Antigenic diversity of the asexual developmental stages of <i>Eimeria tenella</i>

Tomley, Fiona M.

doi:10.1111/j.1365-3024.1994.tb00368.x

Cited by 18 publications

(11 citation statements)

References 17 publications

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“…In common with other Eimeria spp., this cycle is complex, consisting of four distinct, sequential, asexual, replicative generations, followed by a sexual phase (see Materials and Methods). Antigenic diversity between the different developmental stages of eiinerian coccidia is well known (Danforth 1989, Tomley 1994, as is their differential capacity for inducing protective immunity (McDonald et al 1988). It is possible that the second peak represents a response to the development of the large gametocytes characteristic of this species, thought to contain protective antigens (Wallach et a f .…”

Section: Discussionmentioning

confidence: 99%

Avian coccidiosis: changes in intestinal lymphocyte populations associated with the development of immunity to Eimeria maxima

Rothwell

Gramzinski

Rose

et al. 1995

Parasite Immunology

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The effect of infection and subsequent challenge with Eimeria maxima on the populations of lymphocytes in the small intestine of Light Sussex chickens was assessed by immunohistochemistry. T cells were characterized for CD3, CD4, CD8, TCR1 (gamma delta heterodimer) or TCR2 (alpha beta 1 heterodimer) markers, and B cells for the expression of IgM, IgA and IgG. After a primary inoculum there were, in both the epithelium and the lamina propria, two distinct increases in the numbers of T lymphocytes. The first peaked on days 3-5 and the second, greater influx, on day 11 after infection. CD4+ and CD8+ cells were represented in both peaks but, whereas CD4+ cells were found almost exclusively in the lamina propria, CD8+ cells were present in both sites. The area staining positive for CD8+ cells was somewhat greater than the value obtained for CD4+ cells. In the epithelium there was an early, small increase in TCR1(+)-staining, followed by a larger rise to the second peak, at which time there was also an increase in the lamina propria. Staining for TCR2+ cells followed the same pattern with a reversed distribution between epithelium and lamina propria. Changes after challenge were minimal and confined to the epithelium. The most notable changes in the expression of immunoglobulins were, in the lamina propria, a biphasic increase in the amount of IgM(+)-staining in the course of primary infection (corresponding approximately to that of the T cells), and in IgA+ cells shortly after challenge.

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Section: Discussionmentioning

confidence: 99%

Avian coccidiosis: changes in intestinal lymphocyte populations associated with the development of immunity to Eimeria maxima

Rothwell

Gramzinski

Rose

et al. 1995

Parasite Immunology

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“…Genomic DNA (gDNA) and total RNA were extracted from oocysts using the TRIzol® reagent (Invitrogen, Paisley, UK) as detailed previously (Marugan-Hernandez et al, 2016). Protein extracts from sporozoites and merozoites were obtained following standard procedures (Tomley, 1994).…”

Section: Isolation Of Nucleic Acids and Proteins And Synthesis Of Comentioning

confidence: 99%

Development of cross-protective Eimeria-vectored vaccines based on apical membrane antigens

Pastor-Fernández

Kim

Billington

et al. 2018

International Journal for Parasitology

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Recently, the availability of protocols supporting genetic complementation of Eimeria has raised the prospect of generating transgenic parasite lines which can function as vaccine vectors, expressing and delivering heterologous proteins. Complementation with sequences encoding immunoprotective antigens from other Eimeria spp. offers an opportunity to reduce the complexity of species/strains in anticoccidial vaccines. Herein, we characterise and evaluate EtAMA1 and EtAMA2, two members of the apical membrane antigen (AMA) family of parasite surface proteins from Eimeria tenella. Both proteins are stage-regulated, and the sporozoite-specific EtAMA1 is effective at inducing partial protection against homologous challenge with E. tenella when used as a recombinant protein vaccine, whereas the merozoite-specific EtAMA2 is not. In order to test the ability of transgenic parasites to confer heterologous protection, E. tenella parasites were complemented with EmAMA1, the sporozoite-specific orthologue of EtAMA1 from E. maxima, coupled with different delivery signals to modify its trafficking and improve antigen exposure to the host immune system. Vaccination of chickens using these transgenic parasites conferred partial protection against E. maxima challenge, with levels of efficacy comparable to those obtained using recombinant protein or DNA vaccines. In the present work we provide evidence for the first known time of the ability of transgenic Eimeria to induce cross protection against different Eimeria spp. Genetically complemented Eimeria provide a powerful tool to streamline the complex multi-valent anticoccidial vaccine formulations that are currently available in the market by generating parasite lines expressing vaccine targets from multiple eimerian species.

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“…The antibody responses of chickens to Eimeria infections have been characterized with regard to parasite lifecycle stages, immunodominant antigens and dynamics (Xie et al, 1992;Smith et al, 1993;Tomley, 1994;Talebi and Mulcahy, 1995;Tajima et al, 2003;Onaga et al, 2005;Constantinoiu et al, 2007). However, most studies of the antibody responses reported to date have been conducted with wild-type strains that have not been subject to any selection.…”

Section: Introductionmentioning

confidence: 96%

Characterization of the antibody response in birds following infection with wild-type and attenuated strains of Eimeria tenella and Eimeria necatrix

Constantinoiu

Molloy

Jorgensen

et al. 2011

Veterinary Parasitology

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Live vaccines containing attenuated parasite strains are increasingly used to control chicken coccidiosis. In this paper antibody responses elicited by infections with wild-type and attenuated strains of Eimeria tenella and Eimeria necatrix were characterized by immunoblotting and ELISA with homologous and heterologous antisera. Few differences between antisera from birds infected with wild and attenuated strains of E. tenella were evident in immunoblots conducted with merozoite antigen preparations from both E. tenella strains, however the reactivity of sera raised in birds infected with the wild-type strain was noticeably more intense. In ELISAs conducted with merozoite antigen preparations, antisera from birds infected with the wild-type strains of E. tenella and E. necatrix consistently produced a significantly higher (P<0.05) antibody response than antisera from birds infected with the attenuated strains. Likewise, avidity ELISAs conducted with the E. tenella strains demonstrated that antibodies in birds infected with the wild-type strain were of significantly higher avidity (P<0.05) than antibodies in birds infected with the attenuated strain. The differences in the antibody responses are probably due to changes in the attenuated strain as a result of selection for precocious development and the less severe tissue damage and inflammation of the intestine resulting from infection with the attenuated strain.

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Antigenic diversity of the asexual developmental stages of Eimeria tenella

Cited by 18 publications

References 17 publications

Avian coccidiosis: changes in intestinal lymphocyte populations associated with the development of immunity to Eimeria maxima

Avian coccidiosis: changes in intestinal lymphocyte populations associated with the development of immunity to Eimeria maxima

Development of cross-protective Eimeria-vectored vaccines based on apical membrane antigens

Characterization of the antibody response in birds following infection with wild-type and attenuated strains of Eimeria tenella and Eimeria necatrix

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