Identification and characterization of a cDNA encoding a gametocyte-specific protein of the avian coccidial parasite Eimeria necatrix.
Mol Biochem Parasitol
; 240: 111318, 2020 11.
Article
em En
| MEDLINE
| ID: mdl-32956771
ABSTRACT
Gametocyte proteins of Eimeria spp. are essential components of the oocyst wall, and some of these proteins have been analysed to identify targets of transmission-blocking vaccines against avian coccidiosis. In the present study, a cDNA from E. necatrix gametocytes was cloned and sequenced. The cDNA is 1473 bp in length and encodes a 490-amino-acid protein containing a tyrosine-serine (Tyr/Ser)-rich domain and a proline-methionine (Pro/Met)-rich domain. A quantitative real-time PCR (qPCR) analysis showed that the cDNA is expressed only during gametogenesis. A fragment containing the Tyr/Ser-rich domain (rEnGAM59) was expressed in Escherichia coli BL21 (DE3) cells. Immunoblotting showed that rEnGAM59 was recognized by the serum of convalescent chickens after infection with E. necatrix, and that an anti-rEnGAM59 antibody recognized a â¼59 kDa protein and two other proteins (â¼35 kDa and â¼33 kDa) in gametocyte extracts. An immunofluorescence assay showed that the anti-rEnGAM59 antibody recognized wall-forming bodies in the macrogametocytes and oocyst walls. An in vivo vaccination and challenge trial was conducted to test the potential utility of rEnGAM59 as a vaccine. Immunized chickens performed better than the unimmunized and challenged (positive control) chickens. The intestinal lesion scores were significantly lower in the immunized groups than in the positive control group (P < 0.05). In contrast, the body weight gains (BWG) were significantly higher in the immunized groups than in the positive control group (P < 0.05). There were no significant differences in the lesion scores and BWG between the groups immunized with rEnGAM59 protein or with live oocysts (P> 0.05). Chickens immunized with rEnGAM59 protein had a significantly higher antigen-specific serum IgY response (P < 0.05). rEnGAM59 protein can be used as candidate antigen to develop a recombinant coccidiosis vaccine.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
2_ODS3
/
3_ND
Problema de saúde:
2_enfermedades_transmissibles
/
3_zoonosis
Assunto principal:
Expressão Gênica
/
Proteínas de Protozoários
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Clonagem Molecular
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DNA Complementar
/
Eimeria
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
Mol Biochem Parasitol
Ano de publicação:
2020
Tipo de documento:
Article