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Hedtke SM, Kode A, Ukety TO, Mande JL, Abhafule GM, Raciu AA, Uvon CB, Jada SR, Hotterbeekx A, Siewe Fodjo JN, Mitreva M, Sebit W, Colebunders R, Grant WN, Kuesel AC. Procedure for Handling and Storage of Onchocerca volvulus Microfilariae Obtained from Skin Snips for Downstream Genetic Work. Trop Med Infect Dis 2023; 8:445. [PMID: 37755906 PMCID: PMC10536066 DOI: 10.3390/tropicalmed8090445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
WHO and endemic countries target elimination of transmission of Onchocerca volvulus, the parasite causing onchocerciasis. Population genetic analysis of O. volvulus may provide data to improve the evidence base for decisions on when, where, and for how long to deploy which interventions and post-intervention surveillance to achieve elimination. Development of necessary methods and tools requires parasites suitable for genetic analysis. Based on our experience with microfilariae obtained from different collaborators, we developed a microfilariae transfer procedure for large-scale studies in the Democratic Republic of Congo (DRC) comparing safety and efficacy of ivermectin, the mainstay of current onchocerciasis elimination strategies, and moxidectin, a new drug. This procedure is designed to increase the percentage of microfilariae in skin snips suitable for genetic analysis, improve assignment to metadata, and minimize time and materials needed by the researchers collecting the microfilariae. Among 664 microfilariae from South Sudan, 35.7% and 39.5% failed the mitochondrial and nuclear qPCR assay. Among the 576 microfilariae from DRC, 16.0% and 16.7% failed these assays, respectively. This difference may not only be related to the microfilariae transfer procedure but also to other factors, notably the ethanol concentration in the tubes in which microfilariae were stored (64% vs. ≥75%).
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Affiliation(s)
- Shannon M Hedtke
- Department of Environment and Genetics, La Trobe University, Bundoora, VIC 3086, Australia
| | - Anusha Kode
- Department of Environment and Genetics, La Trobe University, Bundoora, VIC 3086, Australia
| | - Tony O Ukety
- Centre de Recherche en Maladies Tropicales (CRMT), Bunia P.O. Box 143, Democratic Republic of the Congo
| | - Jöel L Mande
- Centre de Recherche en Maladies Tropicales (CRMT), Bunia P.O. Box 143, Democratic Republic of the Congo
| | - Germain M Abhafule
- Centre de Recherche en Maladies Tropicales (CRMT), Bunia P.O. Box 143, Democratic Republic of the Congo
| | - Anuarite A Raciu
- Centre de Recherche en Maladies Tropicales (CRMT), Bunia P.O. Box 143, Democratic Republic of the Congo
| | - Claude B Uvon
- Centre de Recherche en Maladies Tropicales (CRMT), Bunia P.O. Box 143, Democratic Republic of the Congo
| | | | - An Hotterbeekx
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium
| | | | - Makedonka Mitreva
- Department of Medicine, Washington University in St. Louis and McDonnell Genome Institute, St. Louis, MO 63108, USA
| | - Wilson Sebit
- National Public Health Laboratory, Juba P.O. Box 88, South Sudan
| | | | - Warwick N Grant
- Department of Environment and Genetics, La Trobe University, Bundoora, VIC 3086, Australia
| | - Annette C Kuesel
- UNICEF/UNDP/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, CH-1211 Geneva, Switzerland
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Scheunemann JF, Risch F, Reichwald JJ, Lenz B, Neumann AL, Garbe S, Frohberger SJ, Koschel M, Ajendra J, Rothe M, Latz E, Coch C, Hartmann G, Schumak B, Hoerauf A, Hübner MP. Potential of Nucleic Acid Receptor Ligands to Improve Vaccination Efficacy against the Filarial Nematode Litomosoides sigmodontis. Vaccines (Basel) 2023; 11:vaccines11050966. [PMID: 37243070 DOI: 10.3390/vaccines11050966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
More than two-hundred-million people are infected with filariae worldwide. However, there is no vaccine available that confers long-lasting protection against filarial infections. Previous studies indicated that vaccination with irradiated infective L3 larvae reduces the worm load. This present study investigated whether the additional activation of cytosolic nucleic acid receptors as an adjuvant improves the efficacy of vaccination with irradiated L3 larvae of the rodent filaria Litomosoides sigmodontis with the aim of identifying novel vaccination strategies for filarial infections. Subcutaneous injection of irradiated L3 larvae in combination with poly(I:C) or 3pRNA resulted in neutrophil recruitment to the skin, accompanied by higher IP-10/CXCL10 and IFN-β RNA levels. To investigate the impact on parasite clearance, BALB/c mice received three subcutaneous injections in 2-week intervals with irradiated L3 larvae in combination with poly(I:C) or 3pRNA prior to the challenge infection. Vaccination with irradiated L3 larvae in combination with poly(I:C) or 3pRNA led to a markedly greater reduction in adult-worm counts by 73% and 57%, respectively, compared to the immunization with irradiated L3 larvae alone (45%). In conclusion, activation of nucleic acid-sensing immune receptors boosts the protective immune response against L. sigmodontis and nucleic acid-receptor agonists as vaccine adjuvants represent a promising novel strategy to improve the efficacy of vaccines against filariae and potentially other helminths.
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Affiliation(s)
- Johanna F Scheunemann
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Frederic Risch
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Julia J Reichwald
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Benjamin Lenz
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Anna-Lena Neumann
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Stephan Garbe
- Clinic for Radiotherapy and Radiation Oncology, University Hospital Bonn, 53127 Bonn, Germany
| | - Stefan J Frohberger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Marianne Koschel
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Jesuthas Ajendra
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Maximilian Rothe
- Institute for Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany
| | - Eicke Latz
- Institute for Innate Immunity, University Hospital Bonn, 53127 Bonn, Germany
| | - Christoph Coch
- Institute for Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127 Bonn, Germany
- Nextevidence GmbH, 81541 Munich, Germany
| | - Gunther Hartmann
- Institute for Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, 53127 Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Beatrix Schumak
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, 53127 Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
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Gaiya DD, Muhammad A, Aimola IA, Udu SK, Balarabe SA, Auta R, Ekpa E, Sheyin A. Potential of Onchocerca ochengi inosine-5'-monophosphate dehydrogenase (IMPDH) and guanosine-5'-monophosphate oxidoreductase (GMPR) as druggable and vaccine candidates: immunoinformatics screening. J Biomol Struct Dyn 2023; 41:14832-14848. [PMID: 36866624 DOI: 10.1080/07391102.2023.2184171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/18/2023] [Indexed: 03/04/2023]
Abstract
Onchocerciasis is a vector-borne disease caused by the filarial nematode Onchocerca volvulus, which is responsible for most of the visual impairments recorded in Africa, Asia and the Americas. It is known that O. volvulus has similar molecular and biological characteristics as Onchocerca ochengi in cattle. This study was designed to screen for immunogenic epitopes and binding pockets of O. ochengi IMPDH and GMPR ligands using immunoinformatic approaches. In this study, a total of 23 B cell epitopes for IMPDH and 7 B cell epitopes for GMPR were predicted using ABCpred tool, Bepipred 2.0 and Kolaskar and Tongaonkar methods. The CD4+ Th computational results showed 16 antigenic epitopes from IMPDH with strong binding affinity for DRB1_0301, DRB3_0101, DRB1_0103 and DRB1_1501 MHC II alleles while 8 antigenic epitopes from GMPR were predicted to bind DRB1_0101 and DRB1_0401 MHC II alleles, respectively. For the CD8+ CTLs analysis, 8 antigenic epitopes from IMPDH showed strong binding affinity to human leukocyte antigen HLA-A*26:01, HLA-A*03:01, HLA-A*24:02 and HLA-A*01:01 MHC I alleles while 2 antigenic epitopes from GMPR showed strong binding affinity to HLA-A*01:01 allele, respectively. The immunogenic B cell and T cell epitopes were further evaluated for antigenicity, non-alllergernicity, toxicity, IFN-gamma, IL4 and IL10. The docking score revealed favorable binding free energy with IMP and MYD scoring the highest binding affinity at -6.6 kcal/mol with IMPDH and -8.3 kcal/mol with GMPR. This study provides valuable insight on IMPDH and GMPR as potential drug targets and for the development of multiple epitope vaccine candidates.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Daniel Danladi Gaiya
