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Updated: Mar 8, 2026
Murine Fecal Isolation and Microbiota Transplantation
Published on: May 26, 2023
Proteomic changes in the ileum of sheep infected with Mycobacterium avium subspecies paratuberculosis
S Pisanu1, T Cubeddu2, S Uzzau3
1Porto Conte Ricerche, S.P. 55 Porto Conte/Capo Caccia Km 8.400, Loc. Tramariglio, 07041 Alghero, SS, Italy.
Abstract:
Johne's disease (JD) is a chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). To identify the processes activated in the sheep intestine during natural MAP infection, and to provide a panel of differential host and pathogen proteins with diagnostic and prognostic potential, a differential shotgun proteomics workflow, including mass spectrometry, label-free quantisation and pathway analysis, was applied to ileal tissues of ewes with and without JD. Out of 2889 total proteins identified, 384 were differentially expressed and 341 were expressed at a higher level in JD. On the basis of Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analysis, these proteins were involved in numerous relevant biological networks and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including inhibition of phagosome acidification (such as V-ATPase), bacterial invasion, leucocyte recruitment and activation, and antimicrobial activity (such as haptoglobin, lactoferrin, cathelicidins, calgranulins and interleukins). A total of 28 MAP proteins were identified, including bacterioferritin, β-lactamase and heparin-binding haemagglutinin (HBHA), a mycobacterial adhesin crucial for dissemination of infection.
Insights
Johne
Area of Science:
- Veterinary Proteomics
- Ruminant Infectious Diseases
- Host-Pathogen Interactions
Background:
- Johne's disease (JD) is a chronic enteritis in ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP).
- Understanding the host and pathogen molecular responses during JD is crucial for developing diagnostic and prognostic tools.
- Sheep ileal tissue is a key site for MAP infection and associated pathological changes.
Purpose of the Study:
- To identify host and pathogen proteins involved in the sheep intestine during natural MAP infection.
- To uncover biological processes and pathways activated by MAP.
- To discover potential protein biomarkers for JD diagnosis and prognosis.
Main Methods:
- Differential shotgun proteomics using mass spectrometry and label-free quantification.
- Analysis of ileal tissues from ewes with and without JD.
- Bioinformatic pathway analysis using STRING and KEGG databases.
Main Results:
- Identified 2889 total proteins, with 384 differentially expressed in JD-affected sheep.
- 341 proteins were upregulated in JD, associated with phagosome acidification inhibition, bacterial invasion, and immune cell activation.
- Detected 28 MAP proteins, including heparin-binding haemagglutinin (HBHA), vital for infection spread.
Conclusions:
- Proteomic analysis reveals key host and pathogen molecular events during JD.
- Upregulated proteins offer potential as diagnostic and prognostic biomarkers for Johne's disease.
- Identification of MAP virulence factors like HBHA aids in understanding disease pathogenesis.
