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Ndawula C, Emudong P, Muwereza N, Currà C. Insights into Theileria transmission-blocking vaccines for East Coast fever control: A disease with an "outdated vaccination approach". Ticks Tick Borne Dis 2024; 15:102386. [PMID: 39128161 DOI: 10.1016/j.ttbdis.2024.102386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/25/2024] [Accepted: 07/29/2024] [Indexed: 08/13/2024]
Abstract
Instead of using the Infection and Treatment Method (ITM)-based vaccine, is it possible to control East Coast Fever (ECF) through blocking Theileria parva transmission in ticks and cattle? This review pursues this question. It's over 100 years since Arnold Theiler (1912) first illustrated the natural ITM as a vaccination approach against ECF-cattle disease. The approach entails infecting cattle with live Theileria sporozoites and co-treatment with long-acting tetracycline. Building on the ITM principle, the "Muguga"-cocktail ECF vaccine was developed in the 1970s and it remains the only commercially available-one. Although the vaccine induces cattle-protection, the vaccination approach still raises several drawbacks. Of those, the most outstanding is the vaccine-safety. This is implied because after ITM vaccination, cattle revert to T. parva pathogen reservoirs, therefore, during blood meal-acquisition, the ticks co-ingest T. parva pathogens. Ultimately, the pathogens are further transmitted transstadial; from larvae to nymph and nymph-adults and later re-transmitted to cattle during blood-meal acquisition. Consequently, the vaccine-constituting T. parva strains are introduced and (re) spread in non-endemic/ endemic areas. Precisely, rather than eradicating the disease, the ITM vaccination-approach promotes ECF endemicity. With advent of novel vaccination approaches toward vector and vector-borne disease control, ECF-control based on ITM of vaccination is considered outdated. The review highlights the need for embracing a holistic integrative vaccination approach entailing blocking Theileria pathogen-development and transmission both in the ticks and cattle, and/or the tick-population.
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Affiliation(s)
- C Ndawula
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda.
| | - P Emudong
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda
| | - N Muwereza
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda
| | - C Currà
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, ISTITUTO SUPERIORE di SANITÀ, Viale Regina Elena 299, 00161 Rome, Italy
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van der Heijden EMDL, Lefevre L, Gossner A, Tzelos T, Connelley TK, Hassan MA. Comparative transcriptional analysis identifies genes associated with the attenuation of Theileria parva infected cells after long-term in vitro culture. Sci Rep 2024; 14:8976. [PMID: 38637584 PMCID: PMC11026401 DOI: 10.1038/s41598-024-59197-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/08/2024] [Indexed: 04/20/2024] Open
Abstract
Autologous administration of attenuated Theileria parva-infected cells induces immunity to T. parva in cattle. The mechanism of attenuation, however, is largely unknown. Here, we used RNA sequencing of pathogenic and attenuated T. parva-infected T-cells to elucidate the transcriptional changes underpinning attenuation. We observed differential expression of several host genes, including TRAIL, PD-1, TGF-β and granzymes that are known to regulate inflammation and proliferation of infected cells. Importantly, many genes linked with the attenuation of the related T. annulata-infected cells were not dysregulated in this study. Furthermore, known T. parva antigens were not dysregulated in attenuated relative to pathogenic cells, indicating that attenuation is not due to enhanced immunogenicity. Overall this study suggests that attenuation is driven by a decrease in proliferation and restoration of the inflammatory profile of T. parva-infected cells. Additionally, it provides a foundation for future mechanistic studies of the attenuation phenotype in Theileria-infected cells.
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Affiliation(s)
- Elisabeth M D L van der Heijden
- Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - Lucas Lefevre
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Anton Gossner
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Thomas Tzelos
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ, UK
| | - Timothy K Connelley
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Centre for Tropical Livestock Genetics and Health, Easter Bush Campus, Edinburgh, UK
| | - Musa A Hassan
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK.