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Aliyu Muhammad
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Idowu Asegame Aimola
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Stella Kuyet Udu
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Sallau Abdullahi Balarabe
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Richard Auta
- Department of Biochemistry, Faculty of Science, Kaduna State University, Kaduna, Kaduna State, Nigeria
| | - Emmanuel Ekpa
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Abraham Sheyin
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
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Rahman MN, Ahmed S, Hasan M, Shuvo MSA, Islam MA, Hasan R, Roy S, Hossain H, Mia MM. Immunoselective progression of a multi-epitope-based subunit vaccine candidate to convey protection against the parasite Onchocerca lupi. INFORMATICS IN MEDICINE UNLOCKED 2023. [DOI: 10.1016/j.imu.2023.101209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
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Frallonardo L, Di Gennaro F, Panico GG, Novara R, Pallara E, Cotugno S, Guido G, De Vita E, Ricciardi A, Totaro V, Camporeale M, De Iaco G, Bavaro DF, Lattanzio R, Patti G, Brindicci G, Papagni R, Pellegrino C, Santoro CR, Segala FV, Putoto G, Nicastri E, Saracino A. Onchocerciasis: Current knowledge and future goals. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.986884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human Onchocerciasis, caused by infection by the filarial nematode Onchocerca volvulus, is a neglected public health disease that affects millions of people in the endemic regions of sub-Saharan Africa and Latin America. It is also called river blindness because the Blackflies that transmit infection breeds in rapidly flowing fresh water streams and rivers. This review features state-of-the-art data on the parasite, its endobacteria Wolbachia, the prevalence of the infection and its geographical distribution, its diagnostics, the interaction between the parasite and its host, and the pathology of Onchocerciasis. By development and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas (Colombia, Ecuador, Mexico, and Guatemala)and inSudan, followed by Onchocerciasis eliminations. The current state and future perspectives for vector control and elimination strategy are described.
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Shey RA, Ghogomu SM, Nebangwa DN, Shintouo CM, Yaah NE, Yengo BN, Nkemngo FN, Esoh KK, Tchatchoua NMT, Mbachick TT, Dede AF, Lemoge AA, Ngwese RA, Asa BF, Ayong L, Njemini R, Vanhamme L, Souopgui J. Rational design of a novel multi-epitope peptide-based vaccine against Onchocerca volvulus using transmembrane proteins. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.1046522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Almost a decade ago, it was recognized that the global elimination of onchocerciasis by 2030 will not be feasible without, at least, an effective prophylactic and/or therapeutic vaccine to complement chemotherapy and vector control strategies. Recent advances in computational immunology (immunoinformatics) have seen the design of novel multi-epitope onchocerciasis vaccine candidates which are however yet to be evaluated in clinical settings. Still, continued research to increase the pool of vaccine candidates, and therefore the chance of success in a clinical trial remains imperative. Here, we designed a multi-epitope vaccine candidate by assembling peptides from 14 O. volvulus (Ov) proteins using an immunoinformatics approach. An initial 126 Ov proteins, retrieved from the Wormbase database, and at least 90% similar to orthologs in related nematode species of economic importance, were screened for localization, presence of transmembrane domain, and antigenicity using different web servers. From the 14 proteins retained after the screening, 26 MHC-1 and MHC-II (T-cell) epitopes, and linear B-lymphocytes epitopes were predicted and merged using suitable linkers. The Mycobacterium tuberculosis Resuscitation-promoting factor E (RPFE_MYCTU), which is an agonist of TLR4, was then added to the N-terminal of the vaccine candidate as a built-in adjuvant. Immune simulation analyses predicted strong B-cell and IFN-γ based immune responses which are necessary for protection against O. volvulus infection. Protein-protein docking and molecular dynamic simulation predicted stable interactions between the 3D structure of the vaccine candidate and human TLR4. These results show that the designed vaccine candidate has the potential to stimulate both humoral and cellular immune responses and should therefore be subject to further laboratory investigation.
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Tagboto S, Orish V. Drug development for onchocerciasis-the past, the present and the future. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.953061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Onchocerciasis affects predominantly rural communities in Africa, and with small foci in South America and the Yemen. The disease is a major cause of blindness and other significant morbidity and mortality. Control programs have achieved a major impact on the incidence and prevalence of onchocerciasis by interrupting transmission with vector control programs, and treatment with mass drug administration using the microfilaricide ivermectin. Over the last few decades, several microfilaricides have been developed. This initially included diethylcarbamazine, which had significant side effects and is no longer used as such. Ivermectin which is a safe and highly effective microfilaricide and moxidectin which is a longer acting microfilaricide are presently recognized therapies. Suramin was the first effective macrofilaricide but was prohibitively toxic. Certain antibiotics including doxycycline can help eliminate adult worms by targeting its endosymbiont bacteria, Wolbachia pipientis. However, the dosing regimens may make this difficult to use as part of a mass disease control program in endemic areas. It is now widely recognized that treatments that are able to kill or permanently sterilize adult filarial worms should help achieve the elimination of this disease. We summarize in detail the historic drug development in onchocerciasis, including prospective future candidate drugs.
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Co-Administration of Adjuvanted Recombinant Ov-103 and Ov-RAL-2 Vaccines Confer Protection against Natural Challenge in A Bovine Onchocerca ochengi Infection Model of Human Onchocerciasis. Vaccines (Basel) 2022; 10:vaccines10060861. [PMID: 35746469 PMCID: PMC9229719 DOI: 10.3390/vaccines10060861] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/20/2022] [Accepted: 05/25/2022] [Indexed: 02/05/2023] Open
Abstract
Onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, is a neglected tropical disease mainly of sub-Saharan Africa. Worldwide, an estimated 20.9 million individuals live with infection and a further 205 million are at risk of disease. Current control methods rely on mass drug administration of ivermectin to kill microfilariae and inhibit female worm fecundity. The identification and development of efficacious vaccines as complementary preventive tools to support ongoing elimination efforts are therefore an important objective of onchocerciasis research. We evaluated the protective effects of co-administering leading O. volvulus-derived recombinant vaccine candidates (Ov-103 and Ov-RAL-2) with subsequent natural exposure to the closely related cattle parasite Onchocerca ochengi. Over a 24-month exposure period, vaccinated calves (n = 11) were shown to acquire infection and microfilaridermia at a significantly lower rate compared to unvaccinated control animals (n = 10). Furthermore, adult female worm burdens were negatively correlated with anti-Ov-103 and Ov-RAL-2 IgG1 and IgG2 responses. Peptide arrays identified several Ov-103 and Ov-RAL-2-specific epitopes homologous to those identified as human B-cell and helper T-cell epitope candidates and by naturally-infected human subjects in previous studies. Overall, this study demonstrates co-administration of Ov-103 and Ov-RAL-2 with Montanide™ ISA 206 VG is highly immunogenic in cattle, conferring partial protection against natural challenge with O. ochengi. The strong, antigen-specific IgG1 and IgG2 responses associated with vaccine-induced protection are highly suggestive of a mixed Th1/Th2 associated antibody responses. Collectively, this evidence suggests vaccine formulations for human onchocerciasis should aim to elicit similarly balanced Th1/Th2 immune responses.
