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Jaenisch T, Heiss K, Fischer N, Geiger C, Bischoff FR, Moldenhauer G, Rychlewski L, Sié A, Coulibaly B, Seeberger PH, Wyrwicz LS, Breitling F, Loeffler FF. High-density Peptide Arrays Help to Identify Linear Immunogenic B-cell Epitopes in Individuals Naturally Exposed to Malaria Infection. Mol Cell Proteomics 2019; 18:642-656. [PMID: 30630936 PMCID: PMC6442360 DOI: 10.1074/mcp.ra118.000992] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/28/2018] [Indexed: 01/31/2023] Open
Abstract
High-density peptide arrays are an excellent means to profile anti-plasmodial antibody responses. Different protein intrinsic epitopes can be distinguished, and additional insights are gained, when compared with assays involving the full-length protein. Distinct reactivities to specific epitopes within one protein may explain differences in published results, regarding immunity or susceptibility to malaria. We pursued three approaches to find specific epitopes within important plasmodial proteins, (1) twelve leading vaccine candidates were mapped as overlapping 15-mer peptides, (2) a bioinformatical approach served to predict immunogenic malaria epitopes which were subsequently validated in the assay, and (3) randomly selected peptides from the malaria proteome were screened as a control. Several peptide array replicas were prepared, employing particle-based laser printing, and were used to screen 27 serum samples from a malaria-endemic area in Burkina Faso, West Africa. The immunological status of the individuals was classified as "protected" or "unprotected" based on clinical symptoms, parasite density, and age. The vaccine candidate screening approach resulted in significant hits in all twelve proteins and allowed us (1) to verify many known immunogenic structures, (2) to map B-cell epitopes across the entire sequence of each antigen and (3) to uncover novel immunogenic epitopes. Predicting immunogenic regions in the proteome of the human malaria parasite Plasmodium falciparum, via the bioinformatics approach and subsequent array screening, confirmed known immunogenic sequences, such as in the leading malaria vaccine candidate CSP and discovered immunogenic epitopes derived from hypothetical or unknown proteins.
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Affiliation(s)
- Thomas Jaenisch
- From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF);; ¶HEiKA - Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Germany;.
| | - Kirsten Heiss
- From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF)
| | - Nico Fischer
- From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF);; ¶HEiKA - Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Germany
| | - Carolin Geiger
- From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF)
| | - F Ralf Bischoff
- ‖German Cancer Research Center, Im Neuenheimer Feld 280, D 69120 Heidelberg, Germany
| | - Gerhard Moldenhauer
- ‖German Cancer Research Center, Im Neuenheimer Feld 280, D 69120 Heidelberg, Germany
| | - Leszek Rychlewski
- BioInfoBank Institute, Św. Marcin 80/82 lok. 355, 61-809 Poznań, Poland
| | - Ali Sié
- Centre de Recherche en Santé de Nouna, BP 02 Nouna, Rue Namory Keita, Burkina Faso
| | - Boubacar Coulibaly
- Centre de Recherche en Santé de Nouna, BP 02 Nouna, Rue Namory Keita, Burkina Faso
| | - Peter H Seeberger
- §§Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, D 14476 Potsdam, Germany
| | - Lucjan S Wyrwicz
- Department of Oncology and Radiotherapy, M Sklodowska Curie Memorial Cancer Center, Wawelska 15, 02-034 Warsaw, Poland
| | - Frank Breitling
- ‖‖Institute of Microstructure Technology, Karlsruhe Institute of Technology, Germany Hermann-von-Helmholtz-Platz 1, D 76344 Eggenstein-Leopoldshafen, Germany
| | - Felix F Loeffler
- ¶HEiKA - Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Germany;; §§Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, D 14476 Potsdam, Germany;.
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102
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Kobayashi T, Jain A, Liang L, Obiero JM, Hamapumbu H, Stevenson JC, Thuma PE, Lupiya J, Chaponda M, Mulenga M, Mamini E, Mharakurwa S, Gwanzura L, Munyati S, Mutambu S, Felgner P, Davies DH, Moss WJ. Distinct Antibody Signatures Associated with Different Malaria Transmission Intensities in Zambia and Zimbabwe. mSphere 2019; 4:e00061-19. [PMID: 30918058 PMCID: PMC6437277 DOI: 10.1128/mspheredirect.00061-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 12/30/2022] Open
Abstract
Antibodies to Plasmodium falciparum are specific biomarkers that can be used to monitor parasite exposure over broader time frames than microscopy, rapid diagnostic tests, or molecular assays. Consequently, seroprevalence surveys can assist with monitoring the impact of malaria control interventions, particularly in the final stages of elimination, when parasite incidence is low. The protein array format to measure antibodies to diverse P. falciparum antigens requires only small sample volumes and is high throughput, permitting the monitoring of malaria transmission on large spatial and temporal scales. We expanded the use of a protein microarray to assess malaria transmission in settings beyond those with a low malaria incidence. Antibody responses in children and adults were profiled, using a P. falciparum protein microarray, through community-based surveys in three areas in Zambia and Zimbabwe at different stages of malaria control and elimination. These three epidemiological settings had distinct serological profiles reflective of their malaria transmission histories. While there was little correlation between transmission intensity and antibody signals (magnitude or breadth) in adults, there was a clear correlation in children younger than 5 years of age. Antibodies in adults appeared to be durable even in the absence of significant recent transmission, whereas antibodies in children provided a more accurate picture of recent levels of transmission intensity. Seroprevalence studies in children could provide a valuable marker of progress toward malaria elimination.IMPORTANCE As malaria approaches elimination in many areas of the world, monitoring the effect of control measures becomes more important but challenging. Low-level infections may go undetected by conventional tests that depend on parasitemia, particularly in immune individuals, who typically show no symptoms of malaria. In contrast, antibodies persist after parasitemia and may provide a more accurate picture of recent exposure. Only a few parasite antigens-mainly vaccine candidates-have been evaluated in seroepidemiological studies. We examined antibody responses to 500 different malaria proteins in blood samples collected through community-based surveillance from areas with low, medium, and high malaria transmission intensities. The breadth of the antibody responses in adults was broad in all three settings and was a poor correlate of recent exposure. In contrast, children represented a better sentinel population for monitoring recent malaria transmission. These data will help inform the use of multiplex serology for malaria surveillance.
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Affiliation(s)
- Tamaki Kobayashi
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Aarti Jain
- Vaccine Research & Development Center, Department of Physiology & Biophysics, School of Medicine, University of California, Irvine, Irvine, California, USA
| | - Li Liang
- Vaccine Research & Development Center, Department of Physiology & Biophysics, School of Medicine, University of California, Irvine, Irvine, California, USA
| | - Joshua M Obiero
- Vaccine Research & Development Center, Department of Physiology & Biophysics, School of Medicine, University of California, Irvine, Irvine, California, USA
| | | | - Jennifer C Stevenson
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Macha Research Trust, Choma, Zambia
| | - Philip E Thuma
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Macha Research Trust, Choma, Zambia
| | - James Lupiya
- Tropical Diseases Research Centre, Ndola, Zambia
| | | | | | - Edmore Mamini
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | | | | | - Shungu Munyati
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Susan Mutambu
- National Institute of Health Research, Harare, Zimbabwe
| | - Philip Felgner
- Vaccine Research & Development Center, Department of Physiology & Biophysics, School of Medicine, University of California, Irvine, Irvine, California, USA
| | - D Huw Davies
- Vaccine Research & Development Center, Department of Physiology & Biophysics, School of Medicine, University of California, Irvine, Irvine, California, USA
| | - William J Moss
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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103
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Abstract
Plasmodium falciparum malaria remains a globally leading infectious disease problem. Despite decades of intense investigation, an efficacious and practical vaccine offering durable protection to people living in areas with transmission of malaria parasites remains an elusive goal. Plasmodium falciparum malaria remains a globally leading infectious disease problem. Despite decades of intense investigation, an efficacious and practical vaccine offering durable protection to people living in areas with transmission of malaria parasites remains an elusive goal. Our fragmentary understanding of the mechanisms of protective immunity to the disease is a major obstacle, and the almost complete focus on a very small subset of P. falciparum proteins as vaccine candidates has left most parasite antigens essentially unexplored as targets of acquired immunity. However, with the protein microarray technology, it is now possible to interrogate the entire parasite proteome for new vaccine candidates and for markers of parasite exposure. Recent mSphere papers describe the results of such research.
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104
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Antibodies to Peptides in Semiconserved Domains of RIFINs and STEVORs Correlate with Malaria Exposure. mSphere 2019; 4:4/2/e00097-19. [PMID: 30894432 PMCID: PMC6429043 DOI: 10.1128/msphere.00097-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria, an infectious disease caused by the parasite Plasmodium falciparum, causes nearly 435,000 deaths annually worldwide. RIFINs and STEVORs are two variant surface antigen families that are involved in malaria pathogenesis and immune evasion. Recent work has shown that a lack of humoral immunity to these proteins is associated with severe malaria vulnerability in Malian children. This is the first study to have compared serologic responses of children and adults to RIFINs and STEVORs in settings of malaria endemicity and to examine such serologic responses before and after a clinical malaria episode. Using microarrays, we determined that the semiconserved domains in these two parasite variant surface antigen families harbor peptides whose seroreactivity reflects malaria exposure. A similar approach has the potential to illuminate the role of variant surface antigens in the development of natural immunity to clinical malaria. Potential vaccines for severe malaria should include consideration of peptides within the semiconserved domains of RIFINs and STEVORs. The repetitive interspersed family (RIFIN) and the subtelomeric variable open reading frame (STEVOR) family represent two of three major Plasmodium falciparum variant surface antigen families involved in malaria pathogenesis and immune evasion and are potential targets in the development of natural immunity. Protein and peptide microarrays populated with RIFINs and STEVORs associated with severe malaria vulnerability in Malian children were probed with adult and pediatric sera to identify epitopes that reflect malaria exposure. Adult sera recognized and reacted with greater intensity to all STEVOR proteins than pediatric sera did. Serorecognition of and seroreactivity to peptides within the semiconserved domain of STEVORs increased with age and seasonal malaria exposure, while serorecognition and seroreactivity increased for the semiconserved and second hypervariable domains of RIFINs only with age. Serologic responses to RIFIN and STEVOR peptides within the semiconserved domains may play a role in natural immunity to severe malaria. IMPORTANCE Malaria, an infectious disease caused by the parasite Plasmodium falciparum, causes nearly 435,000 deaths annually worldwide. RIFINs and STEVORs are two variant surface antigen families that are involved in malaria pathogenesis and immune evasion. Recent work has shown that a lack of humoral immunity to these proteins is associated with severe malaria vulnerability in Malian children. This is the first study to have compared serologic responses of children and adults to RIFINs and STEVORs in settings of malaria endemicity and to examine such serologic responses before and after a clinical malaria episode. Using microarrays, we determined that the semiconserved domains in these two parasite variant surface antigen families harbor peptides whose seroreactivity reflects malaria exposure. A similar approach has the potential to illuminate the role of variant surface antigens in the development of natural immunity to clinical malaria. Potential vaccines for severe malaria should include consideration of peptides within the semiconserved domains of RIFINs and STEVORs.
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105
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Ndungu FM, Mwacharo J, Wambua J, Njuguna P, Marsh K, Drakeley C, Bejon P. A seven-year study on the effect of the pre-erythrocytic malaria vaccine candidate RTS,S/AS01 E on blood stage immunity in young Kenyan children. Wellcome Open Res 2019; 4:42. [PMID: 31168483 PMCID: PMC6545824 DOI: 10.12688/wellcomeopenres.15002.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2019] [Indexed: 01/06/2023] Open
Abstract
Background: RTS,S/AS01
E, the most advanced malaria vaccine confers partial immunity. The vaccine-induced pre-erythrocytic immunity reduces exposure to blood-stage parasites, delaying acquisition of antibodies to blood-stage antigens. However, the duration of this effect is unknown. Methods: We measured, by enzyme-linked immunosorbent assay, IgG-antibodies to 4
Plasmodium falciparum blood-stage antigens (AMA1, MSP1
42, EBA175, and MSP3) on 314 children randomized to receive RTS,S/AS01
E or Rabies vaccine at 5 – 17 months of age in a phase 2b trial in Kenya, and thereafter participated in a 7-year study of the duration of vaccine immunity. Results: Antibody levels to MSP1
42, AMA1 and EBA175 were slightly lower among the RTS,S/AS01
E recipients, relative to the Rabies-control vaccinees, during the first 48 months of surveillance. Irrespective of vaccine arm, antibody levels to merozoite antigens were positively associated with the risk for malaria. However, this was only apparent at high levels for EBA175 and AMA1 and was not evident after adjusting for heterogeneity in malaria-exposure. Among children with asymptomatic parasitaemia, antibody levels were associated with reduced clinical malaria. Conclusions: The reduction in levels of antibodies to blood-stage antigens induced by vaccination with RTS,S/AS01
E can last for several years. In absence of asymptomatic infection, anti-merozoite antibody levels were unreliable correlates of clinical immunity.
