1
|
Joof F, Hu R, Saidi A, Seydel KB, Cohee LM, Zheng Y, Smith JD. Plasma from older children in Malawi inhibits Plasmodium falciparum binding in 3D brain microvessels. J Infect Dis 2024:jiae315. [PMID: 38875153 DOI: 10.1093/infdis/jiae315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/02/2024] [Accepted: 06/12/2024] [Indexed: 06/16/2024] Open
Abstract
A hallmark of cerebral malaria is sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain microcirculation. Antibodies contribute to malaria immunity, but it remains unclear whether functional antibodies targeting parasite-expressed ligand can block cytoadhesion in the brain. Here, we screened the plasma of older children and young adults in Malawi to characterize the antibody response against the P. falciparum-IE surface and used a bioengineered 3D human brain microvessel model incorporating variable flow dynamics to measure adhesion blocking responses. We found a strong correlation between surface antibody reactivity by flow cytometry and reduced P. falciparum-IE binding in 3D microvessels. Moreover, there was a threshold of surface antibody reactivity necessary to achieve robust inhibitory activity. Our findings provide evidence of the acquisition of adhesion blocking antibodies against cerebral binding variants in people exposed to stable P. falciparum transmission and suggest the quality of the inhibitory response can be influenced by flow dynamics.
Collapse
Affiliation(s)
- Fatou Joof
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA USA
| | - Ruoqian Hu
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Alex Saidi
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Karl B Seydel
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ying Zheng
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Joseph D Smith
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA USA
- Department of Pediatrics, School of Medicine, University of Washington, Seattle, WA, USA
| |
Collapse
|
2
|
Kimenyi KM, Akinyi MY, Mwikali K, Gilmore T, Mwangi S, Omer E, Gichuki B, Wambua J, Njunge J, Obiero G, Bejon P, Langhorne J, Abdi A, Ochola-Oyier LI. Distinct transcriptomic signatures define febrile malaria depending on initial infective states, asymptomatic or uninfected. BMC Infect Dis 2024; 24:140. [PMID: 38287287 PMCID: PMC10823747 DOI: 10.1186/s12879-024-08973-2] [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: 09/21/2023] [Accepted: 01/01/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Cumulative malaria parasite exposure in endemic regions often results in the acquisition of partial immunity and asymptomatic infections. There is limited information on how host-parasite interactions mediate the maintenance of chronic symptomless infections that sustain malaria transmission. METHODS Here, we determined the gene expression profiles of the parasite population and the corresponding host peripheral blood mononuclear cells (PBMCs) from 21 children (< 15 years). We compared children who were defined as uninfected, asymptomatic and those with febrile malaria. RESULTS Children with asymptomatic infections had a parasite transcriptional profile characterized by a bias toward trophozoite stage (~ 12 h-post invasion) parasites and low parasite levels, while early ring stage parasites were characteristic of febrile malaria. The host response of asymptomatic children was characterized by downregulated transcription of genes associated with inflammatory responses, compared with children with febrile malaria,. Interestingly, the host responses during febrile infections that followed an asymptomatic infection featured stronger inflammatory responses, whereas the febrile host responses from previously uninfected children featured increased humoral immune responses. CONCLUSIONS The priming effect of prior asymptomatic infection may explain the blunted acquisition of antibody responses seen to malaria antigens following natural exposure or vaccination in malaria endemic areas.
Collapse
Affiliation(s)
- Kelvin M Kimenyi
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Biochemistry, University of Nairobi, Nairobi, Kenya
| | | | - Kioko Mwikali
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Shaban Mwangi
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
| | - Elisha Omer
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - James Njunge
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
| | - George Obiero
- Department of Biochemistry, University of Nairobi, Nairobi, Kenya
| | - Philip Bejon
- KEMRI‑Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | | | | |
Collapse
|
3
|
Walker IS, Rogerson SJ. Pathogenicity and virulence of malaria: Sticky problems and tricky solutions. Virulence 2023; 14:2150456. [PMID: 36419237 PMCID: PMC9815252 DOI: 10.1080/21505594.2022.2150456] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/25/2022] Open
Abstract
Infections with Plasmodium falciparum and Plasmodium vivax cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection. In this article, we review the latest developments in the immunogenicity and pathogenesis of malaria, with a particular focus on P. falciparum, the leading malaria killer. Pathogenic factors include parasite-derived toxins and variant surface antigens on infected erythrocytes that mediate sequestration in the deep vasculature. Host response to parasite toxins and to variant antigens is an important determinant of disease severity. Understanding how parasites sequester, and how antibody to variant antigens could prevent sequestration, may lead to new approaches to treat and prevent disease. Difficulties in malaria diagnosis, drug resistance, and specific challenges of treating P. vivax pose challenges to malaria elimination, but vaccines and other preventive strategies may offer improved disease control.
Collapse
Affiliation(s)
- Isobel S Walker
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| | - Stephen J Rogerson
- Department of Infectious Diseases, The University of Melbourne, The Doherty Institute, Melbourne, Australia
| |
Collapse
|
4
|
Tan MH, Tiedje KE, Feng Q, Zhan Q, Pascual M, Shim H, Chan YB, Day KP. A paradoxical population structure of var DBLα types in Africa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.05.565723. [PMID: 37986738 PMCID: PMC10659346 DOI: 10.1101/2023.11.05.565723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The var multigene family encodes the P. falciparum erythrocyte membrane protein 1 (PfEMP1), which is important in host-parasite interaction as a virulence factor and major surface antigen of the blood stages of the parasite, responsible for maintaining chronic infection. Whilst important in the biology of P. falciparum, these genes (50 to 60 genes per parasite genome) are routinely excluded from whole genome analyses due to their hyper-diversity, achieved primarily through recombination. The PfEMP1 head structure almost always consists of a DBLα-CIDR tandem. Categorised into different groups (upsA, upsB, upsC), different head structures have been associated with different ligand-binding affinities and disease severities. We study how conserved individual DBLα types are at the country, regional, and local scales in Sub-Saharan Africa. Using publicly-available sequence datasets and a novel ups classification algorithm, cUps, we performed an in silico exploration of DBLα conservation through time and space in Africa. In all three ups groups, the population structure of DBLα types in Africa consists of variants occurring at rare, low, moderate, and high frequencies. Non-rare variants were found to be temporally stable in a local area in endemic Ghana. When inspected across different geographical scales, we report different levels of conservation; while some DBLα types were consistently found in high frequencies in multiple African countries, others were conserved only locally, signifying local preservation of specific types. Underlying this population pattern is the composition of DBLα types within each isolate DBLα repertoire, revealed to also consist of a mix of types found at rare, low, moderate, and high frequencies in the population. We further discuss the adaptive forces and balancing selection, including host genetic factors, potentially shaping the evolution and diversity of DBLα types in Africa.
Collapse
Affiliation(s)
- Mun Hua Tan
- Department of Microbiology and Immunology, The University of Melbourne, Bio21 Institute and Peter Doherty Institute, Melbourne, AU
| | - Kathryn E Tiedje
- Department of Microbiology and Immunology, The University of Melbourne, Bio21 Institute and Peter Doherty Institute, Melbourne, AU
| | - Qian Feng
- School of Mathematics and Statistics / Melbourne Integrative Genomics, The University of Melbourne, Melbourne, Australia
| | - Qi Zhan
- Department of Ecology and Evolution, University of Chicago; Chicago, Illinois, USA
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago; Chicago, Illinois, USA
| | - Heejung Shim
- School of Mathematics and Statistics / Melbourne Integrative Genomics, The University of Melbourne, Melbourne, Australia
| | - Yao-Ban Chan
- School of Mathematics and Statistics / Melbourne Integrative Genomics, The University of Melbourne, Melbourne, Australia
| | - Karen P Day
- Department of Microbiology and Immunology, The University of Melbourne, Bio21 Institute and Peter Doherty Institute, Melbourne, AU
| |
Collapse
|
5
|
Barua P, Duffy MF, Manning L, Laman M, Davis TME, Mueller I, Haghiri A, Simpson JA, Beeson JG, Rogerson SJ. Antibody to Plasmodium falciparum Variant Surface Antigens, var Gene Transcription, and ABO Blood Group in Children With Severe or Uncomplicated Malaria. J Infect Dis 2023; 228:1099-1107. [PMID: 37341543 PMCID: PMC10582907 DOI: 10.1093/infdis/jiad217] [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: 11/13/2022] [Revised: 06/08/2023] [Accepted: 06/20/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Antibodies to variant surface antigens (VSAs) such as Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) may vary with malaria severity. The influence of ABO blood group on antibody development is not understood. METHODS Immunoglobulin G antibodies to VSAs in Papua New Guinean children with severe (n = 41) or uncomplicated (n = 30) malaria were measured by flow cytometry using homologous P falciparum isolates. Isolates were incubated with ABO-matched homologous and heterologous acute and convalescent plasma. RNA was used to assess var gene transcription. RESULTS Antibodies to homologous, but not heterologous, isolates were boosted in convalescence. The relationship between antibody and severity varied by blood group. Antibodies to VSAs were similar in severe and uncomplicated malaria at presentation, higher in severe than uncomplicated malaria in convalescence, and higher in children with blood group O than other children. Six var gene transcripts best distinguished severe from uncomplicated malaria, including UpsA and 2 CIDRα1 domains. CONCLUSIONS ABO blood group may influence antibody acquisition to VSAs and susceptibility to severe malaria. Children in Papua New Guinea showed little evidence of acquisition of cross-reactive antibodies following malaria. Var gene transcripts in Papua New Guinean children with severe malaria were similar to those reported from Africa.
Collapse
Affiliation(s)
- Priyanka Barua
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
| | - Michael F Duffy
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, Bio21 Institute, University of Melbourne, Parkville, Victoria
| | | | - Moses Laman
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang
| | | | - Ivo Mueller
- Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Victoria, Australia
- Department of Parasites and Insect Vector, Institut Pasteur, Paris, France
| | - Ali Haghiri
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - James G Beeson
- Malaria Immunity and Vaccines Laboratory, Burnet Institute, Melbourne
- Central Clinical School and Department of Microbiology, Monash University, Clayton
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
6
|
Wiser MF. Knobs, Adhesion, and Severe Falciparum Malaria. Trop Med Infect Dis 2023; 8:353. [PMID: 37505649 PMCID: PMC10385726 DOI: 10.3390/tropicalmed8070353] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 06/30/2023] [Accepted: 07/02/2023] [Indexed: 07/29/2023] Open
Abstract
Plasmodium falciparum can cause a severe disease with high mortality. A major factor contributing to the increased virulence of P. falciparum, as compared to other human malarial parasites, is the sequestration of infected erythrocytes in the capillary beds of organs and tissues. This sequestration is due to the cytoadherence of infected erythrocytes to endothelial cells. Cytoadherence is primarily mediated by a parasite protein expressed on the surface of the infected erythrocyte called P. falciparum erythrocyte membrane protein-1 (PfEMP1). PfEMP1 is embedded in electron-dense protuberances on the surface of the infected erythrocytes called knobs. These knobs are assembled on the erythrocyte membrane via exported parasite proteins, and the knobs function as focal points for the cytoadherence of infected erythrocytes to endothelial cells. PfEMP1 is a member of the var gene family, and there are approximately 60 antigenically distinct PfEMP1 alleles per parasite genome. Var gene expression exhibits allelic exclusion, with only a single allele being expressed by an individual parasite. This results in sequential waves of antigenically distinct infected erythrocytes and this antigenic variation allows the parasite to establish long-term chronic infections. A wide range of endothelial cell receptors can bind to the various PfEMP1 alleles, and thus, antigenic variation also results in a change in the cytoadherence phenotype. The cytoadherence phenotype may result in infected erythrocytes sequestering in different tissues and this difference in sequestration may explain the wide range of possible clinical manifestations associated with severe falciparum malaria.
Collapse
Affiliation(s)
- Mark F Wiser
- Department of Tropical Medicine and Infectious Disease, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, New Orleans, LA 70112, USA
| |
Collapse
|
7
|
CD36-A Host Receptor Necessary for Malaria Parasites to Establish and Maintain Infection. Microorganisms 2022; 10:microorganisms10122356. [PMID: 36557610 PMCID: PMC9785914 DOI: 10.3390/microorganisms10122356] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/21/2022] [Accepted: 11/27/2022] [Indexed: 11/30/2022] Open
Abstract
Plasmodium falciparum-infected erythrocytes (PfIEs) present P. falciparum erythrocyte membrane protein 1 proteins (PfEMP1s) on the cell surface, via which they cytoadhere to various endothelial cell receptors (ECRs) on the walls of human blood vessels. This prevents the parasite from passing through the spleen, which would lead to its elimination. Each P. falciparum isolate has about 60 different PfEMP1s acting as ligands, and at least 24 ECRs have been identified as interaction partners. Interestingly, in every parasite genome sequenced to date, at least 75% of the encoded PfEMP1s have a binding domain for the scavenger receptor CD36 widely distributed on host endothelial cells and many other cell types. Here, we discuss why the interaction between PfIEs and CD36 is optimal to maintain a finely regulated equilibrium that allows the parasite to multiply and spread while causing minimal harm to the host in most infections.
