2023] [Indexed: 10/14/2023] Open
Abstract
Placental malaria is caused by Plasmodium falciparum-infected erythrocytes (IEs) adhering to chondroitin sulfate proteoglycans in placenta via VAR2CSA-type PfEMP1. Human pentameric immunoglobulin M (IgM) binds to several types of PfEMP1, including VAR2CSA via its Fc domain. Here, a 3.6 Å cryo-electron microscopy map of the IgM-VAR2CSA complex reveals that two molecules of VAR2CSA bind to the Cµ4 of IgM through their DBL3X and DBL5ε domains. The clockwise and anti-clockwise rotation of the two VAR2CSA molecules on opposite faces of IgM juxtaposes C-termini of both VAR2CSA near the J chain, where IgM creates a wall between both VAR2CSA molecules and hinders its interaction with its receptor. To support this, we show when VAR2CSA is bound to IgM, its staining on IEs as well as binding of IEs to chondroitin sulfate A in vitro is severely compromised.
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Affiliation(s)
- Reetesh Raj Akhouri
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
- Indian Institute of Technology Madras, Chennai, India.
| | - Suchi Goel
- Indian Institute of Science Education and Research Tirupati, Tirupati, India
| | - Ulf Skoglund
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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18
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Asmerom H, Gemechu K, Sileshi B, Arkew M. Hematological Abnormalities Among Malaria Infected Adult Patients in Association with ABO Blood Groups at Jinella Health Center, Harar, Eastern Ethiopia. J Blood Med 2023; 14:463-476. [PMID: 37638257 PMCID: PMC10457518 DOI: 10.2147/jbm.s419815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023] Open
Abstract
Background Hematological abnormalities are a common complication of malaria infection. However, there is a paucity of evidence regarding it among malaria-infected adult patients in association with the ABO blood group in Ethiopia, particularly in the Harari Region. Therefore, this study aimed to assess the hematological abnormalities among malaria-infected adult patients in association with ABO blood groups at Jinella Health Center, Harar, Eastern Ethiopia. Methods An institutional-based cross-sectional study was conducted from July 10, 2022, to January 10, 2023. Four milliliters of venous blood were collected from each study participant. Drops of blood were used for blood film preparation. ABO blood group was determined by agglutination test using monoclonal anti-sera (Agape Diagnostics Ltd., India). A complete blood count was done using the DxH 800 (Beckman Coulter, Inc, Miami, FL) hematology analyzer. The data were analyzed using SPSS version 26. Bivariable and multivariable logistic regression models were fitted. The level of significance was declared at a p-value of <0.05. Results The study revealed that 47.2% (95% CI: 41.0 53.6) of the participants were anemic. Being female (AOR = 3.18, 95% CI = 1.67, 6.04), having the A blood group (AOR = 2.75, CI = 1.20, 6.31), and being infected with P. falciparum (AOR = 2.64, CI = 1.26, 5.53) were all significantly associated with malaria anemia. The overall prevalence of thrombocytopenia was also 67.7% (95% CI: 61.7-73.4%). It was significantly associated with P. falciparum infection (AOR = 8.03, CI = 3.53, 18.25) and high parasitemia levels (AOR = 4.40, CI = 1.57, 12.32). Conclusion Patients with malaria who belonged to the "A" blood group in the study area had anemia as a serious health problem. Hence, frequently checking for anemia in patients with malaria who have blood group "A" can help with early detection and better management of anemia.
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Affiliation(s)
- Haftu Asmerom
- School of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Kabtamu Gemechu
- School of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Beza Sileshi
- School of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Mesay Arkew
- School of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
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19
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Liu Q, Guan XA, Li DF, Zheng YX, Wang S, Xuan XN, Zhao JL, He L. Babesia gibsoni Whole-Genome Sequencing, Assembling, Annotation, and Comparative Analysis. Microbiol Spectr 2023; 11:e0072123. [PMID: 37432130 PMCID: PMC10434002 DOI: 10.1128/spectrum.00721-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/06/2023] [Indexed: 07/12/2023] Open
Abstract
The intracellular protozoan parasite Babesia gibsoni infects canine erythrocytes and causes babesiosis. The hazards to animal health have increased due to the rise of B. gibsoni infections and medication resistance. However, the lack of high-quality full-genome sequencing sets has expanded the obstacles to the development of pathogeneses, drugs, and vaccines. In this study, the whole genome of B. gibsoni was sequenced, assembled, and annotated. The genomic size of B. gibsoni was 7.94 Mbp in total. Four chromosomes with the size of 0.69 Mb, 2.10 Mb, 2.77 Mb, and 2.38 Mb, respectively, 1 apicoplast (28.4 Kb), and 1 mitochondrion (5.9 Kb) were confirmed. KEGG analysis revealed 2,641 putative proteins enriched on 316 pathways, and GO analysis showed 7,571 annotations of the nuclear genome in total. Synteny analysis showed a high correlation between B. gibsoni and B. bovis. A new divergent point of B. gibsoni occurred around 297.7 million years ago, which was earlier than that of B. bovis, B. ovata, and B. bigemina. Orthology analysis revealed 22 and 32 unique genes compared to several Babesia spp. and apicomplexan species. The metabolic pathways of B.gibsoni were characterized, pointing to a minimal size of the genome. A species-specific secretory protein SA1 and 19 homologous genes were identified. Selected specific proteins, including apetala 2 (AP2) factor, invasion-related proteins BgAMA-1 and BgRON2, and rhoptry function proteins BgWH_04g00700 were predicted, visualized, and modeled. Overall, whole-genome sequencing provided molecular-level support for the diagnosis, prevention, clinical treatment, and further research of B. gibsoni. IMPORTANCE The whole genome of B. gibsoni was first sequenced, annotated, and disclosed. The key part of genome composition, four chromosomes, was comparatively analyzed for the first time. A full-scale phylogeny evolution analysis based on the whole-genome-wide data of B. gibsoni was performed, and a new divergent point on the evolutionary path was revealed. In previous reports, molecular studies were often limited by incomplete genomic data, especially in key areas like life cycle regulation, metabolism, and host-pathogen interaction. With the whole-genome sequencing of B. gibsoni, we provide useful genetic data to encourage the exploration of new terrain and make it feasible to resolve the theoretical and practical problems of babesiosis.
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Affiliation(s)
- Qin Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Xing-Ai Guan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Dong-Fang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Ya-Xin Zheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Sen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Xue-Nan Xuan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro Hokkaido, Japan
| | - Jun-Long Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China
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20
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Ferreira NS, Lima NF, Sulczewski FB, Soares IS, Ferreira MU, Boscardin SB. Plasmodium vivax infection alters the peripheral immunoregulatory network of CD4 T follicular cells and B cells. Eur J Immunol 2023; 53:e2350372. [PMID: 37160134 DOI: 10.1002/eji.202350372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/10/2023] [Accepted: 05/08/2023] [Indexed: 05/11/2023]
Abstract
Regulatory and effector cell responses to Plasmodium vivax, the most common human malaria parasite outside Africa, remain understudied in naturally infected populations. Here, we describe peripheral CD4+ T- and B-cell populations during and shortly after an uncomplicated P. vivax infection in 38 continuously exposed adult Amazonians. Consistent with previous observations, we found an increased frequency in CD4+ CD45RA- CD25+ FoxP3+ T regulatory cells that express the inhibitory molecule CTLA-4 during the acute infection, with a sustained expansion of CD21- CD27- atypical memory cells within the CD19+ B-cell compartment. Both Th1- and Th2-type subsets of CXCR5+ ICOShi PD-1+ circulating T follicular helper (cTfh) cells, which are thought to contribute to antibody production, were induced during P. vivax infection, with a positive correlation between overall cTfh cell frequency and IgG antibody titers to the P. vivax blood-stage antigen MSP119 . We identified significant changes in cell populations that had not been described in human malaria, such as an increased frequency of CTLA-4+ T follicular regulatory cells that antagonize Tfh cells, and a decreased frequency of circulating CD24hi CD27+ B regulatory cells in response to acute infection. In conclusion, we disclose a complex immunoregulatory network that is critical to understand how naturally acquired immunity develops in P. vivax malaria.
