B-cell epitopes in the immunodominant p34 antigen of mycobacterium avium ssp. paratuberculosis recognized by antibodies from infected cattle.
Scand J Immunol
; 58(5): 511-21, 2003 Nov.
Article
em En
| MEDLINE
| ID: mdl-14629623
Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis) causes Johne's disease, a chronic and fatal enteritis in ruminants. In the last stage of the disease, antibody titres rise and levels of interferon-gamma decrease, suggesting that the host-immune response is switching from a T helper 1 (Th1) to a Th2 profile. In infected cattle, the membrane protein p34 elicits the predominant humoral response against M. paratuberculosis. To map the B-cell epitopes of this antigen, affinity-purified bovine antibodies against the carboxy-terminal region of p34 were used to screen a 12-mer phage display library. Several phage clones carrying peptides resembling fragments of p34 were affinity selected. Based on the predicted amino acid sequence, peptides were chemically synthesized, which demonstrated reactivity with serum from naturally infected and p34-vaccinated cattle. Immunization of mice with these peptides elicited an anti-p34 antibody response. Two B-cell epitopes were identified and characterized. Based on the reactivity and the type of immune response elicited, epitope A was determined to be conformational, whereas epitope B was demonstrated to be sequential. Both epitopes were shown to be present in p34 proteins from M. avium ssp. avium or M. paratuberculosis but absent from M. intracellulare, the other member of the M. avium complex. Furthermore, both epitopes were mapped to regions of p34 that display high variability when compared to homologous proteins from other mycobacterial species of public and animal health importance. We hypothesize that these variable regions of p34 may play a role in the immunobiology of M. paratuberculosis infections.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Mycobacterium avium subsp. paratuberculosis
/
Epitopos de Linfócito B
/
Anticorpos Antibacterianos
/
Antígenos de Bactérias
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Scand J Immunol
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Reino Unido