1
|
Patra KP, Kaur H, Kolli SK, Wozniak JM, Prieto JH, Yates JR, Gonzalez DJ, Janse CJ, Vinetz JM. A Hetero-Multimeric Chitinase-Containing Plasmodium falciparum and Plasmodium gallinaceum Ookinete-Secreted Protein Complex Involved in Mosquito Midgut Invasion. Front Cell Infect Microbiol 2021; 10:615343. [PMID: 33489941 PMCID: PMC7821095 DOI: 10.3389/fcimb.2020.615343] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/30/2020] [Indexed: 12/14/2022] Open
Abstract
Malaria parasites are transmitted by Anopheles mosquitoes. During its life cycle in the mosquito vector the Plasmodium ookinete escapes the proteolytic milieu of the post-blood meal midgut by traversing the midgut wall. This process requires penetration of the chitin-containing peritrophic matrix lining the midgut epithelium, which depends in part on ookinete-secreted chitinases. Plasmodium falciparum ookinetes have one chitinase (PfCHT1), whereas ookinetes of the avian-infecting parasite, P. gallinaceum, have two, a long and a short form, PgCHT1 and PgCHT2, respectively. Published data indicates that PgCHT2 forms a high molecular weight (HMW) reduction-sensitive complex; and one binding partner is the ookinete-produced von Willebrand A-domain-containing protein, WARP. Size exclusion chromatography data reported here show that P. gallinaceum PgCHT2 and its ortholog, P. falciparum PfCHT1 are covalently-linked components of a HMW chitinase-containing complex (> 1,300 kDa). Mass spectrometry of ookinete-secreted proteins isolated using a new chitin bead pull-down method identified chitinase-associated proteins in P. falciparum and P. gallinaceum ookinete-conditioned culture media. Mass spectrometry of this complex showed the presence of several micronemal proteins including von Willebrand factor A domain-related protein (WARP), ookinete surface enolase, and secreted ookinete adhesive protein (SOAP). To test the hypothesis that ookinete-produced PfCHT1 can form a high molecular homo-multimer or, alternatively, interacts with P. berghei ookinete-produced proteins to produce an HMW hetero-multimer, we created chimeric P. berghei parasites expressing PfCHT1 to replace PbCHT1, enabling the production of large numbers of PfCHT1-expressing ookinetes. We show that chimeric P. berghei ookinetes express monomeric PfCHT1, but a HMW complex containing PfCHT1 is not present. A better understanding of the chitinase-containing HMW complex may enhance development of next-generation vaccines or drugs that target malaria transmission stages.
Collapse
Affiliation(s)
- Kailash P Patra
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Hargobinder Kaur
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Surendra Kumar Kolli
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Jacob M Wozniak
- Department of Pharmacology and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States
| | - Judith Helena Prieto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,Department of Chemistry, Western Connecticut State University, Danbury, CT, United States
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - David J Gonzalez
- Department of Pharmacology and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Joseph M Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, United States
| |
Collapse
|
2
|
McCall MBB, Kremsner PG, Mordmüller B. Correlating efficacy and immunogenicity in malaria vaccine trials. Semin Immunol 2018; 39:52-64. [PMID: 30219621 DOI: 10.1016/j.smim.2018.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022]
Abstract
The availability of an effective and appropriately implemented malaria vaccine would form a crucial cornerstone of public health efforts to fight this disease. Despite many decades of research, however, no malaria vaccine has yet shown satisfactory protective efficacy or been rolled-out. Validated immunological substitute endpoints have the potential to accelerate clinical vaccine development by reducing the required complexity, size, duration and cost of clinical trials. Besides facilitating clinical development of existing vaccine candidates, understanding immunological mechanisms of protection may drive the development of fundamentally new vaccination approaches. In this review we focus on correlates of protection in malaria vaccine development: Does immunogenicity predict malaria vaccine efficacy and why is this question particularly difficult? Have immunological correlates accelerated malaria vaccine development in the past and will they facilitate it in the future? Does Controlled Human Malaria Infection represent a valid model for identifying such immunological correlates, or a correlate of protection against naturally-acquired malaria in itself?