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Affiliation(s)
- Natália S Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Nathália F Lima
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Fernando B Sulczewski
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Irene S Soares
- Department of Clinical and Toxicological Analyses, University of São Paulo, São Paulo, Brazil
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
| | - Silvia B Boscardin
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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21
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Wichers-Misterek JS, Krumkamp R, Held J, von Thien H, Wittmann I, Höppner YD, Ruge JM, Moser K, Dara A, Strauss J, Esen M, Fendel R, Sulyok Z, Jeninga MD, Kremsner PG, Sim BKL, Hoffman SL, Duffy MF, Otto TD, Gilberger TW, Silva JC, Mordmüller B, Petter M, Bachmann A. The exception that proves the rule: Virulence gene expression at the onset of Plasmodium falciparum blood stage infections. PLoS Pathog 2023; 19:e1011468. [PMID: 37384799 DOI: 10.1371/journal.ppat.1011468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023] Open
Abstract
Controlled human malaria infections (CHMI) are a valuable tool to study parasite gene expression in vivo under defined conditions. In previous studies, virulence gene expression was analyzed in samples from volunteers infected with the Plasmodium falciparum (Pf) NF54 isolate, which is of African origin. Here, we provide an in-depth investigation of parasite virulence gene expression in malaria-naïve European volunteers undergoing CHMI with the genetically distinct Pf 7G8 clone, originating in Brazil. Differential expression of var genes, encoding major virulence factors of Pf, PfEMP1s, was assessed in ex vivo parasite samples as well as in parasites from the in vitro cell bank culture that was used to generate the sporozoites (SPZ) for CHMI (Sanaria PfSPZ Challenge (7G8)). We report broad activation of mainly B-type subtelomeric located var genes at the onset of a 7G8 blood stage infection in naïve volunteers, mirroring the NF54 expression study and suggesting that the expression of virulence-associated genes is generally reset during transmission from the mosquito to the human host. However, in 7G8 parasites, we additionally detected a continuously expressed single C-type variant, Pf7G8_040025600, that was most highly expressed in both pre-mosquito cell bank and volunteer samples, suggesting that 7G8, unlike NF54, maintains expression of some previously expressed var variants during transmission. This suggests that in a new host, the parasite may preferentially express the variants that previously allowed successful infection and transmission. Trial registration: ClinicalTrials.gov - NCT02704533; 2018-004523-36.
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Affiliation(s)
- Jan Stephan Wichers-Misterek
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Ralf Krumkamp
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Hamburg/Borstel/Lübeck/Riems, Germany
| | - Jana Held
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Heidrun von Thien
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Irene Wittmann
- Institute of Microbiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Yannick Daniel Höppner
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Hamburg/Borstel/Lübeck/Riems, Germany
| | - Julia M Ruge
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Hamburg/Borstel/Lübeck/Riems, Germany
| | - Kara Moser
- Institute for Genome Sciences, University of Maryland, School of Medicine, Baltimore, Maryland, United States of America
| | - Antoine Dara
- Institute for Genome Sciences, University of Maryland, School of Medicine, Baltimore, Maryland, United States of America
| | - Jan Strauss
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Meral Esen
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tübingen, Germany
| | - Rolf Fendel
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Zita Sulyok
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Myriam D Jeninga
- Institute of Microbiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Peter G Kremsner
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - B Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, United States of America
| | | | - Michael F Duffy
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Thomas D Otto
- School of Infection & Immunity, University of Glasgow, Glasgow, United Kingdom
| | - Tim-Wolf Gilberger
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland, School of Medicine, Baltimore, Maryland, United States of America
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland, United States of America
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade NOVA de Lisboa, UNL, Lisboa, Portugal
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Michaela Petter
- Institute of Microbiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Hamburg/Borstel/Lübeck/Riems, Germany
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22
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Demarta-Gatsi C, Andenmatten N, Jiménez-Díaz MB, Gobeau N, Cherkaoui-Rabti MH, Fuchs A, Díaz P, Berja S, Sánchez R, Gómez H, Ruiz E, Sainz P, Salazar E, Gil-Merino R, Mendoza LM, Eguizabal C, Leroy D, Moehrle JJ, Tornesi B, Angulo-Barturen I. Predicting Optimal Antimalarial Drug Combinations from a Standardized Plasmodium falciparum Humanized Mouse Model. Antimicrob Agents Chemother 2023; 67:e0157422. [PMID: 37133382 PMCID: PMC10269072 DOI: 10.1128/aac.01574-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/29/2023] [Indexed: 05/04/2023] Open
Abstract
The development of new combinations of antimalarial drugs is urgently needed to prevent the spread of parasites resistant to drugs in clinical use and contribute to the control and eradication of malaria. In this work, we evaluated a standardized humanized mouse model of erythrocyte asexual stages of Plasmodium falciparum (PfalcHuMouse) for the selection of optimal drug combinations. First, we showed that the replication of P. falciparum was robust and highly reproducible in the PfalcHuMouse model by retrospective analysis of historical data. Second, we compared the relative value of parasite clearance from blood, parasite regrowth after suboptimal treatment (recrudescence), and cure as variables of therapeutic response to measure the contributions of partner drugs to combinations in vivo. To address the comparison, we first formalized and validated the day of recrudescence (DoR) as a new variable and found that there was a log-linear relationship with the number of viable parasites per mouse. Then, using historical data on monotherapy and two small cohorts of PfalcHuMice evaluated with ferroquine plus artefenomel or piperaquine plus artefenomel, we found that only measurements of parasite killing (i.e., cure of mice) as a function of drug exposure in blood allowed direct estimation of the individual drug contribution to efficacy by using multivariate statistical modeling and intuitive graphic displays. Overall, the analysis of parasite killing in the PfalcHuMouse model is a unique and robust experimental in vivo tool to inform the selection of optimal combinations by pharmacometric pharmacokinetic and pharmacodynamic (PK/PD) modeling.
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Affiliation(s)
| | | | | | | | | | - Aline Fuchs
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Pablo Díaz
- The Art of Discovery, Derio, Basque Country, Spain
| | - Sandra Berja
- The Art of Discovery, Derio, Basque Country, Spain
| | | | - Hazel Gómez
- The Art of Discovery, Derio, Basque Country, Spain
| | | | - Paula Sainz
- The Art of Discovery, Derio, Basque Country, Spain
| | | | | | | | - Cristina Eguizabal
- Cell Therapy, Stem Cells and Tissues Group, Biocruces Bizkaia Health Research Institute, Barakaldo, Bizkaia, Spain
- Basque Centre for Blood Transfusion and Human Tissues, Galdakao, Bizkaia, Spain
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
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23
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Bezerra JJL, Pinheiro AAV, Dourado D. Antimalarial potential of Moringa oleifera Lam. (Moringaceae): A review of the ethnomedicinal, pharmacological, toxicological, and phytochemical evidence. J Venom Anim Toxins Incl Trop Dis 2023; 29:e20220079. [PMID: 37266375 PMCID: PMC10231345 DOI: 10.1590/1678-9199-jvatitd-2022-0079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/27/2023] [Indexed: 06/03/2023] Open
Abstract
Several regions of the world frequently use the species Moringa oleifera Lam. (Moringaceae) in traditional medicine. This situation is even more common in African countries. Many literature reports point to the antimalarial potential of this species, indicating the efficacy of its chemical compounds against malaria-causing parasites of the genus Plasmodium. From this perspective, the present study reviews the ethnobotanical, pharmacological, toxicological, and phytochemical (flavonoids) evidence of M. oleifera, focusing on the treatment of malaria. Scientific articles were retrieved from Google Scholar, PubMed®, ScienceDirect®, and SciELO databases. Only articles published between 2002 and 2022 were selected. After applying the inclusion and exclusion criteria, this review used a total of 72 articles. These documents mention a large use of M. oleifera for the treatment of malaria in African and Asian countries. The leaves (63%) of this plant are the main parts used in the preparation of herbal medicines. The in vivo antimalarial activity of M. oleifera was confirmed through several studies using polar and nonpolar extracts, fractions obtained from the extracts, infusion, pellets, and oils obtained from this plant and tested in rodents infected by the following parasites of the genus Plasmodium: P. berghei, P. falciparum, P. yoelii, and P. chabaudi. Extracts obtained from M. oleifera showed no toxicity in preclinical tests. A total of 46 flavonoids were identified in the leaves and seeds of M. oleifera by different chromatography and mass spectrometry methods. Despite the scarcity of research on the antimalarial potential of compounds isolated from M. oleifera, the positive effects against malaria-causing parasites in previous studies are likely to correlate with the flavonoids that occur in this species.
