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Dinga JN, Perimbie SN, Gamua SD, Chuma FNG, Njimoh DL, Djikeng A, Pelle R, Titanji VPK. Analysis of the Role of TpUB05 Antigen from Theileria parva in Immune Responses to Malaria in Humans Compared to Its Homologue in Plasmodium falciparum the UB05 Antigen. Pathogens 2020; 9:pathogens9040271. [PMID: 32276308 PMCID: PMC7238281 DOI: 10.3390/pathogens9040271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 11/19/2022] Open
Abstract
Despite the amount of resources deployed and the technological advancements in molecular biology, vaccinology, immunology, genetics, and biotechnology, there are still no effective vaccines against malaria. Immunity to malaria is usually seen to be species- and/or strain-specific. However, there is a growing body of evidence suggesting the possibility of the existence of cross-strain, cross-species, and cross-genus immune responses in apicomplexans. The principle of gene conservation indicates that homologues play a similar role in closely related organisms. The homologue of UB05 in Theileria parva is TpUB05 (XP_763711.1), which has been tested and shown to be associated with protective immunity in East Coast fever. In a bid to identify potent markers of protective immunity to aid malaria vaccine development, TpUB05 was tested in malaria caused by Plasmodium falciparum. It was observed that TpUB05 was better at detecting antigen-specific antibodies in plasma compared to UB05 when tested by ELISA. The total IgG raised against TpUB05 was able to block parasitic growth in vitro more effectively than that raised against UB05. However, there was no significant difference between the two study antigens in recalling peripheral blood mononuclear cell (PBMC) memory through IFN-γ production. This study suggests, for the first time, that TpUB05 from T. parva cross-reacts with UB05 from P. falciparum and is a marker of protective immunity in malaria. Hence, TpUB05 should be considered for possible development as a potential subunit vaccine candidate against malaria.
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Affiliation(s)
- Jerome Nyhalah Dinga
- Biotechnology Unit, Faculty of Science, University of Buea, P O. Box 63 Buea, Cameroon
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P. O. Box 63 Buea, Cameroon
- Correspondence: ; Tel.: +237-233322134
| | - Stephanie Numenyi Perimbie
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P. O. Box 63 Buea, Cameroon
| | - Stanley Dobgima Gamua
- Biotechnology Unit, Faculty of Science, University of Buea, P O. Box 63 Buea, Cameroon
| | - Francis N. G. Chuma
- Biosciences Eastern and Central Africa—International Livestock Research Institute (BecA-ILRI) Hub, P. O. Box 30709 Nairobi, Kenya
| | - Dieudonné Lemuh Njimoh
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P. O. Box 63 Buea, Cameroon
| | - Appolinaire Djikeng
- Biosciences Eastern and Central Africa—International Livestock Research Institute (BecA-ILRI) Hub, P. O. Box 30709 Nairobi, Kenya
- Centre for Tropical Livestock Genetics and Health, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian, Easter Bush Campus, EH25 9RG Edinburgh, UK
| | - Roger Pelle
- Biosciences Eastern and Central Africa—International Livestock Research Institute (BecA-ILRI) Hub, P. O. Box 30709 Nairobi, Kenya
| | - Vincent P. K. Titanji
- Biotechnology Unit, Faculty of Science, University of Buea, P O. Box 63 Buea, Cameroon
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P. O. Box 63 Buea, Cameroon
- Faculty of Science, Engineering and Technology, Cameroon Christian University Institute, P.O. Box 5 Bali, Cameroon
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Dinga JN, Gamua SD, Ghogomu SM, Titanji VPK. Preclinical efficacy and immunogenicity assessment to show that a chimeric Plasmodium falciparum UB05-09 antigen could be a malaria vaccine candidate. Parasite Immunol 2018; 40. [PMID: 29284177 PMCID: PMC5873454 DOI: 10.1111/pim.12514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 12/19/2017] [Indexed: 11/30/2022]
Abstract
Although it is generally agreed that an effective vaccine would greatly accelerate the control of malaria, the lone registered malaria vaccine Mosquirix™ has an efficacy of 30%‐60% that wanes rapidly, indicating a need for improved second‐generation malaria vaccines. Previous studies suggested that immune responses to a chimeric Plasmodium falciparum antigen UB05‐09 are associated with immune protection against malaria. Herein, the preclinical efficacy and immunogenicity of UB05‐09 are tested. Growth inhibition assay was employed to measure the effect of anti‐UB05‐09 antibodies on P. falciparum growth in vitro. BALB/c mice were immunized with UB05‐09 and challenged with the lethal Plasmodium yoelii 17XL infection. ELISA was used to measure antigen‐specific antibody production. ELISPOT assays were employed to measure interferon‐gamma production ex vivo after stimulation with chimeric UB05‐09 and its constituent antigens. Purified immunoglobulins raised in rabbits against UB05‐09 significantly inhibited P. falciparum growth in vitro compared to that of its respective constituent antigens. A combination of antibodies to UB05‐09 and the apical membrane antigen (AMA1) completely inhibited P. falciparum growth in culture. Immunization of BALB/c mice with recombinant UB05‐09 blocked parasitaemia and protected them against lethal P. yoelii 17XL challenge infection. These data suggest that UB05‐09 is a malaria vaccine candidate that could be developed further and used in conjunction with AMA1 to create a potent malaria vaccine.
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Affiliation(s)
- J N Dinga
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - S D Gamua
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - S M Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - V P K Titanji
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon.,Faculty of Science, Engineering and Technology, Cameroon Christian University Institute, Bali, Cameroon
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Dinga JN, Gamua SD, Titanji VPK. Enhanced acquired antibodies to a chimeric Plasmodium falciparum antigen; UB05-09 is associated with protective immunity against malaria. Parasite Immunol 2017; 39. [PMID: 28543553 PMCID: PMC5697641 DOI: 10.1111/pim.12445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 05/16/2017] [Indexed: 12/22/2022]
Abstract
It has been shown that covalently linking two antigens could enhance the immunogenicity of the chimeric construct. To prioritize such a chimera for malaria vaccine development, it is necessary to demonstrate that naturally acquired antibodies against the chimera are associated with protection from malaria. Here, we probe the ability of a chimeric construct of UB05 and UB09 antigens (UB05-09) to better differentiate between acquired immune protection and susceptibility to malaria. In a cross-sectional study, recombinant UB05-09 chimera and the constituent antigens were used to probe for specific antibodies in the plasma from children and adults resident in a malaria-endemic zone, using the enzyme-linked immunosorbent assay (ELISA). Anti-UB05-09 antibody levels doubled that of its constituent antigens, UB09 and UB05, and this correlated with protection against malaria. The presence of enhanced UB05-09-specific antibody correlated with the absence of fever and parasitaemia, which are the main symptoms of malaria infection. The chimera is more effective in detecting and distinguishing acquired protective immunity against malaria than any of its constituents taken alone. Online B-cell epitope prediction tools confirmed the presence of B-cell epitopes in the study antigens. UB05-09 chimera is a marker of protective immunity against malaria that needs to be studied further.
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Affiliation(s)
- J N Dinga
- Faculty of Science, Biotechnology Unit, University of Buea, Buea, South West Region, Cameroon
| | - S D Gamua
- Faculty of Science, Biotechnology Unit, University of Buea, Buea, South West Region, Cameroon
| | - V P K Titanji
- Faculty of Science, Biotechnology Unit, University of Buea, Buea, South West Region, Cameroon.,Cameroon Christian University Institute, Bali, Cameroon, Cameroon
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