Collapse
|
8
|
Rehn T, Lubiana P, Nguyen THT, Pansegrau E, Schmitt M, Roth LK, Brehmer J, Roeder T, Cadar D, Metwally NG, Bruchhaus I. Ectopic Expression of Plasmodium vivax vir Genes in P. falciparum Affects Cytoadhesion via Increased Expression of Specific var Genes. Microorganisms 2022; 10:microorganisms10061183. [PMID: 35744701 PMCID: PMC9230084 DOI: 10.3390/microorganisms10061183] [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: 05/10/2022] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Plasmodium falciparum-infected erythrocytes (PfIEs) adhere to endothelial cell receptors (ECRs) of blood vessels mainly via PfEMP1 proteins to escape elimination via the spleen. Evidence suggests that P. vivax-infected reticulocytes (PvIRs) also bind to ECRs, presumably enabled by VIR proteins, as shown by inhibition experiments and studies with transgenic P. falciparum expressing vir genes. To test this hypothesis, our study investigated the involvement of VIR proteins in cytoadhesion using vir gene-expressing P. falciparum transfectants. Those VIR proteins with a putative transmembrane domain were present in Maurer's clefts, and some were also present in the erythrocyte membrane. The VIR protein without a transmembrane domain (PVX_050690) was not exported. Five of the transgenic P. falciparum cell lines, including the one expressing PVX_050690, showed binding to CD36. We observed highly increased expression of specific var genes encoding PfEMP1s in all CD36-binding transfectants. These results suggest that ectopic vir expression regulates var expression through a yet unknown mechanism. In conclusion, the observed cytoadhesion of P. falciparum expressing vir genes depended on PfEMP1s, making this experimental unsuitable for characterizing VIR proteins.
Collapse
Affiliation(s)
- Torben Rehn
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Pedro Lubiana
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Thi Huyen Trang Nguyen
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Eva Pansegrau
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Marius Schmitt
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Lisa Katharina Roth
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Jana Brehmer
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Thomas Roeder
- Molecular Physiology Department, Zoological Institute, Christian-Albrechts University Kiel, 24118 Kiel, Germany;
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), 24118 Kiel, Germany
| | - Dániel Cadar
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Nahla Galal Metwally
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (T.R.); (P.L.); (T.H.T.N.); (E.P.); (M.S.); (L.K.R.); (J.B.); (D.C.); (N.G.M.)
- Department of Biology, University of Hamburg, 22601 Hamburg, Germany
- Correspondence:
| |
Collapse
|
9
|
Identifying Targets of Protective Antibodies against Severe Malaria in Papua, Indonesia, Using Locally Expressed Domains of Plasmodium falciparum Erythrocyte Membrane Protein 1. Infect Immun 2022; 90:e0043521. [PMID: 34871039 PMCID: PMC8853675 DOI: 10.1128/iai.00435-21] [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] [Indexed: 01/12/2023] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), a diverse family of multidomain proteins expressed on the surface of malaria-infected erythrocytes, is an important target of protective immunity against malaria. Our group recently studied transcription of the var genes encoding PfEMP1 in individuals from Papua, Indonesia, with severe or uncomplicated malaria. We cloned and expressed domains from 32 PfEMP1s, including 22 that were upregulated in severe malaria and 10 that were upregulated in uncomplicated malaria, using a wheat germ cell-free expression system. We used Luminex technology to measure IgG antibodies to these 32 domains and control proteins in 63 individuals (11 children). At presentation to hospital, levels of antibodies to PfEMP1 domains were either higher in uncomplicated malaria or were not significantly different between groups. Using principal component analysis, antibodies to 3 of 32 domains were highly discriminatory between groups. These included two domains upregulated in severe malaria, a DBLβ13 domain and a CIDRα1.6 domain (which has been previously implicated in severe malaria pathogenesis), and a DBLδ domain that was upregulated in uncomplicated malaria. Antibody to control non-PfEMP1 antigens did not differ with disease severity. Antibodies to PfEMP1 domains differ with malaria severity. Lack of antibodies to locally expressed PfEMP1 types, including both domains previously associated with severe malaria and newly identified targets, may in part explain malaria severity in Papuan adults.
Collapse
|
10
|
Ortolan LS, Avril M, Xue J, Seydel KB, Zheng Y, Smith JD. Plasmodium falciparum Parasite Lines Expressing DC8 and Group A PfEMP1 Bind to Brain, Intestinal, and Kidney Endothelial Cells. Front Cell Infect Microbiol 2022; 12:813011. [PMID: 35155278 PMCID: PMC8831842 DOI: 10.3389/fcimb.2022.813011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/10/2022] [Indexed: 11/13/2022] Open
Abstract
Cytoadhesion of Plasmodium falciparum-infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum, CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria.
Collapse
Affiliation(s)
- Luana S. Ortolan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Marion Avril
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Jun Xue
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Karl B. Seydel
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Ying Zheng
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Joseph D. Smith
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington, Seattle, WA, United States
- *Correspondence: Joseph D. Smith,
| |
Collapse
|
11
|
Prata IO, Cubillos EFG, Krüger A, Barbosa D, Martins J, Setubal JC, Wunderlich G. Plasmodium falciparum Acetyl-CoA Synthetase Is Essential for Parasite Intraerythrocytic Development and Chromatin Modification. ACS Infect Dis 2021; 7:3224-3240. [PMID: 34766750 DOI: 10.1021/acsinfecdis.1c00414] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The malaria parasite Plasmodium falciparum possesses a unique Acetyl-CoA Synthetase (PfACS), which provides acetyl moieties for different metabolic and regulatory cellular pathways. We characterized PfACS and studied its role focusing on epigenetic modifications using the var gene family as reporter genes. For this, mutant lines to modulate plasmodial ACS expression by degron-mediated protein degradation and ribozyme-induced transcript decay were created. Additionally, an inhibitor of the human Acetyl-CoA Synthetase 2 was tested for its effectiveness in interfering with PfACS. The knockdown of PfACS or its inhibition resulted in impaired parasite growth. Decreased levels of PfACS also led to differential histone acetylation patterns, altered variant gene expression, and concomitantly decreased cytoadherence of infected red blood cells containing knocked-down parasites. Further, ChIP analysis revealed the presence of PfACS in many loci in ring stage parasites, underscoring its involvement in the regulation of chromatin. Due to its central function in the plasmodial metabolism and significant differences to human ACS, PfACS is an interesting target for drug development.
Collapse
Affiliation(s)
- Isadora Oliveira Prata
- Department of Parasitology, Institute for Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| | - Eliana Fernanda Galindo Cubillos
- Department of Parasitology, Institute for Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| | - Arne Krüger
- Department of Parasitology, Institute for Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| | - Deibs Barbosa
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Avenida Professor Lineu Prestes 748, 05508-000 São Paulo-SP, Brazil
| | - Joaquim Martins
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Avenida Professor Lineu Prestes 748, 05508-000 São Paulo-SP, Brazil
| | - João Carlos Setubal
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Avenida Professor Lineu Prestes 748, 05508-000 São Paulo-SP, Brazil
| | - Gerhard Wunderlich
- Department of Parasitology, Institute for Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| |
Collapse
|
12
|
Webster R, Sekuloski S, Odedra A, Woolley S, Jennings H, Amante F, Trenholme KR, Healer J, Cowman AF, Eriksson EM, Sathe P, Penington J, Blanch AJ, Dixon MWA, Tilley L, Duffy MF, Craig A, Storm J, Chan JA, Evans K, Papenfuss AT, Schofield L, Griffin P, Barber BE, Andrew D, Boyle MJ, de Labastida Rivera F, Engwerda C, McCarthy JS. Safety, infectivity and immunogenicity of a genetically attenuated blood-stage malaria vaccine. BMC Med 2021; 19:293. [PMID: 34802442 PMCID: PMC8606250 DOI: 10.1186/s12916-021-02150-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/30/2021] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND There is a clear need for novel approaches to malaria vaccine development. We aimed to develop a genetically attenuated blood-stage vaccine and test its safety, infectivity, and immunogenicity in healthy volunteers. Our approach was to target the gene encoding the knob-associated histidine-rich protein (KAHRP), which is responsible for the assembly of knob structures at the infected erythrocyte surface. Knobs are required for correct display of the polymorphic adhesion ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1), a key virulence determinant encoded by a repertoire of var genes. METHODS The gene encoding KAHRP was deleted from P. falciparum 3D7 and a master cell bank was produced in accordance with Good Manufacturing Practice. Eight malaria naïve males were intravenously inoculated (day 0) with 1800 (2 subjects), 1.8 × 105 (2 subjects), or 3 × 106 viable parasites (4 subjects). Parasitemia was measured using qPCR; immunogenicity was determined using standard assays. Parasites were rescued into culture for in vitro analyses (genome sequencing, cytoadhesion assays, scanning electron microscopy, var gene expression). RESULTS None of the subjects who were administered with 1800 or 1.8 × 105 parasites developed parasitemia; 3/4 subjects administered 3× 106 parasites developed significant parasitemia, first detected on days 13, 18, and 22. One of these three subjects developed symptoms of malaria simultaneously with influenza B (day 17; 14,022 parasites/mL); one subject developed mild symptoms on day 28 (19,956 parasites/mL); and one subject remained asymptomatic up to day 35 (5046 parasites/mL). Parasitemia rapidly cleared with artemether/lumefantrine. Parasitemia induced a parasite-specific antibody and cell-mediated immune response. Parasites cultured ex vivo exhibited genotypic and phenotypic properties similar to inoculated parasites, although the var gene expression profile changed during growth in vivo. CONCLUSIONS This study represents the first clinical investigation of a genetically attenuated blood-stage human malaria vaccine. A P. falciparum 3D7 kahrp- strain was tested in vivo and found to be immunogenic but can lead to patent parasitemia at high doses. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry (number: ACTRN12617000824369 ; date: 06 June 2017).
Collapse
Affiliation(s)
- Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Silvana Sekuloski
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Current address: PharmOut, 111 Eagle Street, Brisbane, Queensland, 4000, Australia
| | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Liverpool School of Tropical Medicine, Liverpool, UK
| | - Stephen Woolley
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Liverpool School of Tropical Medicine, Liverpool, UK.,Centre of Defence Pathology, Royal Centre for Defence Medicine, Joint Hospital Group, Birmingham, UK
| | - Helen Jennings
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona Amante
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Katharine R Trenholme
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,The University of Queensland, Brisbane, Australia
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
| | - Emily M Eriksson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Priyanka Sathe
- Current address: Medicines Development for Global Health Limited, 18 Kavanagh Street, Southbank, Victoria, 3006, Australia
| | - Jocelyn Penington
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Adam J Blanch
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Matthew W A Dixon
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Leann Tilley
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Michael F Duffy
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia.,Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Department of Medicine, Royal Melbourne Hospital, Melbourne, Australia
| | - Alister Craig
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Janet Storm
- Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Krystal Evans
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Current address: GSK, 436 Johnston Street, Abbotsford, Victoria, 3067, Australia
| | - Anthony T Papenfuss
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Louis Schofield
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Paul Griffin
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,The University of Queensland, Brisbane, Australia.,Department of Medicine and Infectious Diseases, Mater Hospital and Mater Research, Brisbane, Australia
| | | | - Dean Andrew
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia. .,The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
| |
Collapse
|
13
|
Ventimiglia NT, Stucke EM, Coulibaly D, Berry AA, Lyke KE, Laurens MB, Bailey JA, Adams M, Niangaly A, Kone AK, Takala-Harrison S, Kouriba B, Doumbo OK, Felgner PL, Plowe CV, Thera MA, Travassos MA. Malian adults maintain serologic responses to virulent PfEMP1s amid seasonal patterns of fluctuation. Sci Rep 2021; 11:14401. [PMID: 34257318 PMCID: PMC8277812 DOI: 10.1038/s41598-021-92974-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 06/08/2021] [Indexed: 12/03/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein-1s (PfEMP1s), diverse malaria proteins expressed on the infected erythrocyte surface, play an important role in pathogenesis, mediating adhesion to host vascular endothelium. Antibodies to particular non-CD36-binding PfEMP1s are associated with protection against severe disease. We hypothesized that given lifelong P. falciparum exposure, Malian adults would have broad PfEMP1 serorecognition and high seroreactivity levels during follow-up, particularly to non-CD36-binding PfEMP1s such as those that attach to endothelial protein C receptor (EPCR) and intercellular adhesion molecule-1 (ICAM-1). Using a protein microarray, we determined serologic responses to 166 reference PfEMP1 fragments during a dry and subsequent malaria transmission season in Malian adults. Malian adult sera had PfEMP1 serologic responses throughout the year, with decreased reactivity to a small subset of PfEMP1 fragments during the dry season and increases in reactivity to a different subset of PfEMP1 fragments during the subsequent peak malaria transmission season, especially for intracellular PfEMP1 domains. For some individuals, PfEMP1 serologic responses increased after the dry season, suggesting antigenic switching during asymptomatic infection. Adults were more likely to experience variable serorecognition of CD36-binding PfEMP1s than non-CD36-binding PfEMP1s that bind EPCR or ICAM-1, which remained serorecognized throughout the year. Sustained seroreactivity to non-CD36-binding PfEMP1s throughout adulthood amid seasonal fluctuation patterns may reflect underlying protective severe malaria immunity and merits further investigation.