- Centre for Tropical Livestock Genetics and Health, Easter Bush Campus, Edinburgh, UK.
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Chepkwony M, Wragg D, Latré de Laté P, Paxton E, Cook E, Ndambuki G, Kitala P, Gathura P, Toye P, Prendergast J. Longitudinal transcriptome analysis of cattle infected with Theileria parva. Int J Parasitol 2022; 52:799-813. [PMID: 36244429 DOI: 10.1016/j.ijpara.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/01/2022] [Accepted: 07/14/2022] [Indexed: 11/05/2022]
Abstract
The apicomplexan cattle parasite Theileria parva is a major barrier to improving the livelihoods of smallholder farmers in Africa, killing over one million cattle on the continent each year. Although exotic breeds not native to Africa are highly susceptible to the disease, previous studies have illustrated that such breeds often show innate tolerance to infection by the parasite. The mechanisms underlying this tolerance remain largely unclear. To better understand the host response to T. parva infection we characterised the transcriptional response over 15 days in tolerant and susceptible cattle (n = 29) naturally exposed to the parasite. We identify key genes and pathways activated in response to infection as well as, importantly, several genes differentially expressed between the animals that ultimately survived or succumbed to infection. These include genes linked to key cell proliferation and infection pathways. Furthermore, we identify response expression quantitative trait loci containing genetic variants whose impact on the expression level of nearby genes changes in response to the infection. These therefore provide an indication of the genetic basis of differential host responses. Together these results provide a comprehensive analysis of the host transcriptional response to this under-studied pathogen, providing clues as to the mechanisms underlying natural tolerance to the disease.
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Affiliation(s)
- M Chepkwony
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, P.O. Box 30709, Nairobi 00100, Kenya
| | - D Wragg
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, EH25 9RG, UK
| | - P Latré de Laté
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, P.O. Box 30709, Nairobi 00100, Kenya
| | - E Paxton
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, EH25 9RG, UK
| | - E Cook
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, P.O. Box 30709, Nairobi 00100, Kenya
| | - G Ndambuki
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, P.O. Box 30709, Nairobi 00100, Kenya
| | - P Kitala
- College of Agriculture and Veterinary Sciences (CAVS), University of Nairobi, P.O. Box 29053-00624, Kangemi, Nairobi, Kenya
| | - P Gathura
- College of Agriculture and Veterinary Sciences (CAVS), University of Nairobi, P.O. Box 29053-00624, Kangemi, Nairobi, Kenya
| | - P Toye
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, P.O. Box 30709, Nairobi 00100, Kenya.
| | - J Prendergast
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, EH25 9RG, UK.
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Lopez BS. Can Infectious Disease Control Be Achieved without Antibiotics by Exploiting Mechanisms of Disease Tolerance? Immunohorizons 2022; 6:730-740. [DOI: 10.4049/immunohorizons.2200043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/04/2022] [Indexed: 01/04/2023] Open
Abstract
Abstract
Antimicrobial use in animal agriculture may be contributing to the emerging public health crisis of antimicrobial resistance. The sustained prevalence of infectious diseases driving antimicrobial use industry-wide suggests that traditional methods of bolstering disease resistance are, for some diseases, ineffective. A paradigm shift in our approach to infectious disease control is needed to reduce antimicrobial use and sustain animal and human health and the global economy. Targeting the defensive mechanisms that promote the health of an infected host without impacting pathogen fitness, termed “disease tolerance,” is a novel disease control approach ripe for discovery. This article presents examples of disease tolerance dictating clinical outcomes for several infectious diseases in humans, reveals evidence suggesting a similarly critical role of disease tolerance in the progression of infectious diseases plaguing animal agriculture, and thus substantiates the assertion that exploiting disease tolerance mechanisms can positively impact animal and human health.