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Affiliation(s)
- José Jailson Lima Bezerra
- Graduate Program in Plant Biology, Department of Botany, Federal University of Pernambuco, Recife, PE, Brazil
| | | | - Douglas Dourado
- Graduate Program in Biosciences and Biotechnology in Health, Department of Immunology, Aggeu Magalhães-Fiocruz Institute, Recife, PE, Brazil
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24
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Ezema CA, Okagu IU, Ezeorba TPC. Escaping the enemy's bullets: an update on how malaria parasites evade host immune response. Parasitol Res 2023:10.1007/s00436-023-07868-6. [PMID: 37219610 DOI: 10.1007/s00436-023-07868-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
Malaria continues to cause untold hardship to inhabitants of malaria-endemic regions, causing significant morbidity and mortality that severely impact global health and the economy. Considering the complex life cycle of malaria parasites (MPs) and malaria biology, continued research efforts are ongoing to improve our understanding of the pathogenesis of the diseases. Female Anopheles mosquito injects MPs into its hosts during a blood meal, and MPs invade the host skin and the hepatocytes without causing any serious symptoms. Symptomatic infections occur only during the erythrocytic stage. In most cases, the host's innate immunity (for malaria-naïve individuals) and adaptive immunity (for pre-exposed individuals) mount severe attacks and destroy most MPs. It is increasingly understood that MPs have developed several mechanisms to escape from the host's immune destruction. This review presents recent knowledge on how the host's immune system destroys invading MPs as well as MPs survival or host immune evasion mechanisms. On the invasion of host cells, MPs release molecules that bind to cell surface receptors to reprogram the host in a way to lose the capacity to destroy them. MPs also hide from the host immune cells by inducing the clustering of both infected and uninfected erythrocytes (rosettes), as well as inducing endothelial activation. We hope this review will inspire more research to provide a complete understanding of malaria biology and promote interventions to eradicate the notorious disease.
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Affiliation(s)
- Chinonso Anthony Ezema
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria
- Division of Soft Matter, Hokkaido University, Sapporo, 060-0810, Japan
| | - Innocent Uzochukwu Okagu
- Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria
| | - Timothy Prince Chidike Ezeorba
- Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria.
- Department of Genetics and Biotechnology, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria.
- Department of Molecular Biotechnology, School of Biosciences, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK.
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25
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Ji C, Shen H, Su C, Li Y, Chen S, Sharp TH, Xiao J. Plasmodium falciparum has evolved multiple mechanisms to hijack human immunoglobulin M. Nat Commun 2023; 14:2650. [PMID: 37156765 PMCID: PMC10167334 DOI: 10.1038/s41467-023-38320-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 04/25/2023] [Indexed: 05/10/2023] Open
Abstract
Plasmodium falciparum causes the most severe malaria in humans. Immunoglobulin M (IgM) serves as the first line of humoral defense against infection and potently activates the complement pathway to facilitate P. falciparum clearance. A number of P. falciparum proteins bind IgM, leading to immune evasion and severe disease. However, the underlying molecular mechanisms remain unknown. Here, using high-resolution cryo-electron microscopy, we delineate how P. falciparum proteins VAR2CSA, TM284VAR1, DBLMSP, and DBLMSP2 target IgM. Each protein binds IgM in a different manner, and together they present a variety of Duffy-binding-like domain-IgM interaction modes. We further show that these proteins interfere directly with IgM-mediated complement activation in vitro, with VAR2CSA exhibiting the most potent inhibitory effect. These results underscore the importance of IgM for human adaptation of P. falciparum and provide critical insights into its immune evasion mechanism.
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Affiliation(s)
- Chenggong Ji
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
- Changping Laboratory, Beijing, PR China
| | - Hao Shen
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Chen Su
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Yaxin Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Shihua Chen
- Joint Graduate Program of Peking-Tsinghua-NIBS, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Thomas H Sharp
- Department of Cell and Chemical Biology, Section Electron Microscopy, Leiden University Medical Center, 2300, RC, Leiden, The Netherlands
| | - Junyu Xiao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.
- Changping Laboratory, Beijing, PR China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
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26
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Bhattacharjee S, Ghosh D, Saha R, Sarkar R, Kumar S, Khokhar M, Pandey RK. Mechanism of Immune Evasion in Mosquito-Borne Diseases. Pathogens 2023; 12:pathogens12050635. [PMID: 37242305 DOI: 10.3390/pathogens12050635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.
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Affiliation(s)
| | - Debanjan Ghosh
- Department of Biotechnology, Pondicherry University, Puducherry 605014, India
| | - Rounak Saha
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry 605014, India
| | - Rima Sarkar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Saurav Kumar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Manoj Khokhar
- Department of Biochemistry, AIIMS, Jodhpur 342005, India
| | - Rajan Kumar Pandey
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Solna, Sweden
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27
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Patterns of Heterochromatin Transitions Linked to Changes in the Expression of Plasmodium falciparum Clonally Variant Genes. Microbiol Spectr 2023; 11:e0304922. [PMID: 36515553 PMCID: PMC9927496 DOI: 10.1128/spectrum.03049-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The survival of malaria parasites in the changing human blood environment largely depends on their ability to alter gene expression by epigenetic mechanisms. The active state of Plasmodium falciparum clonally variant genes (CVGs) is associated with euchromatin characterized by the histone mark H3K9ac, whereas the silenced state is characterized by H3K9me3-based heterochromatin. Expression switches are linked to euchromatin-heterochromatin transitions, but these transitions have not been characterized for the majority of CVGs. To define the heterochromatin distribution patterns associated with the alternative transcriptional states of CVGs, we compared H3K9me3 occupancy at a genome-wide level among several parasite subclones of the same genetic background that differed in the transcriptional state of many CVGs. We found that de novo heterochromatin formation or the complete disruption of a heterochromatin domain is a relatively rare event, and for the majority of CVGs, expression switches can be explained by the expansion or retraction of heterochromatin domains. We identified different modalities of heterochromatin changes linked to transcriptional differences, but despite this complexity, heterochromatin distribution patterns generally enable the prediction of the transcriptional state of specific CVGs. We also found that in some subclones, several var genes were simultaneously in an active state. Furthermore, the heterochromatin levels in the putative regulatory region of the gdv1 antisense noncoding RNA, a regulator of sexual commitment, varied between parasite lines with different sexual conversion rates. IMPORTANCE The malaria parasite P. falciparum is responsible for more than half a million deaths every year. P. falciparum clonally variant genes (CVGs) mediate fundamental host-parasite interactions and play a key role in parasite adaptation to fluctuations in the conditions of the human host. The expression of CVGs is regulated at the epigenetic level by changes in the distribution of a type of chromatin called heterochromatin. Here, we describe at a genome-wide level the changes in the heterochromatin distribution associated with the different transcriptional states of CVGs. Our results also reveal a likely role for heterochromatin at a particular locus in determining the parasite investment in transmission to mosquitoes. Additionally, this data set will enable the prediction of the transcriptional state of CVGs from epigenomic data, which is important for the study of parasite adaptation to the conditions of the host in natural malaria infections.