Collapse
Affiliation(s)
| | - Emily M Stucke
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Drissa Coulibaly
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Andrea A Berry
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E Lyke
- University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Jason A Bailey
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew Adams
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amadou Niangaly
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K Kone
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | | | - Bourema Kouriba
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Ogobara K Doumbo
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | | | | | | | | |
Collapse
|
14
|
Petersen JEV, Saelens JW, Freedman E, Turner L, Lavstsen T, Fairhurst RM, Diakité M, Taylor SM. Sickle-trait hemoglobin reduces adhesion to both CD36 and EPCR by Plasmodium falciparum-infected erythrocytes. PLoS Pathog 2021; 17:e1009659. [PMID: 34115805 PMCID: PMC8221791 DOI: 10.1371/journal.ppat.1009659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/23/2021] [Accepted: 05/20/2021] [Indexed: 01/01/2023] Open
Abstract
Sickle-trait hemoglobin protects against severe Plasmodium falciparum malaria. Severe malaria is governed in part by the expression of the Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) that are encoded by var genes, specifically those variants that bind Endothelial Protein C Receptor (EPCR). In this study, we investigate the effect of sickle-trait on parasite var gene expression and function in vitro and in field-collected parasites. We mapped var gene reads generated from RNA sequencing in parasite cultures in normal and sickle-cell trait blood throughout the asexual lifecycle. We investigated sickle-trait effect on PfEMP1 interactions with host receptors CD36 and EPCR using static adhesion assays and flow cytometry. Var expression in vivo was compared by assembling var domains sequenced from total RNA in parasites infecting Malian children with HbAA and HbAS. Sickle-trait did not alter the abundance or type of var gene transcripts in vitro, nor the abundance of overall transcripts or of var functional domains in vivo. In adhesion assays using recombinant host receptors, sickle-trait reduced adhesion by 73-86% to CD36 and 83% to EPCR. Similarly, sickle-trait reduced the surface expression of EPCR-binding PfEMP1. In conclusion, Sickle-cell trait does not directly affect var gene transcription but does reduce the surface expression and function of PfEMP1. This provides a direct mechanism for protection against severe malaria conferred by sickle-trait hemoglobin. Trial Registration: ClinicalTrials.gov Identifier: NCT02645604.
Collapse
Affiliation(s)
- Jens E. V. Petersen
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
- * E-mail:
| | - Joseph W. Saelens
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Elizabeth Freedman
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Louise Turner
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mahamadou Diakité
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Steve M. Taylor
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| |
Collapse
|
15
|
Padilla A, Dovell S, Chesnokov O, Hoggard M, Oleinikov AV, Marí F. Conus venom fractions inhibit the adhesion of Plasmodium falciparum erythrocyte membrane protein 1 domains to the host vascular receptors. J Proteomics 2020; 234:104083. [PMID: 33373718 DOI: 10.1016/j.jprot.2020.104083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/28/2020] [Accepted: 12/20/2020] [Indexed: 11/16/2022]
Abstract
Using high-throughput BioPlex assays, we determined that six fractions from the venom of Conus nux inhibit the adhesion of various recombinant PfEMP-1 protein domains (PF08_0106 CIDR1α3.1, PF11_0521 DBL2β3, and PFL0030c DBL3X and DBL5e) to their corresponding receptors (CD36, ICAM-1, and CSA, respectively). The protein domain-receptor interactions permit P. falciparum-infected erythrocytes (IE) to evade elimination in the spleen by adhering to the microvasculature in various organs including the placenta. The sequences for the main components of the fractions, determined by tandem mass spectrometry, yielded four T-superfamily conotoxins, one (CC-Loop-CC) with I-IV, II-III connectivity and three (CC-Loop-CXaaC) with a I-III, II-IV connectivity. The 3D structure for one of the latter, NuxVA = GCCPAPLTCHCVIY, revealed a novel scaffold defined by double turns forming a hairpin-like structure stabilized by the two disulfide bonds. Two other main fraction components were a miniM conotoxin, and a O2-superfamily conotoxin with cysteine framework VI/VII. This study is the first one of its kind suggesting the use of conotoxins for developing pharmacological tools for anti-adhesion adjunct therapy against malaria. Similarly, mitigation of emerging diseases like AIDS and COVID-19, can also benefit from conotoxins as inhibitors of protein-protein interactions as treatment. BIOLOGICAL SIGNIFICANCE: Among the 850+ species of cone snail species there are hundreds of thousands of diverse venom exopeptides that have been selected throughout several million years of evolution to capture prey and deter predators. They do so by targeting several surface proteins present in target excitable cells. This immense biomolecular library of conopeptides can be explored for potential use as therapeutic leads against persistent and emerging diseases affecting non-excitable systems. We aim to expand the pharmacological reach of conotoxins/conopeptides by revealing their in vitro capacity to disrupt protein-protein and protein-polysaccharide interactions that directly contribute to pathology of Plasmodium falciparum malaria. This is significant for severe forms of malaria, which might be deadly even after treated with current parasite-killing drugs because of persistent cytoadhesion of P. falciparum infected erythrocytes even when parasites within red blood cells are dead. Anti-adhesion adjunct drugs would de-sequester or prevent additional sequestration of infected erythrocytes and may significantly improve survival of malaria patients. These results provide a lead for further investigations into conotoxins and other venom peptides as potential candidates for anti-adhesion or blockade-therapies. This study is the first of its kind and it suggests that conotoxins can be developed as pharmacological tools for anti-adhesion adjunct therapy against malaria. Similarly, mitigation of emerging diseases like AIDS and COVID-19, can also benefit from conotoxins as potential inhibitors of protein-protein interactions as treatment.
Collapse
Affiliation(s)
- Alberto Padilla
- Department of Biological Sciences, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Sanaz Dovell
- Department of Chemistry & Biochemistry, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Olga Chesnokov
- Department of Biomedical Science, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Mickelene Hoggard
- Chemical Sciences Division, Hollings Marine Laboratory, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Andrew V Oleinikov
- Department of Biomedical Science, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA.
| | - Frank Marí
- Chemical Sciences Division, Hollings Marine Laboratory, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, SC 29412, USA.
| |
Collapse
|
16
|
Obeng-Adjei N, Larremore DB, Turner L, Ongoiba A, Li S, Doumbo S, Yazew TB, Kayentao K, Miller LH, Traore B, Pierce SK, Buckee CO, Lavstsen T, Crompton PD, Tran TM. Longitudinal analysis of naturally acquired PfEMP1 CIDR domain variant antibodies identifies associations with malaria protection. JCI Insight 2020; 5:137262. [PMID: 32427581 DOI: 10.1172/jci.insight.137262] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/06/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUNDMalaria pathogenicity is determined, in part, by the adherence of Plasmodium falciparum-infected erythrocytes to the microvasculature mediated via specific interactions between P. falciparum erythrocyte membrane protein (PfEMP1) variant domains and host endothelial receptors. Naturally acquired antibodies against specific PfEMP1 variants can play an important role in clinical protection against malaria.METHODSWe evaluated IgG responses against a repertoire of PfEMP1 CIDR domain variants to determine the rate and order of variant-specific antibody acquisition and their association with protection against febrile malaria in a prospective cohort study conducted in an area of intense, seasonal malaria transmission.RESULTSUsing longitudinal data, we found that IgG antibodies against the pathogenic domain variants CIDRα1.7 and CIDRα1.8 were acquired the earliest. Furthermore, IgG antibodies against CIDRγ3 were associated with reduced prospective risk of febrile malaria and recurrent malaria episodes.CONCLUSIONThis study provides evidence that acquisition of IgG antibodies against PfEMP1 variants is ordered and demonstrates that antibodies against CIDRα1 domains are acquired the earliest in children residing in an area of intense, seasonal malaria transmission. Future studies will need to validate these findings in other transmission settings and determine the functional activity of these naturally acquired CIDR variant-specific antibodies.TRIAL REGISTRATIONClinicalTrials.gov NCT01322581.FUNDINGDivision of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH.
Collapse
Affiliation(s)
- Nyamekye Obeng-Adjei
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Innate Immunity Research Unit, GlaxoSmithKline, Collegeville, Pennsylvania, USA
| | - Daniel B Larremore
- Department of Computer Science and.,BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Shanping Li
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Safiatou Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Kassoum Kayentao
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, Maryland, USA
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Caroline O Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Tuan M Tran
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Division of Infectious Diseases, Department of Medicine, and.,Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| |
Collapse
|
17
|
Pereira DMS, Carvalho Júnior AR, Lacerda EMDCB, da Silva LCN, Marinho CRF, André E, Fernandes ES. Oxidative and nitrosative stresses in cerebral malaria: can we target them to avoid a bad prognosis? J Antimicrob Chemother 2020; 75:1363-1373. [PMID: 32105324 DOI: 10.1093/jac/dkaa032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is currently a global effort to reduce malaria morbidity and mortality. However, malaria still results in the deaths of thousands of people every year. Malaria is caused by Plasmodium spp., parasites transmitted through the bite of an infected female Anopheles mosquito. Treatment timing plays a decisive role in reducing mortality and sequelae associated with the severe forms of the disease such as cerebral malaria (CM). The available antimalarial therapy is considered effective but parasite resistance to these drugs has been observed in some countries. Antimalarial drugs act by increasing parasite lysis, especially through targeting oxidative stress pathways. Here we discuss the roles of reactive oxygen species and reactive nitrogen intermediates in CM as a result of host-parasite interactions. We also present evidence of the potential contribution of oxidative and nitrosative stress-based antimalarial drugs to disease treatment and control.
Collapse
Affiliation(s)
| | | | | | | | | | - Eunice André
- Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Elizabeth Soares Fernandes
- Programa de Pós-graduação, Universidade CEUMA, São Luís, MA, Brazil.,Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, PR, Brazil.,Faculdades Pequeno Príncipe, Curitiba, PR, Brazil
| |
Collapse
|
18
|
Harmsen C, Turner L, Thrane S, Sander AF, Theander TG, Lavstsen T. Immunization with virus-like particles conjugated to CIDRα1 domain of Plasmodium falciparum erythrocyte membrane protein 1 induces inhibitory antibodies. Malar J 2020; 19:132. [PMID: 32228596 PMCID: PMC7106694 DOI: 10.1186/s12936-020-03201-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/23/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND During the erythrocytic cycle, Plasmodium falciparum malaria parasites express P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) that anchor the infected erythrocytes (IE) to the vascular lining of the host. The CIDRα1 domain of PfEMP1 is responsible for binding host endothelial protein C receptor (EPCR), and increasing evidence support that this interaction triggers severe malaria, accounting for the majority of malaria-related deaths. In high transmission regions, children develop immunity to severe malaria after the first few infections. This immunity is believed to be mediated by antibodies targeting and inhibiting PfEMP1, causing infected erythrocytes to circulate and be cleared in the spleen. The development of immunity to malaria coincides with acquisition of broad antibody reactivity across the CIDRα1 protein family. Altogether, this identifies CIDRα1 as an important vaccine target. However, the antigenic diversity of the CIDRα1 domain family is a challenge for vaccine development. METHODS Immune responses in mice vaccinated with Virus-Like Particles (VLP) presenting CIDRα1 antigens were investigated. Antibody reactivity was tested to a panel of recombinant CIDRα1 domains, and the antibodies ability to inhibit EPCR binding by the recombinant CIDRα1 domains was tested in Luminex-based multiplex assays. RESULTS VLP-presented CIDRα1.4 antigens induced a rapid and strong IgG response capable of inhibiting EPCR-binding of multiple CIDRα1 domains mainly within the group A CIDRα1.4-7 subgroups. CONCLUSIONS The study observations mirror those from previous CIDRα1 vaccine studies using other vaccine constructs and platforms. This suggests that broad CIDRα1 antibody reactivity may be achieved through vaccination with a limited number of CIDRα1 variants. In addition, this study suggest that this may be achieved through vaccination with a human compatible VLP vaccine platform.