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Zhan B, Bottazzi ME, Hotez PJ, Lustigman S. Advancing a Human Onchocerciasis Vaccine From Antigen Discovery to Efficacy Studies Against Natural Infection of Cattle With Onchocerca ochengi. Front Cell Infect Microbiol 2022; 12:869039. [PMID: 35444961 PMCID: PMC9015098 DOI: 10.3389/fcimb.2022.869039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Human onchocerciasis is a devastating neglected tropical disease caused by infection of the filarial nematode Onchocerca volvulus. The infection can cause irreversible visual impairment or blindness and stigmatizing dermatitis. More than 32 million people were estimated to be infected with O. volvulus in Africa, and 385,000 suffered from blindness. Even though the implementation of mass drug administration (MDA) with ivermectin has reduced the global prevalence of onchocerciasis, O. volvulus infection remains challenging to control because MDA with ivermectin cannot be implemented in endemic areas co-endemic with loiasis due to the risk of severe adverse events. There is also emerging drug resistance to ivermectin that further complicates the elimination of onchocerciasis. Thus, the development of a vaccine that would induce protective immunity and reduce infection burden is essential. Efforts to develop prophylactic and/or therapeutic vaccines for onchocerciasis have been explored since the late 1980s by many researchers and entities, and here we summarize the recent advances made in the development of vaccines against the infection of O. volvulus and onchocerciasis.
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Affiliation(s)
- Bin Zhan
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
- *Correspondence: Bin Zhan,
| | - Maria Elena Bottazzi
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
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Abstract
INTRODUCTION : Human infections with helminth worm parasites are extraordinarily prevalent across tropical and subtropical parts of the world, and control relies primarily on drugs that offer short-term suppression of infection. There is an urgent need for new vaccines that would confer long-lived immunity, protecting children in particular and minimizing community transmission. AREAS COVERED : This article discusses the development of helminth vaccines, from the first successful veterinary vaccines that demonstrated the feasibility of inducing protective immunity to helminths, to more recent initiatives to test human helminth antigens. The field has focussed primarily on evaluating individual antigens that could constitute targets amenable to antibody attack to inhibit parasite establishment. In a new direction, vaccines employing extracellular vesicles released by helminths have also given exciting results. EXPERT OPINION : Taking into account the complex life cycles and sophisticated immune evasion strategies of many helminths, a combination of antigens and approaches designed to target essential functional pathways of the parasite will be required to achieve a high level of protection in future anti-helminth vaccines.
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Affiliation(s)
- Rick M. Maizels
- Wellcome Centre for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK,CONTACT Rick M. Maizels Wellcome Centre for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, GlasgowG12 8TA, UK
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Abraham D, Graham-Brown J, Carter D, Gray SA, Hess JA, Makepeace BL, Lustigman S. Development of a recombinant vaccine against human onchocerciasis. Expert Rev Vaccines 2021; 20:1459-1470. [PMID: 34488533 DOI: 10.1080/14760584.2021.1977125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Human onchocerciasis caused by the filarial nematode parasite Onchocerca volvulus remains a major cause of debilitating disease infecting millions primarily in Sub-Saharan Africa. The development of a prophylactic vaccine, along with mass drug administration, would facilitate meeting the goal of onchocerciasis elimination by 2030. AREAS COVERED Models used to study immunity to Onchocerca include natural infection of cattle with Onchocerca ochengi and O. volvulus infective third-stage larvae implanted within diffusion chambers in mice. A vaccine, comprised of two adjuvanted recombinant antigens, induced protective immunity in genetically diverse mice suggesting that it will function similarly in diverse human populations. These antigens were recognized by immune humans and also induced protective immunity against Brugia malayi. We describe the development of a fusion protein composed of the two vaccine antigens with the plan to test the vaccine in cows and non-human primates as a prelude to the initiation of phase 1 clinical trials. EXPERT OPINION The adjuvanted O. volvulus vaccine composed of two antigens Ov-103 and Ov-RAL-2 was shown to be consistently effective at inducing protective immunity using multiple immune mechanisms. The vaccine is ready for further evaluation in other animal models before moving to clinical trials in humans.
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Affiliation(s)
- David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - John Graham-Brown
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | | | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
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Abstract
About half of the world's population and 80% of the world's biodiversity can be found in the tropics. Many diseases are specific to the tropics, with at least 41 diseases caused by endemic bacteria, viruses, parasites, and fungi. Such diseases are of increasing concern, as the geographic range of tropical diseases is expanding due to climate change, urbanization, change in agricultural practices, deforestation, and loss of biodiversity. While traditional medicines have been used for centuries in the treatment of tropical diseases, the active natural compounds within these medicines remain largely unknown. In this review, we describe infectious diseases specific to the tropics, including their causative pathogens, modes of transmission, recent major outbreaks, and geographic locations. We further review current treatments for these tropical diseases, carefully consider the biodiscovery potential of the tropical biome, and discuss a range of technologies being used for drug development from natural resources. We provide a list of natural products with antimicrobial activity, detailing the source organisms and their effectiveness as treatment. We discuss how technological advancements, such as next-generation sequencing, are driving high-throughput natural product screening pipelines to identify compounds with therapeutic properties. This review demonstrates the impact natural products from the vast tropical biome have in the treatment of tropical infectious diseases and how high-throughput technical capacity will accelerate this discovery process.
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Krücken J, Holden-Dye L, Keiser J, Prichard RK, Townson S, Makepeace BL, Hübner MP, Hahnel SR, Scandale I, Harder A, Kulke D. Development of emodepside as a possible adulticidal treatment for human onchocerciasis-The fruit of a successful industrial-academic collaboration. PLoS Pathog 2021; 17:e1009682. [PMID: 34293063 PMCID: PMC8297762 DOI: 10.1371/journal.ppat.1009682] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Current mass drug administration (MDA) programs for the treatment of human river blindness (onchocerciasis) caused by the filarial worm Onchocerca volvulus rely on ivermectin, an anthelmintic originally developed for animal health. These treatments are primarily directed against migrating microfilariae and also suppress fecundity for several months, but fail to eliminate adult O. volvulus. Therefore, elimination programs need time frames of decades, well exceeding the life span of adult worms. The situation is worsened by decreased ivermectin efficacy after long-term therapy. To improve treatment options against onchocerciasis, a drug development candidate should ideally kill or irreversibly sterilize adult worms. Emodepside is a broad-spectrum anthelmintic used for the treatment of parasitic nematodes in cats and dogs (Profender and Procox). Our current knowledge of the pharmacology of emodepside is the result of more than 2 decades of intensive collaborative research between academia and the pharmaceutical industry. Emodepside has a novel mode of action with a broad spectrum of activity, including against extraintestinal nematode stages such as migrating larvae or macrofilariae. Therefore, emodepside is considered to be among the most promising candidates for evaluation as an adulticide treatment against onchocerciasis. Consequently, in 2014, Bayer and the Drugs for Neglected Diseases initiative (DNDi) started a collaboration to develop emodepside for the treatment of patients suffering from the disease. Macrofilaricidal activity has been demonstrated in various models, including Onchocerca ochengi in cattle, the parasite most closely related to O. volvulus. Emodepside has now successfully passed Phase I clinical trials, and a Phase II study is planned. This Bayer–DNDi partnership is an outstanding example of “One World Health,” in which experience gained in veterinary science and drug development is translated to human health and leads to improved tools to combat neglected tropical diseases (NTDs) and shorten development pathways and timelines in an otherwise neglected area. Onchocerca volvulus is the causative agent of human river blindness, and current elimination programs rely on the use of ivermectin to kill microfilariae. Since no adulticidal drug is available and adult worms have a life span of up to 15 years, elimination programs need to be sustained over several decades. Emodepside is an anthelmintic that is licensed as a dewormer for cats and dogs. Due to its ability to eliminate nematodes located in various extraintestinal host tissues, including migrating larvae and adult filarial worms, it is considered to be an excellent candidate for the treatment of onchocerciasis. Intense collaboration between academia and the pharmaceutical industry has led to a deep understanding of the novel mode of action of the drug and of its parasite target spectrum. Phase I clinical trials with emodepside have demonstrated its safety and adulticide activity against the closely related cattle parasite Onchocerca ochengi. Currently, Phase II clinical trials are planned to confirm that emodepside, developed initially to improve animal health, has also the potential to improve human health by tackling a very important neglected tropical disease (NTD).