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28
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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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29
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Diffendall GM, Barcons-Simon A, Baumgarten S, Dingli F, Loew D, Scherf A. Discovery of RUF6 ncRNA-interacting proteins involved in P. falciparum immune evasion. Life Sci Alliance 2022; 6:6/1/e202201577. [PMID: 36379669 PMCID: PMC9670795 DOI: 10.26508/lsa.202201577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Non-coding RNAs (ncRNAs) are emerging regulators of immune evasion and transmission of Plasmodium falciparum RUF6 is an ncRNA gene family that is transcribed by RNA polymerase III but actively regulates the Pol II-transcribed var virulence gene family. Understanding how RUF6 ncRNA connects to downstream effectors is lacking. We developed an RNA-directed proteomic discovery (ChIRP-MS) protocol to identify in vivo RUF6 ncRNA-protein interactions. The RUF6 ncRNA interactome was purified with biotinylated antisense oligonucleotides. Quantitative label-free mass spectrometry identified several unique proteins linked to gene transcription including RNA Pol II subunits, nucleosome assembly proteins, and a homologue of DEAD box helicase 5 (DDX5). Affinity purification of Pf-DDX5 identified proteins originally found by our RUF6-ChIRP protocol, validating the technique's robustness for identifying ncRNA interactomes in P. falciparum Inducible displacement of nuclear Pf-DDX5 resulted in significant down-regulation of the active var gene. Our work identifies a RUF6 ncRNA-protein complex that interacts with RNA Pol II to sustain the var gene expression, including a helicase that may resolve G-quadruplex secondary structures in var genes to facilitate transcriptional activation and progression.
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Affiliation(s)
- Gretchen M Diffendall
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France,Sorbonne Université Ecole doctorale Complexité du Vivant ED515, Paris, France
| | - Anna Barcons-Simon
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France,Sorbonne Université Ecole doctorale Complexité du Vivant ED515, Paris, France,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Florent Dingli
- Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Damarys Loew
- Institut Curie, PSL Research University, Centre de Recherche, CurieCoreTech Mass Spectrometry Proteomics, Paris, France
| | - Artur Scherf
- Universite Paris Cité, Institut Pasteur, Biology of Host-Parasite Interactions Unit, INSERM U1201, CNRS EMR9195, Paris, France
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30
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Rotich AK, Takashima E, Yanow SK, Gitaka J, Kanoi BN. Towards identification and development of alternative vaccines against pregnancy-associated malaria based on naturally acquired immunity. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.988284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pregnant women are particularly susceptible to Plasmodium falciparum malaria, leading to substantial maternal and infant morbidity and mortality. While highly effective malaria vaccines are considered an essential component towards malaria elimination, strides towards development of vaccines for pregnant women have been minimal. The leading malaria vaccine, RTS,S/AS01, has modest efficacy in children suggesting that it needs to be strengthened and optimized if it is to be beneficial for pregnant women. Clinical trials against pregnancy-associated malaria (PAM) focused on the classical VAR2CSA antigen are ongoing. However, additional antigens have not been identified to supplement these initiatives despite the new evidence that VAR2CSA is not the only molecule involved in pregnancy-associated naturally acquired immunity. This is mainly due to a lack of understanding of the immune complexities in pregnancy coupled with difficulties associated with expression of malaria recombinant proteins, low antigen immunogenicity in humans, and the anticipated complications in conducting and implementing a vaccine to protect pregnant women. With the accelerated evolution of molecular technologies catapulted by the global pandemic, identification of novel alternative vaccine antigens is timely and feasible. In this review, we discuss approaches towards novel antigen discovery to support PAM vaccine studies.
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Milne R, Wiedemar N, Corpas-Lopez V, Moynihan E, Wall RJ, Dawson A, Robinson DA, Shepherd SM, Smith RJ, Hallyburton I, Post JM, Dowers K, Torrie LS, Gilbert IH, Baragaña B, Patterson S, Wyllie S. Toolkit of Approaches To Support Target-Focused Drug Discovery for Plasmodium falciparum Lysyl tRNA Synthetase. ACS Infect Dis 2022; 8:1962-1974. [PMID: 36037410 PMCID: PMC9469095 DOI: 10.1021/acsinfecdis.2c00364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
There is a pressing need for new medicines to prevent and treat malaria. Most antimalarial drug discovery is reliant upon phenotypic screening. However, with the development of improved target validation strategies, target-focused approaches are now being utilized. Here, we describe the development of a toolkit to support the therapeutic exploitation of a promising target, lysyl tRNA synthetase (PfKRS). The toolkit includes resistant mutants to probe resistance mechanisms and on-target engagement for specific chemotypes; a hybrid KRS protein capable of producing crystals suitable for ligand soaking, thus providing high-resolution structural information to guide compound optimization; chemical probes to facilitate pulldown studies aimed at revealing the full range of specifically interacting proteins and thermal proteome profiling (TPP); as well as streamlined isothermal TPP methods to provide unbiased confirmation of on-target engagement within a biologically relevant milieu. This combination of tools and methodologies acts as a template for the development of future target-enabling packages.
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32
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Suurbaar J, Moussiliou A, Tahar R, Olsen RW, Adams Y, Dalgaard N, Baafour EK, Adukpo S, Hviid L, Kusi KA, Alao J, Ofori MF, Ndam NT, Jensen AR. ICAM-1-binding Plasmodium falciparum erythrocyte membrane protein 1 variants elicits opsonic-phagocytosis IgG responses in Beninese children. Sci Rep 2022; 12:12994. [PMID: 35906450 PMCID: PMC9338288 DOI: 10.1038/s41598-022-16305-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/07/2022] [Indexed: 11/09/2022] Open
Abstract
Members of the highly polymorphic Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family expressed on the surface of infected erythrocytes (IEs) are important virulence factors, which mediate vascular adhesion of IEs via endothelial host receptors and are targets of naturally acquired immunity. The PfEMP1 family can be divided into clinically relevant subgroups, of which some bind intercellular adhesion molecule 1 (ICAM-1). While the acquisition of IgG specific for ICAM-1-binding DBLβ domains is known to differ between PfEMP1 groups, its ability to induce antibody-dependent cellular phagocytosis (ADCP) is unclear. We therefore measured plasma levels of DBLβ-specific IgG, the ability of such IgG to inhibit PfEMP1-binding to ICAM-1, and its ability to opsonize IEs for ADCP, using plasma from Beninese children with severe (SM) or uncomplicated malaria (UM). IgG specific for DBLβ from group A and B ICAM-1-binding PfEMP1 were dominated by IgG1 and IgG3, and were similar in SM and UM. However, levels of plasma IgG inhibiting ICAM-1-binding of group A DBLβ of PFD1235w was significantly higher in children with UM than SM, and acute UM plasma induced a higher ADCP response than acute SM plasma.