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Affiliation(s)
- Francis M Ndungu
- Department of Biosciences, KEMRI/Wellcome Trust Research Programme, Kilifi, 80108, Kenya
| | - Jedida Mwacharo
- Department of Biosciences, KEMRI/Wellcome Trust Research Programme, Kilifi, 80108, Kenya
| | - Juliana Wambua
- Department of Biosciences, KEMRI/Wellcome Trust Research Programme, Kilifi, 80108, Kenya
| | - Patricia Njuguna
- Department of Biosciences, KEMRI/Wellcome Trust Research Programme, Kilifi, 80108, Kenya
| | - Kevin Marsh
- Department of Biosciences, KEMRI/Wellcome Trust Research Programme, Kilifi, 80108, Kenya
| | - Chris Drakeley
- Infection & Immunity Department, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Philip Bejon
- Infection & Immunity Department, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
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106
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Cooper MM, Loiseau C, McCarthy JS, Doolan DL. Human challenge models: tools to accelerate the development of malaria vaccines. Expert Rev Vaccines 2019; 18:241-251. [PMID: 30732492 DOI: 10.1080/14760584.2019.1580577] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Malaria challenge models, where healthy human volunteers are intentionally infected with Plasmodium species parasites under controlled conditions, can be undertaken in several well-defined ways. These challenge models enable evaluation of the kinetics of parasite growth and clearance, host-pathogen interactions and the host immune response. They can facilitate discovery of candidate diagnostic biomarkers and novel vaccine targets. As translational tools they can facilitate testing of candidate vaccines and drugs and evaluation of diagnostic tests. AREAS COVERED Until recently, malaria human challenge models have been limited to only a few Plasmodium falciparum strains and used exclusively in malaria-naïve volunteers in non-endemic regions. Several recent advances include the use of alternate P. falciparum strains and other species of Plasmodia, as well as strains attenuated by chemical, radiation or genetic modification, and the conduct of studies in pre-exposed individuals. Herein, we discuss how this diversification is enabling more thorough vaccine efficacy testing and informing rational vaccine development. EXPERT OPINION The ability to comprehensively evaluate vaccine efficacy in controlled settings will continue to accelerate the translation of candidate malaria vaccines to the clinic, and inform the development and optimisation of potential vaccines that would be effective against multiple strains in geographically and demographically diverse settings.
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Affiliation(s)
- Martha M Cooper
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - Claire Loiseau
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - James S McCarthy
- b Infectious Diseases Programme , QIMR Berghofer Medical Research Institute , Brisbane , Australia
| | - Denise L Doolan
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
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107
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Akter J, Khoury DS, Aogo R, Lansink LIM, SheelaNair A, Thomas BS, Laohamonthonkul P, Pernold CPS, Dixon MWA, Soon MSF, Fogg LG, Engel JA, Elliott T, Sebina I, James KR, Cromer D, Davenport MP, Haque A. Plasmodium-specific antibodies block in vivo parasite growth without clearing infected red blood cells. PLoS Pathog 2019; 15:e1007599. [PMID: 30811498 PMCID: PMC6411214 DOI: 10.1371/journal.ppat.1007599] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/11/2019] [Accepted: 01/28/2019] [Indexed: 01/01/2023] Open
Abstract
Plasmodium parasites invade and multiply inside red blood cells (RBC). Through a cycle of maturation, asexual replication, rupture and release of multiple infective merozoites, parasitised RBC (pRBC) can reach very high numbers in vivo, a process that correlates with disease severity in humans and experimental animals. Thus, controlling pRBC numbers can prevent or ameliorate malaria. In endemic regions, circulating parasite-specific antibodies associate with immunity to high parasitemia. Although in vitro assays reveal that protective antibodies could control pRBC via multiple mechanisms, in vivo assessment of antibody function remains challenging. Here, we employed two mouse models of antibody-mediated immunity to malaria, P. yoelii 17XNL and P. chabaudi chabaudi AS infection, to study infection-induced, parasite-specific antibody function in vivo. By tracking a single generation of pRBC, we tested the hypothesis that parasite-specific antibodies accelerate pRBC clearance. Though strongly protective against homologous re-challenge, parasite-specific IgG did not alter the rate of pRBC clearance, even in the presence of ongoing, systemic inflammation. Instead, antibodies prevented parasites progressing from one generation of RBC to the next. In vivo depletion studies using clodronate liposomes or cobra venom factor, suggested that optimal antibody function required splenic macrophages and dendritic cells, but not complement C3/C5-mediated killing. Finally, parasite-specific IgG bound poorly to the surface of pRBC, yet strongly to structures likely exposed by the rupture of mature schizonts. Thus, in our models of humoral immunity to malaria, infection-induced antibodies did not accelerate pRBC clearance, and instead co-operated with splenic phagocytes to block subsequent generations of pRBC. Malaria occurs when Plasmodium parasites replicate inside red blood cells, with the number of parasitised cells (pRBC) correlating with disease severity. Antibodies are highly effective at controlling pRBC numbers in the bloodstream, and yet we know very little about how they function in vivo. Human in vitro studies predict that antibodies may function in a number of ways, including via phagocytes or different complement mechanisms. However, to date it has been challenging to explore how antibodies might control parasite numbers in vivo. Here, we have used a unique method in mice, where clearance and replication of a single cohort of pRBC was closely tracked in the presence of protective antibodies. Surprisingly, antibodies played no role whatsoever in accelerating the removal of pRBC. Instead, antibodies were highly effective at preventing parasites from progressing from one generation of pRBC to the next. This process partly depended on host phagocytes. However, we found no role for complement-mediated direct killing. Together, our in vivo data suggest in mouse models that naturally-acquired antibodies do not clear pRBC, and instead prevent transition from one red blood cell to the next.
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Affiliation(s)
- Jasmin Akter
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - David S. Khoury
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | - Rosemary Aogo
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | | | - Arya SheelaNair
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Bryce S. Thomas
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | | | | | - Matthew W. A. Dixon
- University of Melbourne, Department of Biochemistry and Molecular Biology, Melbourne, Victoria, Australia
| | - Megan S. F. Soon
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Lily G. Fogg
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Jessica A. Engel
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Trish Elliott
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Ismail Sebina
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Kylie R. James
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
| | - Deborah Cromer
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
| | - Miles P. Davenport
- Infection Analytics Program, Kirby Institute, UNSW Australia, Kensington NSW, Australia
- * E-mail: (MPD); (AH)
| | - Ashraful Haque
- QIMR Berghofer Medical Research Institute, Herston, Brisbane QLD, Australia
- * E-mail: (MPD); (AH)
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108
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Shaw TN, Inkson CA, Villegas-Mendez A, Pattinson DJ, Strangward P, Else KJ, Draper SJ, Zeef LAH, Couper KN. Infection-Induced Resistance to Experimental Cerebral Malaria Is Dependent Upon Secreted Antibody-Mediated Inhibition of Pathogenic CD8 + T Cell Responses. Front Immunol 2019; 10:248. [PMID: 30846985 PMCID: PMC6394254 DOI: 10.3389/fimmu.2019.00248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 01/29/2019] [Indexed: 12/27/2022] Open
Abstract
Cerebral malaria (CM) is one of the most severe complications of Plasmodium falciparum infection. There is evidence that repeated parasite exposure promotes resistance against CM. However, the immunological basis of this infection-induced resistance remains poorly understood. Here, utilizing the Plasmodium berghei ANKA (PbA) model of experimental cerebral malaria (ECM), we show that three rounds of infection and drug-cure protects against the development of ECM during a subsequent fourth (4X) infection. Exposure-induced resistance was associated with specific suppression of CD8+ T cell activation and CTL-related pathways, which corresponded with the development of heterogeneous atypical B cell populations as well as the gradual infection-induced generation and maintenance of high levels of anti-parasite IgG. Mechanistically, transfer of high-titer anti-parasite IgG did not protect 1X infected mice against ECM and depletion of atypical and regulatory B cells during 4X infection failed to abrogate infection-induced resistance to ECM. However, IgMi mice that were unable to produce secreted antibody, or undergo class switching, during the repeated rounds of infection failed to develop resistance against ECM. The failure of infection-induced protection in IgMi mice was associated with impaired development of atypical B cell populations and the inability to suppress pathogenic CD8+ T cell responses. Our results, therefore, suggest the importance of anti-parasite antibody responses, gradually acquired, and maintained through repeated Plasmodium infections, for modulating the B cell compartment and eventually suppressing memory CD8+ T cell reactivation to establish infection-induced resistance to ECM.
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Affiliation(s)
- Tovah N. Shaw
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
- Manchester Collaborative Centre for Inflammation Research, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
| | - Colette A. Inkson
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
| | - Ana Villegas-Mendez
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
| | | | - Patrick Strangward
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
| | - Kathryn J. Else
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
| | - Simon J. Draper
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Leo A. H. Zeef
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Kevin N. Couper
- Faculty of Biology, Medicine and Health, The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom
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109
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Taghavian O, Jain A, Joyner CJ, Ketchum S, Nakajima R, Jasinskas A, Liang L, Fong R, King C, Greenhouse B, Murphy M, Bailey J, Galinski MR, Barnwell JW, Plowe CV, Davies DH, Felgner PL. Antibody Profiling by Proteome Microarray with Multiplex Isotype Detection Reveals Overlap between Human and Aotus nancymaae Controlled Malaria Infections. Proteomics 2019; 18. [PMID: 29266845 DOI: 10.1002/pmic.201700277] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 11/21/2017] [Indexed: 12/13/2022]
Abstract
The development of vaccines against malaria and serodiagnostic tests for detecting recent exposure requires tools for antigen discovery and suitable animal models. The protein microarray is a high-throughput, sample sparing technique, with applications in infectious disease research, clinical diagnostics, epidemiology, and vaccine development. We recently demonstrated Qdot-based indirect immunofluorescence together with portable optical imager ArrayCAM using single isotype detection could replicate data using the conventional laser confocal scanner system. We developed a multiplexing protocol for simultaneous detection of IgG, IgA, and IgM and compared samples from a controlled human malaria infection model with those from controlled malaria infections of Aotus nancymaae, a widely used non-human primate model of human malaria. IgG profiles showed the highest concordance in number of reactive antigens; thus, of the 139 antigens recognized by human IgG antibody, 111 were also recognized by Aotus monkeys. Interestingly, IgA profiles were largely non-overlapping. Finally, on the path toward wider deployment of the portable platform, we show excellent correlations between array data obtained in five independent laboratories around the United States using the multiplexing protocol (R2 : 0.60-0.92). This study supports the use of this platform for wider deployment, particularly in endemic areas where such a tool will have the greatest impact on global human health.
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Affiliation(s)
- Omid Taghavian
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Aarti Jain
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Chester J Joyner
- International Center for Malaria Research, Education and Development, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | | | - Rie Nakajima
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Algis Jasinskas
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Li Liang
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Rich Fong
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Christopher King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Jason Bailey
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, USA
| | - Mary R Galinski
- International Center for Malaria Research, Education and Development, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, USA
| | - John W Barnwell
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Christopher V Plowe
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
| | - D Huw Davies
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Philip L Felgner
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
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110
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Siau A, Huang X, Loh HP, Zhang N, Meng W, Sze SK, Renia L, Preiser P. Immunomic Identification of Malaria Antigens Associated With Protection in Mice. Mol Cell Proteomics 2019; 18:837-853. [PMID: 30718293 DOI: 10.1074/mcp.ra118.000997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 01/22/2019] [Indexed: 11/06/2022] Open
Abstract
Efforts to develop vaccines against malaria represent a major research target. The observations that 1) sterile protection can be obtained when the host is exposed to live parasites and 2) the immunity against blood stage parasite is principally mediated by protective antibodies suggest that a protective vaccine is feasible. However, only a small number of proteins have been investigated so far and most of the Plasmodium proteome has yet to be explored. To date, only few immunodominant antigens have emerged for testing in clinical trials but no formulation has led to substantial protection in humans. The nature of parasite molecules associated with protection remains elusive. Here, immunomic screening of mice immune sera with different protection efficiencies against the whole parasite proteome allowed us to identify a large repertoire of antigens validated by screening a library expressing antigens. The calculation of weighted scores reflecting the likelihood of protection of each antigen using five predictive criteria derived from immunomic and proteomic data sets, highlighted a priority list of protective antigens. Altogether, the approach sheds light on conserved antigens across Plasmodium that are amenable to targeting by the host immune system upon merozoite invasion and blood stage development. Most of these antigens have preliminary protection data but have not been widely considered as candidate for vaccine trials, opening new perspectives that overcome the limited choice of immunodominant, poorly protective vaccines currently being the focus of malaria vaccine researches.
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Affiliation(s)
- Anthony Siau
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
| | - Ximei Huang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Han Ping Loh
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Neng Zhang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Wei Meng
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Siu Kwan Sze
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Laurent Renia
- §Singapore Immunology Network (SIgN), A*STAR, Biopolis, Singapore
| | - Peter Preiser
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
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111
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Targets of complement-fixing antibodies in protective immunity against malaria in children. Nat Commun 2019; 10:610. [PMID: 30723225 PMCID: PMC6363798 DOI: 10.1038/s41467-019-08528-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/07/2019] [Indexed: 12/31/2022] Open
Abstract
Antibodies against P. falciparum merozoites fix complement to inhibit blood-stage replication in naturally-acquired and vaccine-induced immunity; however, specific targets of these functional antibodies and their importance in protective immunity are unknown. Among malaria-exposed individuals, we show that complement-fixing antibodies to merozoites are more strongly correlated with protective immunity than antibodies that inhibit growth quantified using the current reference assay for merozoite vaccine evaluation. We identify merozoite targets of complement-fixing antibodies and identify antigen-specific complement-fixing antibodies that are strongly associated with protection from malaria in a longitudinal study of children. Using statistical modelling, combining three different antigens targeted by complement-fixing antibodies could increase the potential protective effect to over 95%, and we identify antigens that were common in the most protective combinations. Our findings support antibody-complement interactions against merozoite antigens as important anti-malaria immune mechanisms, and identify specific merozoite antigens for further evaluation as vaccine candidates. Antibodies against Plasmodium falciparum merozoites that fix complement can inhibit blood-stage replication. Here, Reiling et al. show that complement-fixing antibodies strongly correlate with protective immunity in children, identify the merozoite targets, and predict antigen combinations that should result in strong protection.