Collapse
Affiliation(s)
- Charlotte Harmsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Susan Thrane
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Adam F Sander
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark.
| |
Collapse
|
19
|
Lubiana P, Bouws P, Roth LK, Dörpinghaus M, Rehn T, Brehmer J, Wichers JS, Bachmann A, Höhn K, Roeder T, Thye T, Gutsmann T, Burmester T, Bruchhaus I, Metwally NG. Adhesion between P. falciparum infected erythrocytes and human endothelial receptors follows alternative binding dynamics under flow and febrile conditions. Sci Rep 2020; 10:4548. [PMID: 32161335 PMCID: PMC7066226 DOI: 10.1038/s41598-020-61388-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/25/2020] [Indexed: 11/10/2022] Open
Abstract
Characterizing the adhesive dynamics of Plasmodium falciparum infected erythrocytes (IEs) to different endothelial cell receptors (ECRs) in flow is a big challenge considering available methods. This study investigated the adhesive dynamics of IEs to five ECRs (CD36, ICAM-1, P-selectin, CD9, CSA) using simulations of in vivo-like flow and febrile conditions. To characterize the interactions between ECRs and knobby and knobless IEs of two laboratory-adapted P. falciplarum isolates, cytoadhesion analysis over time was performed using a new tracking bioinformatics method. The results revealed that IEs performed rolling adhesion exclusively over CD36, but exhibited stationary binding to the other four ECRs. The absence of knobs affected rolling adhesion both with respect to the distance travelled by IEs and their velocity. Knobs played a critical role at febrile temperatures by stabilizing the binding interaction. Our results clearly underline the complexity of the IE-receptor interaction and the importance of knobs for the survival of the parasite at fever temperatures, and lead us to propose a new hypothesis that could open up new strategies for the treatment of malaria.
Collapse
Affiliation(s)
- Pedro Lubiana
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Philip Bouws
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | | | - Torben Rehn
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jana Brehmer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Katharina Höhn
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Roeder
- Molecular Physiology Department, Zoological Institute, Christian-Albrechts University Kiel, Kiel, Germany
| | - Thorsten Thye
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thomas Gutsmann
- Division of Biophysics, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Thorsten Burmester
- Zoological Institute, Department of Molecular Physiology, Hamburg University, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. .,Department of Biology, University of Hamburg, Hamburg, Germany.
| | | |
Collapse
|
20
|
Stringent Selection of Knobby Plasmodium falciparum-Infected Erythrocytes during Cytoadhesion at Febrile Temperature. Microorganisms 2020; 8:microorganisms8020174. [PMID: 31991814 PMCID: PMC7074740 DOI: 10.3390/microorganisms8020174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 11/17/2022] Open
Abstract
Changes in the erythrocyte membrane induced by Plasmodium falciparum invasion allow cytoadhesion of infected erythrocytes (IEs) to the host endothelium, which can lead to severe complications. Binding to endothelial cell receptors (ECRs) is mainly mediated by members of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family, encoded by var genes. Malaria infection causes several common symptoms, with fever being the most apparent. In this study, the effects of febrile conditions on cytoadhesion of predominately knobless erythrocytes infected with the laboratory isolate IT4 to chondroitin-4-sulfate A (CSA), intercellular adhesion molecule 1 (ICAM-1), and CD36 were investigated. IEs enriched for binding to CSA at 40 °C exhibited significantly increased binding capacity relative to parasites enriched at 37 °C. This interaction was due to increased var2csa expression and trafficking of the corresponding PfEMP1 to the IE surface as well as to a selection of knobby IEs. Furthermore, the enrichment of IEs to ICAM-1 at 40 °C also led to selection of knobby IEs over knobless IEs, whereas enrichment on CD36 did not lead to a selection. In summary, these findings demonstrate that knobs are crucial for parasitic survival in the host, especially during fever episodes, and thus, that selection pressure on the formation of knobs could be controlled by the host.
Collapse
|
21
|
Jensen AR, Adams Y, Hviid L. Cerebral Plasmodium falciparum malaria: The role of PfEMP1 in its pathogenesis and immunity, and PfEMP1-based vaccines to prevent it. Immunol Rev 2020; 293:230-252. [PMID: 31562653 PMCID: PMC6972667 DOI: 10.1111/imr.12807] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022]
Abstract
Malaria, a mosquito-borne infectious disease caused by parasites of the genus Plasmodium continues to be a major health problem worldwide. The unicellular Plasmodium-parasites have the unique capacity to infect and replicate within host erythrocytes. By expressing variant surface antigens Plasmodium falciparum has evolved to avoid protective immune responses; as a result in endemic areas anti-malaria immunity develops gradually over many years of multiple and repeated infections. We are studying the role of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) expressed by asexual stages of P. falciparum responsible for the pathogenicity of severe malaria. The immunopathology of falciparum malaria has been linked to cyto-adhesion of infected erythrocytes to specific host receptors. A greater appreciation of the PfEMP1 molecules important for the development of protective immunity and immunopathology is a prerequisite for the rational discovery and development of a safe and protective anti-disease malaria vaccine. Here we review the role of ICAM-1 and EPCR receptor adhering falciparum-parasites in the development of severe malaria; we discuss our current research to understand the factors involved in the pathogenesis of cerebral malaria and the feasibility of developing a vaccine targeted specifically to prevent this disease.
Collapse
Affiliation(s)
- Anja Ramstedt Jensen
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Infectious DiseasesRigshospitaletCopenhagenDenmark
| |
Collapse
|
22
|
Gangnard S, Chêne A, Dechavanne S, Srivastava A, Avril M, Smith JD, Gamain B. VAR2CSA binding phenotype has ancient origin and arose before Plasmodium falciparum crossed to humans: implications in placental malaria vaccine design. Sci Rep 2019; 9:16978. [PMID: 31740695 PMCID: PMC6861233 DOI: 10.1038/s41598-019-53334-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
VAR2CSA is a leading candidate for developing a placental malaria (PM) vaccine that would protect pregnant women living in malaria endemic areas against placental infections and improve birth outcomes. Two VAR2CSA-based PM vaccines are currently under clinical trials, but it is still unclear if the use of a single VAR2CSA variant will be sufficient to induce a broad enough humoral response in humans to cross-react with genetically diverse parasite populations. Additional immuno-focusing vaccine strategies may therefore be required to identify functionally conserved antibody epitopes in VAR2CSA. We explored the possibility that conserved epitopes could exist between VAR2CSA from the chimpanzee parasite Plasmodium reichenowi and Plasmodium falciparum sequences. Making use of VAR2CSA recombinant proteins originating from both species, we showed that VAR2CSA from P. reichenowi (Pr-VAR2CSA) binds to the placental receptor CSA with high specificity and affinity. Antibodies raised against Pr-VAR2CSA were able to recognize native VAR2CSA from different P. falciparum genotypes and to inhibit the interaction between CSA and P. falciparum-infected erythrocytes expressing different VAR2CSA variants. Our work revealed the existence of cross-species inhibitory epitopes in VAR2CSA and calls for pre-clinical studies assessing the efficacy of novel VAR2CSA-based cross-species boosting regimens.
Collapse
Affiliation(s)
- Stéphane Gangnard
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Arnaud Chêne
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Sébastien Dechavanne
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Anand Srivastava
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Marion Avril
- Seattle Children's Research Institute, Seattle, WA, 98109, USA
| | - Joseph D Smith
- Seattle Children's Research Institute, Seattle, WA, 98109, USA.,Department of Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Benoît Gamain
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France. .,Institut National de la Transfusion Sanguine, F-75015, Paris, France. .,Laboratory of excellence GR-Ex, F-75015, Paris, France.
| |
Collapse
|
23
|
Rambhatla JS, Turner L, Manning L, Laman M, Davis TME, Beeson JG, Mueller I, Warrel J, Theander TG, Lavstsen T, Rogerson SJ. Acquisition of Antibodies Against Endothelial Protein C Receptor-Binding Domains of Plasmodium falciparum Erythrocyte Membrane Protein 1 in Children with Severe Malaria. J Infect Dis 2019; 219:808-818. [PMID: 30365003 DOI: 10.1093/infdis/jiy564] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration in postcapillary venules in P. falciparum malaria. PfEMP1 types can be classified based on their cysteine-rich interdomain region (CIDR) domains. Antibodies to different PfEMP1 types develop gradually after repeated infections as children age, and antibodies to specific CIDR types may confer protection. METHODS Levels of immunoglobulin G to 35 recombinant CIDR domains were measured by means of Luminex assay in acute-stage (baseline) and convalescent-stage plasma samples from Papua New Guinean children with severe or uncomplicated malaria and in healthy age-matched community controls. RESULTS At baseline, antibody levels were similar across the 3 groups. After infection, children with severe malaria had higher antibody levels than those with uncomplicated malaria against the endothelial protein C receptor (EPCR) binding CIDRα1 domains, and this difference was largely confined to older children. Antibodies to EPCR-binding domains increased from presentation to follow-up in severe malaria, but not in uncomplicated malaria. CONCLUSIONS The acquisition of antibodies against EPCR-binding CIDRα1 domains of PfEMP1 after a severe malaria episode suggest that EPCR-binding PfEMP1 may have a role in the pathogenesis of severe malaria in Papua New Guinea.
Collapse
Affiliation(s)
- Janavi S Rambhatla
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - James G Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Ivo Mueller
- Department of Medical Biology, University of Melbourne, Parkville.,Walter and Eliza Hall Institute of Medical Research, Parkville.,Parasite and Insect Vectors Department, Institut Pasteur, Paris, France
| | | | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Stephen J Rogerson
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
| |
Collapse
|
24
|
Lennartz F, Smith C, Craig AG, Higgins MK. Structural insights into diverse modes of ICAM-1 binding by Plasmodium falciparum-infected erythrocytes. Proc Natl Acad Sci U S A 2019; 116:20124-20134. [PMID: 31527263 PMCID: PMC6778195 DOI: 10.1073/pnas.1911900116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A major determinant of pathogenicity in malaria caused by Plasmodium falciparum is the adhesion of parasite-infected erythrocytes to the vasculature or tissues of infected individuals. This occludes blood flow, leads to inflammation, and increases parasitemia by reducing spleen-mediated clearance of the parasite. This adhesion is mediated by PfEMP1, a multivariant family of around 60 proteins per parasite genome which interact with specific host receptors. One of the most common of these receptors is intracellular adhesion molecule-1 (ICAM-1), which is bound by 2 distinct groups of PfEMP1, A-type and B or C (BC)-type. Here, we present the structure of a domain from a B-type PfEMP1 bound to ICAM-1, revealing a complex binding site. Comparison with the existing structure of an A-type PfEMP1 bound to ICAM-1 shows that the 2 complexes share a globally similar architecture. However, while the A-type PfEMP1 bind ICAM-1 through a highly conserved binding surface, the BC-type PfEMP1 use a binding site that is more diverse in sequence, similar to how PfEMP1 interact with other human receptors. We also show that A- and BC-type PfEMP1 present ICAM-1 at different angles, perhaps influencing the ability of neighboring PfEMP1 domains to bind additional receptors. This illustrates the deep diversity of the PfEMP1 and demonstrates how variations in a single domain architecture can modulate binding to a specific ligand to control function and facilitate immune evasion.
Collapse
Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom
| | - Cameron Smith
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom
| | - Alister G Craig
- Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom;
| |
Collapse
|
25
|
Olsen RW, Ecklu-Mensah G, Bengtsson A, Ofori MF, Kusi KA, Koram KA, Hviid L, Adams Y, Jensen ATR. Acquisition of IgG to ICAM-1-Binding DBLβ Domains in the Plasmodium falciparum Erythrocyte Membrane Protein 1 Antigen Family Varies between Groups A, B, and C. Infect Immun 2019; 87:e00224-19. [PMID: 31308082 PMCID: PMC6759304 DOI: 10.1128/iai.00224-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is an important malaria virulence factor. The protein family can be divided into clinically relevant subfamilies. ICAM-1-binding group A PfEMP1 proteins also bind endothelial protein C receptor and have been associated with cerebral malaria in children. IgG to these PfEMP1 proteins is acquired later in life than that to group A PfEMP1 not binding ICAM-1. The kinetics of acquisition of IgG to group B and C PfEMP1 proteins binding ICAM-1 is unclear and was studied here. Gene sequences encoding group B and C PfEMP1 with DBLβ domains known to bind ICAM-1 were used to identify additional binders. Levels of IgG specific for DBLβ domains from group A, B, and C PfEMP1 binding or not binding ICAM-1 were measured in plasma from Ghanaian children with or without malaria. Seven new ICAM-1-binding DBLβ domains from group B and C PfEMP1 were identified. Healthy children had higher levels of IgG specific for ICAM-1-binding DBLβ domains from group A than from groups B and C. However, the opposite pattern was found in children with malaria, particularly among young patients. Acquisition of IgG specific for DBLβ domains binding ICAM-1 differs between PfEMP1 groups.