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Affiliation(s)
- Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Roger K. Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada
| | - Simon Townson
- The Griffin Institute, Northwick Park and St. Mark’s Hospital, Harrow, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Steffen R. Hahnel
- Elanco Animal Health, Research & Exploratory Development, Monheim, Germany
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Geneva, Switzerland
| | | | - Daniel Kulke
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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Brattig NW, Cheke RA, Garms R. Onchocerciasis (river blindness) - more than a century of research and control. Acta Trop 2021; 218:105677. [PMID: 32857984 DOI: 10.1016/j.actatropica.2020.105677] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/06/2020] [Accepted: 08/21/2020] [Indexed: 12/14/2022]
Abstract
This review summarises more than a century of research on onchocerciasis, also known as river blindness, and its control. River blindness is an infection caused by the tissue filaria Onchocerca volvulus affecting the skin, subcutaneous tissue and eyes and leading to blindness in a minority of infected persons. The parasite is transmitted by its intermediate hosts Simulium spp. which breed in rivers. Featured are history and milestones in onchocerciasis research and control, state-of-the-art data on the parasite, its endobacteria Wolbachia, on the vectors, previous and current prevalence of the infection, its diagnostics, the interaction between the parasite and its host, immune responses and the pathology of onchocerciasis. Detailed information is documented on the time course of control programmes in the afflicted countries in Africa and the Americas, a long road from previous programmes to current successes in control of the transmission of this infectious disease. By development, adjustment and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas, in Uganda, in Sudan and elsewhere, followed by onchocerciasis eliminations. The current state and future perspectives for control, elimination and eradication within the next 20-30 years are described and discussed. This review contributes to a deeper comprehension of this disease by a tissue-dwelling filaria and it will be helpful in efforts to control and eliminate other filarial infections.
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15
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Moore SR, Menon SS, Cortes C, Ferreira VP. Hijacking Factor H for Complement Immune Evasion. Front Immunol 2021; 12:602277. [PMID: 33717083 PMCID: PMC7947212 DOI: 10.3389/fimmu.2021.602277] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
The complement system is an essential player in innate and adaptive immunity. It consists of three pathways (alternative, classical, and lectin) that initiate either spontaneously (alternative) or in response to danger (all pathways). Complement leads to numerous outcomes detrimental to invaders, including direct killing by formation of the pore-forming membrane attack complex, recruitment of immune cells to sites of invasion, facilitation of phagocytosis, and enhancement of cellular immune responses. Pathogens must overcome the complement system to survive in the host. A common strategy used by pathogens to evade complement is hijacking host complement regulators. Complement regulators prevent attack of host cells and include a collection of membrane-bound and fluid phase proteins. Factor H (FH), a fluid phase complement regulatory protein, controls the alternative pathway (AP) both in the fluid phase of the human body and on cell surfaces. In order to prevent complement activation and amplification on host cells and tissues, FH recognizes host cell-specific polyanionic markers in combination with complement C3 fragments. FH suppresses AP complement-mediated attack by accelerating decay of convertases and by helping to inactivate C3 fragments on host cells. Pathogens, most of which do not have polyanionic markers, are not recognized by FH. Numerous pathogens, including certain bacteria, viruses, protozoa, helminths, and fungi, can recruit FH to protect themselves against host-mediated complement attack, using either specific receptors and/or molecular mimicry to appear more like a host cell. This review will explore pathogen complement evasion mechanisms involving FH recruitment with an emphasis on: (a) characterizing the structural properties and expression patterns of pathogen FH binding proteins, as well as other strategies used by pathogens to capture FH; (b) classifying domains of FH important in pathogen interaction; and (c) discussing existing and potential treatment strategies that target FH interactions with pathogens. Overall, many pathogens use FH to avoid complement attack and appreciating the commonalities across these diverse microorganisms deepens the understanding of complement in microbiology.
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Affiliation(s)
- Sara R Moore
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Smrithi S Menon
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Claudio Cortes
- Department of Foundational Medical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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16
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Moreno Y, Geary TG, Tritten L. When Secretomes Meet Anthelmintics: Lessons for Therapeutic Interventions. Trends Parasitol 2021; 37:468-475. [PMID: 33563557 DOI: 10.1016/j.pt.2021.01.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/17/2022]
Abstract
Helminth secretomes comprise many potential immunomodulators. The molecular and functional diversity of these entities and their importance at the host-parasite interface have been increasingly recognized. It is now common to hypothesize that parasite-derived molecules (PDMs) are essential mediators used by parasites to establish and remain in their hosts. Suppression of PDM release has been reported for two anthelmintic drug classes, the benzimidazoles and macrocyclic lactones, the mechanisms of action of which remain incompletely resolved. We propose that bringing together recent insights from different streams of parasitology research, for example, immunoparasitology and pharmacology, will stimulate the development of new ways to alter the host-parasite interface in the search for novel anthelmintic strategies.
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Affiliation(s)
- Yovany Moreno
- Boehringer-Ingelheim Animal Health, Duluth, GA, USA.
| | - Timothy G Geary
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, QC, Canada; School of Biological Sciences, Queen's University - Belfast, Belfast, UK
| | - Lucienne Tritten
- Institute of Parasitology, University of Zürich, Zürich, Switzerland.
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17
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Drews SJ, Spencer BR, Wendel S, Bloch EM. Filariasis and transfusion-associated risk: a literature review. Vox Sang 2021; 116:741-754. [PMID: 33491765 DOI: 10.1111/vox.13073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/19/2020] [Accepted: 12/28/2020] [Indexed: 01/17/2023]
Abstract
BACKGROUND AND OBJECTIVES Filariae are parasitic worms that include the pathogens Loa loa, Onchocerca volvulus, Wuchereria bancrofti, Brugia spp. and Mansonella spp. which are endemic in parts of Africa, Asia, Asia-Pacific, South and Central America. Filariae have a wide clinical spectrum spanning asymptomatic infection to chronic debilitating disease including blindness and lymphedema. Despite successful eradication programmes, filarial infections remain an important -albeit neglected - source of morbidity. We sought to characterize the risk of transfusion transmission of microfilaria with a view to guide mitigation practices in both endemic and non-endemic countries. MATERIALS AND METHODS A scoping review of scientific publications as well as grey literature was carried out by a group of domain experts in microbiology, transfusion medicine and infectious diseases, representing the parasite subgroup of the International Society of Blood Transfusion. RESULTS Cases of transfusion-transmitted filariasis are rare and confined to case reports of variable quality. Transfusion-associated adverse events related to microfilariae are confined to isolated reports of transfusion reactions. Serious outcomes have not been reported. No known strategies have been implemented, specifically, to mitigate transfusion-transmitted filariasis yet routine blood donor screening for other transfusion-transmissible infections (e.g. hepatitis B, malaria) may indirectly defer donors with microfilaremia in endemic areas. CONCLUSION Rare examples of transfusion-transmitted filariasis, without serious clinical effect, suggest that filariasis poses low transfusion risk. Dedicated mitigation strategies against filarial transfusion transmission are not recommended. Given endemicity in low-resource regions, priority should be on the control of filariasis with public health measures.
