|
1000
|
Abstract/Summary
|
-
<jats:title>Abstract</jats:title><jats:p>Current diagnostic methods for Johne’s disease in cattle allow reliable detection of infections with <jats:italic>Mycobacterium avium</jats:italic> ssp. <jats:italic>paratuberculosis</jats:italic> (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), <jats:italic>M. avium</jats:italic> ssp. <jats:italic>avium</jats:italic> or <jats:italic>M. phlei</jats:italic> for 6 days followed by labeling of intracellular IFN-γ in CD4<jats:sup>+</jats:sup> and CD8<jats:sup>+</jats:sup> T cells. No antigen-specific IFN-γ production was detectable in CD8<jats:sup>+</jats:sup> cells throughout and the responses of CD4<jats:sup>+</jats:sup> cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4<jats:sup>+</jats:sup> cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4<jats:sup>+</jats:sup> cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle.</jats:p>
|
|
1000
|
Hinweis
|
-
DeepGreen-ID: 467f445f3ca84fc9959881c6b4aa673a ; metadata provieded by: DeepGreen (https://www.oa-deepgreen.de/api/v1/), LIVIVO search scope life sciences (http://z3950.zbmed.de:6210/livivo), Crossref Unified Resource API (https://api.crossref.org/swagger-ui/index.html), to.science.api (https://frl.publisso.de/), ZDB JSON-API (beta) (https://zeitschriftendatenbank.de/api/), lobid - Dateninfrastruktur für Bibliotheken (https://lobid.org/resources/search)
|