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112
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Yman V, White MT, Asghar M, Sundling C, Sondén K, Draper SJ, Osier FHA, Färnert A. Antibody responses to merozoite antigens after natural Plasmodium falciparum infection: kinetics and longevity in absence of re-exposure. BMC Med 2019; 17:22. [PMID: 30696449 PMCID: PMC6352425 DOI: 10.1186/s12916-019-1255-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 01/08/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antibodies against merozoite antigens are key components of malaria immunity. The naturally acquired antibody response to these antigens is generally considered short-lived; however, the underlying mechanisms remain unclear. Prospective studies of travellers with different levels of prior exposure, returning to malaria-free countries with Plasmodium infection, offer a unique opportunity to investigate the kinetics and composition of the antibody response after natural infection. METHODS Adults diagnosed with P. falciparum malaria in Stockholm, Sweden (20 likely malaria naïve and 41 with repeated previous exposure during residency in sub-Saharan Africa) were sampled at diagnosis and 10 days and 1, 3, 6, and 12 months after treatment. Total and subclass-specific IgG responses to P. falciparum merozoite antigens (AMA-1, MSP-119, MSP-2, MSP-3, and RH5) and tetanus toxoid were measured by multiplex bead-based immunoassays and ELISA. Mathematical modelling was used to estimate the exposure-dependent longevity of antibodies and antibody-secreting cells (ASCs). RESULTS A majority of individuals mounted detectable antibody responses towards P. falciparum merozoite antigens at diagnosis; however, the magnitude and breadth were greater in individuals with prior exposure. In both exposure groups, antibody levels increased rapidly for 2 weeks and decayed thereafter. Previously exposed individuals maintained two- to ninefold greater antibody levels throughout the 1-year follow-up. The half-lives of malaria-specific long-lived ASCs, responsible for maintaining circulating antibodies, ranged from 1.8 to 3.7 years for merozoite antigens and were considerably short compared to tetanus-specific ASCs. Primary infected individuals did acquire a long-lived component of the antibody response; however, the total proportion of long-lived ASCs generated in response to infection was estimated not to exceed 10%. In contrast, previously exposed individuals maintained substantially larger numbers of long-lived ASCs (10-56% of total ASCs). CONCLUSION The short-lived nature of the naturally acquired antibody response, to all tested merozoite antigens, following primary malaria infection can be attributed to a combination of a poor acquisition and short half-life of long-lived ASCs. Greater longevity is acquired with repeated infections and can be explained by the maintenance of larger numbers of long-lived ASCs. These insights advance our understanding of naturally acquired malaria immunity and will guide strategies for further development of both vaccines and serological tools to monitor exposure.
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Affiliation(s)
- Victor Yman
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden.
| | - Michael T White
- Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 Rue du Dr Roux, 75015, Paris, France
| | - Muhammad Asghar
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden
| | - Christopher Sundling
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden
| | - Klara Sondén
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, 171 76, Stockholm, Sweden
| | - Simon J Draper
- Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Faith H A Osier
- Kenya Medical Research Institute - Wellcome Trust Research Program, Centre for Geographic Medicine Research-Coast, PO Box 230-80108, Kilifi, Kenya
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Anna Färnert
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, 171 76, Stockholm, Sweden
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113
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Abstract
The enzyme-linked immunosorbent assay (ELISA) is a reliable and relatively low-cost method for measuring soluble ligands such as antibodies and proteins in biological samples. For analysis of specific antibodies in serum, a capture antigen is immobilized onto a solid polystyrene surface from which it can capture the antibodies. The captured antibodies are subsequently detected using a secondary antibody conjugated to an enzyme. Detection is accomplished by addition of a colorimetric substrate, and the readout is absorbance (optical density). Here, we provide a detailed standardized ELISA protocol for the quantification of antibodies against malaria antigens.
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114
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Liu EW, Skinner J, Tran TM, Kumar K, Narum DL, Jain A, Ongoiba A, Traoré B, Felgner PL, Crompton PD. Protein-Specific Features Associated with Variability in Human Antibody Responses to Plasmodium falciparum Malaria Antigens. Am J Trop Med Hyg 2018; 98:57-66. [PMID: 29141757 PMCID: PMC5928716 DOI: 10.4269/ajtmh.17-0437] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The magnitude of antibody responses varies across the individual proteins that constitute any given microorganism, both in the context of natural infection and vaccination with attenuated or inactivated pathogens. The protein-specific factors underlying this variability are poorly understood. In 267 individuals exposed to intense seasonal malaria, we examined the relationship between immunoglobulin G (IgG) responses to 861 Plasmodium falciparum proteins and specific features of these proteins, including their subcellular location, relative abundance, degree of polymorphism, and whether they are predicted to have human orthologs. We found that IgG reactivity was significantly higher to extracellular and plasma membrane proteins and also correlated positively with both protein abundance and degree of protein polymorphism. Conversely, IgG reactivity was significantly lower to proteins predicted to have human orthologs. These findings provide insight into protein-specific factors that are associated with variability in the magnitude of antibody responses to natural P. falciparum infection-data that could inform vaccine strategies to optimize antibody-mediated immunity as well as the selection of antigens for sero-diagnostic purposes.
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Affiliation(s)
- Eugene W Liu
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Jeff Skinner
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Tuan M Tran
- Division of Infectious Diseases, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Aarti Jain
- University of California, Irvine, Irvine, California
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences,Techniques and Technologies of Bamako, Bamako, Mali
| | - Boubacar Traoré
- Mali International Center of Excellence in Research, University of Sciences,Techniques and Technologies of Bamako, Bamako, Mali
| | | | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
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115
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Kamuyu G, Tuju J, Kimathi R, Mwai K, Mburu J, Kibinge N, Chong Kwan M, Hawkings S, Yaa R, Chepsat E, Njunge JM, Chege T, Guleid F, Rosenkranz M, Kariuki CK, Frank R, Kinyanjui SM, Murungi LM, Bejon P, Färnert A, Tetteh KKA, Beeson JG, Conway DJ, Marsh K, Rayner JC, Osier FHA. KILchip v1.0: A Novel Plasmodium falciparum Merozoite Protein Microarray to Facilitate Malaria Vaccine Candidate Prioritization. Front Immunol 2018; 9:2866. [PMID: 30619257 PMCID: PMC6298441 DOI: 10.3389/fimmu.2018.02866] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/21/2018] [Indexed: 12/12/2022] Open
Abstract
Passive transfer studies in humans clearly demonstrated the protective role of IgG antibodies against malaria. Identifying the precise parasite antigens that mediate immunity is essential for vaccine design, but has proved difficult. Completion of the Plasmodium falciparum genome revealed thousands of potential vaccine candidates, but a significant bottleneck remains in their validation and prioritization for further evaluation in clinical trials. Focusing initially on the Plasmodium falciparum merozoite proteome, we used peer-reviewed publications, multiple proteomic and bioinformatic approaches, to select and prioritize potential immune targets. We expressed 109 P. falciparum recombinant proteins, the majority of which were obtained using a mammalian expression system that has been shown to produce biologically functional extracellular proteins, and used them to create KILchip v1.0: a novel protein microarray to facilitate high-throughput multiplexed antibody detection from individual samples. The microarray assay was highly specific; antibodies against P. falciparum proteins were detected exclusively in sera from malaria-exposed but not malaria-naïve individuals. The intensity of antibody reactivity varied as expected from strong to weak across well-studied antigens such as AMA1 and RH5 (Kruskal–Wallis H test for trend: p < 0.0001). The inter-assay and intra-assay variability was minimal, with reproducible results obtained in re-assays using the same chip over a duration of 3 months. Antibodies quantified using the multiplexed format in KILchip v1.0 were highly correlated with those measured in the gold-standard monoplex ELISA [median (range) Spearman's R of 0.84 (0.65–0.95)]. KILchip v1.0 is a robust, scalable and adaptable protein microarray that has broad applicability to studies of naturally acquired immunity against malaria by providing a standardized tool for the detection of antibody correlates of protection. It will facilitate rapid high-throughput validation and prioritization of potential Plasmodium falciparum merozoite-stage antigens paving the way for urgently needed clinical trials for the next generation of malaria vaccines.
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Affiliation(s)
- Gathoni Kamuyu
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.,Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - James Tuju
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.,Department of Biochemistry, Pwani University, Kilifi, Kenya
| | - Rinter Kimathi
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Kennedy Mwai
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - James Mburu
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Nelson Kibinge
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Marisa Chong Kwan
- Arrayjet, Innovative Microarray Solutions, Edinburgh, United Kingdom
| | - Sam Hawkings
- Arrayjet, Innovative Microarray Solutions, Edinburgh, United Kingdom
| | - Reuben Yaa
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Emily Chepsat
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - James M Njunge
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Timothy Chege
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Fatuma Guleid
- Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Micha Rosenkranz
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher K Kariuki
- Department of Tropical and Infectious Diseases, Institute of Primate Research, Nairobi, Kenya.,Cellular and Molecular Immunology, Vrije Universiteit Brussels, Brussels, Belgium
| | - Roland Frank
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Samson M Kinyanjui
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.,Department of Biochemistry, Pwani University, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Linda M Murungi
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Anna Färnert
- Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.,Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Kevin K A Tetteh
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - David J Conway
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kevin Marsh
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom.,African Academy of Sciences, Nairobi, Kenya
| | - Julian C Rayner
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Faith H A Osier
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.,Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany.,Department of Biochemistry, Pwani University, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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116
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New insights into the development of B cell responses: Implications for solid organ transplantation. Hum Immunol 2018; 80:378-384. [PMID: 30240897 DOI: 10.1016/j.humimm.2018.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/12/2018] [Accepted: 09/12/2018] [Indexed: 12/23/2022]
Abstract
A resurgent interest in the role of B cells following solid organ transplantation is being driven by clinical data suggesting that antibody mediated rejection (AMR) is a major cause of dysfunction and organ transplant failure. These observations suggest that, in a subset of patients, current immunotherapies are failing to control the development of alloantibody responses, and/or failing to reverse the production or the effects of alloantibodies. Quantification of donor-specific antibodies (DSA) has proven to be an imperfect predictor of AMR, and efforts to improve DSA quantification anticipate that this will result in improved predictive power. At the same time, attempts to control of ABMR have focused on the non-specific elimination of B cells, plasma cells (PCs) or circulating antibodies. In the past decade, there has been an improvement in our understanding of the processes that drive B cell differentiation into germinal center (GC)-dependent or GC-independent memory B cells and antibody-secreting PC. These insights are suggesting new ways to more specifically target the DSA response, which may lead to better long-term allograft survival outcomes while preserving protective immunity. In this review, new insights into processes that lead to antibody production upon primary and secondary antigen encounter are discussed, and the potential implications to DSA production as well as future areas of investigation to control AMR are discussed.
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117
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Affiliation(s)
- Limor Cohen
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - David R. Walt
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
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118
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Plasmodium falciparum MSP3 Exists in a Complex on the Merozoite Surface and Generates Antibody Response during Natural Infection. Infect Immun 2018; 86:IAI.00067-18. [PMID: 29760216 DOI: 10.1128/iai.00067-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022] Open
Abstract
Plasmodium falciparum merozoite surface protein 3 (MSP3) is an abundantly expressed secreted merozoite surface protein and a leading malaria vaccine candidate antigen. However, it is unclear how MSP3 is retained on the surface of merozoites without a glycosylphosphatidylinositol (GPI) anchor or a transmembrane domain. In the present study, we identified an MSP3-associated network on the Plasmodium merozoite surface by immunoprecipitation of Plasmodium merozoite lysate using antibody to the N terminus of MSP3 (anti-MSP3N) followed by mass spectrometry analysis. The results suggested the association of MSP3 with other merozoite surface proteins: MSP1, MSP6, MSP7, RAP2, and SERA5. Protein-protein interaction studies by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) analysis showed that MSP3 complex consists of MSP1, MSP6, and MSP7 proteins. Immunological characterization of MSP3 revealed that MSP3N is strongly recognized by hyperimmune serum from African and Asian populations. Furthermore, we demonstrate that human antibodies, affinity purified against recombinant MSP3N (rMSP3N), promote opsonic phagocytosis of merozoites in cooperation with monocytes. At nonphysiological concentrations, anti-MSP3N antibodies inhibited the growth of P. falciparum in vitro Together, the data suggest that MSP3 and especially its N-terminal region containing known B/T cell epitopes are targets of naturally acquired immunity against malaria and also comprise an important candidate for a multisubunit malaria vaccine.