Collapse
Affiliation(s)
- Matthew B B McCall
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
| | - Peter G Kremsner
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Universität Tübingen and Deutsches Zentrum für Infektionsforschung, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| |
Collapse
|
3
|
Theisen M, Adu B, Mordmüller B, Singh S. The GMZ2 malaria vaccine: from concept to efficacy in humans. Expert Rev Vaccines 2017; 16:907-917. [PMID: 28699823 DOI: 10.1080/14760584.2017.1355246] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION GMZ2 is a recombinant protein consisting of conserved domains of GLURP and MSP3, two asexual blood-stage antigens of Plasmodium falciparum, and is designed with the aim of mimicking naturally acquired anti-malarial immunity. The rationale for combining these two antigens is based on a series of immune epidemiological studies from geographically diverse malaria endemic regions; functional in vitro studies; and pre-clinical studies in rodents and New World monkeys. GMZ2 adjuvanted with alhydrogel® (alum) was well tolerated and immunogenic in three phase 1 studies. The recently concluded phase 2 trial of GMZ2/alum, involving 1849 participants 12 to 60 month of age in four countries in West, Central and Eastern Africa, showed that GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects for clinical development of GMZ2 sub-unit vaccine. We will focus on discovery, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production, pre-clinical and clinical studies. Expert commentary: GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. More immunogenic formulations should be developed.
Collapse
Affiliation(s)
- Michael Theisen
- a Department for Congenital Disorders , Statens Serum Institut , Copenhagen , Denmark.,b Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology , University of Copenhagen , Copenhagen , Denmark.,c Department of Infectious Diseases , Copenhagen University Hospital , Rigshospitalet , Denmark
| | - Bright Adu
- d Noguchi Memorial Institute for Medical Research , University of Ghana , Legon , Ghana
| | - Benjamin Mordmüller
- e Institute of Tropical Medicine and Center for Infection Research, partner site Tübingen , University of Tübingen , Tübingen , Germany
| | - Subhash Singh
- f Indian Institute of Integrative Medicine , Jammu , India
| |
Collapse
|
4
|
Abdul-Ghani R, Mahdy MAK, Beier JC, Basco LK. Hidden reservoir of resistant parasites: the missing link in the elimination of falciparum malaria. Infect Dis Poverty 2017; 6:12. [PMID: 28166813 PMCID: PMC5294824 DOI: 10.1186/s40249-016-0227-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 12/20/2016] [Indexed: 11/29/2022] Open
Abstract
Background To successfully eliminate malaria, an integrated system that includes a number of approaches and interventions—aimed at overcoming the threat of antimalarial drug resistance—is required. Significant progress has been made in reducing malaria incidence through large-scale use of artemisinin-based combination therapies and insecticide-treated nets. To consolidate these gains, attention should be paid to the missing links in the elimination of malaria. One of these gaps is the residual reservoir of submicroscopic resistant parasites, which remains after case management or other control measures have been carried out. Therefore, the present opinion piece highlights the importance of exploring the role that submicroscopic resistant parasites could play in hindering malaria elimination by allowing the persistence of transmission, particularly in areas of low transmission or in the pre-elimination and/or elimination phase. Discussion If malaria elimination interventions are to be effective, the relative role of the hidden reservoir of resistant parasites needs to be assessed, particularly in regions that are low-transmission settings and/or in pre-elimination and/or elimination phases. Various ongoing studies are focusing on the role of submicroscopic malaria infections in malaria transmission but overlook the possible build-up of resistance to antimalarial drugs among submicroscopic parasite populations. This is an important factor as it may eventually limit the effectiveness of malaria elimination strategies. Conclusions An evidence-based estimation of the “true” reservoir of resistant parasites can help target the existing and emerging foci of resistant parasites before they spread. Emergence and spread of artemisinin-resistant Plasmodium falciparum malaria in Southeast Asia underline the need to contain drug resistance. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0227-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Rashad Abdul-Ghani
- Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen. .,Tropical Disease Research Center, University of Science and Technology, Sana'a, Yemen.