Collapse
MESH Headings
- Antibodies, Protozoan/biosynthesis
- Child
- Child, Preschool
- Erythrocytes/immunology
- Erythrocytes/parasitology
- Female
- Gene Expression
- Ghana
- Humans
- Immunoglobulin G/biosynthesis
- Infant
- Intercellular Adhesion Molecule-1/genetics
- Intercellular Adhesion Molecule-1/immunology
- Malaria, Cerebral/genetics
- Malaria, Cerebral/immunology
- Malaria, Cerebral/parasitology
- Malaria, Cerebral/pathology
- Malaria, Falciparum/genetics
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/pathology
- Male
- Plasmodium falciparum/immunology
- Plasmodium falciparum/pathogenicity
- Polymorphism, Genetic
- Protein Binding
- Protein Domains
- Protozoan Proteins/classification
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Seasons
- Severity of Illness Index
Collapse
Affiliation(s)
- Rebecca W Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gertrude Ecklu-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Anja Bengtsson
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Kwadwo A Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Kwadwo A Koram
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, 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
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja T R Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
26
|
Rosetting revisited: a critical look at the evidence for host erythrocyte receptors in Plasmodium falciparum rosetting. Parasitology 2019; 147:1-11. [PMID: 31455446 PMCID: PMC7050047 DOI: 10.1017/s0031182019001288] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Malaria remains a major cause of mortality in African children, with no adjunctive treatments currently available to ameliorate the severe clinical forms of the disease. Rosetting, the adhesion of infected erythrocytes (IEs) to uninfected erythrocytes, is a parasite phenotype strongly associated with severe malaria, and hence is a potential therapeutic target. However, the molecular mechanisms of rosetting are complex and involve multiple distinct receptor–ligand interactions, with some similarities to the diverse pathways involved in P. falciparum erythrocyte invasion. This review summarizes the current understanding of the molecular interactions that lead to rosette formation, with a particular focus on host uninfected erythrocyte receptors including the A and B blood group trisaccharides, complement receptor one, heparan sulphate, glycophorin A and glycophorin C. There is strong evidence supporting blood group A trisaccharides as rosetting receptors, but evidence for other molecules is incomplete and requires further study. It is likely that additional host erythrocyte rosetting receptors remain to be discovered. A rosette-disrupting low anti-coagulant heparin derivative is being investigated as an adjunctive therapy for severe malaria, and further research into the receptor–ligand interactions underlying rosetting may reveal additional therapeutic approaches to reduce the unacceptably high mortality rate of severe malaria.
Collapse
|
27
|
Bachmann A, Bruske E, Krumkamp R, Turner L, Wichers JS, Petter M, Held J, Duffy MF, Sim BKL, Hoffman SL, Kremsner PG, Lell B, Lavstsen T, Frank M, Mordmüller B, Tannich E. Controlled human malaria infection with Plasmodium falciparum demonstrates impact of naturally acquired immunity on virulence gene expression. PLoS Pathog 2019; 15:e1007906. [PMID: 31295334 PMCID: PMC6650087 DOI: 10.1371/journal.ppat.1007906] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 07/23/2019] [Accepted: 06/10/2019] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of Plasmodium falciparum malaria is linked to the variant surface antigen PfEMP1, which mediates tethering of infected erythrocytes to the host endothelium and is encoded by approximately 60 var genes per parasite genome. Repeated episodes of malaria infection result in the gradual acquisition of protective antibodies against PfEMP1 variants. The antibody repertoire is believed to provide a selective pressure driving the clonal expansion of parasites expressing unrecognized PfEMP1 variants, however, due to the lack of experimental in vivo models there is only limited experimental evidence in support of this concept. To get insight into the impact of naturally acquired immunity on the expressed var gene repertoire early during infection we performed controlled human malaria infections of 20 adult African volunteers with life-long malaria exposure using aseptic, purified, cryopreserved P. falciparum sporozoites (Sanaria PfSPZ Challenge) and correlated serological data with var gene expression patterns from ex vivo parasites. Among the 10 African volunteers who developed patent infections, individuals with low antibody levels showed a steep rise in parasitemia accompanied by broad activation of multiple, predominantly subtelomeric var genes, similar to what we previously observed in naïve volunteers. In contrast, individuals with intermediate antibody levels developed asymptomatic infections and the ex vivo parasite populations expressed only few var gene variants, indicative of clonal selection. Importantly, in contrast to parasites from naïve volunteers, expression of var genes coding for endothelial protein C receptor (EPCR)-binding PfEMP1 that are associated with severe childhood malaria was rarely detected in semi-immune adult African volunteers. Moreover, we followed var gene expression for up to six parasite replication cycles and demonstrated for the first time in vivo a shift in the dominant var gene variant. In conclusion, our data suggest that P. falciparum activates multiple subtelomeric var genes at the onset of blood stage infection facilitating rapid expansion of parasite clones which express PfEMP1 variants unrecognized by the host's immune system, thus promoting overall parasite survival in the face of host immunity.
Collapse
Affiliation(s)
- Anna Bachmann
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
| | - Ellen Bruske
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Ralf Krumkamp
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
- Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Louise Turner
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen K, Denmark
| | - J. Stephan Wichers
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Michaela Petter
- Mikrobiologisches Institut–Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Jana Held
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Michael F. Duffy
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | | | | | - Peter G. Kremsner
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Germany
| | - Bertrand Lell
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), African partner institution, CERMEL, Gabon
| | - Thomas Lavstsen
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen K, Denmark
| | - Matthias Frank
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Germany
| | - Egbert Tannich
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
| |
Collapse
|
28
|
Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1. mBio 2019; 10:mBio.00420-19. [PMID: 31138740 PMCID: PMC6538777 DOI: 10.1128/mbio.00420-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cerebral malaria research has been hindered by the inaccessibility of the brain. Here, we have developed an engineered 3D human brain microvessel model that mimics the blood flow rates and architecture of small blood vessels to study how P. falciparum-infected human erythrocytes attach to brain endothelial cells. By studying parasite lines with different adhesive properties, we show that the malaria parasite binding rate is heterogeneous and strongly influenced by physiological differences in flow and whether the endothelium has been previously activated by TNF-α, a proinflammatory cytokine that is linked to malaria disease severity. We also show the importance of human EPCR and ICAM-1 in parasite binding. Our model sheds new light on how P. falciparum binds within brain microvessels and provides a powerful method for future investigations of recruitment of human brain pathogens to the blood vessel lining of the brain. Cerebral malaria is a severe neurological complication associated with sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the brain microvasculature, but the specific binding interactions remain under debate. Here, we have generated an engineered three-dimensional (3D) human brain endothelial microvessel model and studied P. falciparum binding under the large range of physiological flow velocities that occur in both health and disease. Perfusion assays on 3D microvessels reveal previously unappreciated phenotypic heterogeneity in parasite binding to tumor necrosis factor alpha (TNF-α)-activated brain endothelial cells. While clonal parasite lines expressing a group B P. falciparum erythrocyte membrane protein 1 (PfEMP1) present an increase in binding to activated 3D microvessels, P. falciparum-IE expressing DC8-PfEMP1 present a decrease in binding. The differential response to endothelium activation is mediated by surface expression changes of endothelial protein C receptor (EPCR) and intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate heterogeneity in parasite binding and provide evidence for a parasite strategy to adapt to a changing microvascular environment during infection. The engineered 3D human brain microvessel model provides new mechanistic insight into parasite binding and opens opportunities for further studies on malaria pathogenesis and parasite-vessel interactions.
Collapse
|
29
|
Meta-analysis of Plasmodium falciparum var Signatures Contributing to Severe Malaria in African Children and Indian Adults. mBio 2019; 10:mBio.00217-19. [PMID: 31040236 PMCID: PMC6495371 DOI: 10.1128/mbio.00217-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The clinical presentation of severe Plasmodium falciparum malaria differs between children and adults, but the mechanistic basis for this remains unclear. Contributing factors to disease severity include total parasite biomass and the diverse cytoadhesive properties mediated by the polymorphic var gene parasite ligand family displayed on infected erythrocytes. To explore these factors, we performed a multicohort analysis of the contribution of var expression and parasite biomass to severe malaria in two previously published pediatric cohorts in Tanzania and Malawi and an adult cohort in India. Machine learning analysis revealed independent and complementary roles for var adhesion types and parasite biomass in adult and pediatric severe malaria and showed that similar var profiles, including upregulation of group A and DC8 var, predict severe malaria in adults and children. Among adults, patients with multiorgan complications presented infections with significantly higher parasite biomass without significant differences in var adhesion types. Conversely, pediatric patients with specific complications showed distinct var signatures. Cerebral malaria patients showed broadly increased expression of var genes, in particular group A and DC8 var, while children with severe malaria anemia were classified based on high transcription of DC8 var only. This study represents the first large multisite meta-analysis of var expression, and it demonstrates the presence of common var profiles in severe malaria patients of different ages across distant geographical sites, as well as syndrome-specific disease signatures. The complex associations between parasite biomass, var adhesion type, and clinical presentation revealed here represent the most comprehensive picture so far of the relationship between cytoadhesion, parasite load, and clinical syndrome.IMPORTANCE P. falciparum malaria can cause multiple disease complications that differ by patient age. Previous studies have attempted to address the roles of parasite adhesion and biomass in disease severity; however, these studies have been limited to single geographical sites, and there is limited understanding of how parasite adhesion and biomass interact to influence disease manifestations. In this meta-analysis, we compared parasite disease determinants in African children and Indian adults. This study demonstrates that parasite biomass and specific subsets of var genes are independently associated with detrimental outcomes in both childhood and adult malaria. We also explored how parasite var adhesion types and biomass play different roles in the development of specific severe malaria pathologies, including childhood cerebral malaria and multiorgan complications in adults. This work represents the largest study to date of the role of both var adhesion types and biomass in severe malaria.
Collapse
|
30
|
Chesnokov O, Merritt J, Tcherniuk SO, Milman N, Oleinikov AV. Plasmodium falciparum infected erythrocytes can bind to host receptors integrins αVβ3 and αVβ6 through DBLδ1_D4 domain of PFL2665c PfEMP1 protein. Sci Rep 2018; 8:17871. [PMID: 30552383 PMCID: PMC6294747 DOI: 10.1038/s41598-018-36071-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/14/2018] [Indexed: 02/05/2023] Open
Abstract
Major complications and mortality from Plasmodium falciparum malaria are associated with cytoadhesion of parasite-infected erythrocytes (IE). The main parasite ligands for cytoadhesion are members of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family. Interactions of different host receptor-ligand pairs may lead to various pathological outcomes, like placental or cerebral malaria. It has been shown previously that IE can bind integrin αVβ3. Using bead-immobilized PfEMP1 constructs, we have identified that the PFL2665c DBLδ1_D4 domain binds to αVβ3 and αVβ6. A parasite line expressing PFL2665c binds to surface-immobilized αVβ3 and αVβ6; both are RGD motif-binding integrins. Interactions can be inhibited by cyloRGDFV peptide, an antagonist of RGD-binding integrins. This is a first, to the best of our knowledge, implication of a specific PfEMP1 domain for binding to integrins. These host receptors have important physiological functions in endothelial and immune cells; therefore, these results will contribute to future studies and a better understanding, at the molecular level, of the physiological outcome of interactions between IE and integrin receptors on the surface of host cells.
Collapse
Affiliation(s)
- Olga Chesnokov
- Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Jordan Merritt
- Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Sergey O Tcherniuk
- Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Neta Milman
- Seattle Biomedical Research Institute, Seattle, WA, USA
| | - Andrew V Oleinikov
- Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, USA.
| |
Collapse
|
31
|
Ecklu-Mensah G, Olsen RW, Bengtsson A, Ofori MF, Hviid L, Jensen ATR, Adams Y. Blood outgrowth endothelial cells (BOECs) as a novel tool for studying adhesion of Plasmodium falciparum-infected erythrocytes. PLoS One 2018; 13:e0204177. [PMID: 30300360 PMCID: PMC6177148 DOI: 10.1371/journal.pone.0204177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/03/2018] [Indexed: 11/19/2022] Open
Abstract
The lack of suitable animal models for the study of cytoadhesion of P. falciparum-infected erythrocytes (IEs) has necessitated in vitro studies employing a range of cell lines of either human tumour origin (e.g., BeWo and C32 cells) or non-human origin (e.g., CHO cells). Of the human cells available, many were isolated from adults, or derived from a pool of donors (e.g., HBEC-5i). Here we demonstrate, for the first time, the successful isolation of blood outgrowth endothelial cells (BOECs) from frozen stabilates of peripheral blood mononuclear cells obtained from small-volume peripheral blood samples from paediatric malaria patients. BOECs are a sub-population of human endothelial cells, found within the peripheral blood. We demonstrate that these cells express receptors such as Intercellular Adhesion Molecule 1 (ICAM-1/CD54), Endothelial Protein C Receptor (EPCR/CD201), platelet/endothelial cell adhesion molecule 1 (PECAM-1/CD31), Thrombomodulin (CD141), and support adhesion of P. falciparum IEs.