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Affiliation(s)
- Brina S. Lopez
- Department of Farm Animal Medicine, Midwestern University College of Veterinary Medicine, Glendale, AZ
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Wragg D, Cook EAJ, Latré de Laté P, Sitt T, Hemmink JD, Chepkwony MC, Njeru R, Poole EJ, Powell J, Paxton EA, Callaby R, Talenti A, Miyunga AA, Ndambuki G, Mwaura S, Auty H, Matika O, Hassan M, Marshall K, Connelley T, Morrison LJ, Bronsvoort BMD, Morrison WI, Toye PG, Prendergast JGD. A locus conferring tolerance to Theileria infection in African cattle. PLoS Genet 2022; 18:e1010099. [PMID: 35446841 PMCID: PMC9022807 DOI: 10.1371/journal.pgen.1010099] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/14/2022] [Indexed: 12/30/2022] Open
Abstract
East Coast fever, a tick-borne cattle disease caused by the Theileria parva parasite, is among the biggest natural killers of cattle in East Africa, leading to over 1 million deaths annually. Here we report on the genetic analysis of a cohort of Bos indicus (Boran) cattle demonstrating heritable tolerance to infection with T. parva (h2 = 0.65, s.e. 0.57). Through a linkage analysis we identify a 6 Mb genomic region on bovine chromosome 15 that is significantly associated with survival outcome following T. parva exposure. Testing this locus in an independent cohort of animals replicates this association with survival following T. parva infection. A stop gained variant in a paralogue of the FAF1 gene in this region was found to be highly associated with survival across both related and unrelated animals, with only one of the 20 homozygote carriers (T/T) of this change succumbing to the disease in contrast to 44 out of 97 animals homozygote for the reference allele (C/C). Consequently, we present a genetic locus linked to tolerance of one of Africa’s most important cattle diseases, raising the promise of marker-assisted selection for cattle that are less susceptible to infection by T. parva. More than a million cattle die of East Coast fever in Africa each year, the impact of which disproportionately falls onto low-income, smallholder farmers. The lack of a widely accessible vaccine, heavy reliance on chemicals to control the tick vector and inadequate drug treatments means that new approaches for controlling the disease are urgently required. Through a genetic study of an extended pedigree of Boran cattle that are more than three times less likely to succumb to the disease than matched controls, we identify a region on chromosome 15 of the cattle genome associated with a high level of tolerance to the disease. We show that a nonsense variant in a predicted paralogue of FAS-associated factor 1 (FAF1) in this region is also associated with survival in an independent cohort, and is linked to rates of cell expansion during infection. This genetic variant can therefore support marker-assisted selection, allowing farmers to breed tolerant cattle and offers a route to introduce this beneficial DNA to non-native breeds, enabling reduced disease incidence and increased productivity, which would be of benefit to millions of rural smallholder farmers across Africa.
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Affiliation(s)
- David Wragg
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Elizabeth A. J. Cook
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Perle Latré de Laté
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Johanneke D. Hemmink
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Regina Njeru
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Jessica Powell
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Edith A. Paxton
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Rebecca Callaby
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- The Epidemiology, Economics and Risk Assessment (EEA) Group, Easter Bush Campus, Edinburgh, United Kingdom
| | - Andrea Talenti
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Antoinette A. Miyunga
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Gideon Ndambuki
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | | | - Harriet Auty
- Institute of Biodiversity Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Oswald Matika
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Musa Hassan
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Karen Marshall
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
| | - Timothy Connelley
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Liam J. Morrison
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - B. Mark deC. Bronsvoort
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - W. Ivan Morrison
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Philip G. Toye
- Centre for Tropical Livestock Genetics and Health (CTLGH), ILRI Kenya, Nairobi, Kenya
- ILRI Kenya, Nairobi, Kenya
- * E-mail: (PGT); (JGDP)
| | - James G. D. Prendergast
- Centre for Tropical Livestock Genetics and Health (CTLGH), Easter Bush Campus, Edinburgh, United Kingdom
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (PGT); (JGDP)
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