| | - Mohammed A K Mahdy
- Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.,Tropical Disease Research Center, University of Science and Technology, Sana'a, Yemen
| | - John C Beier
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Leonardo K Basco
- Unité de Recherche 198, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Institut de Recherche pour le Développement, Faculté de Médecine La Timone, Aix-Marseille Université, Marseille, France
| |
Collapse
|
5
|
Abdul-Ghani R, Mahdy MAK, Saif-Ali R, Alkubati SA, Alqubaty AR, Al-Mikhlafy AA, Al-Eryani SM, Al-Mekhlafi AM, Alhaj A. Glucose-6-phosphate dehydrogenase deficiency among Yemeni children residing in malaria-endemic areas of Hodeidah governorate and evaluation of a rapid diagnostic test for its detection. Malar J 2016; 15:327. [PMID: 27329471 PMCID: PMC4915072 DOI: 10.1186/s12936-016-1372-9] [Citation(s) in RCA: 6] [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: 04/11/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common genetic enzymopathy worldwide, is associated with an acute haemolytic anaemia in individuals exposed to primaquine. The present study aimed to determine G6PD deficiency among Yemeni children in malaria-endemic areas as well as to assess the performance of the CareStart™ G6PD rapid diagnostic test (RDT) for its detection. METHODS A cross-sectional study recruiting 400 children from two rural districts in Hodeidah governorate was conducted. Socio-demographic data and blood samples were collected and G6PD deficiency was qualitatively detected in fresh blood in the field using the CareStart™ G6PD RDT, while the enzymatic assay was used to quantitatively measure enzyme activity. Performance of the CareStart™ G6PD RDT was assessed by calculating its sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) against the reference enzymatic assay. RESULTS The ranges of enzyme activity were 0.14-18.45 and 0.21-15.94 units/g haemoglobin (U/gHb) for males and females, respectively. However, adjusted male median G6PD activity was 5.0 U/gHb. Considering the adjusted male median as representing 100 % normal enzyme activity, the prevalence rates of G6PD deficiency were 12.0 and 2.3 % at the cut-off activities of ≤60 and ≤10 %, respectively. Multivariable analysis showed that gender, district of residence and consanguinity between parents were independent risk factors for G6PD deficiency at the cut-off activity of ≤30 % of normal. The CareStart™ G6PD RDT showed 100 % sensitivity and NPV for detecting G6PD deficiency at the cut-off activities of ≤10 and ≤20 % of normal activity compared to the reference enzymatic method. However, it showed specificity levels of 90.0 and 95.4 % as well as positive/deficient predictive values (PPVs) of 18.0 and 66.0 % at the cut-off activities of ≤10 and ≤20 %, respectively, compared to the reference method. CONCLUSIONS G6PD deficiency with enzyme activity of ≤60 % of normal is prevalent among 12.0 % of children residing in malaria-endemic areas of Hodeidah governorate, with 2.3 % having severe G6PD deficiency. Gender, district of residence and consanguinity between parents are significant independent predictors of G6PD deficiency at the cut-off activity of ≤30 % of normal among children in malaria-endemic areas of Hodeidah. The CareStart™ G6PD RDT proved reliable as a point-of-care test to screen for severely G6PD-deficient patients, with 100 % sensitivity and NPV, and it can be used for making clinical decisions prior to the administration of primaquine in malaria elimination strategies.
Collapse
Affiliation(s)
- Rashad Abdul-Ghani
- />Tropical Disease Research Center, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen
- />Department of Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen
| | - Mohammed A. K. Mahdy
- />Tropical Disease Research Center, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen
- />Department of Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen
| | - Reyadh Saif-Ali
- />Department of Biochemistry, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen
| | - Sameer A. Alkubati
- />Department of Critical Care Nursing, Faculty of Medicine and Health Sciences, Hodeidah University, Hodeidah, Yemen
| | - Abdulhabib R. Alqubaty
- />Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen
| | - Abdullah A. Al-Mikhlafy
- />Department of Community Medicine, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen
| | - Samira M. Al-Eryani
- />Department of Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen
| | - Abdusalam M. Al-Mekhlafi
- />Department of Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen
| | - Ali Alhaj
- />Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen
| |
Collapse
|