Efficacy of Eimeria tenella rhomboid-like protein as a subunit vaccine in protective immunity against homologous challenge

Abstract

The immune responses and protective efficacy against homologous challenge in chickens elicited by recombinant proteins of a rhomboid-like gene (ETRHO1) from Eimeria tenella was investigated in the present study. When chickens were immunized with the recombinant rhomboid antigen, specific antibody was generated by ELISA assay. In comparison with the PBS group, the expression levels of interleukin-2, interferon-γ, as well as the percentages of CD4⁺ and CD8⁺ cells in the group immunized with the recombinant rhomboid proteins were significantly increased (p < 0.01, p < 0.05, and p < 0.05, respectively). These results suggest that rhomboid was capable of eliciting humoral and cell-mediated immunity response in birds. Challenge experiments demonstrated that the recombinant rhomboid protein could provide chickens with a protection rate around 77.3%. Numbers of oocysts and cecal lesion from chickens in the group immunized with recombinant rhomboid proteins decreased significantly, and the body weight increased significantly when compared with chickens in the PBS group (p < 0.05). These results suggested that the recombinant rhomboid antigen was able to impart partial protection against homologous challenge in chicken and could be a potential candidate for an E. tenella vaccine development.

Identification of common immunodominant antigens of Eimeria tenella, Eimeria acervulina and Eimeria maxima by immunoproteomic analysis

“…Laurent et al screened a 19-kilodalton antigen present in several Eimeria species using sera raised to E. acervulina or E. tenella [23]. Some immunodominant antigens were screened from cDNA libraries by corresponding Eimeria antisera, such as TA4 [24], LPMC-61 [25], rhomboid proteins ETRH01 of E. tenella [26] and so on, and these identified immunodominant antigen were further demonstrated to be able to confer protection against Eimeria challenge [27, 28]. Therefore, we also used the Eimeria antisera to screen the immunodominant antigens of Eimeria species and obtained 85 immunodominant proteins.…”

Adjuvant effect of ginsenoside-based nanoparticles (ginsomes) on the recombinant vaccine against Eimeria tenella in chickens

“…More and more E. tenella antigens are found to be efficient as vaccine candidates with or without specific adjuvant (Song et al 2009c;Subramanian et al 2008;Xu et al 2008;Li et al 2011;Ding et al 2008). Profilin is expressed in all sexual stages of E. tenella, stimulates cell-mediated immunity, and contains a putative conserved domain for the actin-regulatory protein profilin (Ding et al 2004;Jang et al 2010;Lee et al 2010b;Song et al 2000;Lillehoj et al 2000;Zhao et al 2011).…”

Rhomboid Protein 2 of Eimeria Maxima Provided Partial Protection Against Infection by Homologous Species

“…GAPDH and 14-3-3) [8,32]. Since ROMs are involved in the invasion of apicomplexan protozoa, they were considered as a new candidate antigen for developing new-generation vaccine [13,14]. For example, vaccination with rETRHO1 (recombinant protein of E. tenella rhomboid-like protein) and pVAX1-Rho (a DNA vaccine of E. tenella rhomboid-like protein) elicited humoral and cell-mediated immunity and generated protection against infection by E. tenella in chickens [14,33].…”

“…It is thought that ROMs can cleave adhesins result in parasites can break away from receptors and nally entry into the host cell completely [12,13]. Therefore, ROMs can be regarded as a new candidate antigen for developing new-generation vaccine [13,14].…”