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Affiliation(s)
- Steven J Drews
- Canadian Blood Services, Microbiology, Donor and Clinical Services, Edmonton, AB, Canada.,Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
| | | | - Silvano Wendel
- Banco de Sangue Medical Director, Blood Bank, Hospital Sirio Libanês, São Paulo, Brasil
| | - Evan M Bloch
- Department of Pathology, Transfusion Medicine Division, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Shey RA, Ghogomu SM, Shintouo CM, Nkemngo FN, Nebangwa DN, Esoh K, Yaah NE, Manka’aFri M, Nguve JE, Ngwese RA, Njume FN, Bertha FA, Ayong L, Njemini R, Vanhamme L, Souopgui J. Computational Design and Preliminary Serological Analysis of a Novel Multi-Epitope Vaccine Candidate against Onchocerciasis and Related Filarial Diseases. Pathogens 2021; 10:99. [PMID: 33494344 PMCID: PMC7912539 DOI: 10.3390/pathogens10020099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
: Onchocerciasis is a skin and eye disease that exerts a heavy socio-economic burden, particularly in sub-Saharan Africa, a region which harbours greater than 96% of either infected or at-risk populations. The elimination plan for the disease is currently challenged by many factors including amongst others; the potential emergence of resistance to the main chemotherapeutic agent, ivermectin (IVM). Novel tools, including preventative and therapeutic vaccines, could provide additional impetus to the disease elimination tool portfolio. Several observations in both humans and animals have provided evidence for the development of both natural and artificial acquired immunity. In this study, immuno-informatics tools were applied to design a filarial-conserved multi-epitope subunit vaccine candidate, (designated Ov-DKR-2) consisting of B-and T-lymphocyte epitopes of eight immunogenic antigens previously assessed in pre-clinical studies. The high-percentage conservation of the selected proteins and epitopes predicted in related nematode parasitic species hints that the generated chimera may be instrumental for cross-protection. Bioinformatics analyses were employed for the prediction, refinement, and validation of the 3D structure of the Ov-DKR-2 chimera. In-silico immune simulation projected significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2 responses. Preliminary immunological analyses revealed that the multi-epitope vaccine candidate reacted with antibodies in sera from both onchocerciasis-infected individuals, endemic normals as well as loiasis-infected persons but not with the control sera from European individuals. These results support the premise for further characterisation of the engineered protein as a vaccine candidate for onchocerciasis.
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Affiliation(s)
- Robert Adamu Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Stephen Mbigha Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Cabirou Mounchili Shintouo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium;
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
| | - Francis Nongley Nkemngo
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea 99999, Cameroon;
- Centre for Research in Infectious Diseases (CRID), Department of Parasitology and Medical Entomology, Yaounde BP 13591, Cameroon
| | - Derrick Neba Nebangwa
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Kevin Esoh
- Division of Human Genetics, Health Sciences Campus, Department of Pathology, University of Cape Town, Anzio Rd, Observatory, Cape Town 7925, South Africa;
| | - Ntang Emmaculate Yaah
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Muyanui Manka’aFri
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Joel Ebai Nguve
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Roland Akwelle Ngwese
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Ferdinand Ngale Njume
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Fru Asa Bertha
- Department of Public Health and Hygiene, Faculty of Health Science, University of Buea, Buea 99999, Cameroon;
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé Rue 2005, Cameroon;
| | - Rose Njemini
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium;
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
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Entomological Assessment of Onchocerca Species Transmission by Black Flies in Selected Communities in the West Region of Cameroon. Pathogens 2020; 9:pathogens9090722. [PMID: 32887231 PMCID: PMC7559537 DOI: 10.3390/pathogens9090722] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022] Open
Abstract
The enormity of the public health burden of onchocerciasis motivated the creation of various large-scale control programs that have depended principally on mass treatment of endemic communities with ivermectin for the elimination of the disease. Parasitological evaluation of Onchocerca species in the West Region of Cameroon indicates significant progress in the interruption of parasite transmission in some communities under ivermectin treatment. However, to verify the complete elimination of onchocerciasis, entomological assessment through O-150 PCR poolscreen of black flies is mandatory. Thus, in the present study, we assessed transmission of Onchocerca species using an O-150 PCR technique to screen pools of black flies—in seven onchocerciasis endemic communities (Makouopsap, Bankambe, Lemgo, Tsesse, Ndionzou, Kouffen, and Bayon) in Cameroon. Two thousand black flies were assessed—in each community—for the presence of Onchocerca species DNA. Our results show that the frequency of infective flies was 0.6% in Makouopsap and 0.0% in the other communities. On the other hand, the frequency of infected flies was 0.8% in Makouopsap, 0.2% in Bankambe, 0.1% in Bayon, and 0.0% in Lemgo, Tsesse, Ndionzou, and Kouffen. These results provide entomologic evidence for continuous transmission of Onchocerca species in Makouopsap, risk of active transmission in Bankambe, and Bayon, and a suppressed transmission in the four other studied communities.
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20
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Meibalan E, Barry A, Gibbins MP, Awandu S, Meerstein-Kessel L, Achcar F, Bopp S, Moxon C, Diarra A, Debe S, Ouédraogo N, Barry-Some I, Badoum ES, Fagnima T, Lanke K, Gonçalves BP, Bradley J, Wirth D, Drakeley C, Guelbeogo WM, Tiono AB, Marti M, Bousema T. Plasmodium falciparum Gametocyte Density and Infectivity in Peripheral Blood and Skin Tissue of Naturally Infected Parasite Carriers in Burkina Faso. J Infect Dis 2019; 223:1822-1830. [PMID: 31875909 PMCID: PMC8161640 DOI: 10.1093/infdis/jiz680] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/23/2019] [Indexed: 12/22/2022] Open
Abstract
Background Plasmodium falciparum transmission depends on mature gametocytes that can be ingested by mosquitoes taking a blood meal on human skin. Although gametocyte skin sequestration has long been hypothesized as important contributor to efficient malaria transmission, this has never been formally tested. Methods In naturally infected gametocyte carriers from Burkina Faso, we assessed infectivity to mosquitoes by direct skin feeding and membrane feeding. We directly quantified male and female gametocytes and asexual parasites in finger-prick and venous blood samples, skin biopsy samples, and in of mosquitoes that fed on venous blood or directly on skin. Gametocytes were visualized in skin tissue with confocal microscopy. Results Although more mosquitoes became infected when feeding directly on skin then when feeding on venous blood (odds ratio, 2.01; 95% confidence interval, 1.21–3.33; P = .007), concentrations of gametocytes were not higher in the subdermal skin vasculature than in other blood compartments; only sparse gametocytes were observed in skin tissue. Discussion Our data strongly suggest that there is no significant skin sequestration of P. falciparum gametocytes. Gametocyte densities in peripheral blood are thus informative for predicting onward transmission potential to mosquitoes and can be used to target and monitor malaria elimination initiatives.