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119
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Maziarz M, Nabalende H, Otim I, Legason ID, Kinyera T, Ogwang MD, Talisuna AO, Reynolds SJ, Kerchan P, Bhatia K, Biggar RJ, Goedert JJ, Pfeiffer RM, Mbulaiteye SM. A cross-sectional study of asymptomatic Plasmodium falciparum infection burden and risk factors in general population children in 12 villages in northern Uganda. Malar J 2018; 17:240. [PMID: 29925378 PMCID: PMC6011516 DOI: 10.1186/s12936-018-2379-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/08/2018] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Plasmodium falciparum malaria is an important cause of morbidity in northern Uganda. This study was undertaken to assess village-, household-, and individual-level risk factors of asymptomatic falciparum malaria in children in 12 villages in northern Uganda. METHODS Between 10/2011 and 02/2014, 1006 apparently healthy children under 16 years old were enrolled in 12 villages using a stratified, multi-stage, cluster survey design and assessed for P. falciparum malaria infection using the rapid diagnostic test (RDT) and thick film microscopy (TFM), and structured interviewer-administered questionnaires. Associations between weighted P. falciparum malaria prevalence (pfPR), based on RDT, and covariates were estimated as odds ratios and 95% confidence intervals (ORs, 95% CIs) using logistic models accounting for the survey design. RESULTS Among 942 (93.5%) children successfully tested, pfPR was 52.4% by RDT and 32.7% by TFM. Overall pfPR was lower in villages where indoor residual insecticide spray (IRS) was, versus not, implemented (18.4% versus 75.2%, P < 0.0001). However, pfPR was heterogeneous both within IRS (10.6-34.8%) and non-IRS villages (63.6-86.2%). Elevated pfPR was associated with having a sibling who was RDT positive (OR 5.39, 95% CI 2.94-9.90, P = 0.0006) and reporting a fever at enrollment (aOR 4.80, 95% CI 1.94-11.9, P = 0.0094). Decreased pfPR was associated with living in an IRS village (adjusted OR 0.06, 95% CI 0.04-0.07, P < 0.0001), in a household with one (aOR 0.48, 95% CI 0.30-0.76) or more than one child below 5 years (aOR 0.23, 95% CI 0.12-0.44, Ptrend = 0.014), and reporting keeping a goat inside or near the house (aOR 0.42, 95% CI 0.29-0.62, P = 0.0021). CONCLUSIONS The results show high but heterogeneous pfPR in villages in northern Uganda, confirm significantly decreased pfPR associated with IRS implementation, and suggest significant associations with some household characteristics. Further research is needed to elucidate the factors influencing malaria heterogeneity in villages in Uganda.
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Affiliation(s)
- Marlena Maziarz
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Hadijah Nabalende
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Ismail D Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Tobias Kinyera
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Martin D Ogwang
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Ambrose O Talisuna
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
| | - Steven J Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Patrick Kerchan
- EMBLEM Study, African Field Epidemiology Network, Kampala & St. Mary's Hospital, Lacor, Gulu, Uganda
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Robert J Biggar
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm. 6E118 MSC 9706, Bethesda, MD, 20892-9704, USA.
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Negm OH, Hamed M, Monaghan TM. A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection. J Vis Exp 2018. [PMID: 29985307 DOI: 10.3791/57399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We provide a detailed overview of a novel high-throughput protein microarray assay for the determination of anti-Clostridium difficile antibody levels in human sera and in separate preparations of polyclonal intravenous immunoglobulin (IVIg). The protocol describes the methodological steps involved in sample preparation, printing of arrays, assay procedure, and data analysis. In addition, this protocol could be further developed to incorporate diverse clinical samples including plasma and cell culture supernatants. We show how protein microarray can be used to determine a combination of isotype (IgG, IgA, IgM), subclass (IgG1, IgG2, IgG3, IgG4, IgA1, IgA2), and strain-specific antibodies to highly purified whole C. difficile toxins A and B (toxinotype 0, strain VPI 10463, ribotype 087), toxin B from a C. difficile toxin-B-only expressing strain (CCUG 20309), a precursor form of a B fragment of binary toxin, pCDTb, ribotype-specific whole surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid and Candida albicans). During the experiment, microarrays are probed with sera from individuals with C. difficile infection (CDI), individuals with cystic fibrosis (CF) without diarrhea, healthy controls (HC), and from individuals pre- and post-IVIg therapy for the treatment of CDI, combined immunodeficiency disorder, and chronic inflammatory demyelinating polyradiculopathy. We encounter significant differences in toxin neutralization efficacies and multi-isotype specific antibody levels between patient groups, commercial preparations of IVIg, and sera before and following IVIg administration. Also, there is a significant correlation between microarray and enzyme-linked immunosorbent assay (ELISA) for antitoxin IgG levels in serum samples. These results suggest that microarray could become a promising tool for profiling antibody responses to C.difficile antigens in vaccinated or infected humans. With further refinement of antigen panels and a reduction in production costs, we anticipate that microarray technology may help optimize and select the most clinically useful immunotherapies for C. difficile infection in a patient-specific manner.
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Affiliation(s)
- Ola H Negm
- Breast Surgery Group, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, Queen's Medical Centre, University of Nottingham; Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University;
| | - Mohamed Hamed
- Breast Surgery Group, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, Queen's Medical Centre, University of Nottingham; Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University
| | - Tanya M Monaghan
- Nottingham Digestive Diseases Centre and NIHR Nottingham Digestive Diseases Biomedical Research Centre, School of Medicine, Queen's Medical Centre, University of Nottingham;
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121
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Liu X, Wang Y, Liang J, Wang L, Qin N, Zhao Y, Zhao G. In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome. BMC Genomics 2018; 19:312. [PMID: 29716542 PMCID: PMC5930813 DOI: 10.1186/s12864-018-4654-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 04/10/2018] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium falciparum is the most virulent malaria parasite capable of parasitizing human erythrocytes. The identification of genes related to this capability can enhance our understanding of the molecular mechanisms underlying human malaria and lead to the development of new therapeutic strategies for malaria control. With the availability of several malaria parasite genome sequences, performing computational analysis is now a practical strategy to identify genes contributing to this disease. Results Here, we developed and used a virtual genome method to assign 33,314 genes from three human malaria parasites, namely, P. falciparum, P. knowlesi and P. vivax, and three rodent malaria parasites, namely, P. berghei, P. chabaudi and P. yoelii, to 4605 clusters. Each cluster consisted of genes whose protein sequences were significantly similar and was considered as a virtual gene. Comparing the enriched values of all clusters in human malaria parasites with those in rodent malaria parasites revealed 115 P. falciparum genes putatively responsible for parasitizing human erythrocytes. These genes are mainly located in the chromosome internal regions and participate in many biological processes, including membrane protein trafficking and thiamine biosynthesis. Meanwhile, 289 P. berghei genes were included in the rodent parasite-enriched clusters. Most are located in subtelomeric regions and encode erythrocyte surface proteins. Comparing cluster values in P. falciparum with those in P. vivax and P. knowlesi revealed 493 candidate genes linked to virulence. Some of them encode proteins present on the erythrocyte surface and participate in cytoadhesion, virulence factor trafficking, or erythrocyte invasion, but many genes with unknown function were also identified. Cerebral malaria is characterized by accumulation of infected erythrocytes at trophozoite stage in brain microvascular. To discover cerebral malaria-related genes, fast Fourier transformation (FFT) was introduced to extract genes highly transcribed at the trophozoite stage. Finally, 55 candidate genes were identified. Considering that parasite-infected erythrocyte surface protein 2 (PIESP2) contains gap-junction-related Neuromodulin_N domain and that anti-PIESP2 might provide protection against malaria, we chose PIESP2 for further experimental study. Conclusions Our analysis revealed a limited number of genes linked to human disease in P. falciparum genome. These genes could be interesting targets for further functional characterization. Electronic supplementary material The online version of this article (10.1186/s12864-018-4654-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xuewu Liu
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuanyuan Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Jiao Liang
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Luojun Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Na Qin
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Ya Zhao
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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122
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Kessler A, Campo JJ, Harawa V, Mandala WL, Rogerson SJ, Mowrey WB, Seydel KB, Kim K. Convalescent Plasmodium falciparum-specific seroreactivity does not correlate with paediatric malaria severity or Plasmodium antigen exposure. Malar J 2018; 17:178. [PMID: 29695240 PMCID: PMC5918990 DOI: 10.1186/s12936-018-2323-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/18/2018] [Indexed: 12/17/2022] Open
Abstract
Background Antibody immunity is thought to be essential to prevent severe Plasmodium falciparum infection, but the exact correlates of protection are unknown. Over time, children in endemic areas acquire non-sterile immunity to malaria that correlates with development of antibodies to merozoite invasion proteins and parasite proteins expressed on the surface of infected erythrocytes. Results A 1000 feature P. falciparum 3D7 protein microarray was used to compare P. falciparum-specific seroreactivity during acute infection and 30 days after infection in 23 children with uncomplicated malaria (UM) and 25 children with retinopathy-positive cerebral malaria (CM). All children had broad P. falciparum antibody reactivity during acute disease. IgM reactivity decreased and IgG reactivity increased in convalescence. Antibody reactivity to CIDR domains of “virulent” PfEMP1 proteins was low with robust reactivity to the highly conserved, intracellular ATS domain of PfEMP1 in both groups. Although children with UM and CM differed markedly in parasite burden and PfEMP1 exposure during acute disease, neither acute nor convalescent PfEMP1 seroreactivity differed between groups. Greater seroprevalence to a conserved Group A-associated ICAM binding extracellular domain was observed relative to linked extracellular CIDRα1 domains in both case groups. Pooled immune IgG from Malawian adults revealed greater reactivity to PfEMP1 than observed in children. Conclusions Children with uncomplicated and cerebral malaria have similar breadth and magnitude of P. falciparum antibody reactivity. The utility of protein microarrays to measure serological recognition of polymorphic PfEMP1 antigens needs to be studied further, but the study findings support the hypothesis that conserved domains of PfEMP1 are more prominent targets of cross reactive antibodies than variable domains in children with symptomatic malaria. Protein microarrays represent an additional tool to identify cross-reactive Plasmodium antigens including PfEMP1 domains that can be investigated as strain-transcendent vaccine candidates. Electronic supplementary material The online version of this article (10.1186/s12936-018-2323-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne Kessler
- Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Visopo Harawa
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,College of Medicine, Biomedical Department, University of Malawi, Blantyre, Malawi
| | - Wilson L Mandala
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,College of Medicine, Biomedical Department, University of Malawi, Blantyre, Malawi.,Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | | | | | - Karl B Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA. .,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Kami Kim
- Albert Einstein College of Medicine, Bronx, NY, USA. .,Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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123
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Children with cerebral malaria or severe malarial anaemia lack immunity to distinct variant surface antigen subsets. Sci Rep 2018; 8:6281. [PMID: 29674705 PMCID: PMC5908851 DOI: 10.1038/s41598-018-24462-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/28/2018] [Indexed: 01/08/2023] Open
Abstract
Variant surface antigens (VSAs) play a critical role in severe malaria pathogenesis. Defining gaps, or “lacunae”, in immunity to these Plasmodium falciparum antigens in children with severe malaria would improve our understanding of vulnerability to severe malaria and how protective immunity develops. Using a protein microarray with 179 antigen variants from three VSA families as well as more than 300 variants of three other blood stage P. falciparum antigens, reactivity was measured in sera from Malian children with cerebral malaria or severe malarial anaemia and age-matched controls. Sera from children with severe malaria recognized fewer extracellular PfEMP1 fragments and were less reactive to specific fragments compared to controls. Following recovery from severe malaria, convalescent sera had increased reactivity to certain non-CD36 binding PfEMP1s, but not other malaria antigens. Sera from children with severe malarial anaemia reacted to fewer VSAs than did sera from children with cerebral malaria, and both of these groups had lacunae in their seroreactivity profiles in common with children who had both cerebral malaria and severe malarial anaemia. This microarray-based approach may identify a subset of VSAs that could inform the development of a vaccine to prevent severe disease or a diagnostic test to predict at-risk children.
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124
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Early AM, Lievens M, MacInnis BL, Ockenhouse CF, Volkman SK, Adjei S, Agbenyega T, Ansong D, Gondi S, Greenwood B, Hamel M, Odero C, Otieno K, Otieno W, Owusu-Agyei S, Asante KP, Sorgho H, Tina L, Tinto H, Valea I, Wirth DF, Neafsey DE. Host-mediated selection impacts the diversity of Plasmodium falciparum antigens within infections. Nat Commun 2018; 9:1381. [PMID: 29643376 PMCID: PMC5895824 DOI: 10.1038/s41467-018-03807-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/14/2018] [Indexed: 12/28/2022] Open
Abstract
Host immunity exerts strong selective pressure on pathogens. Population-level genetic analysis can identify signatures of this selection, but these signatures reflect the net selective effect of all hosts and vectors in a population. In contrast, analysis of pathogen diversity within hosts provides information on individual, host-specific selection pressures. Here, we combine these complementary approaches in an analysis of the malaria parasite Plasmodium falciparum using haplotype sequences from thousands of natural infections in sub-Saharan Africa. We find that parasite genotypes show preferential clustering within multi-strain infections in young children, and identify individual amino acid positions that may contribute to strain-specific immunity. Our results demonstrate that natural host defenses to P. falciparum act in an allele-specific manner to block specific parasite haplotypes from establishing blood-stage infections. This selection partially explains the extreme amino acid diversity of many parasite antigens and suggests that vaccines targeting such proteins should account for allele-specific immunity. Host immune responses exert selective pressure on Plasmodium falciparum. Here, the authors show that allele-specific immunity impacts the antigenic diversity of individual malaria infections. This process partially explains the extreme amino acid diversity of many parasite antigens and suggests that vaccines should account for allele-specific immunity.