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Affiliation(s)
- Jennifer Suurbaar
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.,Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana.,Department of Biochemistry and Molecular Medicine, School of Medicine and Health Sciences, University for Development Studies, Tamale, Ghana.,Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Université de Paris Cité, MERIT, IRD, 75006, Paris, France
| | | | - Rachida Tahar
- Université de Paris Cité, MERIT, IRD, 75006, Paris, France
| | - Rebecca W Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nanna Dalgaard
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eric K Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Selorme Adukpo
- Department of Pharmaceutics and Microbiology, School of Pharmacy, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Kwadwo A Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.,Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Jules Alao
- Paediatric Department, Mother and Child University and Hospital Center (CHUMEL), Cotonou, Benin
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.,Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana
| | - Nicaise T Ndam
- Université de Paris Cité, MERIT, IRD, 75006, Paris, France
| | - Anja R Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Abstract
In eukaryotic organisms, noncoding RNAs (ncRNAs) have been implicated as important regulators of multifaceted biological processes, including transcriptional, posttranscriptional, and epigenetic regulation of gene expression. In recent years, it is becoming clear that protozoan parasites encode diverse ncRNA transcripts; however, little is known about their cellular functions. Recent advances in high-throughput “omic” studies identified many novel long ncRNAs (lncRNAs) in apicomplexan parasites, some of which undergo splicing, polyadenylation, and encode small proteins. To date, only a few of them are characterized, leaving a big gap in our understanding regarding their origin, mode of action, and functions in parasite biology. In this review, we focus on lncRNAs of the human malaria parasite Plasmodium falciparum and highlight their cellular functions and possible mechanisms of action.
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Affiliation(s)
- Karina Simantov
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Manish Goyal
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ron Dzikowski
- Department of Microbiology & Molecular Genetics, The Kuvin Center for the Study of Infectious and Tropical Diseases, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
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Sethumadhavan DV, Tiburcio M, Kanyal A, Jabeena CA, Govindaraju G, Karmodiya K, Rajavelu A. Chromodomain Protein Interacts with H3K9me3 and Controls RBC Rosette Formation by Regulating the Expression of a Subset of RIFINs in the Malaria Parasite. J Mol Biol 2022; 434:167601. [PMID: 35460670 DOI: 10.1016/j.jmb.2022.167601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/04/2022] [Accepted: 04/17/2022] [Indexed: 11/27/2022]
Abstract
Plasmodium falciparum expresses clonally variant proteins on the surface of infected erythrocytes to evade the host immune system. The clonally variant multigene families include var, rifin, and stevor, which express Erythrocyte Membrane Protein 1 (EMP1), Repetitive Interspersed Families of polypeptides (RIFINs), and Sub-telomeric Variable Open Reading frame (STEVOR) proteins, respectively. The rifins are the largest multigene family and are essentially involved in the RBC rosetting, the hallmark of severe malaria. The molecular regulators that control the RIFINs expression in Plasmodium spp. have not been reported so far. This study reports a chromodomain-containing protein (PfCDP) that binds to H3K9me3 modification on P. falciparum chromatin. Conditional deletion of the chromodomain (CD) gene in P. falciparum using an inducible DiCre-LoxP system leads to selective up-regulation of a subset of virulence genes, including rifins, a few var, and stevor genes. Further, we show that PfCDP conditional knockout (PfΔCDP) promotes RBC rosette formation. This study provides the first evidence of an epigenetic regulator mediated control on a subset of RIFINs expression and RBC rosetting by P. falciparum.
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Affiliation(s)
- Devadathan Valiyamangalath Sethumadhavan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Madras, Chennai, Tamil Nadu 600 036, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka 576 104, India
| | - Marta Tiburcio
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, United Kingdom
| | - Abhishek Kanyal
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India. https://twitter.com/AbhishekKanyal7
| | - C A Jabeena
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Madras, Chennai, Tamil Nadu 600 036, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka 576 104, India
| | - Gayathri Govindaraju
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Madras, Chennai, Tamil Nadu 600 036, India; Ph.D registered with Manipal Academy of Higher Education (MAHE), Tiger Circle Road, Madhav Nagar, Manipal, Karnataka 576 104, India
| | - Krishanpal Karmodiya
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, Maharashtra, India. https://twitter.com/Krishanpal_K
| | - Arumugam Rajavelu
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology, Madras, Chennai, Tamil Nadu 600 036, India; Pathogen Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud PO, Thiruvananthapuram 695 014, Kerala, India.
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35
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Shao J. Labeling Strategies for Surface-Exposed Protein Visualization and Determination in Plasmodium falciparum Malaria. Front Cell Infect Microbiol 2022; 12:914297. [PMID: 35755836 PMCID: PMC9226428 DOI: 10.3389/fcimb.2022.914297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jinfeng Shao
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
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36
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Peterson MS, Joyner CJ, Lapp SA, Brady JA, Wood JS, Cabrera-Mora M, Saney CL, Fonseca LL, Cheng WT, Jiang J, Soderberg SR, Nural MV, Hankus A, Machiah D, Karpuzoglu E, DeBarry JD, Tirouvanziam R, Kissinger JC, Moreno A, Gumber S, Voit EO, Gutierrez JB, Cordy RJ, Galinski MR. Plasmodium knowlesi Cytoadhesion Involves SICA Variant Proteins. Front Cell Infect Microbiol 2022; 12:888496. [PMID: 35811680 PMCID: PMC9260704 DOI: 10.3389/fcimb.2022.888496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/22/2022] [Indexed: 11/13/2022] Open
Abstract
Plasmodium knowlesi poses a health threat throughout Southeast Asian communities and currently causes most cases of malaria in Malaysia. This zoonotic parasite species has been studied in Macaca mulatta (rhesus monkeys) as a model for severe malarial infections, chronicity, and antigenic variation. The phenomenon of Plasmodium antigenic variation was first recognized during rhesus monkey infections. Plasmodium-encoded variant proteins were first discovered in this species and found to be expressed at the surface of infected erythrocytes, and then named the Schizont-Infected Cell Agglutination (SICA) antigens. SICA expression was shown to be spleen dependent, as SICA expression is lost after P. knowlesi is passaged in splenectomized rhesus. Here we present data from longitudinal P. knowlesi infections in rhesus with the most comprehensive analysis to date of clinical parameters and infected red blood cell sequestration in the vasculature of tissues from 22 organs. Based on the histopathological analysis of 22 tissue types from 11 rhesus monkeys, we show a comparative distribution of parasitized erythrocytes and the degree of margination of the infected erythrocytes with the endothelium. Interestingly, there was a significantly higher burden of parasites in the gastrointestinal tissues, and extensive margination of the parasites along the endothelium, which may help explain gastrointestinal symptoms frequently reported by patients with P. knowlesi malarial infections. Moreover, this margination was not observed in splenectomized rhesus that were infected with parasites not expressing the SICA proteins. This work provides data that directly supports the view that a subpopulation of P. knowlesi parasites cytoadheres and sequesters, likely via SICA variant antigens acting as ligands. This process is akin to the cytoadhesive function of the related variant antigen proteins, namely Erythrocyte Membrane Protein-1, expressed by Plasmodium falciparum.