Collapse
Affiliation(s)
- Gertrude Ecklu-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rebecca W. Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja Bengtsson
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael F. Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Anja T. R. Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| |
Collapse
|
32
|
Comprehensive analysis of antibody responses to Plasmodium falciparum erythrocyte membrane protein 1 domains. Vaccine 2018; 36:6826-6833. [PMID: 30262245 DOI: 10.1016/j.vaccine.2018.08.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/03/2018] [Accepted: 08/22/2018] [Indexed: 12/31/2022]
Abstract
Acquired antibodies directed towards antigens expressed on the surface of merozoites and infected erythrocytes play an important role in protective immunity to Plasmodium falciparum malaria. P. falciparum erythrocyte membrane protein 1 (PfEMP1), the major parasite component of the infected erythrocyte surface, has been implicated in malaria pathology, parasite sequestration and host immune evasion. However, the extent to which unique PfEMP1 domains interact with host immune response remains largely unknown. In this study, we sought to comprehensively understand the naturally acquired antibody responses targeting different Duffy binding-like (DBL), and Cysteine-rich interdomain region (CIDR) domains in a Ugandan cohort. Consequently, we created a protein library consisting of full-length DBL (n = 163) and CIDR (n = 108) domains derived from 62-var genes based on 3D7 genome. The proteins were expressed by a wheat germ cell-free system; a system that yields plasmodial proteins that are comparatively soluble, intact, biologically active and immunoreactive to human sera. Our findings suggest that all PfEMP1 DBL and CIDR domains, regardless of PfEMP1 group, are targets of naturally acquired immunity. The breadth of the immune response expands with children's age. We concurrently identified 10 DBL and 8 CIDR domains whose antibody responses were associated with reduced risk to symptomatic malaria in the Ugandan children cohort. This study highlights that only a restricted set of specific domains are essential for eliciting naturally acquired protective immunity in malaria. In light of current data, tandem domains in PfEMP1s PF3D7_0700100 and PF3D7_0425800 (DC4) are recommended for extensive evaluation in larger population cohorts to further assess their potential as alternative targets for malaria vaccine development.
Collapse
|
33
|
Alampalli SV, Grover M, Chandran S, Tatu U, Acharya P. Proteome and Structural Organization of the Knob Complex on the Surface of the Plasmodium
Infected Red Blood Cell. Proteomics Clin Appl 2017; 12:e1600177. [DOI: 10.1002/prca.201600177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 08/16/2017] [Indexed: 02/04/2023]
Affiliation(s)
| | - Manish Grover
- Department of Biochemistry; Indian Institute of Science; Bangalore India
| | - Syama Chandran
- Department of Biochemistry; Indian Institute of Science; Bangalore India
| | - Utpal Tatu
- Department of Biochemistry; Indian Institute of Science; Bangalore India
| | - Pragyan Acharya
- Department of Biochemistry; All India Institute of Medical Sciences; New Delhi India
| |
Collapse
|
34
|
Kessler A, Dankwa S, Bernabeu M, Harawa V, Danziger SA, Duffy F, Kampondeni SD, Potchen MJ, Dambrauskas N, Vigdorovich V, Oliver BG, Hochman SE, Mowrey WB, MacCormick IJC, Mandala WL, Rogerson SJ, Sather DN, Aitchison JD, Taylor TE, Seydel KB, Smith JD, Kim K. Linking EPCR-Binding PfEMP1 to Brain Swelling in Pediatric Cerebral Malaria. Cell Host Microbe 2017; 22:601-614.e5. [PMID: 29107642 DOI: 10.1016/j.chom.2017.09.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/06/2017] [Accepted: 09/22/2017] [Indexed: 11/16/2022]
Abstract
Brain swelling is a major predictor of mortality in pediatric cerebral malaria (CM). However, the mechanisms leading to swelling remain poorly defined. Here, we combined neuroimaging, parasite transcript profiling, and laboratory blood profiles to develop machine-learning models of malarial retinopathy and brain swelling. We found that parasite var transcripts encoding endothelial protein C receptor (EPCR)-binding domains, in combination with high parasite biomass and low platelet levels, are strong indicators of CM cases with malarial retinopathy. Swelling cases presented low platelet levels and increased transcript abundance of parasite PfEMP1 DC8 and group A EPCR-binding domains. Remarkably, the dominant transcript in 50% of swelling cases encoded PfEMP1 group A CIDRα1.7 domains. Furthermore, a recombinant CIDRα1.7 domain from a pediatric CM brain autopsy inhibited the barrier-protective properties of EPCR in human brain endothelial cells in vitro. Together, these findings suggest a detrimental role for EPCR-binding CIDRα1 domains in brain swelling.
Collapse
Affiliation(s)
- Anne Kessler
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA
| | - Selasi Dankwa
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Maria Bernabeu
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Visopo Harawa
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; University of Malawi, College of Medicine, Biomedical Department, Blantyre BT3, Malawi
| | | | - Fergal Duffy
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | | | - Michael J Potchen
- Department of Imaging Sciences, University of Rochester, Rochester, NY 14642, USA
| | | | | | - Brian G Oliver
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Sarah E Hochman
- Department of Medicine, New York University Langone Health, New York, NY 10016, USA
| | - Wenzhu B Mowrey
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA
| | - Ian J C MacCormick
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Department of Eye and Vision Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Wilson L Mandala
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; University of Malawi, College of Medicine, Biomedical Department, Blantyre BT3, Malawi; Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo BT3, Malawi
| | - Stephen J Rogerson
- Department of Medicine at the Doherty Institute, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - D Noah Sather
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | | | - Terrie E Taylor
- Blantyre Malaria Project, Blantyre BT3, Malawi; Department of Osteopathic Medical Specialities, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Karl B Seydel
- Blantyre Malaria Project, Blantyre BT3, Malawi; Department of Osteopathic Medical Specialities, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA.
| | - Joseph D Smith
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
| | - Kami Kim
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA.
| |
Collapse
|
35
|
Shabani E, Hanisch B, Opoka RO, Lavstsen T, John CC. Plasmodium falciparum EPCR-binding PfEMP1 expression increases with malaria disease severity and is elevated in retinopathy negative cerebral malaria. BMC Med 2017; 15:183. [PMID: 29025399 PMCID: PMC5639490 DOI: 10.1186/s12916-017-0945-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Expression of group A and the A-like subset of group B Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is associated with severe malaria (SM). The diversity of var sequences combined with the challenges of distinct classification of patient pathologies has made studying the role of distinct PfEMP1 variants on malaria disease severity challenging. The application of retinopathy in the recent years has provided a further method to clinically evaluate children with cerebral malaria (CM). The question of whether children with clinical CM but no retinopathy represent a completely different disease process or a subgroup within the spectrum of CM remains an important question in malaria. In the current study, we use newly designed primer sets with the best coverage to date in a large cohort of children with SM to determine the role of var genes in malaria disease severity and especially CM as discriminated by retinopathy. METHODS We performed qRT-PCR targeting the different subsets of these var genes on samples from Ugandan children with CM (n = 98, of whom 50 had malarial retinopathy [RP] and 47 did not [RN]), severe malarial anemia (SMA, n = 47), and asymptomatic parasitemia (AP, n = 14). The primers used in this study were designed based on var sequences from 226 Illumina whole genome sequenced P. falciparum field isolates. RESULTS Increasing severity of illness was associated with increasing levels of endothelial protein C receptor (EPCR)-binding PfEMP1. EPCR-binding PfEMP1 transcript levels were highest in children with combined CM and SMA and then decreased by level of disease severity: RP CM > RN CM > SMA > AP. CONCLUSIONS The study findings indicate that PfEMP1 binding to EPCR is important in the pathogenesis of SM, including RN CM, and suggest that increased expression of EPCR-binding PfEMP1 is associated with progressively more severe disease. Agents that block EPCR-binding of PfEMP1 could provide novel interventions to prevent or decrease disease severity in malaria.
Collapse
Affiliation(s)
- Estela Shabani
- Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University, 1044 W Walnut St R4 402D, Indianapolis, Indiana, USA.,Department of Pediatrics, Division of Global Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Robert O Opoka
- Department of Pediatrics and Child Health, Makerere University School of Medicine, Kampala, Uganda
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen, Denmark
| | - Chandy C John
- Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University, 1044 W Walnut St R4 402D, Indianapolis, Indiana, USA. .,Department of Pediatrics, Division of Global Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA.
| |
Collapse
|
36
|
Githinji G, Bull PC. A re-assessment of gene-tag classification approaches for describing var gene expression patterns during human Plasmodium falciparum malaria parasite infections. Wellcome Open Res 2017; 2:86. [PMID: 29062916 PMCID: PMC5635463 DOI: 10.12688/wellcomeopenres.12053.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2017] [Indexed: 11/20/2022] Open
Abstract
PfEMP1 are variant parasite antigens that are inserted on the surface of Plasmodium falciparum infected erythrocytes (IE). Through interactions with various host molecules, PfEMP1 mediate IE sequestration in tissues and play a key role in the pathology of severe malaria. PfEMP1 is encoded by a diverse multi-gene family called var. Previous studies have shown that that expression of specific subsets of var genes are associated with low levels of host immunity and severe malaria. However, in most clinical studies to date, full-length var gene sequences were unavailable and various approaches have been used to make comparisons between var gene expression profiles in different parasite isolates using limited information. Several studies have relied on the classification of a 300 - 500 base-pair "DBLα tag" region in the DBLα domain located at the 5' end of most var genes. We assessed the relationship between various DBLα tag classification methods, and sequence features that are only fully assessable through full-length var gene sequences. We compared these different sequence features in full-length var gene from six fully sequenced laboratory isolates. These comparisons show that despite a long history of recombination, DBLα sequence tag classification can provide functional information on important features of full-length var genes. Notably, a specific subset of DBLα tags previously defined as "group A-like" is associated with CIDRα1 domains proposed to bind to endothelial protein C receptor. This analysis helps to bring together different sources of data that have been used to assess var gene expression in clinical parasite isolates.
Collapse
Affiliation(s)
- George Githinji
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Peter C Bull
- Department of Pathology, University of Cambridge, Cambridge, UK
| |
Collapse
|
37
|
Lennartz F, Adams Y, Bengtsson A, Olsen RW, Turner L, Ndam NT, Ecklu-Mensah G, Moussiliou A, Ofori MF, Gamain B, Lusingu JP, Petersen JEV, Wang CW, Nunes-Silva S, Jespersen JS, Lau CKY, Theander TG, Lavstsen T, Hviid L, Higgins MK, Jensen ATR. Structure-Guided Identification of a Family of Dual Receptor-Binding PfEMP1 that Is Associated with Cerebral Malaria. Cell Host Microbe 2017; 21:403-414. [PMID: 28279348 PMCID: PMC5374107 DOI: 10.1016/j.chom.2017.02.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/20/2017] [Accepted: 02/10/2017] [Indexed: 11/09/2022]
Abstract
Cerebral malaria is a deadly outcome of infection by Plasmodium falciparum, occurring when parasite-infected erythrocytes accumulate in the brain. These erythrocytes display parasite proteins of the PfEMP1 family that bind various endothelial receptors. Despite the importance of cerebral malaria, a binding phenotype linked to its symptoms has not been identified. Here, we used structural biology to determine how a group of PfEMP1 proteins interacts with intercellular adhesion molecule 1 (ICAM-1), allowing us to predict binders from a specific sequence motif alone. Analysis of multiple Plasmodium falciparum genomes showed that ICAM-1-binding PfEMP1s also interact with endothelial protein C receptor (EPCR), allowing infected erythrocytes to synergistically bind both receptors. Expression of these PfEMP1s, predicted to bind both ICAM-1 and EPCR, is associated with increased risk of developing cerebral malaria. This study therefore reveals an important PfEMP1-binding phenotype that could be targeted as part of a strategy to prevent cerebral malaria. Structural basis for P. falciparum PfEMP1 binding to endothelial receptor ICAM-1defined A sequence motif derived from structure predicts group A PfEMP1 binding to ICAM-1 These ICAM-1-binding PfEMP1s also all bind to endothelial protein C receptor (EPCR) Expression of dual ICAM-1- and EPCR-binding PfEMP1 is associated with cerebral malaria
Collapse
Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK
| | - Yvonne Adams
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Anja Bengtsson
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Rebecca W Olsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Nicaise T Ndam
- Faculté de Pharmacie, Institut de Recherche pour le Développement (IRD), COMUE Sorbonne Paris Cité, 75013 Paris, France; Faculté des Sciences de la Santé (FSS), Université d'Aboméy Calavi, 01 BP 526 Cotonou, Benin
| | - Gertrude Ecklu-Mensah
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark; Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Azizath Moussiliou
- Faculté des Sciences de la Santé (FSS), Université d'Aboméy Calavi, 01 BP 526 Cotonou, Benin
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Benoit Gamain
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France
| | - John P Lusingu
- National Institute for Medical Research, Tanga Centre, 11101 Dar es Salaam, Tanzania
| | - Jens E V Petersen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Sofia Nunes-Silva
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France
| | - Jakob S Jespersen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Clinton K Y Lau
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK
| | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK.
| | - Anja T R Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark.
| |
Collapse
|
38
|
Metwally NG, Tilly AK, Lubiana P, Roth LK, Dörpinghaus M, Lorenzen S, Schuldt K, Witt S, Bachmann A, Tidow H, Gutsmann T, Burmester T, Roeder T, Tannich E, Bruchhaus I. Characterisation of Plasmodium falciparum populations selected on the human endothelial receptors P-selectin, E-selectin, CD9 and CD151. Sci Rep 2017. [PMID: 28642573 PMCID: PMC5481354 DOI: 10.1038/s41598-017-04241-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The ability of the parasite Plasmodium falciparum to evade the immune system and be sequestered within human small blood vessels is responsible for severe forms of malaria. The sequestration depends on the interaction between human endothelial receptors and P. falciparum erythrocyte membrane protein 1 (PfEMP1) exposed on the surface of the infected erythrocytes (IEs). In this study, the transcriptomes of parasite populations enriched for parasites that bind to human P-selectin, E-selectin, CD9 and CD151 receptors were analysed. IT4_var02 and IT4_var07 were specifically expressed in IT4 parasite populations enriched for P-selectin-binding parasites; eight var genes (IT4_var02/07/09/13/17/41/44/64) were specifically expressed in isolate populations enriched for CD9-binding parasites. Interestingly, IT4 parasite populations enriched for E-selectin- and CD151-binding parasites showed identical expression profiles to those of a parasite population exposed to wild-type CHO-745 cells. The same phenomenon was observed for the 3D7 isolate population enriched for binding to P-selectin, E-selectin, CD9 and CD151. This implies that the corresponding ligands for these receptors have either weak binding capacity or do not exist on the IE surface. Conclusively, this work expanded our understanding of P. falciparum adhesive interactions, through the identification of var transcripts that are enriched within the selected parasite populations.