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Affiliation(s)
- Angela M Early
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA. .,Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
| | | | - Bronwyn L MacInnis
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.,Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | | | - Sarah K Volkman
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.,Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.,Simmons College, School of Nursing and Health Sciences, Boston, MA, 02115, USA
| | - Samuel Adjei
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, KNUST - Kumasi, Ghana
| | - Tsiri Agbenyega
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, KNUST - Kumasi, Ghana
| | - Daniel Ansong
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, KNUST - Kumasi, Ghana
| | - Stacey Gondi
- KEMRI-Walter Reed Project, Kombewa, 40102, Kenya
| | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Mary Hamel
- KEMRI/CDC Research and Public Health Collaboration, Kisumu, 40100, Kenya
| | - Chris Odero
- KEMRI/CDC Research and Public Health Collaboration, Kisumu, 40100, Kenya
| | - Kephas Otieno
- KEMRI/CDC Research and Public Health Collaboration, Kisumu, 40100, Kenya
| | | | - Seth Owusu-Agyei
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.,Kintampo Health Research Centre, Kintampo, 200, Ghana.,University of Health and Allied Science, PMB 31, Ho, Volta Region, Ghana
| | | | - Hermann Sorgho
- Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso/Institute of Tropical Medicine, 2000, Antwerp, Belgium
| | - Lucas Tina
- KEMRI-Walter Reed Project, Kombewa, 40102, Kenya
| | - Halidou Tinto
- Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso/Institute of Tropical Medicine, 2000, Antwerp, Belgium
| | - Innocent Valea
- Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso/Institute of Tropical Medicine, 2000, Antwerp, Belgium
| | - Dyann F Wirth
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.,Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Daniel E Neafsey
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA. .,Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
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125
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Stone WJR, Campo JJ, Ouédraogo AL, Meerstein-Kessel L, Morlais I, Da D, Cohuet A, Nsango S, Sutherland CJ, van de Vegte-Bolmer M, Siebelink-Stoter R, van Gemert GJ, Graumans W, Lanke K, Shandling AD, Pablo JV, Teng AA, Jones S, de Jong RM, Fabra-García A, Bradley J, Roeffen W, Lasonder E, Gremo G, Schwarzer E, Janse CJ, Singh SK, Theisen M, Felgner P, Marti M, Drakeley C, Sauerwein R, Bousema T, Jore MM. Unravelling the immune signature of Plasmodium falciparum transmission-reducing immunity. Nat Commun 2018; 9:558. [PMID: 29422648 PMCID: PMC5805765 DOI: 10.1038/s41467-017-02646-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/15/2017] [Indexed: 02/02/2023] Open
Abstract
Infection with Plasmodium can elicit antibodies that inhibit parasite survival in the mosquito, when they are ingested in an infectious blood meal. Here, we determine the transmission-reducing activity (TRA) of naturally acquired antibodies from 648 malaria-exposed individuals using lab-based mosquito-feeding assays. Transmission inhibition is significantly associated with antibody responses to Pfs48/45, Pfs230, and to 43 novel gametocyte proteins assessed by protein microarray. In field-based mosquito-feeding assays the likelihood and rate of mosquito infection are significantly lower for individuals reactive to Pfs48/45, Pfs230 or to combinations of the novel TRA-associated proteins. We also show that naturally acquired purified antibodies against key transmission-blocking epitopes of Pfs48/45 and Pfs230 are mechanistically involved in TRA, whereas sera depleted of these antibodies retain high-level, complement-independent TRA. Our analysis demonstrates that host antibody responses to gametocyte proteins are associated with reduced malaria transmission efficiency from humans to mosquitoes.
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Affiliation(s)
- Will J R Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | | | | | - Lisette Meerstein-Kessel
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Isabelle Morlais
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaoundé, Cameroon.,Institut de Recherche pour le Développement, MIVEGEC (IRD, CNRS, Univ. Montpellier), 911 Avenue Agropolis, 34394, Montpellier, France
| | - Dari Da
- Institut de Recherche en Sciences de la Santé, 399 Avenue de la Liberté, 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Anna Cohuet
- Institut de Recherche pour le Développement, MIVEGEC (IRD, CNRS, Univ. Montpellier), 911 Avenue Agropolis, 34394, Montpellier, France.,Institut de Recherche en Sciences de la Santé, 399 Avenue de la Liberté, 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Sandrine Nsango
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaoundé, Cameroon.,Faculty of Medecine and Pharmaceutical Science, PO Box 2701, Douala, Cameroon
| | - Colin J Sutherland
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Marga van de Vegte-Bolmer
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Rianne Siebelink-Stoter
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Wouter Graumans
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | | | | | - Andy A Teng
- Antigen Discovery Inc., Irvine, CA, 92618, USA
| | - Sophie Jones
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Roos M de Jong
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Amanda Fabra-García
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Will Roeffen
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Edwin Lasonder
- School of Biomedical and Healthcare Sciences, Plymouth University, Drakes Circus, Plymouth, PL4 8AA, UK
| | - Giuliana Gremo
- Department of Oncology, University of Torino, Via Santena 5bis, 10126, Torino, Italy
| | - Evelin Schwarzer
- Department of Oncology, University of Torino, Via Santena 5bis, 10126, Torino, Italy
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Susheel K Singh
- Department for Congenital Diseases, Statens Serum Institut, Copenhagen, DK 2300, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, DK 2200, Denmark
| | - Michael Theisen
- Department for Congenital Diseases, Statens Serum Institut, Copenhagen, DK 2300, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, DK 2200, Denmark
| | - Phil Felgner
- Department of Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, 02115, USA.,Wellcome Center for Molecular Parasitology, University of Glasgow, Glasgow, G12 8TA, UK
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Robert Sauerwein
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Matthijs M Jore
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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Meerstein-Kessel L, van der Lee R, Stone W, Lanke K, Baker DA, Alano P, Silvestrini F, Janse CJ, Khan SM, van de Vegte-Bolmer M, Graumans W, Siebelink-Stoter R, Kooij TWA, Marti M, Drakeley C, Campo JJ, van Dam TJP, Sauerwein R, Bousema T, Huynen MA. Probabilistic data integration identifies reliable gametocyte-specific proteins and transcripts in malaria parasites. Sci Rep 2018; 8:410. [PMID: 29323249 PMCID: PMC5765010 DOI: 10.1038/s41598-017-18840-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/15/2017] [Indexed: 12/02/2022] Open
Abstract
Plasmodium gametocytes are the sexual forms of the malaria parasite essential for transmission to mosquitoes. To better understand how gametocytes differ from asexual blood-stage parasites, we performed a systematic analysis of available 'omics data for P. falciparum and other Plasmodium species. 18 transcriptomic and proteomic data sets were evaluated for the presence of curated "gold standards" of 41 gametocyte-specific versus 46 non-gametocyte genes and integrated using Bayesian probabilities, resulting in gametocyte-specificity scores for all P. falciparum genes. To illustrate the utility of the gametocyte score, we explored newly predicted gametocyte-specific genes as potential biomarkers of gametocyte carriage and exposure. We analyzed the humoral immune response in field samples against 30 novel gametocyte-specific antigens and found five antigens to be differentially recognized by gametocyte carriers as compared to malaria-infected individuals without detectable gametocytes. We also validated the gametocyte-specificity of 15 identified gametocyte transcripts on culture material and samples from naturally infected individuals, resulting in eight transcripts that were >1000-fold higher expressed in gametocytes compared to asexual parasites and whose transcript abundance allowed gametocyte detection in naturally infected individuals. Our integrated genome-wide gametocyte-specificity scores provide a comprehensive resource to identify targets and monitor P. falciparum gametocytemia.
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Affiliation(s)
- Lisette Meerstein-Kessel
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Robin van der Lee
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Will Stone
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - David A Baker
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Pietro Alano
- Dipartimento Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | | | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Shahid M Khan
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Wouter Graumans
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Rianne Siebelink-Stoter
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Taco W A Kooij
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Matthias Marti
- Wellcome Trust Center for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Chris Drakeley
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Teunis J P van Dam
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - Martijn A Huynen
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands.
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127
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Immune Response to Opisthorchis viverrini Infection and Its Role in Pathology. ADVANCES IN PARASITOLOGY 2018; 102:73-95. [PMID: 30442311 DOI: 10.1016/bs.apar.2018.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Human liver fluke infection caused by Opisthorchis viverrini is a major public health problem in Mekong countries such as Thailand, Laos, Cambodia, Vietnam, and Myanmar with over 10 million infected through consumption of fish containing infective metacercariae. With no tissue migration phase and living entirely within the larger secondary (intrahepatic) bile ducts, liver flukes are only exposed to a biliary mucosal immune response, while their excretory and secretory products also stimulate chronic inflammation of biliary epithelium. Neither mucosal nor tissue immune responses appear to cause parasite death or protect against newly established flukes, as evidenced by the persistence of infection for decades in the body and rapid reinfection following treatment. Experimental studies suggest that specific immune suppressive mechanisms may promote parasite persistence, therefore allowing continued secretion of parasite products that damage the biliary epithelium, both directly through mechanical damage and mitogenicity and through innate and adaptive inflammatory responses. Chronic infection is associated with several hepatobiliary diseases, specifically gallbladder and bile duct inflammation (cholecystitis and cholangitis), periductal fibrosis, and cholangiocarcinoma, the fatal bile duct cancer. Various studies have linked the chronic immune response to parasite antigens to both fibrosis and many steps in the carcinogenic process. Here, we review research-based understandings of the basic immune response to liver fluke infection and its roles in host protection and immunopathogenesis from available literature and also from recent studies conducted by the authors.
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128
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Ademolue TW, Awandare GA. Evaluating antidisease immunity to malaria and implications for vaccine design. Immunology 2017; 153:423-434. [PMID: 29211303 PMCID: PMC5838420 DOI: 10.1111/imm.12877] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 12/29/2022] Open
Abstract
Immunity to malaria could be categorized broadly as antiparasite or antidisease immunity. While most vaccine research efforts have focused on antiparasite immunity, the evidence from endemic populations suggest that antidisease immunity is an important component of natural immunity to malaria. The processes that mediate antidisease immunity have, however, attracted little to no attention, and most interests have been directed towards the antibody responses. This review evaluates the evidence for antidisease immunity in endemic areas and discusses the possible mechanisms responsible for it. Given the key role that inflammation plays in the pathogenesis of malaria, regulation of the inflammatory response appears to be a major mechanism for antidisease immunity in naturally exposed individuals.
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Affiliation(s)
- Temitope W Ademolue
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Gordon A Awandare
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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129
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Portugal S, Tran TM, Ongoiba A, Bathily A, Li S, Doumbo S, Skinner J, Doumtabe D, Kone Y, Sangala J, Jain A, Davies DH, Hung C, Liang L, Ricklefs S, Homann MV, Felgner PL, Porcella SF, Färnert A, Doumbo OK, Kayentao K, Greenwood BM, Traore B, Crompton PD. Treatment of Chronic Asymptomatic Plasmodium falciparum Infection Does Not Increase the Risk of Clinical Malaria Upon Reinfection. Clin Infect Dis 2017; 64:645-653. [PMID: 28362910 DOI: 10.1093/cid/ciw849] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/13/2016] [Indexed: 11/14/2022] Open
Abstract
Background Chronic asymptomatic Plasmodium falciparum infections are common in endemic areas and are thought to contribute to the maintenance of malaria immunity. Whether treatment of these infections increases the subsequent risk of clinical episodes of malaria is unclear. Methods In a 3-year study in Mali, asymptomatic individuals with or without P. falciparum infection at the end of the 6-month dry season were identified by polymerase chain reaction (PCR), and clinical malaria risk was compared during the ensuing 6-month malaria transmission season. At the end of the second dry season, 3 groups of asymptomatic children were identified: (1) children infected with P. falciparum as detected by rapid diagnostic testing (RDT) who were treated with antimalarials (n = 104), (2) RDT-negative children whose untreated P. falciparum infections were detected retrospectively by PCR (n = 55), and (3) uninfected children (RDT/PCR negative) (n = 434). Clinical malaria risk during 2 subsequent malaria seasons was compared. Plasmodium falciparum-specific antibody kinetics during the dry season were compared in children who did or did not harbor asymptomatic P. falciparum infections. Results Chronic asymptomatic P. falciparum infection predicted decreased clinical malaria risk during the subsequent malaria season(s); treatment of these infections did not alter this reduced risk. Plasmodium falciparum-specific antibodies declined similarly in children who did or did not harbor chronic asymptomatic P. falciparum infection during the dry season. Conclusions These findings challenge the notion that chronic asymptomatic P. falciparum infection maintains malaria immunity and suggest that mass drug administration during the dry season should not increase the subsequent risk of clinical malaria.