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Affiliation(s)
- Mariko S. Peterson
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Chester J. Joyner
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Stacey A. Lapp
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Jessica A. Brady
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA, United States
| | - Jennifer S. Wood
- Division of Animal Resources, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Monica Cabrera-Mora
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Celia L. Saney
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Luis L. Fonseca
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Wayne T. Cheng
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Jianlin Jiang
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Stephanie R. Soderberg
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Mustafa V. Nural
- Institute of Bioinformatics, University of Georgia, Athens, GA, United States
| | - Allison Hankus
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Deepa Machiah
- Division of Pathology, Yerkes National Primate Research Center, Atlanta, GA, United States
| | - Ebru Karpuzoglu
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Jeremy D. DeBarry
- Institute of Bioinformatics, University of Georgia, Athens, GA, United States
| | - Rabindra Tirouvanziam
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Jessica C. Kissinger
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Institute of Bioinformatics, University of Georgia, Athens, GA, United States
- Department of Genetics, University of Georgia, Athens, GA, United States
| | - Alberto Moreno
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Sanjeev Gumber
- Division of Pathology, Yerkes National Primate Research Center, Atlanta, GA, United States
- Department of Pathology and Laboratory Medicine, Emory School of Medicine, Atlanta, GA, United States
| | - Eberhard O. Voit
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Juan B. Gutierrez
- Department of Mathematics, University of Georgia, Athens, GA, United States
| | - Regina Joice Cordy
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Mary R. Galinski
- Emory National Primate Research Center, Emory University, Atlanta, GA, United States
- Emory Vaccine Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
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Sakoguchi A, Arase H. Mechanisms for Host Immune Evasion Mediated by Plasmodium falciparum-Infected Erythrocyte Surface Antigens. Front Immunol 2022; 13:901864. [PMID: 35784341 PMCID: PMC9240312 DOI: 10.3389/fimmu.2022.901864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/10/2022] [Indexed: 12/20/2022] Open
Abstract
Plasmodium falciparum infection causes the most severe form of malaria. It has been hypothesized that P. falciparum directly suppresses host immune responses because sufficient acquired immunity is often not induced even by repeated P. falciparum infections in malaria-endemic areas. It is known that many kinds of P. falciparum-derived proteins are expressed on the surface of P. falciparum-infected erythrocytes (IEs), and these proteins have long been thought to be a key to the elucidation of the host immune evasion mechanisms. Our recent studies have revealed that the P. falciparum-derived erythrocyte surface antigen, RIFIN, the largest multiple gene family protein in the P. falciparum genome, suppresses host immune cell activation through direct interaction with human inhibitory immune receptors. In this review, we will discuss the molecular mechanisms for host immune evasion by P. falciparum-infected erythrocyte surface antigens. In addition, we will discuss the recently identified host immune response to P. falciparum using specialized antibodies that target host-P. falciparum-derived molecule interactions.
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Affiliation(s)
- Akihito Sakoguchi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Hisashi Arase
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Japan
- Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
- *Correspondence: Hisashi Arase,
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Oresegun DR, Thorpe P, Benavente ED, Campino S, Muh F, Moon RW, Clark TG, Cox-Singh J. De Novo Assembly of Plasmodium knowlesi Genomes From Clinical Samples Explains the Counterintuitive Intrachromosomal Organization of Variant SICAvar and kir Multiple Gene Family Members. Front Genet 2022; 13:855052. [PMID: 35677565 PMCID: PMC9169567 DOI: 10.3389/fgene.2022.855052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/15/2022] [Indexed: 12/31/2022] Open
Abstract
Plasmodium knowlesi, a malaria parasite of Old World macaque monkeys, is used extensively to model Plasmodium biology. Recently, P. knowlesi was found in the human population of Southeast Asia, particularly Malaysia. P. knowlesi causes uncomplicated to severe and fatal malaria in the human host with features in common with the more prevalent and virulent malaria caused by Plasmodium falciparum. As such, P. knowlesi presents a unique opportunity to develop experimental translational model systems for malaria pathophysiology informed by clinical data from same-species human infections. Experimental lines of P. knowlesi represent well-characterized genetically stable parasites, and to maximize their utility as a backdrop for understanding malaria pathophysiology, genetically diverse contemporary clinical isolates, essentially wild-type, require comparable characterization. The Oxford Nanopore PCR-free long-read sequencing platform was used to sequence and de novo assemble P. knowlesi genomes from frozen clinical samples. The sequencing platform and assembly pipelines were designed to facilitate capturing data and describing, for the first time, P. knowlesi schizont-infected cell agglutination (SICA) var and Knowlesi-Interspersed Repeats (kir) multiple gene families in parasites acquired from nature. The SICAvar gene family members code for antigenically variant proteins analogous to the virulence-associated P. falciparum erythrocyte membrane protein (PfEMP1) multiple var gene family. Evidence presented here suggests that the SICAvar family members have arisen through a process of gene duplication, selection pressure, and variation. Highly evolving genes including PfEMP1family members tend to be restricted to relatively unstable sub-telomeric regions that drive change with core genes protected in genetically stable intrachromosomal locations. The comparable SICAvar and kir gene family members are counter-intuitively located across chromosomes. Here, we demonstrate that, in contrast to conserved core genes, SICAvar and kir genes occupy otherwise gene-sparse chromosomal locations that accommodate rapid evolution and change. The novel methods presented here offer the malaria research community not only new tools to generate comprehensive genome sequence data from small clinical samples but also new insight into the complexity of clinically important real-world parasites.
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Affiliation(s)
- Damilola R. Oresegun
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Peter Thorpe
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Ernest Diez Benavente
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Fauzi Muh
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
| | - Robert William Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Taane Gregory Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Janet Cox-Singh
- Division of Infection and Global Health, School of Medicine, University of St Andrews, Scotland, United Kingdom
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Castellanos M, Verhey TB, Goldstein M, Chaconas G. The Putative Endonuclease Activity of MutL Is Required for the Segmental Gene Conversion Events That Drive Antigenic Variation of the Lyme Disease Spirochete. Front Microbiol 2022; 13:888494. [PMID: 35663861 PMCID: PMC9159922 DOI: 10.3389/fmicb.2022.888494] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/18/2022] [Indexed: 11/30/2022] Open
Abstract
The Lyme disease spirochete Borrelia burgdorferi, encodes an elaborate antigenic variation system that promotes the ongoing variation of a major surface lipoprotein, VlsE. Changes in VlsE are continual and always one step ahead of the host acquired immune system, which requires 1–2 weeks to generate specific antibodies. By the time this happens, new VlsE variants have arisen that escape immunosurveillance, providing an avenue for persistent infection. This antigenic variation system is driven by segmental gene conversion events that transfer information from a series of silent cassettes (vls2-16) to the expression locus, vlsE. The molecular details of this process remain elusive. Recombinational switching at vlsE is RecA-independent and the only required factor identified to date is the RuvAB branch migrase. In this work we have used next generation long-read sequencing to analyze the effect of several DNA replication/recombination/repair gene disruptions on the frequency of gene conversions at vlsE and report a requirement for the mismatch repair protein MutL. Site directed mutagenesis of mutL suggests that the putative MutL endonuclease activity is required for recombinational switching at vlsE. This is the first report of an unexpected essential role for MutL in a bacterial recombination system and expands the known function of this protein as well as our knowledge of the details of the novel recombinational switching mechanism for vlsE variation.
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Affiliation(s)
- Mildred Castellanos
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Theodore B. Verhey
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Madeleine Goldstein
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - George Chaconas
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
- *Correspondence: George Chaconas,
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Liu Q, Zhan X, Li D, Zhao J, Wei H, Alzan H, He L. Establishment and Application of an Indirect Enzyme-Linked Immunosorbent Assay for Measuring GPI-Anchored Protein 52 (P52) Antibodies in Babesia gibsoni-Infected Dogs. Animals (Basel) 2022; 12:1197. [PMID: 35565622 PMCID: PMC9099545 DOI: 10.3390/ani12091197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/11/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022] Open
Abstract
Babesia gibsoni is a malaria-like protozoan that parasitizes the red blood cells of canids to cause babesiosis. Due to its high expression and essential function in the survival of parasites, the Glycosylphosphatidylinositol (GPI) anchor protein family is considered an excellent immunodiagnostic marker. Herein, we identified a novel GPI-anchored protein named as BgGPI52-WH with a size of 52 kDa; the recombinant BgGPI52-WH with high antigenicity and immunogenicity was used as a diagnostic antigen to establish a new iELISA method. The iELISA had a sensitivity of 1:400, and no cross-reaction with other apicomplexan parasites occurred. We further demonstrated that the degree of variation was less than 10% using the same samples from the same or different batches of an enzyme-labeled strip. It was found that the method was able to detect early infection (6 days after infection) in the sera of the B. gibsoni-infected experimental dogs in which antibody response to rBgGPI52-WH was evaluated. Clinical sera from pet hospitals were further tested, and the average positive rate was about 11.41% (17/149). The results indicate that BgGPI52-WH is a reliable diagnostic antigen, and the new iELISA could be used as a practical method for the early diagnosis of B. gibsoni.