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Affiliation(s)
- Elamaran Meibalan
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Aissata Barry
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.,Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | - Matthew P Gibbins
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Shehu Awandu
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | | | - Fiona Achcar
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Selina Bopp
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Christopher Moxon
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Amidou Diarra
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Siaka Debe
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Nicolas Ouédraogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Ines Barry-Some
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Emilie S Badoum
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Traoré Fagnima
- Centre Hospitalier Universitaire Régional de Ouahigoua, Université de Ouahigouya, Burkina Faso
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands
| | - Bronner P Gonçalves
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Dyann Wirth
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Chris Drakeley
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, the Netherlands.,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
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George PJ, Hess JA, Jain S, Patton JB, Zhan T, Tricoche N, Zhan B, Bottazzi ME, Hotez PJ, Abraham D, Lustigman S. Antibody responses against the vaccine antigens Ov-103 and Ov-RAL-2 are associated with protective immunity to Onchocerca volvulus infection in both mice and humans. PLoS Negl Trop Dis 2019; 13:e0007730. [PMID: 31525197 PMCID: PMC6762197 DOI: 10.1371/journal.pntd.0007730] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 09/26/2019] [Accepted: 08/25/2019] [Indexed: 11/23/2022] Open
Abstract
Background The current strategy for the elimination of onchocerciasis is based on annual or bi-annual mass drug administration with ivermectin. However, due to several limiting factors there is a growing concern that elimination of onchocerciasis cannot be achieved solely through the current strategy. Additional tools are critically needed including a prophylactic vaccine. Presently Ov-103 and Ov-RAL-2 are the most promising vaccine candidates against an Onchocerca volvulus infection. Methodology/Principal findings Protection induced by immunization of mice with the alum-adjuvanted Ov-103 or Ov-RAL-2 vaccines appeared to be antibody dependent since AID-/- mice that could not mount antigen-specific IgG antibody responses were not protected from an Onchocerca volvulus challenge. To determine a possible association between antigen-specific antibody responses and anti-larvae protective immunity in humans, we analyzed the presence of anti-Ov-103 and anti-Ov-RAL-2 cytophilic antibody responses (IgG1 and IgG3) in individuals classified as putatively immune, and in infected individuals who developed concomitant immunity with age. It was determined that 86% of putatively immune individuals and 95% individuals with concomitant immunity had elevated IgG1 and IgG3 responses to Ov-103 and Ov-RAL-2. Based on the elevated chemokine levels associated with protection in the Ov-103 or Ov-RAL-2 immunized mice, the profile of these chemokines was also analyzed in putatively immune and infected individuals; both groups contained significantly higher levels of KC, IP-10, MCP-1 and MIP-1β in comparison to normal human sera. Moreover, human monospecific anti-Ov-103 antibodies but not anti-Ov-RAL-2 significantly inhibited the molting of third-stage larvae (L3) in vitro by 46% in the presence of naïve human neutrophils, while both anti-Ov-103 and anti-Ov-RAL-2 antibodies significantly inhibited the molting by 70–80% when cultured in the presence of naive human monocytes. Interestingly, inhibition of molting by Ov-103 antibodies and monocytes was only in part dependent on contact with the cells, while inhibition of molting with Ov-RAL-2 antibodies was completely dependent on contact with the monocytes. In comparison, significant levels of parasite killing in Ov-103 and Ov-RAL-2 vaccinated mice only occurred when cells enter the parasite microenvironment. Taken together, antibodies to Ov-103 and Ov-RAL-2 and cells are required for protection in mice as well as for the development of immunity in humans. Conclusions/Significance Alum-adjuvanted Ov-103 and Ov-RAL-2 vaccines have the potential of reducing infection and thus morbidity associated with onchocerciasis in humans. The development of cytophilic antibodies, that function in antibody-dependent cellular cytotoxicity, is essential for a successful prophylactic vaccine against this infection. Onchocerca volvulus is the causative agent of river blindness that infects approximately 17 million people, mostly in Africa. The current strategy for elimination of O. volvulus focuses on controlling transmission through ivermectin-based mass drug administration programs. Due to potential ivermectin resistance, the lack of macrofilaricidal activity by ivermectin, and the prolonged time (>20 years) needed for successful interruption of transmission in endemic areas, additional tools are critically needed including a vaccine against onchocerciasis. Ov-103 and Ov-RAL-2 are presently the most promising vaccine candidates for a prophylactic vaccine. The mechanism of protective immunity induced in mice by the alum-adjuvanted Ov-103 or Ov-RAL-2 vaccines appear to be multifactorial with essential roles for antibodies, chemokines and the specific effector cells they recruit. In this study, we show for the first time that, anti-Ov-103 and anti-Ov-RAL-2 antibodies, chemokines and innate cells also appear to be associated with protective immunity against O. volvulus infection in humans, similar to the vaccine studies observed in the O. volvulus mouse model.
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Affiliation(s)
- Parakkal Jovvian George
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, New York, United States of America
- * E-mail:
| | - Jessica A. Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Sonia Jain
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - John B. Patton
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Tingting Zhan
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Nancy Tricoche
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - Bin Zhan
- Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatric Tropical Medicine and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Maria Elena Bottazzi
- Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatric Tropical Medicine and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatric Tropical Medicine and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, New York, United States of America
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Njume FN, Ghogomu SM, Shey RA, Gainkam LOT, Poelvoorde P, Humblet P, Kamgno J, Robert A, Mutesa L, Lelubre C, Edelweiss E, Poterszman A, Anheuser S, Vanhamme L, Souopgui J. Identification and characterization of the Onchocerca volvulus Excretory Secretory Product Ov28CRP, a putative GM2 activator protein. PLoS Negl Trop Dis 2019; 13:e0007591. [PMID: 31329585 PMCID: PMC6675134 DOI: 10.1371/journal.pntd.0007591] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 08/01/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022] Open
Abstract
Onchocerca volvulus is the nematode pathogen responsible for human onchocerciasis also known as "River blindness", a neglected tropical disease that affects up to 18 million people worldwide. Helminths Excretory Secretory Products (ESPs) constitute a rich repertoire of molecules that can be exploited for host-parasite relationship, diagnosis and vaccine studies. Here, we report, using a range of molecular techniques including PCR, western blot, recombinant DNA technology, ELISA, high performance thin-layer chromatography and mass spectrometry that the 28 KDa cysteine-rich protein (Ov28CRP) is a reliable component of the O. volvulus ESPs to address the biology of this parasite. We showed that (1) Ov28CRP is a putative ganglioside GM2 Activator Protein (GM2AP) conserved in nematode; (2) OvGM2AP gene is transcriptionally activated in all investigated stages of the parasitic life cycle, including larval and adult stages; (3) The full-length OvGM2AP was detected in in-vitro O. volvulus ESPs of adult and larval stages; (4) the mass expressed and purified recombinant OvGM2AP purified from insect cell culture medium was found to be glycosylated at asparagine 173 and lacked N-terminal signal peptide sequence; (5) the recombinant OvGM2AP discriminated serum samples of infected and uninfected individuals; (6) OvGM2AP competitively inhibits MUG degradation by recombinant β-hexosaminidase A but not MUGS, and could not hydrolyze the GM2 to GM3; (7) humoral immune responses to the recombinant OvGM2AP revealed a negative correlation with ivermectin treatment. Altogether, our findings suggest for the first time that OvGM2AP is an antigenic molecule whose biochemical and immunological features are important to gain more insight into our understanding of host-parasite relationship, as well as its function in parasite development at large.