Collapse
Affiliation(s)
- Nahla Galal Metwally
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,Medical Parasitology Department, Faculty of Medicine-Suez Canal University, Ismailia, Egypt
| | | | - Pedro Lubiana
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Lisa K Roth
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Stephan Lorenzen
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Kathrin Schuldt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Susanne Witt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Henning Tidow
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Thomas Gutsmann
- Division of Biophysics, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Thorsten Burmester
- Institute of Zoology, Biocenter Grindel, University of Hamburg, Hamburg, Germany
| | - Thomas Roeder
- Zoological Institute, Department of Molecular Physiology, Christian-Albrechts University Kiel, Kiel, Germany
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
| |
Collapse
|
39
|
Acharya P, Garg M, Kumar P, Munjal A, Raja KD. Host-Parasite Interactions in Human Malaria: Clinical Implications of Basic Research. Front Microbiol 2017; 8:889. [PMID: 28572796 PMCID: PMC5435807 DOI: 10.3389/fmicb.2017.00889] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/02/2017] [Indexed: 12/21/2022] Open
Abstract
The malaria parasite, Plasmodium, is one of the oldest parasites documented to infect humans and has proven particularly hard to eradicate. One of the major hurdles in designing an effective subunit vaccine against the malaria parasite is the insufficient understanding of host–parasite interactions within the human host during infections. The success of the parasite lies in its ability to evade the human immune system and recruit host responses as physiological cues to regulate its life cycle, leading to rapid acclimatization of the parasite to its immediate host environment. Hence understanding the environmental niche of the parasite is crucial in developing strategies to combat this deadly infectious disease. It has been increasingly recognized that interactions between parasite proteins and host factors are essential to establishing infection and virulence at every stage of the parasite life cycle. This review reassesses all of these interactions and discusses their clinical importance in designing therapeutic approaches such as design of novel vaccines. The interactions have been followed from the initial stages of introduction of the parasite under the human dermis until asexual and sexual blood stages which are essential for transmission of malaria. We further classify the interactions as “direct” or “indirect” depending upon their demonstrated ability to mediate direct physical interactions of the parasite with host factors or their indirect manipulation of the host immune system since both forms of interactions are known to have a crucial role during infections. We also discuss the many ways in which this understanding has been taken to the field and the success of these strategies in controlling human malaria.
Collapse
Affiliation(s)
- Pragyan Acharya
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Manika Garg
- Department of Biochemistry, Jamia Hamdard UniversityNew Delhi, India
| | - Praveen Kumar
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - Akshay Munjal
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| | - K D Raja
- Department of Biochemistry, All India Institute of Medical SciencesNew Delhi, India
| |
Collapse
|
40
|
Cunningham DA, Lin JW, Brugat T, Jarra W, Tumwine I, Kushinga G, Ramesar J, Franke-Fayard B, Langhorne J. ICAM-1 is a key receptor mediating cytoadherence and pathology in the Plasmodium chabaudi malaria model. Malar J 2017; 16:185. [PMID: 28468674 PMCID: PMC5415785 DOI: 10.1186/s12936-017-1834-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/25/2017] [Indexed: 02/07/2023] Open
Abstract
Background Parasite cytoadherence within the microvasculature of tissues and organs of infected individuals is implicated in the pathogenesis of several malaria syndromes. Multiple host receptors may mediate sequestration. The identity of the host receptor(s), or the parasite ligand(s) responsible for sequestration of Plasmodium species other than Plasmodium falciparum is largely unknown. The rodent malaria parasites may be useful to model interactions of parasite species, which lack the var genes with their respective hosts, as other multigene families are shared between the species. The role of the endothelial receptors ICAM-1 and CD36 in cytoadherence and in the development of pathology was investigated in a Plasmodium chabaudi infection in C57BL/6 mice lacking these receptors. The schizont membrane-associated cytoadherence (SMAC) protein of Plasmodium berghei has been shown to exhibit reduced CD36-associated cytoadherence in P. berghei ANKA-infected mice. Methods Parasite tissue sequestration and the development of acute stage pathology in P. chabaudi infections of mice lacking CD36 or ICAM-1, their respective wild type controls, and in infections with mutant P. chabaudi parasites lacking the smac gene were compared. Peripheral blood parasitaemia, red blood cell numbers and weight change were monitored throughout the courses of infection. Imaging of bioluminescent parasites in isolated tissues (spleen, lungs, liver, kidney and gut) was used to measure tissue parasite load. Results This study shows that neither the lack of CD36 nor the deletion of the smac gene from P. chabaudi significantly impacted on acute-stage pathology or parasite sequestration. By contrast, in the absence of ICAM-1, infected animals experience less anaemia and weight loss, reduced parasite accumulation in both spleen and liver and higher peripheral blood parasitaemia during acute stage malaria. The reduction in parasite tissue sequestration in infections of ICAM-1 null mice is maintained after mosquito transmission. Conclusions These results indicate that ICAM-1-mediated cytoadherence is important in the P. chabaudi model of malaria and suggest that for rodent malarias, as for P. falciparum, there may be multiple host and parasite molecules involved in sequestration. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1834-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Jing-Wen Lin
- The Francis Crick Institute, London, NW1 1AT, UK
| | | | | | | | | | - Jai Ramesar
- Leiden Malaria Research Group, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | | |
Collapse
|
41
|
Thylur RP, Wu X, Gowda NM, Punnath K, Neelgund SE, Febbraio M, Gowda DC. CD36 receptor regulates malaria-induced immune responses primarily at early blood stage infection contributing to parasitemia control and resistance to mortality. J Biol Chem 2017; 292:9394-9408. [PMID: 28416609 DOI: 10.1074/jbc.m117.781294] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/12/2017] [Indexed: 12/31/2022] Open
Abstract
In malaria, CD36 plays several roles, including mediating parasite sequestration to host organs, phagocytic clearance of parasites, and regulation of immunity. Although the functions of CD36 in parasite sequestration and phagocytosis have been clearly defined, less is known about its role in malaria immunity. Here, to understand the function of CD36 in malaria immunity, we studied parasite growth, innate and adaptive immune responses, and host survival in WT and Cd36-/- mice infected with a non-lethal strain of Plasmodium yoelii Compared with Cd36-/- mice, WT mice had lower parasitemias and were resistant to death. At early but not at later stages of infection, WT mice had higher circulatory proinflammatory cytokines and lower anti-inflammatory cytokines than Cd36-/- mice. WT mice showed higher frequencies of proinflammatory cytokine-producing and lower frequencies of anti-inflammatory cytokine-producing dendritic cells (DCs) and natural killer cells than Cd36-/- mice. Cytokines produced by co-cultures of DCs from infected mice and ovalbumin-specific, MHC class II-restricted α/β (OT-II) T cells reflected CD36-dependent DC function. WT mice also showed increased Th1 and reduced Th2 responses compared with Cd36-/- mice, mainly at early stages of infection. Furthermore, in infected WT mice, macrophages and neutrophils expressed higher levels of phagocytic receptors and showed enhanced phagocytosis of parasite-infected erythrocytes than those in Cd36-/- mice in an IFN-γ-dependent manner. However, there were no differences in malaria-induced humoral responses between WT and Cd36-/- mice. Overall, the results show that CD36 plays a significant role in controlling parasite burden by contributing to proinflammatory cytokine responses by DCs and natural killer cells, Th1 development, phagocytic receptor expression, and phagocytic activity.
Collapse
Affiliation(s)
- Ramesh P Thylur
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Xianzhu Wu
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Nagaraj M Gowda
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Kishore Punnath
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Shivayogeeshwara E Neelgund
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| | - Maria Febbraio
- the Department of Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - D Channe Gowda
- From the Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033 and
| |
Collapse
|
42
|
Three Is a Crowd – New Insights into Rosetting in Plasmodium falciparum. Trends Parasitol 2017; 33:309-320. [DOI: 10.1016/j.pt.2016.12.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/17/2016] [Accepted: 12/19/2016] [Indexed: 12/29/2022]
|
43
|
Abstract
Of the five Plasmodium species that infect humans, infection with P. falciparum is the most lethal, causing severe malaria syndromes, that result in over half a million annual deaths. With parasites becoming increasingly resistant to artemisinin there is an urgent need for new preventative and therapeutic options, for which understanding of the mechanisms that cause death and disability in malaria is essential. The recent discoveries that certain variants of P. falciparum erythrocyte membrane protein 1 (PfEMP1) expressed on infected erythrocytes are intimately linked to the precipitation of severe malaria syndromes and that these PfEMP1 variants contain EPCR binding domains provides new opportunities to improve our understanding of the molecular mechanisms responsible for the pathogenesis of severe malaria. EPCR is known for its essential role in the protein C (PC) system and for its ability to support the cytoprotective effects of activated protein C (APC) that result in vascular and tissue protective effects in many organ systems of the body, including the brain, lung, kidney, and liver. Observations that binding of PfEMP1 to EPCR results in an acquired functional PC system deficiency support the new paradigm that EPCR plays a central role in the pathogenesis of severe malaria. Thus, targeting of the PfEMP1-EPCR interaction and restoring the functionality of the PC system may provide new strategies for the development of novel adjuvant therapies for severe malaria.
Collapse
|
44
|
Pathogenicity Determinants of the Human Malaria Parasite Plasmodium falciparum Have Ancient Origins. mSphere 2017; 2:mSphere00348-16. [PMID: 28101534 PMCID: PMC5227068 DOI: 10.1128/msphere.00348-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 12/21/2016] [Indexed: 11/20/2022] Open
Abstract
Cytoadhesion of P. falciparum-infected erythrocytes in the microcirculation is a major virulence determinant. P. falciparum is descended from a subgenus of parasites that also infect chimpanzees and gorillas and exhibits strict host species specificity. Despite their high genetic similarity to P. falciparum, it is unknown whether ape parasites encode adhesion properties similar to those of P. falciparum or are as virulent in their natural hosts. Consequently, it has been unclear when virulent adhesion traits arose in P. falciparum and how long they have been present in the parasite population. It is also unknown whether cytoadhesive interactions pose a barrier to cross-species transmission. We show that parasite domains from the chimpanzee malaria parasite P. reichenowi bind human receptors with specificity similar to that of P. falciparum. Our findings suggest that parasite adhesion traits associated with both mild and severe malaria have much earlier origins than previously appreciated and have important implications for virulence evolution in a major human pathogen. Plasmodium falciparum, the most deadly of the human malaria parasites, is a member of the Laverania subgenus that also infects African Great Apes. The virulence of P. falciparum is related to cytoadhesion of infected erythrocytes in microvasculature, but the origin of dangerous parasite adhesion traits is poorly understood. To investigate the evolutionary history of the P. falciparum cytoadhesion pathogenicity determinant, we studied adhesion domains from the chimpanzee malaria parasite P. reichenowi. We demonstrate that the P. reichenowi var gene repertoire encodes cysteine-rich interdomain region (CIDR) domains which bind human CD36 and endothelial protein C receptor (EPCR) with the same levels of affinity and at binding sites similar to those bound by P. falciparum. Moreover, P. reichenowi domains interfere with the protective function of the activated protein C-EPCR pathway on endothelial cells, a presumptive virulence trait in humans. These findings provide evidence for ancient evolutionary origins of two key cytoadhesion properties of P. falciparum that contribute to human infection and pathogenicity. IMPORTANCE Cytoadhesion of P. falciparum-infected erythrocytes in the microcirculation is a major virulence determinant. P. falciparum is descended from a subgenus of parasites that also infect chimpanzees and gorillas and exhibits strict host species specificity. Despite their high genetic similarity to P. falciparum, it is unknown whether ape parasites encode adhesion properties similar to those of P. falciparum or are as virulent in their natural hosts. Consequently, it has been unclear when virulent adhesion traits arose in P. falciparum and how long they have been present in the parasite population. It is also unknown whether cytoadhesive interactions pose a barrier to cross-species transmission. We show that parasite domains from the chimpanzee malaria parasite P. reichenowi bind human receptors with specificity similar to that of P. falciparum. Our findings suggest that parasite adhesion traits associated with both mild and severe malaria have much earlier origins than previously appreciated and have important implications for virulence evolution in a major human pathogen.