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Affiliation(s)
- Qin Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Q.L.); (X.Z.); (D.L.); (J.Z.)
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China
| | - Xueyan Zhan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Q.L.); (X.Z.); (D.L.); (J.Z.)
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China
| | - Dongfang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Q.L.); (X.Z.); (D.L.); (J.Z.)
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Q.L.); (X.Z.); (D.L.); (J.Z.)
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan 430070, China
| | - Haiyong Wei
- Liuzhou Animal Husbandry Station in Guangxi Province, Liuzhou 545025, China;
| | - Heba Alzan
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99163, USA;
- Parasitology and Animal Diseases Department, National Research Center, Dokki, Giza 12622, Egypt
- Tick and Tick-Borne Disease Research Unit, National Research Center, Dokki, Giza 12622, Egypt
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Q.L.); (X.Z.); (D.L.); (J.Z.)
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan 430070, China
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Zuo H, Qiang J, Wang Y, Wang R, Wang G, Chai L, Ren G, Zhao Y, Zhang G, Zhang S. Design of red blood cell membrane-cloaked dihydroartemisinin nanoparticles with enhanced antimalarial efficacy. Int J Pharm 2022; 618:121665. [PMID: 35288223 DOI: 10.1016/j.ijpharm.2022.121665] [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: 10/13/2021] [Revised: 03/06/2022] [Accepted: 03/10/2022] [Indexed: 01/06/2023]
Abstract
Targeting delivery and prolonging action duration of artemisinin drugs are effective strategies for improving antimalarial treatment outcomes. Here, dihydroartemisinin (DHA) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (PDNs) were prepared and further cloaked with red blood cell (RBC) membranes via electrostatic interactions to yield RBC membrane-cloaked PDNs (RPDNs). The prepared RPDNs displayed a notable "core-shell" structure, with a negative surface charge of -29.2 ± 4.19 mV, a relatively uniform size distribution (86.4 ± 2.54 nm, polydispersity index of 0.179 ± 0.011), an average encapsulation efficiency (70.1 ± 0.79%), and a 24-h sustained-release behavior in vitro. Compared with PDNs, RPDNs showed markedly decreased phagocytic activity by RAW 264.7 cells and had prolonged blood circulation duration. The Pearson correlation coefficient of RPDNs distribution in infected red blood cells (iRBCs) was 0.7173, suggesting that RPDNs could effectively target Plasmodium-iRBCs. In PyBy265-infected mice, RPDNs showed a higher inhibition ratio (88.39 ± 2.69%) than PDNs (83.13 ± 2.12%) or DHA (58.74 ± 3.78%), at the same dose of 8.8 μmol/kg. The ED90 of RPDNs (8.13 ± 0.18 μmol/kg) was substantially lower than that of PDNs (14.48 ± 0.23 μmol/kg) and DHA (17.67 ± 3.38 μmol/kg). Furthermore, no apparent abnormalities were detected in routine blood examination, liver function indexes, and pathological analysis of tissue sections of PyBy265-infected mice following RPDNs treatment. In conclusion, the prepared RPDNs exhibited enhanced antimalarial efficacy, prolonged circulation, targeted delivery to Plasmodium-iRBCs, and satisfactory biocompatibility.
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Affiliation(s)
- Hengtong Zuo
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Jihong Qiang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Yidan Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Rongrong Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Geng Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Liqing Chai
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China; Shanxi Provincial People's Hospital, Taiyuan, 030012, China
| | - Guolian Ren
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Yongdan Zhao
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Guoshun Zhang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China
| | - Shuqiu Zhang
- School of Pharmacy, Shanxi Medical University, Taiyuan 030001, China.
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Ahmadi R, Emami S. Recent applications of vinyl sulfone motif in drug design and discovery. Eur J Med Chem 2022; 234:114255. [DOI: 10.1016/j.ejmech.2022.114255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/20/2022] [Accepted: 03/03/2022] [Indexed: 01/10/2023]
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Bandoh B, Kyei-Baafour E, Aculley B, van der Puije W, Tornyigah B, Akyea-Mensah K, Hviid L, Ngala RA, Frempong MT, Ofori MF. Influence of α2-Macroglobulin, Anti-Parasite IgM and ABO Blood Group on Rosetting in Plasmodium falciparum Clinical Isolates and Their Associations with Disease Severity in a Ghanaian Population. J Blood Med 2022; 13:151-164. [PMID: 35330697 PMCID: PMC8939864 DOI: 10.2147/jbm.s329177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/07/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose The severity of Plasmodium falciparum infections is associated with the ability of the infected red blood cells to cytoadhere to host vascular endothelial surfaces and to uninfected RBCs. Host blood group antigens and two serum proteins α2-macroglobulin (α2M) and IgM have been implicated in rosette formation in laboratory-adapted P. falciparum. However, there is only limited information about these phenotypes in clinical isolates. Methods This was a hospital-based study involving children under 12 years-of-age reporting to the Hohoe Municipal Hospital with different clinical presentations of malaria. Parasite isolates were grown and rosette capabilities and characteristics were investigated by fluorescence microscopy. α2M and IgM were detected by ELISA. Results Rosette formation was observed in 46.8% (75/160) of the parasite isolates from all the blood groups tested. Rosettes were more prevalent (55%) among isolates from patients with severe malaria compared to isolates from patients with uncomplicated malaria (45%). Rosette prevalence was highest (30%) among patients with blood group O (30%) and B (29%), while the mean rosette frequency was higher in isolates from patients with blood group A (28.7). Rosette formation correlated negatively with age (r = −0.09, P= 0.008). Participants with severe malaria had a lower IgM concentration (3.683±3.553) than those with uncomplicated malaria (5.256±4.294) and the difference was significant (P= 0.0228). The mean concentrations of anti-parasite IgM measured among the clinical isolates which formed rosettes was lower (4.2 ±3.930 mg/mL), than that in the non rosetting clinical isolates (4.604 ±4.159 mg/mL) but the difference was not significant (P=0.2733). There was no significant difference in plasma α2M concentration between rosetting and non rosetting isolates (P=0.442). Conclusion P. falciparum parasite rosette formation was affected by blood group type and plasma concentration of IgM. A lower IgM concentration was associated with severe malaria whilst a higher α2M concentration was associated with uncomplicated malaria.
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Affiliation(s)
- Betty Bandoh
- Department of Molecular Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Belinda Aculley
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - William van der Puije
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Bernard Tornyigah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Kwadwo Akyea-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Lars Hviid
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Robert A Ngala
- Department of Molecular Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Margaret T Frempong
- Department of Molecular Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- Correspondence: Michael F Ofori, Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Post Office Box LG581, Legon, Accra, Ghana, Tel +233 244 715975, Fax +233 302 502182, Email
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Shang X, Wang C, Shen L, Sheng F, He X, Wang F, Fan Y, He X, Jiang M. PfAP2-EXP2, an Essential Transcription Factor for the Intraerythrocytic Development of Plasmodium falciparum. Front Cell Dev Biol 2022; 9:782293. [PMID: 35083215 PMCID: PMC8785209 DOI: 10.3389/fcell.2021.782293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.