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Affiliation(s)
- Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, Yaounde, Cameroon
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB)—Unité 222, CHU Charleroi (Hôpital André Vésale), Rue de Gozée, Montigny-Le-Tilleul, Belgium
| | - Evelina Edelweiss
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Arnaud Poterszman
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Susi Anheuser
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
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Hotez PJ. Immunizations and vaccines: a decade of successes and reversals, and a call for ‘vaccine diplomacy’. Int Health 2019; 11:331-333. [DOI: 10.1093/inthealth/ihz024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 04/14/2019] [Indexed: 12/22/2022] Open
Abstract
Abstract
Over the last decade we have seen extraordinary public health gains due to expansions in global vaccination programs led by United Nations (UN) agencies, including Gavi, the Vaccine Alliance, UNICEF and the WHO. These initiatives have reduced childhood deaths from measles, tetanus and other vaccine-preventable diseases by almost one half. There is additional excitement over the potential development and introduction of new vaccines to prevent highly lethal respiratory virus infections, as well as tuberculosis, malaria, HIV/AIDS and several neglected tropical diseases. However, these successes are under threat due to political instability, conflict and an accelerating antivaccine movement. New initiatives in vaccine diplomacy will be required to combat these challenges.
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Affiliation(s)
- Peter J Hotez
- Departments of Pediatrics and Molecular Virology & Microbiology, National School of Tropical Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Biology, Baylor University, 1301 S University Parks Dr, Waco, TX 76706, USA
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24
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Shey RA, Ghogomu SM, Esoh KK, Nebangwa ND, Shintouo CM, Nongley NF, Asa BF, Ngale FN, Vanhamme L, Souopgui J. In-silico design of a multi-epitope vaccine candidate against onchocerciasis and related filarial diseases. Sci Rep 2019; 9:4409. [PMID: 30867498 PMCID: PMC6416346 DOI: 10.1038/s41598-019-40833-x] [Citation(s) in RCA: 199] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 02/25/2019] [Indexed: 01/02/2023] Open
Abstract
Onchocerciasis is a parasitic disease with high socio-economic burden particularly in sub-Saharan Africa. The elimination plan for this disease has faced numerous challenges. A multi-epitope prophylactic/therapeutic vaccine targeting the infective L3 and microfilaria stages of the parasite's life cycle would be invaluable to achieve the current elimination goal. There are several observations that make the possibility of developing a vaccine against this disease likely. For example, despite being exposed to high transmission rates of infection, 1 to 5% of people have no clinical manifestations of the disease and are thus considered as putatively immune individuals. An immuno-informatics approach was applied to design a filarial multi-epitope subunit vaccine peptide consisting of linear B-cell and T-cell epitopes of proteins reported to be potential novel vaccine candidates. Conservation of the selected proteins and predicted epitopes in other parasitic nematode species suggests that the generated chimera could be helpful for cross-protection. The 3D structure was predicted, refined, and validated using bioinformatics tools. Protein-protein docking of the chimeric vaccine peptide with the TLR4 protein predicted efficient binding. Immune simulation predicted significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2. Overall, the constructed recombinant putative peptide demonstrated antigenicity superior to current vaccine candidates.
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Affiliation(s)
- Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Kevin Kum Esoh
- Department of Biochemistry, Faculty of Science, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Neba Derrick Nebangwa
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Cabirou Mounchili Shintouo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Nkemngo Francis Nongley
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Bertha Fru Asa
- Department of Public Health and Hygiene, Faculty of Health Science, University of Buea, Buea, Cameroon
| | - Ferdinand Njume Ngale
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium.
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25
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Lagatie O, Verheyen A, Van Dorst B, Batsa Debrah L, Debrah A, Stuyver LJ. Linear epitopes in Onchocerca volvulus vaccine candidate proteins and excretory-secretory proteins. Parasite Immunol 2018; 40:e12587. [PMID: 30188578 PMCID: PMC6220944 DOI: 10.1111/pim.12587] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/21/2018] [Accepted: 09/04/2018] [Indexed: 11/27/2022]
Abstract
In our previous study, a proteome‐wide screen was conducted to identify linear epitopes in this parasite's proteome, resulting in the discovery of three immunodominant motifs. Here, we investigated whether such antigenic peptides were found in proteins that were already known as vaccine candidates and excretome/secretome proteins for Onchocerca volvulus This approach led to the identification of 71 immunoreactive stretches in 46 proteins. A deep‐dive into the immunoreactivity profiles of eight vaccine candidates that were chosen as most promising candidates for further development (Ov‐CPI‐2, Ov‐ALT‐1, Ov‐RAL‐2, Ov‐ASP‐1, Ov‐103, Ov‐RBP‐1, Ov‐CHI‐1, and Ov‐B20), resulted in the identification of a poly‐glutamine stretch in Ov‐RAL‐2 that has properties for use as a serodiagnostic marker for O. volvulus infection. A peptide ELISA was developed, and the performance of this assay was evaluated. Based on this assessment, it was found that this assay has a sensitivity of 75.0% [95% CI: 64.9%‐83.5%] and a specificity of 98.5% [95% CI: 94.6%‐99.8%]. Furthermore, 8.7% reactivity in Asian parasite‐infected individuals (8 out of 92) was observed. Besides this identification of a linear epitope marker, the information on the presence of linear epitopes in vaccine candidate proteins might be useful in the study of vaccines for river blindness.
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Affiliation(s)
- Ole Lagatie
- Janssen Diagnostics, Janssen R&D, Beerse, Belgium
| | - Ann Verheyen
- Janssen Diagnostics, Janssen R&D, Beerse, Belgium
| | | | - Linda Batsa Debrah
- Department of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Alex Debrah
- Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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26
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Shey RA, Ghogomu SM, Njume FN, Gainkam LOT, Poelvoorde P, Mutesa L, Robert A, Humblet P, Munyampundu JP, Kamgno J, Lelubre C, Vanhamme L, Souopgui J. Prediction and validation of the structural features of Ov58GPCR, an immunogenic determinant of Onchocerca volvulus. PLoS One 2018; 13:e0202915. [PMID: 30256790 PMCID: PMC6157839 DOI: 10.1371/journal.pone.0202915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/11/2018] [Indexed: 11/18/2022] Open
Abstract
Onchocerciasis is a severely debilitating yet neglected tropical disease (NTD) that creates social stigma, generates and perpetuates poverty, and leads ultimately in some cases to irreversible unilateral or bilateral blindness if untreated. Consequently, the disease is a major impediment to socioeconomic development. Many control programs have been launched for the disease with moderate successes achieved. This mitigated hit is partially due to the lingering need for reliable, non-invasive and easily applicable tools for mapping endemic regions and post-elimination surveillance. In this work, bioinformatics analyses combined with immunological assays were applied in a bid to develop potential tools for diagnosis and assessing the success of drug treatment programs. We report that (i) the O. volvulus antigen, Ov58GPCR is a G-protein coupled receptor (GPCR) conserved in related nematodes, (ii) synthetic peptides predicted to be in the extracellular domain (ECD) of Ov58GPCR are indeed immunogenic epitopes in actively-infected individuals, (iii) synthetic peptide cocktails discriminate between actively-infected individuals, treated individuals and healthy African controls, (iv) polyclonal antibodies against one of the peptides or against the bacterially-expressed ECD reacted specifically with the native antigen of O. volvulus total and surface extracts, (v) Ov58GPCR is transcribed in both larvae and adult parasite stages, (vi) IgG and IgE responses to the recombinant ECD decline with ivermectin treatment. All these findings suggest that the extracellular domain and synthetic peptides of Ov58GPCR, as well as the specific immune response generated could be harnessed in the context of disease diagnosis and surveillance.