Collapse
|
45
|
Bernabeu M, Smith JD. EPCR and Malaria Severity: The Center of a Perfect Storm. Trends Parasitol 2016; 33:295-308. [PMID: 27939609 DOI: 10.1016/j.pt.2016.11.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022]
Abstract
Severe malaria due to Plasmodium falciparum infection causes nearly half a million deaths per year. The different symptomatology and disease manifestations among patients have hampered understanding of severe malaria pathology and complicated efforts to develop targeted disease interventions. Infected erythrocyte sequestration in the microvasculature plays a critical role in the development of severe disease, and there is increasing evidence that cytoadherent parasites interact with host factors to enhance the damage caused by the parasite. The recent discovery that parasite binding to endothelial protein C receptor (EPCR) is associated with severe disease has suggested new mechanisms of pathology and provided new avenues for severe malaria adjunctive therapy research.
Collapse
Affiliation(s)
- Maria Bernabeu
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Joseph D Smith
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
46
|
Cytoadhesion to gC1qR through Plasmodium falciparum Erythrocyte Membrane Protein 1 in Severe Malaria. PLoS Pathog 2016; 12:e1006011. [PMID: 27835682 PMCID: PMC5106025 DOI: 10.1371/journal.ppat.1006011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 10/19/2016] [Indexed: 11/19/2022] Open
Abstract
Cytoadhesion of Plasmodium falciparum infected erythrocytes to gC1qR has been associated with severe malaria, but the parasite ligand involved is currently unknown. To assess if binding to gC1qR is mediated through the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family, we analyzed by static binding assays and qPCR the cytoadhesion and var gene transcriptional profile of 86 P. falciparum isolates from Mozambican children with severe and uncomplicated malaria, as well as of a P. falciparum 3D7 line selected for binding to gC1qR (Pf3D7gC1qR). Transcript levels of DC8 correlated positively with cytoadhesion to gC1qR (rho = 0.287, P = 0.007), were higher in isolates from children with severe anemia than with uncomplicated malaria, as well as in isolates from Europeans presenting a first episode of malaria (n = 21) than Mozambican adults (n = 25), and were associated with an increased IgG recognition of infected erythrocytes by flow cytometry. Pf3D7gC1qR overexpressed the DC8 type PFD0020c (5.3-fold transcript levels relative to Seryl-tRNA-synthetase gene) compared to the unselected line (0.001-fold). DBLβ12 from PFD0020c bound to gC1qR in ELISA-based binding assays and polyclonal antibodies against this domain were able to inhibit binding to gC1qR of Pf3D7gC1qR and four Mozambican P. falciparum isolates by 50%. Our results show that DC8-type PfEMP1s mediate binding to gC1qR through conserved surface epitopes in DBLβ12 domain which can be inhibited by strain-transcending functional antibodies. This study supports a key role for gC1qR in malaria-associated endovascular pathogenesis and suggests the feasibility of designing interventions against severe malaria targeting this specific interaction. Plasmodium falciparum sequesters in vital organs. This phenomenon mediated by cytoadhesion of infected-erythrocytes to host receptors in the microvasculature, contributes to the development of severe malaria. Although cytoadhesion to Endothelial Protein-C Receptor has a central role in severe malaria, other host receptors are also likely to be involved. Our results generated by the analysis of P. falciparum isolates from Mozambican patients and laboratory parasite lines indicate that a specific domain (DBLβ12) from DC8-type PfEMP1s can bind to the human receptor gC1qR, previously associated with severe malaria. Our findings revealed that antibodies against PfEMP1 could provide strain-transcending inhibition of gC1qR-binding. Overall, these results support a key role for the adhesion to gC1qR in malaria-associated endovascular pathogenesis and the feasibility of new interventions targeting this specific interaction.
Collapse
|
47
|
Hsieh FL, Turner L, Bolla JR, Robinson CV, Lavstsen T, Higgins MK. The structural basis for CD36 binding by the malaria parasite. Nat Commun 2016; 7:12837. [PMID: 27667267 PMCID: PMC5052687 DOI: 10.1038/ncomms12837] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/04/2016] [Indexed: 12/18/2022] Open
Abstract
CD36 is a scavenger receptor involved in fatty acid metabolism, innate immunity and angiogenesis. It interacts with lipoprotein particles and facilitates uptake of long chain fatty acids. It is also the most common target of the PfEMP1 proteins of the malaria parasite, Plasmodium falciparum, tethering parasite-infected erythrocytes to endothelial receptors. This prevents their destruction by splenic clearance and allows increased parasitaemia. Here we describe the structure of CD36 in complex with long chain fatty acids and a CD36-binding PfEMP1 protein domain. A conserved hydrophobic pocket allows the hugely diverse PfEMP1 protein family to bind to a conserved phenylalanine residue at the membrane distal tip of CD36. This phenylalanine is also required for CD36 to interact with lipoprotein particles. By targeting a site on CD36 that is required for its physiological function, PfEMP1 proteins maintain the ability to tether to the endothelium and avoid splenic clearance. Targeting of the CD36 scavenger receptor by the malaria parasite effector PfEMP1 prevents splenic clearance of infected erythrocytes. Here, the authors propose that diverse PfEMP1 achieve this by binding to a conserved phenylalanine residue in CD36 that is also required for lipoprotein binding.
Collapse
Affiliation(s)
- Fu-Lien Hsieh
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Louise Turner
- Centre for Medical Parasitology, Department of International Health, Immunology &Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigshospitalet, Copenhagen 1017, Denmark
| | - Jani Reddy Bolla
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks, Oxford OX1 3QZ, UK
| | - Carol V Robinson
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks, Oxford OX1 3QZ, UK
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of International Health, Immunology &Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigshospitalet, Copenhagen 1017, Denmark
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| |
Collapse
|
48
|
Jespersen JS, Wang CW, Mkumbaye SI, Minja DT, Petersen B, Turner L, Petersen JE, Lusingu JP, Theander TG, Lavstsen T. Plasmodium falciparum var genes expressed in children with severe malaria encode CIDRα1 domains. EMBO Mol Med 2016; 8:839-50. [PMID: 27354391 PMCID: PMC4967939 DOI: 10.15252/emmm.201606188] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Most severe Plasmodium falciparum infections are experienced by young children. Severe symptoms are precipitated by vascular sequestration of parasites expressing a particular subset of the polymorphic P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesion molecules. Parasites binding human endothelial protein C receptor (EPCR) through the CIDRα1 domain of certain PfEMP1 were recently associated with severe malaria in children. However, it has remained unclear to which extend the EPCR‐binding CIDRα1 domains epitomize PfEMP1 expressed in severe malaria. Here, we characterized the near full‐length transcripts dominating the var transcriptome in children with severe malaria and found that the only common feature of the encoded PfEMP1 was CIDRα1 domains. Such genes were highly and dominantly expressed in both children with severe malarial anaemia and cerebral malaria. These observations support the hypothesis that the CIDRα1‐EPCR interaction is key to the pathogenesis of severe malaria and strengthen the rationale for pursuing a vaccine or adjunctive treatment aiming at inhibiting or reducing the damaging effects of this interaction.
Collapse
Affiliation(s)
- Jakob S Jespersen
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Sixbert I Mkumbaye
- Kilimanjaro Christian Medical University College, Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - Daniel Tr Minja
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Bent Petersen
- Centre for Biological Sequence Analysis, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Jens Ev Petersen
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - John Pa Lusingu
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology & Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
49
|
Interaction between Endothelial Protein C Receptor and Intercellular Adhesion Molecule 1 to Mediate Binding of Plasmodium falciparum-Infected Erythrocytes to Endothelial Cells. mBio 2016; 7:mBio.00615-16. [PMID: 27406562 PMCID: PMC4958245 DOI: 10.1128/mbio.00615-16] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intercellular adhesion molecule 1 (ICAM-1) and the endothelial protein C receptor (EPCR) are candidate receptors for the deadly complication cerebral malaria. However, it remains unclear if Plasmodium falciparum parasites with dual binding specificity are involved in cytoadhesion or different parasite subpopulations bind in brain microvessels. Here, we investigated this issue by studying different subtypes of ICAM-1-binding parasite lines. We show that two parasite lines expressing domain cassette 13 (DC13) of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family have dual binding specificity for EPCR and ICAM-1 and further mapped ICAM-1 binding to the first DBLβ domain following the PfEMP1 head structure in both proteins. As PfEMP1 head structures have diverged between group A (EPCR binders) and groups B and C (CD36 binders), we also investigated how ICAM-1-binding parasites with different coreceptor binding traits influence P. falciparum-infected erythrocyte binding to endothelial cells. Whereas levels of binding to tumor necrosis factor alpha (TNF-α)-stimulated endothelial cells from the lung and brain by all ICAM-1-binding parasite lines increased, group A (EPCR and ICAM-1) was less dependent than group B (CD36 and ICAM-1) on ICAM-1 upregulation. Furthermore, both group A DC13 parasite lines had higher binding levels to brain endothelial cells (a microvascular niche with limited CD36 expression). This study shows that ICAM-1 is a coreceptor for a subset of EPCR-binding parasites and provides the first evidence of how EPCR and ICAM-1 interact to mediate parasite binding to both resting and TNF-α-activated primary brain and lung endothelial cells. Cerebral malaria is a severe neurological complication of P. falciparum infection associated with infected erythrocyte (IE) binding in cerebral vessels. Yet little is known about the mechanisms by which parasites adhere in the brain or other microvascular sites. Here, we studied parasite lines expressing group A DC13-containing PfEMP1 variants, a subset that has previously been shown to have high brain cell- and other endothelial cell-binding activities. We show that DC13-containing PfEMP1 variants have dual EPCR- and ICAM-1-binding activities and that both receptors are involved in parasite adherence to lung and brain endothelial cells. As both EPCR and ICAM-1 are implicated in cerebral malaria, these findings suggest the possibility that parasites with dual binding activities are involved in parasite sequestration to microvascular beds with low CD36 expression, such as the brain, and we urge more research into the multiadhesive properties of PfEMP1 variants.
Collapse
|
50
|
Duffy MF, Noviyanti R, Tsuboi T, Feng ZP, Trianty L, Sebayang BF, Takashima E, Sumardy F, Lampah DA, Turner L, Lavstsen T, Fowkes FJI, Siba P, Rogerson SJ, Theander TG, Marfurt J, Price RN, Anstey NM, Brown GV, Papenfuss AT. Differences in PfEMP1s recognized by antibodies from patients with uncomplicated or severe malaria. Malar J 2016; 15:258. [PMID: 27149991 PMCID: PMC4858840 DOI: 10.1186/s12936-016-1296-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variants are encoded by var genes and mediate pathogenic cytoadhesion and antigenic variation in malaria. PfEMP1s can be broadly divided into three principal groups (A, B and C) and they contain conserved arrangements of functional domains called domain cassettes. Despite their tremendous diversity there is compelling evidence that a restricted subset of PfEMP1s is expressed in severe disease. In this study antibodies from patients with severe and uncomplicated malaria were compared for differences in reactivity with a range of PfEMP1s to determine whether antibodies to particular PfEMP1 domains were associated with severe or uncomplicated malaria. METHODS Parts of expressed var genes in a severe malaria patient were identified by RNAseq and several of these partial PfEMP1 domains were expressed together with others from laboratory isolates. Antibodies from Papuan patients to these parts of multiple PfEMP1 proteins were measured. RESULTS Patients with uncomplicated malaria were more likely to have antibodies that recognized PfEMP1 of Group C type and recognized a broader repertoire of group A and B PfEMP1s than patients with severe malaria. CONCLUSION These data suggest that exposure to a broad range of group A and B PfEMP1s is associated with protection from severe disease in Papua, Indonesia.
Collapse
Affiliation(s)
- Michael F. Duffy
- />Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Rintis Noviyanti
- />The Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Takafumi Tsuboi
- />Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime Japan
| | - Zhi-Ping Feng
- />Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- />Department of Medical Biology, University of Melbourne, Parkville, Victoria Australia
| | - Leily Trianty
- />The Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Boni F. Sebayang
- />The Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Eizo Takashima
- />Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime Japan
| | - Fransisca Sumardy
- />Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Daniel A. Lampah
- />Timika Malaria Research Program, Papuan Health and Community Development Foundation, Timika, Papua Indonesia
| | - Louise Turner
- />Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Lavstsen
- />Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | | | - Peter Siba
- />The Papua New Guinea Institute for Medical Research, Madang, Papua New Guinea
| | - Stephen J. Rogerson
- />Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Thor G. Theander
- />Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Jutta Marfurt
- />Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
| | - Ric N. Price
- />Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
- />Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Nicholas M. Anstey
- />Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
| | - Graham V. Brown
- />The Nossal Institute for Global Health, The University of Melbourne, Parkville, Victoria Australia
| | - Anthony T. Papenfuss
- />Bioinformatics Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- />Department of Medical Biology, University of Melbourne, Parkville, Victoria Australia
- />Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
- />Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria Australia
| |
Collapse
|