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Affiliation(s)
- Xiaomin Shang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.,Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Changhong Wang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Li Shen
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Fei Sheng
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaohui He
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.,National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Fei Wang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yanting Fan
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiaoqin He
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Mei Jiang
- Department of Medical Genetics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
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Indari O, Sk MF, Jakhmola S, Jonniya NA, Jha HC, Kar P. Decoding the Host-Parasite Protein Interactions Involved in Cerebral Malaria Through Glares of Molecular Dynamics Simulations. J Phys Chem B 2022; 126:387-402. [PMID: 34989590 DOI: 10.1021/acs.jpcb.1c07850] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Malaria causes millions of deaths every year. The malaria parasite spends a substantial part of its life cycle inside human erythrocytes. Inside erythrocytes, it synthesizes and displays various proteins onto the erythrocyte surface, such as Plasmodium falciparum erythrocytic membrane protein-1 (PfEMP1). This protein contains cysteine-rich interdomain region (CIDR) domains which have many subtypes based on sequence diversity and can cross-talk with host molecules. The CIDRα1.4 subtype can attach host endothelial protein C receptor (EPCR). This interaction facilitates infected erythrocyte adherence to brain endothelium and subsequent development of cerebral malaria. Through molecular dynamics simulations in conjunction with the molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) method, we explored the mechanism of interaction in the CIDRα1-EPCR complex. We examined the structural behavior of two CIDRα1 molecules (encoded by HB3-isolate var03-gene and IT4-isolate var07-gene) with EPCR unbound and bound (complex) forms. HB3var03CIDRα1 in apo and complexed with EPCR was comparatively more stable than IT4var07CIDRα1. Both of the complexes adopted two distinct conformational energy states. The hydrophobic residues played a crucial role in the binding of both complexes. For HB3var03CIDRα1-EPCR, the dominant energetic components were total polar interactions, while in IT4var07CIDRα1-EPCR, the primary interaction was van der Waals and nonpolar solvation energy. The study also revealed details such as correlated conformational motions and secondary structure evolution. Further, it elucidated various hotspot residues involved in protein-protein recognition. Overall, our study provides additional information on the structural behavior of CIDR molecules in unbound and receptor-bound states, which will help to design potent inhibitors.
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Affiliation(s)
- Omkar Indari
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
| | - Md Fulbabu Sk
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
| | - Shweta Jakhmola
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
| | - Nisha Amarnath Jonniya
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
| | - Hem Chandra Jha
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
| | - Parimal Kar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, MP 453552, India
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ABO blood group and risk of malaria during pregnancy: a systematic review and meta-analysis. Epidemiol Infect 2022; 150:e25. [PMID: 35193716 PMCID: PMC8888275 DOI: 10.1017/s095026882200005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The association between the ABO blood group and the risk of malaria during pregnancy has not been clearly established. The present study summarised relevant knowledge and reassessed the association through meta-analysis. Articles in MEDICINE and PubMed published before 30 November 2021 were searched. Five studies satisfied the inclusion criteria and were enrolled in the meta-analysis. It was shown that primiparae with different ABO blood group, multiparae with blood group A and non-A, AB and non-AB had a comparable risk of malaria. However, multiparae with blood group B had a significantly higher risk than non-B group [odds ratio (OR) = 1.23, 95% confidence interval (CI) was 1.01 to 1.50, P = 0.04], while multiparae with blood group O had a significantly lower risk than non-O group (OR = 0.78, 95% CI was 0.63 to 0.97, P = 0.03). Therefore, the ABO blood group may not result in a different risk of malaria in primiparae. Blood group B is potentially a risk factor while blood group O is a protective factor for multiparae.
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Tornyigah B, Ndam NT. Preservation of Parasite RNA in the Field. Methods Mol Biol 2022; 2470:19-25. [PMID: 35881335 DOI: 10.1007/978-1-0716-2189-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The pathogenesis of malaria is largely attributable to the parasite's ability to modulate its cytoadhesion phenotype. This relates to the multigenic families comprising dozens to hundreds of members, whose expression, often mutually exclusive, allows the parasite to vary its adhesive properties and antigenic appearance. This phenomenon is mainly described for the variant surface antigens that the parasite expresses on the infected erythrocyte. In order to decipher these gene expression spectra and identify potential antigenic candidates and/or targets of therapeutic interest, the analysis of the transcriptomes of the parasites directly isolated from patients with well-defined clinical presentation is important. RNA stabilization is an absolute prerequisite for a precise and accurate transcriptome profiling. Immediate stabilization of RNA of biological samples is therefore necessary to prevent degradation by ribonucleases (RNase) or cellular changes. This chapter described methodology for preserving parasite RNA samples from malaria patients in the field for transcriptome studies.
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Affiliation(s)
- Bernard Tornyigah
- Université de Paris, MERIT, IRD, Paris, France
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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Azasi Y, Rowe JA. Selecting Plasmodium falciparum Infected Erythrocytes for Adhesion to Cell Lines. Methods Mol Biol 2022; 2470:91-100. [PMID: 35881341 DOI: 10.1007/978-1-0716-2189-9_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Plasmodium falciparum expresses variant surface antigens on the surface of mature infected erythrocytes (IEs) for binding to various receptors on host cells (cytoadhesion) to evade host immunity. This enables IEs to sequester in the microvasculature of different organs and tissues of the host, contributing to different outcomes of disease. The in vitro study of cytoadhesion involves the use of IEs and human endothelial cells or other cell lines that express host cell receptors. To enrich for IE populations that bind to certain cell types or receptors, we describe a method for panning mature pigmented trophozoite IEs on cell lines. The method enables coculturing of IEs with cells of interest and the selection of IEs that cytoadhere for continuous culturing. The method serves as a tool for generating IEs with specific cell or cell receptor adhesion phenotypes to allow detailed studies of cytoadhesion interactions.
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Affiliation(s)
- Yvonne Azasi
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
| | - J Alexandra Rowe
- Ashworth Laboratories, Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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Tanaka M, Lanzer M. Receptor-Functionalized Lipid Membranes as Biomimetic Surfaces for Adhesion of Plasmodium falciparum-Infected Erythrocytes. Methods Mol Biol 2022; 2470:601-613. [PMID: 35881377 DOI: 10.1007/978-1-0716-2189-9_45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Here, we describe a detailed protocol of how to manufacture biomimetic, host receptor-functionalized membranes and how to use them in adhesion assays. Receptor-functionalized membranes have the advantage that the receptor identity and the receptor density can be controlled, which, in turn, enables studies on the kinetics, dynamics and biomechanics of receptor/ligand interactions. Such information is difficult to obtain from currently used in vitro systems, including cultured primary human microvascular endothelial cells or receptor-coated surfaces, which often display either multiple receptors or receptors with uncertain density and arrangement.
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Affiliation(s)
- Motomu Tanaka
- Physical Chemistry of Biosystems, Heidelberg University, Heidelberg, Germany
- Center for Integrative Medicine and Physics, Institute for Advanced Study, Kyoto University, Kyoto, Japan
| | - Michael Lanzer
- Department of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Heidelberg, Germany.
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50
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Oleinikov AV. High-Throughput BioPlex Assay for the Study of Functionally Active Plasmodium Falciparum Antigens That Are Expressed on the Surface of Infected Erythrocytes. Methods Mol Biol 2022; 2470:327-342. [PMID: 35881356 DOI: 10.1007/978-1-0716-2189-9_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Identification of P. falciparum infected erythrocyte surface ligands (such as PfEMP1) matched with the host receptors they interact with, as well as identification of PfEMP1 domains that are targets of protective immunity, are important for understanding of the pathophysiology of severe malaria (SM) and for design of novel vaccine candidates. In addition, identification of small-molecule drugs that can prevent or reverse receptor-ligand domain interactions could provide new tools for adjunctive therapy in SM. This protocol describes how to prepare functionally intact PfEMP1 proteins in mammalian cells (COS-7) and immobilize them on the surface of BioPlex beads. Furthermore, the protocol described how to identify PfEMP1 constructs that bind to specific host receptors or to immunoglobulins (IgG, IgM, etc.), and how to measure inhibition of the receptor binding to PfEMP1 constructs by small-molecule compounds or serum/plasma.
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Affiliation(s)
- Andrew V Oleinikov
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
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