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Affiliation(s)
- Silvia Portugal
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Tuan M Tran
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA.,Division of Infectious Diseases, Department of Medicine, Indianapolis University School of Medicine, Indiana
| | - Aissata Ongoiba
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Aboudramane Bathily
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Shanping Li
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Safiatou Doumbo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Jeff Skinner
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Didier Doumtabe
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Younoussou Kone
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Jules Sangala
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Aarti Jain
- University of California, Irvine, California, USA
| | - D Huw Davies
- University of California, Irvine, California, USA
| | | | - Li Liang
- University of California, Irvine, California, USA
| | - Stacy Ricklefs
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Manijeh Vafa Homann
- Department of Infectious Diseases, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden
| | | | - Stephen F Porcella
- Rocky Mountain Laboratory Research Technologies Section, Genomics Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Anna Färnert
- Department of Infectious Diseases, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden
| | - Ogobara K Doumbo
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Kassoum Kayentao
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Brian M Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK
| | - Boubacar Traore
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali
| | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
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Sakamoto H, Takeo S, Takashima E, Miura K, Kanoi BN, Kaneko T, Han ET, Tachibana M, Matsuoka K, Sattabongkot J, Udomsangpetch R, Ishino T, Tsuboi T. Identification of target proteins of clinical immunity to Plasmodium falciparum in a region of low malaria transmission. Parasitol Int 2017; 67:203-208. [PMID: 29217416 DOI: 10.1016/j.parint.2017.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/29/2017] [Accepted: 12/04/2017] [Indexed: 01/03/2023]
Abstract
The target molecules of antibodies against falciparum malaria remain largely unknown. Recently we have identified multiple proteins as targets of immunity against Plasmodium falciparum using African serum samples. To investigate whether potential targets of clinical immunity differ with transmission intensity, we assessed immune responses in residents of low malaria transmission region in Thailand. Malaria asymptomatic volunteers (Asy: n=19) and symptomatic patients (Sym: n=21) were enrolled into the study. Serum immunoreactivity to 186 wheat germ cell-free system (WGCFS)-synthesized recombinant P. falciparum asexual-blood stage proteins were determined by AlphaScreen, and subsequently compared between the study groups. Forty proteins were determined as immunoreactive with antibody responses to 35 proteins being higher in Asy group than in Sym group. Among the 35 proteins, antibodies to MSP3, MSPDBL1, RH2b, and MSP7 were significantly higher in Asy than Sym (unadjusted p<0.005) suggesting these antigens may have a protective role in clinical malaria. MSP3 reactivity remained significantly different between Asy and Sym groups even after multiple comparison adjustments (adjusted p=0.033). Interestingly, while our two preceding studies using African sera were conducted differently (e.g., cross-sectional vs. longitudinal design, observed clinical manifestation vs. functional activity), those studies similarly identified MSP3 and MSPDBL1 as potential targets of protective immunity. This study further provides a strong rationale for the application of WGCFS-based immunoprofiling to malaria vaccine candidate and biomarker discovery even in low or reduced malaria transmission settings.
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Affiliation(s)
- Hirokazu Sakamoto
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Satoru Takeo
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Bernard N Kanoi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Takamasa Kaneko
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do 200-701, Republic of Korea
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan
| | - Kazuhiro Matsuoka
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan
| | - Jetsumon Sattabongkot
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - Rachanee Udomsangpetch
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Salaya, Nakhosn Pathom 73170, Thailand
| | - Tomoko Ishino
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
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131
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Abdi A, Yu L, Goulding D, Rono MK, Bejon P, Choudhary J, Rayner J. Proteomic analysis of extracellular vesicles from a Plasmodium falciparum Kenyan clinical isolate defines a core parasite secretome. Wellcome Open Res 2017; 2:50. [PMID: 28944300 PMCID: PMC5583745 DOI: 10.12688/wellcomeopenres.11910.2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Many pathogens secrete effector molecules to subvert host immune responses, to acquire nutrients, and/or to prepare host cells for invasion. One of the ways that effector molecules are secreted is through extracellular vesicles (EVs) such as exosomes. Recently, the malaria parasite P. falciparum has been shown to produce EVs that can mediate transfer of genetic material between parasites and induce sexual commitment. Characterizing the content of these vesicles may improve our understanding of P. falciparum pathogenesis and virulence. METHODS Previous studies of P. falciparum EVs have been limited to long-term adapted laboratory isolates. In this study, we isolated EVs from a Kenyan P. falciparum clinical isolate adapted to in vitro culture for a short period and characterized their protein content by mass spectrometry (data are available via ProteomeXchange, with identifier PXD006925). RESULTS We show that P. falciparum extracellular vesicles ( PfEVs) are enriched in proteins found within the exomembrane compartments of infected erythrocytes such as Maurer's clefts (MCs), as well as the secretory endomembrane compartments in the apical end of the merozoites, suggesting that these proteins play a role in parasite-host interactions. Comparison of this novel clinically relevant dataset with previously published datasets helps to define a core secretome present in Plasmodium EVs. CONCLUSIONS P. falciparum extracellular vesicles contain virulence-associated parasite proteins. Therefore, analysis of PfEVs contents from a range of clinical isolates, and their functional validation may improve our understanding of the virulence mechanisms of the parasite, and potentially identify targets for interventions or diagnostics.
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Affiliation(s)
- Abdirahman Abdi
- Pwani University Bioscience Research Centre, Pwani University, Kilifi, Kenya.,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - David Goulding
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Martin K Rono
- Pwani University Bioscience Research Centre, Pwani University, Kilifi, Kenya.,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jyoti Choudhary
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Julian Rayner
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
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132
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Abdi A, Yu L, Goulding D, Rono MK, Bejon P, Choudhary J, Rayner J. Proteomic analysis of extracellular vesicles from a Plasmodium falciparum Kenyan clinical isolate defines a core parasite secretome. Wellcome Open Res 2017. [PMID: 28944300 DOI: 10.12688/wellcomeopenres.11910.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Many pathogens secrete effector molecules to subvert host immune responses, to acquire nutrients, and/or to prepare host cells for invasion. One of the ways that effector molecules are secreted is through extracellular vesicles (EVs) such as exosomes. Recently, the malaria parasite P. falciparum has been shown to produce EVs that can mediate transfer of genetic material between parasites and induce sexual commitment. Characterizing the content of these vesicles may improve our understanding of P. falciparum pathogenesis and virulence. METHODS Previous studies of P. falciparum EVs have been limited to long-term adapted laboratory isolates. In this study, we isolated EVs from a Kenyan P. falciparum clinical isolate adapted to in vitro culture for a short period and characterized their protein content by mass spectrometry (data are available via ProteomeXchange, with identifier PXD006925). RESULTS We show that P. falciparum extracellular vesicles ( PfEVs) are enriched in proteins found within the exomembrane compartments of infected erythrocytes such as Maurer's clefts (MCs), as well as the secretory endomembrane compartments in the apical end of the merozoites, suggesting that these proteins play a role in parasite-host interactions. Comparison of this novel clinically relevant dataset with previously published datasets helps to define a core secretome present in Plasmodium EVs. CONCLUSIONS P. falciparum extracellular vesicles contain virulence-associated parasite proteins. Therefore, analysis of PfEVs contents from a range of clinical isolates, and their functional validation may improve our understanding of the virulence mechanisms of the parasite, and potentially identify targets for interventions or diagnostics.
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Affiliation(s)
- Abdirahman Abdi
- Pwani University Bioscience Research Centre, Pwani University, Kilifi, Kenya.,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - David Goulding
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Martin K Rono
- Pwani University Bioscience Research Centre, Pwani University, Kilifi, Kenya.,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jyoti Choudhary
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Julian Rayner
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
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133
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Mechanisms of naturally acquired immunity to P. falciparum and approaches to identify merozoite antigen targets. Parasitology 2017; 145:839-847. [PMID: 29144217 DOI: 10.1017/s0031182017001949] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Malaria is one the most serious infectious diseases with over 200 million clinical cases annually. Most cases of the severe disease are caused by Plasmodium falciparum. The blood stage of Plasmodium parasite is entirely responsible for malaria-associated pathology. The population most susceptible to severe malaria are children under the age of 5, with low levels of immunity. It is only after many years of repeated exposure that individuals living in endemic areas develop clinical immunity. This form of protection prevents clinical episodes by substantially reducing parasite burden. Naturally acquired immunity predominantly targets blood-stage parasites with antibody responses being the main mediators of protection. The targets of clinical immunity are the extracellular merozoite and the infected erythrocyte surface, with the extremely diverse PfEMP1 proteins the main target here. This observation provides a strong rationale that an effective anti-malaria vaccine targeting blood-stage parasites is achievable. Thus the identification of antigenic targets of naturally acquired immunity remains an important step towards the formulation of novel vaccine combinations before testing their efficacy in clinical trials. This review summarizes the main findings to date defining antigenic targets present on the extracellular merozoite associated with naturally acquired immunity to P. falciparum malaria.
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134
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Schussek S, Trieu A, Apte SH, Sidney J, Sette A, Doolan DL. Novel Plasmodium antigens identified via genome-based antibody screen induce protection associated with polyfunctional T cell responses. Sci Rep 2017; 7:15053. [PMID: 29118376 PMCID: PMC5678182 DOI: 10.1038/s41598-017-15354-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022] Open
Abstract
The development of vaccines against complex intracellular pathogens, such as Plasmodium spp., where protection is likely mediated by cellular immune responses, has proven elusive. The availability of whole genome, proteome and transcriptome data has the potential to advance rational vaccine development but yet there are no licensed vaccines against malaria based on antigens identified from genomic data. Here, we show that the Plasmodium yoelii orthologs of four Plasmodium falciparum proteins identified by an antibody-based genome-wide screening strategy induce a high degree of sterile infection-blocking protection against sporozoite challenge in a stringent rodent malaria model. Protection increased in multi-antigen formulations. Importantly, protection was highly correlated with the induction of multifunctional triple-positive T cells expressing high amounts of IFN-γ, IL-2 and TNF. These data demonstrate that antigens identified by serological screening are targets of multifunctional cellular immune responses that correlate with protection. Our results provide experimental validation for the concept of rational vaccine design from genomic sequence data.
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Affiliation(s)
- Sophie Schussek
- QIMR Berghofer Medical Research Institute, Infectious Diseases Programme, Herston, QLD 4006, Australia.,University of Queensland, School of Medicine, Herston, QLD 4006, Australia
| | - Angela Trieu
- QIMR Berghofer Medical Research Institute, Infectious Diseases Programme, Herston, QLD 4006, Australia
| | - Simon H Apte
- QIMR Berghofer Medical Research Institute, Infectious Diseases Programme, Herston, QLD 4006, Australia
| | - John Sidney
- La Jolla Institute of Allergy and Immunology, San Diego, CA, 92121, USA
| | - Alessandro Sette
- La Jolla Institute of Allergy and Immunology, San Diego, CA, 92121, USA
| | - Denise L Doolan
- QIMR Berghofer Medical Research Institute, Infectious Diseases Programme, Herston, QLD 4006, Australia. .,Centre for Biosecurity and Tropical Infectious Diseases, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4879, Australia.
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135
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Merozoite Surface Protein 1 from Plasmodium falciparum Is a Major Target of Opsonizing Antibodies in Individuals with Acquired Immunity against Malaria. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00155-17. [PMID: 28877929 DOI: 10.1128/cvi.00155-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/31/2017] [Indexed: 11/20/2022]
Abstract
Naturally acquired immunity against malaria is largely mediated by serum antibodies controlling levels of blood-stage parasites. A limited understanding of the antigenic targets and functional mechanisms of protective antibodies has hampered the development of efficient malaria vaccines. Besides directly inhibiting the growth of Plasmodium parasites, antibodies can opsonize merozoites and recruit immune effector cells such as monocytes and neutrophils. Antibodies against the vaccine candidate merozoite surface protein 1 (MSP-1) are acquired during natural infections and have been associated with protection against malaria in several epidemiological studies. Here we analyzed serum antibodies from semi-immune individuals from Burkina Faso for their potential (i) to directly inhibit the growth of P. falciparum blood stages in vitro and (ii) to opsonize merozoites and to induce the antibody-dependent respiratory burst (ADRB) activity of neutrophils. While a few sera that directly inhibited the growth of P. falciparum blood stages were identified, immunoglobulin G (IgG) from all individuals clearly mediated the activation of neutrophils. The level of neutrophil activation correlated with levels of antibodies to MSP-1, and affinity-purified MSP-1-specific antibodies elicited ADRB activity. Furthermore, immunization of nonhuman primates with recombinant full-size MSP-1 induced antibodies that efficiently opsonized P. falciparum merozoites. Reversing the function by preincubation with recombinant antigens allowed us to quantify the contribution of MSP-1 to the antiparasitic effect of serum antibodies. Our data suggest that MSP-1, especially the partially conserved subunit MSP-183, is a major target of opsonizing antibodies acquired during natural exposure to malaria. Induction of opsonizing antibodies might be a crucial effector mechanism for MSP-1-based malaria vaccines.
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136
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malERA: An updated research agenda for characterising the reservoir and measuring transmission in malaria elimination and eradication. PLoS Med 2017; 14:e1002452. [PMID: 29190279 PMCID: PMC5708619 DOI: 10.1371/journal.pmed.1002452] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
This paper summarises key advances in defining the infectious reservoir for malaria and the measurement of transmission for research and programmatic use since the Malaria Eradication Research Agenda (malERA) publication in 2011. Rapid and effective progress towards elimination requires an improved understanding of the sources of transmission as well as those at risk of infection. Characterising the transmission reservoir in different settings will enable the most appropriate choice, delivery, and evaluation of interventions. Since 2011, progress has been made in a number of areas. The extent of submicroscopic and asymptomatic infections is better understood, as are the biological parameters governing transmission of sexual stage parasites. Limitations of existing transmission measures have been documented, and proof-of-concept has been established for new innovative serological and molecular methods to better characterise transmission. Finally, there now exists a concerted effort towards the use of ensemble datasets across the spectrum of metrics, from passive and active sources, to develop more accurate risk maps of transmission. These can be used to better target interventions and effectively monitor progress toward elimination. The success of interventions depends not only on the level of endemicity but also on how rapidly or recently an area has undergone changes in transmission. Improved understanding of the biology of mosquito-human and human-mosquito transmission is needed particularly in low-endemic settings, where heterogeneity of infection is pronounced and local vector ecology is variable. New and improved measures of transmission need to be operationally feasible for the malaria programmes. Outputs from these research priorities should allow the development of a set of approaches (applicable to both research and control programmes) that address the unique challenges of measuring and monitoring transmission in near-elimination settings and defining the absence of transmission.