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Affiliation(s)
- Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jean-Pierre Munyampundu
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, (CRFilMT), Yaoundé, Cameroon
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB) - Unité 222, CHU Charleroi (Hôpital André Vésale), Montigny-Le-Tilleul, Belgium
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
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27
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Murdoch ME. Onchodermatitis: Where Are We Now? Trop Med Infect Dis 2018; 3:E94. [PMID: 30274490 PMCID: PMC6160948 DOI: 10.3390/tropicalmed3030094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 02/07/2023] Open
Abstract
Onchocerciasis causes debilitating pruritus and rashes as well as visual impairment and blindness. Prior to control measures, eye disease was particularly prominent in savanna areas of sub-Saharan Africa whilst skin disease was more common across rainforest regions of tropical Africa. Mass drug distribution with ivermectin is changing the global scene of onchocerciasis. There has been successful progressive elimination in Central and Southern American countries and the World Health Organization has set a target for elimination in Africa of 2025. This literature review was conducted to examine progress regarding onchocercal skin disease. PubMed searches were performed using keywords 'onchocerciasis', 'onchodermatitis' and 'onchocercal skin disease' over the past eight years. Articles in English, or with an English abstract, were assessed for relevance, including any pertinent references within the articles. Recent progress in awareness of, understanding and treatment of onchocercal skin disease is reviewed with particular emphasis on publications within the past five years. The global burden of onchodermatitis is progressively reducing and is no longer seen in children in many formerly endemic foci.
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Affiliation(s)
- Michele E Murdoch
- Department of Dermatology, West Herts Hospitals NHS Trust, Vicarage Road, Watford, Hertfordshire WD18 0HB, UK.
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28
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Blum AJ, Hotez PJ. Global "worming": Climate change and its projected general impact on human helminth infections. PLoS Negl Trop Dis 2018; 12:e0006370. [PMID: 30024871 PMCID: PMC6053132 DOI: 10.1371/journal.pntd.0006370] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Alexander J. Blum
- Department of Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Peter J. Hotez
- Texas Children's Hospital Center for Vaccine Development, Houston, Texas, United States of America
- National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States America
- James A. Baker III Institute of Public Policy, Rice University, Houston, Texas, United States America
- Scowcroft Institute of International Affairs, Bush School of Government and Public Policy, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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29
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Boursou D, Ndjonka D, Eisenbarth A, Manchang K, Paguem A, Ngwasiri NN, Vildina JD, Abanda B, Krumkamp R, van Hoorn S, Renz A, Achukwi MD, Liebau E, Brattig NW. Onchocerca - infected cattle produce strong antibody responses to excretory-secretory proteins released from adult male Onchocerca ochengi worms. BMC Infect Dis 2018; 18:200. [PMID: 29716541 PMCID: PMC5930424 DOI: 10.1186/s12879-018-3109-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 04/24/2018] [Indexed: 11/10/2022] Open
Abstract
Background The front line molecules from filarial worms and other nematodes or helminthes are their Excretory-Secretory (ES) products. Their interaction with the host cells, proteins and immune system accounts for the skin and eye pathology or hyposensitivity observed in human onchocerciasis. ES products and adult worms’ crude extracts from Onchocerca ochengi, a filarial nematode that infects the African zebu cattle, were utilized in the present study as a model for studying Onchocerca volvulus that causes river blindness in man. Methods The ES products were generated from adult male and female worms in vitro and analyzed with poly acrylamide gel electrophoresis (PAGE) and enzyme-linked immunosorbent assay (ELISA) using sera from Onchocerca-infected cattle and humans. The cattle sera were collected from a herd that had been exposed for six years to natural transmission of Onchocerca spp. The expressed reactivity was evaluated and differences analyzed statistically using Kruskal-Wallis rank and Chi-square tests. Results The gel electrophoretic analyses of 156 ES products from O. ochengi female and male worms and of two somatic extracts from three females and 25 males revealed differences in the protein pattern showing pronounced bands at 15, 30–50 and 75 kDa for male ES proteins and 15, 25 and 40–75 kDa for somatic extracts, respectively and less than 100 kDa for female worms. Proteins in the ES products and somatic extracts from female and male Onchocerca ochengi worms were recognized by IgG in sera from both Onchocerca-exposed cattle and humans. Bovine serum antibodies reacted more strongly with proteins in the somatic extracts than with those in the ES products. Interestingly, the reaction was higher with male ES products than with ES products from female worms, suggesting that the males which migrate from one nodule to another are more exposed to the host immune system than the females which remain encapsulated in intradermal nodules. Conclusions This study demonstrates that O. ochengi ES products and, in particular, extracts from male filariae may represent a good source of immunogenic proteins and potential vaccine candidates.
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Affiliation(s)
- Djafsia Boursou
- University of Ngaoundéré, Faculty of Science, Ngaoundéré, Cameroon
| | | | - Albert Eisenbarth
- Programme Onchocercoses, Field research station of the University of Tübingen, Ngaoundéré, Cameroon.,Eberhard Karls University, Institute of Evolution and Ecology, Comparative Zoology, Tübingen, Germany
| | - Kingsley Manchang
- Veterinary Research Laboratory, IRAD Wakwa Regional Centre, Ngaoundéré, Cameroon
| | - Archille Paguem
- University of Ngaoundéré, Faculty of Science, Ngaoundéré, Cameroon
| | | | | | - Babette Abanda
- University of Ngaoundéré, Faculty of Science, Ngaoundéré, Cameroon
| | - Ralf Krumkamp
- Bernhard Nocht Institute of Tropical Medicine, Disease Epidemiology Department, Hamburg, Germany
| | - Silke van Hoorn
- Bernhard Nocht Institute of Tropical Medicine, Disease Epidemiology Department, Hamburg, Germany
| | - Alfons Renz
- Eberhard Karls University, Institute of Evolution and Ecology, Comparative Zoology, Tübingen, Germany
| | | | | | - Norbert W Brattig
- Bernhard Nocht Institute of Tropical Medicine, Disease Epidemiology Department, Hamburg, Germany
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Hotez PJ. Human Parasitology and Parasitic Diseases: Heading Towards 2050. ADVANCES IN PARASITOLOGY 2018; 100:29-38. [PMID: 29753341 DOI: 10.1016/bs.apar.2018.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
By 2050 our civilized planet may be comprised predominantly of networked megacities embedded in warm subtropical and tropical climates, and under stress from climate change and catastrophic weather events. Urban slum areas in these cities, including those found in wealthier middle- and high-income nations (blue marble health), will be especially vulnerable to disease. Moreover, regional conflicts fought over shifting and limited resources, including water, will collapse health systems infrastructures to further promote disease emergence and reemergence. Thus while by 2050 we might congratulate ourselves for successfully eliminating some key parasitic and neglected tropical diseases such as dracunculiasis, lymphatic filariasis, onchocerciasis, and human African trypanosomiasis, there could be a commensurate rise in other parasitic diseases based on the scenarios highlighted above. Of particular concern are urban and newly urbanized helminth infections, including schistosomiasis and some soil-transmitted helminth infections, as well zoonotic helminthiases, such as toxocariasis, food-borne trematodiases, and cysticercosis. Protozoan infections persisting in urban environments, including leishmaniasis, Chagas disease, malaria, and intestinal protozoan infections, will also remain, as will zoonotic diseases such as toxoplasmosis. Our best hope to counteract the parasitic diseases emerging in our steaming 21st century megacities is to develop new and innovative technologies through gene editing, systems biology, and immunology, and the new single-celled OMICs. However, success on this front will require our ability to contain the globalization of antiscience beliefs and sentiments.
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