Population, genetic and antigenic diversity of the apicomplexan Eimeria tenella and their relevance to vaccine development

Blake, Damer P. ; Clark, Emily L. ; Macdonald, Sarah E. ; Thenmozhi, Venkatachalam ; Kundu, Krishnendu ; Garg, Rajat ; Jatau, Isa D. ; Ayoade, Simeon ; Kawahara, Fumiya ; Moftah, Abdalgader ; Reid, Adam James ; Adebambo, Ayotunde O. ; Álvarez Zapata, Ramon ; Srinivasa Rao, Arni S. R. ; Thangaraj, Kumarasamy ; Banerjee, Partha S. ; Dhinakar-Raj, G. ; Raman, M. ; Tomley, Fiona M. (2015) Population, genetic and antigenic diversity of the apicomplexan Eimeria tenella and their relevance to vaccine development Proceedings of National Academy of Science, 112 (38). E5343-E5350. ISSN 0027-8424


Official URL: http://www.pnas.org/content/112/38/E5343

Related URL: http://dx.doi.org/10.1073/pnas.1506468112


The phylum Apicomplexa includes serious pathogens of humans and animals. Understanding the distribution and population structure of these protozoan parasites is of fundamental importance to explain disease epidemiology and develop sustainable controls. Predicting the likely efficacy and longevity of subunit vaccines in field populations relies on knowledge of relevant preexisting antigenic diversity, population structure, the likelihood of coinfection by genetically distinct strains, and the efficiency of cross-fertilization. All four of these factors have been investigated for Plasmodium species parasites, revealing both clonal and panmictic population structures with exceptional polymorphism associated with immunoprotective antigens such as Apical Membrane Antigen 1 (AMA1). For the coccidian Toxoplasma gondii only genomic diversity and population structure have been defined in depth so far; for the closely related Eimeria species, all four variables are currently unknown. Using Eimeria tenella, a major cause of the enteric disease coccidiosis, which exerts a profound effect on chicken productivity and welfare, we determined population structure, genotype distribution, and likelihood of cross-fertilization during coinfection and also investigated the extent of naturally occurring antigenic diversity for the E. tenella AMA1 homolog. Using genome-wide Sequenom SNP-based haplotyping, targeted sequencing, and single-cell genotyping, we show that in this coccidian the functionality of EtAMA1 appears to outweigh immune evasion. This result is in direct contrast to the situation in Plasmodium and most likely is underpinned by the biology of the direct and acute coccidian life cycle in the definitive host.

Item Type:Article
Source:Copyright of this article belongs to National Academy of Sciences.
Keywords:Eimeria; Coccidiosis; Population Structure; Chickens; Food Security
ID Code:107513
Deposited On:24 Jul 2017 10:17
Last Modified:24 Jul 2017 10:17

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