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137
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Valletta JJ, Recker M. Identification of immune signatures predictive of clinical protection from malaria. PLoS Comput Biol 2017; 13:e1005812. [PMID: 29065113 PMCID: PMC5669498 DOI: 10.1371/journal.pcbi.1005812] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 11/03/2017] [Accepted: 10/04/2017] [Indexed: 11/18/2022] Open
Abstract
Antibodies are thought to play an essential role in naturally acquired immunity to malaria. Prospective cohort studies have frequently shown how continuous exposure to the malaria parasite Plasmodium falciparum cause an accumulation of specific responses against various antigens that correlate with a decreased risk of clinical malaria episodes. However, small effect sizes and the often polymorphic nature of immunogenic parasite proteins make the robust identification of the true targets of protective immunity ambiguous. Furthermore, the degree of individual-level protection conferred by elevated responses to these antigens has not yet been explored. Here we applied a machine learning approach to identify immune signatures predictive of individual-level protection against clinical disease. We find that commonly assumed immune correlates are poor predictors of clinical protection in children. On the other hand, antibody profiles predictive of an individual's malaria protective status can be found in data comprising responses to a large set of diverse parasite proteins. We show that this pattern emerges only after years of continuous exposure to the malaria parasite, whereas susceptibility to clinical episodes in young hosts (< 10 years) cannot be ascertained by measured antibody responses alone.
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Affiliation(s)
- John Joseph Valletta
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Mario Recker
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn, United Kingdom
- * E-mail:
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138
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Synergistic malaria vaccine combinations identified by systematic antigen screening. Proc Natl Acad Sci U S A 2017; 114:12045-12050. [PMID: 29078270 PMCID: PMC5692528 DOI: 10.1073/pnas.1702944114] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Malaria still kills hundreds of thousands of children each year. Malaria vaccine development is complicated by high levels of parasite genetic diversity, which makes single target vaccines vulnerable to the development of variant-specific immunity. To overcome this hurdle, we systematically screened a panel of 29 blood-stage antigens from the most deadly human malaria parasite, Plasmodium falciparum. We identified several targets that were able to inhibit erythrocyte invasion in two genetically diverse strains. Testing these targets in combination identified several pairs that blocked invasion more effectively in combination than in isolation. Video microscopy and studies of natural immune responses to malaria in patients suggest that targeting multiple steps in invasion is more likely to produce a synergistic vaccine response. A highly effective vaccine would be a valuable weapon in the drive toward malaria elimination. No such vaccine currently exists, and only a handful of the hundreds of potential candidates in the parasite genome have been evaluated. In this study, we systematically evaluated 29 antigens likely to be involved in erythrocyte invasion, an essential developmental stage during which the malaria parasite is vulnerable to antibody-mediated inhibition. Testing antigens alone and in combination identified several strain-transcending targets that had synergistic combinatorial effects in vitro, while studies in an endemic population revealed that combinations of the same antigens were associated with protection from febrile malaria. Video microscopy established that the most effective combinations targeted multiple discrete stages of invasion, suggesting a mechanistic explanation for synergy. Overall, this study both identifies specific antigen combinations for high-priority clinical testing and establishes a generalizable approach that is more likely to produce effective vaccines.
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139
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Perraut R, Varela ML, Joos C, Diouf B, Sokhna C, Mbengue B, Tall A, Loucoubar C, Touré A, Mercereau-Puijalon O. Association of antibodies to Plasmodium falciparum merozoite surface protein-4 with protection against clinical malaria. Vaccine 2017; 35:6720-6726. [PMID: 29042203 DOI: 10.1016/j.vaccine.2017.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 09/10/2017] [Accepted: 10/05/2017] [Indexed: 11/17/2022]
Abstract
Identification of parasite antigens targeted by immune effector mechanisms that confer protection against malaria is important for the design of a multi-component malaria vaccine. Here, the association of antibodies reacting with the Plasmodium falciparum merozoite surface protein-4 (MSP4) with protection against clinical malaria was investigated in a Senegalese community living in an area of moderate, seasonal malaria transmission. Blood samples were collected at the end of an 8-month long dry season without any recorded parasite transmission from 206 residents enrolled in a prospective follow-up study. Active daily clinical monitoring was implemented during the subsequent five months. Entomologic monitoring documented parasite transmission during the first three months of follow-up. Serum IgG levels were determined by ELISA against three MSP4 baculovirus-encoded recombinant protein constructs, namely the full-length MSP4p40, MSP4p30 devoid of a highly polymorphic sequence stretch and the conserved C-terminal EGF-containing MSP4p20, as well as against a merozoite crude extract. Community seroprevalence against all three constructs was quite high, the lowest being against MSP4p30. Seroprevalence and antibody levels against the three MSP4 constructs were age-dependent. IgG1 dominated the anti-MSP4p20 responses, while both IgG1 and IgG3 were observed against MSP4p40. Anti-MSP4 antibodies were associated with the antibody-dependent respiratory burst (ADRB) activity in a functional assay of merozoite phagocytosis by polymorphonuclear cells. Importantly, high antibody levels against each of the three MSP4 constructs at the end of the dry season were associated with reduced morbidity during the subsequent transmission season in an age-adjusted Poisson regression model (IRR = 0.65 [0.50-0.83], P<0.001 for responses over the median values). These data are consistent with a protective role for the naturally acquired anti-MSP4 antibodies and support further development of MSP4 as a candidate component of malaria vaccine.
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Affiliation(s)
- Ronald Perraut
- Unité d'Immunologie, Institut Pasteur de Dakar, Senegal.
| | | | | | - Babacar Diouf
- Unité d'Immunologie, Institut Pasteur de Dakar, Senegal
| | - Cheikh Sokhna
- Institut de Recherche pour le Développement (IRD), URMITE, UMR 198, Dakar, Senegal
| | | | - Adama Tall
- Unité d'Epidémiologie, Institut Pasteur de Dakar, Senegal
| | - Cheikh Loucoubar
- Institut Pasteur de Dakar, G4 Biostatistiques Bioinformatique et Modélisation, Dakar, Senegal
| | | | - Odile Mercereau-Puijalon
- Institut Pasteur, Département Parasites et Insectes Vecteurs, 25 Rue du Dr. Roux, 75015 Paris, France
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140
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Mother-Newborn Pairs in Malawi Have Similar Antibody Repertoires to Diverse Malaria Antigens. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00136-17. [PMID: 28835359 DOI: 10.1128/cvi.00136-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/31/2017] [Indexed: 11/20/2022]
Abstract
Maternal antibodies may play a role in protecting newborns against malaria disease. Plasmodium falciparum parasite surface antigens are diverse, and protection from infection requires allele-specific immunity. Although malaria-specific antibodies have been shown to cross the placenta, the extent to which antibodies that respond to the full repertoire of diverse antigens are transferred from the mother to the infant has not been explored. Understanding the breadth of maternal antibody responses and to what extent these antibodies are transferred to the child can inform vaccine design and evaluation. We probed plasma from cord blood and serum from mothers at delivery using a customized protein microarray that included variants of malaria vaccine target antigens to assess the intensity and breadth of seroreactivity to three malaria vaccine candidate antigens in mother-newborn pairs in Malawi. Among the 33 paired specimens that were assessed, mothers and newborns had similar intensity and repertoire of seroreactivity. Maternal antibody levels against vaccine candidate antigens were the strongest predictors of infant antibody levels. Placental malaria did not significantly impair transplacental antibody transfer. However, mothers with placental malaria had significantly higher antibody levels against these blood-stage antigens than mothers without placental malaria. The repertoire and levels of infant antibodies against a wide range of malaria vaccine candidate antigen variants closely mirror maternal levels in breadth and magnitude regardless of evidence of placental malaria. Vaccinating mothers with an effective malaria vaccine during pregnancy may induce high and potentially protective antibody repertoires in newborns.
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141
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Abstract
Evidence accumulated through the years clearly indicates that antiparasite immune responses can efficiently control malaria parasite infection at all development stages, and under certain circumstances they can prevent parasite infection. Translating these findings into vaccines or immunotherapeutic interventions has been difficult in part because of the extraordinary biological complexity of this parasite, which has several developmental stages expressing unique sets of stage-specific genes and multiple antigens, most of which are antigenically diverse. Nevertheless, in the last 30 years major advances have resulted in characterization of a number of vaccine candidates, exploration of the repertoire of host immune responses to the various parasite stages, and also identification of significant hurdles that need to be overcome. Most important, these advances strengthened the concept that the induction of host immune responses that target all developmental stages of Plasmodium can efficiently control or abrogate Plasmodium infections and strongly support the notion that an effective vaccine can be developed. This vaccine would be a critical component for programs aimed at controlling or eradicating malaria.
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Affiliation(s)
- Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institute of Health, Rockville, Maryland 20852
| | - Fidel Zavala
- Departmentof Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
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142
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Sotillo J, Toledo R, Mulvenna J, Loukas A. Exploiting Helminth-Host Interactomes through Big Data. Trends Parasitol 2017; 33:875-888. [PMID: 28734897 DOI: 10.1016/j.pt.2017.06.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 12/19/2022]
Abstract
Helminths facilitate their parasitic existence through the production and secretion of different molecules, including proteins. Some helminth proteins can manipulate the host's immune system, a phenomenon that is now being exploited with a view to developing therapeutics for inflammatory diseases. In recent years, hundreds of helminth genomes have been sequenced, but as a community we are still taking baby steps when it comes to identifying proteins that govern host-helminth interactions. The information generated from genomic, immunomic, and proteomic studies, as well as from cutting-edge approaches such as proteogenomics, is leading to a substantial volume of big data that can be utilised to shed light on fundamental biology and provide solutions for the development of bioactive-molecule-based therapeutics.
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Affiliation(s)
- Javier Sotillo
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.
| | - Rafael Toledo
- Departament de Farmacia, Tecnologia Farmacéutica y Parasitologia, Facultat de Farmacia, Universitat de Valencia, Spain
| | - Jason Mulvenna
- QIMR-Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.
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143
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Fang R, Wey A, Bobbili NK, Leke RFG, Taylor DW, Chen JJ. An analytical approach to reduce between-plate variation in multiplex assays that measure antibodies to Plasmodium falciparum antigens. Malar J 2017; 16:287. [PMID: 28716094 PMCID: PMC5513105 DOI: 10.1186/s12936-017-1933-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 07/11/2017] [Indexed: 11/29/2022] Open
Abstract
Background Antibodies play an important role in immunity to malaria. Recent studies show that antibodies to multiple antigens, as well as, the overall breadth of the response are associated with protection from malaria. Yet, the variability and reliability of antibody measurements against a combination of malarial antigens using multiplex assays have not been well characterized. Methods A normalization procedure for reducing between-plate variation using replicates of pooled positive and negative controls was investigated. Sixty test samples (30 from malaria-positive and 30 malaria-negative individuals), together with five pooled positive-controls and two pooled negative-controls, were screened for antibody levels to 9 malarial antigens, including merozoite antigens (AMA1, EBA175, MSP1, MSP2, MSP3, MSP11, Pf41), sporozoite CSP, and pregnancy-associated VAR2CSA. The antibody levels were measured in triplicate on each of 3 plates, and the experiments were replicated on two different days by the same technician. The performance of the proposed normalization procedure was evaluated with the pooled controls for the test samples on both the linear and natural-log scales. Results Compared with data on the linear scale, the natural-log transformed data were less skewed and reduced the mean–variance relationship. The proposed normalization procedure using pooled controls on the natural-log scale significantly reduced between-plate variation. Conclusions For malaria-related research that measure antibodies to multiple antigens with multiplex assays, the natural-log transformation is recommended for data analysis and use of the normalization procedure with multiple pooled controls can improve the precision of antibody measurements. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1933-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rui Fang
- Office of Biostatistics and Quantitative Health Sciences, University of Hawaii John A. Burns School of Medicine, Honolulu, HI, 96813, USA
| | - Andrew Wey
- Office of Biostatistics and Quantitative Health Sciences, University of Hawaii John A. Burns School of Medicine, Honolulu, HI, 96813, USA
| | - Naveen K Bobbili
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii John A. Burns School of Medicine, 651 Ilalo Street, BSB 211, Honolulu, HI, 96813, USA
| | - Rose F G Leke
- Biotechnology Center, Faculty of Medicine and Biomedical Research, University of Yaounde 1, Yaounde, Cameroon
| | - Diane Wallace Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii John A. Burns School of Medicine, 651 Ilalo Street, BSB 211, Honolulu, HI, 96813, USA
| | - John J Chen
- Office of Biostatistics and Quantitative Health Sciences, University of Hawaii John A. Burns School of Medicine, Honolulu, HI, 96813, USA.
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144
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Portugal S, Obeng-Adjei N, Moir S, Crompton PD, Pierce SK. Atypical memory B cells in human chronic infectious diseases: An interim report. Cell Immunol 2017; 321:18-25. [PMID: 28735813 DOI: 10.1016/j.cellimm.2017.07.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/03/2017] [Indexed: 01/08/2023]
Abstract
Immunological memory is a remarkable phenomenon in which survival of an initial infection by a pathogen leads to life-long protection from disease upon subsequent exposure to that same pathogen. For many infectious diseases, long-lived protective humoral immunity is induced after only a single infection in a process that depends on the generation of memory B cells (MBCs) and long-lived plasma cells. However, over the past decade it has become increasingly evident that many chronic human infectious diseases to which immunity is not readily established, including HIV-AIDS, malaria and TB, are associated with fundamental alterations in the composition and functionality of MBC compartments. A common feature of these diseases appears to be a large expansion of what have been termed exhausted B cells, tissue-like memory B cells or atypical memory B cells (aMBCs) that, for simplicity's sake, we refer to here as aMBCs. It has been suggested that chronic immune activation and inflammation drive the expansion of aMBCs and that in some way aMBCs contribute to deficiencies in the acquisition of immunity in chronic infectious diseases. Although aMBCs are heterogeneous both within individuals and between diseases, they have several features in common including low expression of the cell surface markers that define classical MBCs in humans including CD21 and CD27 and high expression of genes not usually expressed by classical MBCs including T-bet, CD11c and a variety of inhibitory receptors, notably members of the FcRL family. Another distinguishing feature is their greatly diminished ability to be stimulated through their B cell receptors to proliferate, secrete cytokines or produce antibodies. In this review, we describe our current understanding of the phenotypic markers of aMBCs, their specificity in relation to the disease-causing pathogen, their functionality, the drivers of their expansion in chronic infections and their life span. We briefly summarize the features of aMBCs in healthy individuals and in autoimmune disease. We also comment on the possible relationship of human aMBCs and T-bet+, CD11c+ age/autoimmune-associated B cells, also a topic of this review volume.
