Open AccessIdentification of Immune Parameters To Differentiate Disease States among Sheep Infected with Mycobacterium avium subsp. paratuberculosis
Author(s) -
Sonia Gillan,
Rory O’Brien,
A.D. Hughes,
J.F.T. Griffin
Publication year - 2010
Publication title -
clinical and vaccine immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.649
H-Index - 77
eISSN - 1556-6811
pISSN - 1556-679X
DOI - 10.1128/cvi.00359-09
Subject(s) - paratuberculosis , mycobacterium avium subsp. paratuberculosis , identification (biology) , biology , immune system , mycobacterium , microbiology and biotechnology , disease , virology , immunology , bacteria , medicine , genetics , ecology , pathology
Johne's disease, a chronic enteritis of ruminants, is caused by infection withMycobacterium avium subsp.paratuberculosis . Three distinct forms have been observed in sheep: paucibacillary disease (PB), multibacillary disease (MB), and asymptomatic infection (AS). In this study, immune parameters for animals naturally infected withM .avium subsp.paratuberculosis and identifiedpostmortem as having PB, MB, or AS were compared to provide a further understanding of the immunological reactivity contributing to or resulting from these different disease states in sheep. PB was associated with strong ex vivoM .avium subsp.paratuberculosis antigen-stimulated gamma interferon responses, pronounced increases in CD25+ T-cell frequencies in circulation, antibody production, and a B-cell population that expanded significantly uponex vivo antigenic stimulation. The MB group featured the highest antibody levels and a lack of cellular immune responsiveness to theM .avium subsp.paratuberculosis antigen. The AS group expressed an immunological phenotype intermediate between that for noninfected control animals and that for the PB group. The relationship between immune responses and disease severity within the PB group was investigated more closely; significant positive correlations were observed between disease severity and both the CD8+ population in the circulating blood and the expression of interleukin-4 mRNA in antigen-stimulated blood samplesex vivo . Together, these data point toward distinct immune profiles in sheep that correspond to different Johne's disease states, which can be determined from circulating blood and/or from localized intestinal tract tissue samples.