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Affiliation(s)
- Silvia Portugal
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Nyamekye Obeng-Adjei
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Susan Moir
- Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter D Crompton
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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145
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Figueiredo MM, Costa PAC, Diniz SQ, Henriques PM, Kano FS, Tada MS, Pereira DB, Soares IS, Martins-Filho OA, Jankovic D, Gazzinelli RT, Antonelli LRDV. T follicular helper cells regulate the activation of B lymphocytes and antibody production during Plasmodium vivax infection. PLoS Pathog 2017; 13:e1006484. [PMID: 28700710 PMCID: PMC5519210 DOI: 10.1371/journal.ppat.1006484] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/20/2017] [Accepted: 06/21/2017] [Indexed: 01/24/2023] Open
Abstract
Although the importance of humoral immunity to malaria has been established, factors that control antibody production are poorly understood. Follicular helper T cells (Tfh cells) are pivotal for generating high-affinity, long-lived antibody responses. While it has been proposed that expansion of antigen-specific Tfh cells, interleukin (IL) 21 production and robust germinal center formation are associated with protection against malaria in mice, whether Tfh cells are found during Plasmodium vivax (P. vivax) infection and if they play a role during disease remains unknown. Our goal was to define the role of Tfh cells during P. vivax malaria. We demonstrate that P. vivax infection triggers IL-21 production and an increase in Tfh cells (PD-1+ICOS+CXCR5+CD45RO+CD4+CD3+). As expected, FACS-sorted Tfh cells, the primary source of IL-21, induced immunoglobulin production by purified naïve B cells. Furthermore, we found that P. vivax infection alters the B cell compartment and these alterations were dependent on the number of previous infections. First exposure leads to increased proportions of activated and atypical memory B cells and decreased frequencies of classical memory B cells, whereas patients that experienced multiple episodes displayed lower proportions of atypical B cells and higher frequencies of classical memory B cells. Despite the limited sample size, but consistent with the latter finding, the data suggest that patients who had more than five infections harbored more Tfh cells and produce more specific antibodies. P. vivax infection triggers IL-21 production by Tfh that impact B cell responses in humans. Plasmodium vivax is the most widely spread malaria parasite species and represents a significant impediment to social and economic development in endemic countries. Our goal was to assess the importance of T follicular helper cells in the development of the immune response during malaria. We found that P. vivax infection promotes expansion of circulating Tfh cells that secrete IL-21 to boost immunoglobulin production by B-cells. Accordingly, malaria infection led to marked changes in B cell subpopulations, including expansion of plasma cells and increased production of antigen-specific IgG1 and IgG3. Re-exposure to P. vivax led to amplified Tfh cells cell responses that were concomitantly associated with increased frequencies of classical memory B cells. Thus, Tfh cells that are induced during P. vivax infection could impact the efficiency of humoral immune responses that underlie protective immunity.
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Affiliation(s)
- Maria Marta Figueiredo
- Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.,Laboratório de Imunopatologia, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Pedro Augusto Carvalho Costa
- Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Suelen Queiroz Diniz
- Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.,Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Priscilla Miranda Henriques
- Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Flora Satiko Kano
- Laboratório de Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Mauro Sugiro Tada
- Centro de Pesquisas em Medicina Tropical de Rondônia, Porto Velho, Rondônia, Brazil
| | | | - Irene Silva Soares
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Olindo Assis Martins-Filho
- Laboratório de Biomarcadores de Diagnóstico e Monitoração, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Dragana Jankovic
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ricardo Tostes Gazzinelli
- Laboratório de Imunopatologia, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.,Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Lis Ribeiro do Valle Antonelli
- Laboratório de Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
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146
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Hill DL, Schofield L, Wilson DW. IgG opsonization of merozoites: multiple immune mechanisms for malaria vaccine development. Int J Parasitol 2017; 47:585-595. [PMID: 28668325 DOI: 10.1016/j.ijpara.2017.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/12/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023]
Abstract
Global eradication of the human-infecting malaria parasite Plasmodium falciparum, the major cause of malaria mortality, is unlikely to be achieved without an effective vaccine. However, our limited understanding of how protective immune responses target malaria parasites in humans, and how to best elicit these immune responses through vaccination, has hampered vaccine development. The red blood cell invading stage of the parasite lifecycle (merozoite) displays antigens that are attractive vaccine candidates as they are accessible to antibodies and raise high antibody titres in naturally immune individuals. The number of merozoite antigens that elicit an immune response, and their structural and functional diversity, has led to a large number of lead antigens being pursued as vaccine candidates. Despite being seemingly spoilt for choice in terms of vaccine candidates, there is still a lack of consensus on exactly how merozoite antibodies reduce parasitemia and malaria disease. In this review we describe the various immune mechanisms that can result from IgG opsonization of merozoites, and highlight recent developments that support a role for these functional antibodies in naturally acquired and vaccine-induced immunity.
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Affiliation(s)
- Danika L Hill
- Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom; The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
| | - Louis Schofield
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia; Burnet Institute, 85 Commercial Road, Melbourne 3004, Victoria, Australia.
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147
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Felgner J, Jain A, Nakajima R, Liang L, Jasinskas A, Gotuzzo E, Vinetz JM, Miyajima F, Pirmohamed M, Hassan-Hanga F, Umoru D, Jibir BW, Gambo S, Olateju K, Felgner PL, Obaro S, Davies DH. Development of ELISAs for diagnosis of acute typhoid fever in Nigerian children. PLoS Negl Trop Dis 2017. [PMID: 28640809 PMCID: PMC5498068 DOI: 10.1371/journal.pntd.0005679] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Improved serodiagnostic tests for typhoid fever (TF) are needed for surveillance, to facilitate patient management, curb antibiotic resistance, and inform public health programs. To address this need, IgA, IgM and IgG ELISAs using Salmonella enterica serovar Typhi (S. Typhi) lipopolysaccharide (LPS) and hemolysin E (t1477) protein were conducted on 86 Nigerian pediatric TF and 29 non-typhoidal Salmonella (NTS) cases, 178 culture-negative febrile cases, 28 "other" (i.e., non-Salmonella) pediatric infections, and 48 healthy Nigerian children. The best discrimination was achieved between TF and healthy children. LPS-specific IgA and IgM provided receiver operator characteristic areas under the curve (ROC AUC) values of 0.963 and 0.968, respectively, and 0.978 for IgA+M combined. Similar performance was achieved with t1477-specific IgA and IgM (0.968 and 0.968, respectively; 0.976 combined). IgG against LPS and t1477 was less accurate for discriminating these groups, possibly as a consequence of previous exposure, although ROC AUC values were still high (0.928 and 0.932, respectively). Importantly, discrimination between TF and children with other infections was maintained by LPS-specific IgA and IgM (AUC = 0.903 and 0.934, respectively; 0.938 combined), and slightly reduced for IgG (0.909), while t1477-specific IgG performed best (0.914). A similar pattern was seen when comparing TF with other infections from outside Nigeria. The t1477 may be recognized by cross-reactive antibodies from other acute infections, although a robust IgG response may provide some diagnostic utility in populations where incidence of other infections is low, such as in children. The data are consistent with IgA and IgM against S. Typhi LPS being specific markers of acute TF.
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Affiliation(s)
- Jiin Felgner
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Aarti Jain
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Rie Nakajima
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Li Liang
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Algis Jasinskas
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Eduardo Gotuzzo
- Alexander von Humboldt Institute of Tropical Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
- Hospital Nacional Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Alexander von Humboldt Institute of Tropical Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Fabio Miyajima
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Munir Pirmohamed
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | | | | | | | - Safiya Gambo
- Department of Pediatrics, Murtala Specialist Hospital, Kano, Nigeria
| | | | - Philip L. Felgner
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Stephen Obaro
- Department of Pediatrics, Aminu Kano Teaching Hospital, Kano, Nigeria
- University of Abuja Teaching Hospital, Gwagwalada, Nigeria
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- International Foundation against Infectious Diseases in Nigeria (IFAIN), Abuja, Nigeria
| | - D. Huw Davies
- Division of Infectious Diseases, School of Medicine, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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148
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Ntege EH, Takashima E, Morita M, Nagaoka H, Ishino T, Tsuboi T. Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates. Expert Rev Vaccines 2017; 16:769-779. [PMID: 28604122 DOI: 10.1080/14760584.2017.1341317] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.
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Affiliation(s)
- Edward H Ntege
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Eizo Takashima
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Masayuki Morita
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Hikaru Nagaoka
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Tomoko Ishino
- b Division of Molecular Parasitology , Proteo-Science Center, Ehime University , Toon , Ehime , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
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149
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Perraut R, Varela ML, Loucoubar C, Niass O, Sidibé A, Tall A, Trape JF, Wotodjo AN, Mbengue B, Sokhna C, Vigan-Womas I, Touré A, Richard V, Mercereau-Puijalon O. Serological signatures of declining exposure following intensification of integrated malaria control in two rural Senegalese communities. PLoS One 2017; 12:e0179146. [PMID: 28609450 PMCID: PMC5469466 DOI: 10.1371/journal.pone.0179146] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/24/2017] [Indexed: 01/26/2023] Open
Abstract
Recent control scale-up has reduced malaria in many areas but new tools are needed to monitor further progress, including indicators of decreasing exposure to parasite infection. Although serology is considered a promising approach in this regard, the serological impact of control interventions has been so far studied using indirect quantification of exposure. Cohort surveys concomitantly recording entomological and malariometric indices have been conducted in two Senegalese settings where supervised control intensification implemented in 2006 shifted malaria from historically holoendemic in Dielmo and mesoendemic in Ndiop to hypoendemic in both settings by 2013. We analyse here serological signatures of declining transmission using archived blood samples. Responses against ten pre-erythrocytic and erythrocytic antigens from Plasmodium falciparum and P. malariae alongside an Anopheles gambiae salivary gland antigen were analysed. Cross-sectional surveys conducted before (2002) and after (2013) control intensification showed a major impact of control intensification in both settings. The age-associated prevalence, magnitude and breadth of the IgG responses to all antigens were village-specific in 2002. In 2013, remarkably similar patterns were observed in both villages, with marginal responses against all parasite antigens in the 0-5y children and reduced responses in all previously seropositive age groups. Waning of humoral responses of individuals who were immune at the time of control intensification was studied from 2006 to 2013 using yearly samplings. Longitudinal data were analysed using the Cochran-Armittage trend test and an age-related reversible catalytic conversion model. This showed that the antigen-specific antibody declines were more rapid in older children than adults. There was a strong association of antibody decline with the declining entomological inoculation rate. We thus identified serological markers of declining exposure to malaria parasites that should help future monitoring of progress towards malaria elimination.
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Affiliation(s)
- Ronald Perraut
- Institut Pasteur de Dakar, Unité d’Immunologie, Dakar, Sénégal
- * E-mail:
| | - Marie-Louise Varela
- Institut Pasteur de Dakar, G4 Biostatistiques Bioinformatique et Modélisation, Dakar, Sénégal
| | - Cheikh Loucoubar
- Institut Pasteur de Dakar, G4 Biostatistiques Bioinformatique et Modélisation, Dakar, Sénégal
| | - Oumy Niass
- Institut Pasteur de Dakar, Unité d’Immunologie, Dakar, Sénégal
| | - Awa Sidibé
- Institut Pasteur de Dakar, Unité d’Immunologie, Dakar, Sénégal
| | - Adama Tall
- Institut Pasteur de Dakar, Unité d’Epidémiologie, Dakar, Sénégal
| | | | | | - Babacar Mbengue
- Institut Pasteur de Dakar, Unité d’Immunogénétique, Dakar, Sénégal
| | - Cheikh Sokhna
- Institut de Recherche pour le Développement (IRD), URMITE, Dakar, Sénégal
| | - Inès Vigan-Womas
- Institut Pasteur de Madagascar, Unité d’Immunologie des Maladies Infectieuses, Antanarivo, Madagascar
- Institut Pasteur, Department of Parasitology and Insect Vectors, 25 Rue du Dr Roux, Paris, France
| | - Aissatou Touré
- Institut Pasteur de Dakar, Unité d’Immunologie, Dakar, Sénégal
| | - Vincent Richard
- Institut Pasteur de Dakar, Unité d’Epidémiologie, Dakar, Sénégal
| | - Odile Mercereau-Puijalon
- Institut Pasteur, Department of Parasitology and Insect Vectors, 25 Rue du Dr Roux, Paris, France
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Matuschewski K. Vaccines against malaria-still a long way to go. FEBS J 2017; 284:2560-2568. [DOI: 10.1111/febs.14107] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/09/2017] [Accepted: 05/10/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Kai Matuschewski
- Department of Molecular Parasitology; Institute of Biology; Humboldt University Berlin; Germany
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