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Published on: January 31, 2018
Expression cloning of gamma interferon-inducing antigens of Mycobacterium avium subsp. paratuberculosis
Reiko Nagata1, Yoshihiro Muneta, Kazuhiro Yoshihara
1Immune System Section, Department of Immunology, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki, Japan 305-0856. kikuma@affrc.go.jp
Abstract:
Three recombinant proteins, Map10, Map39, and Map41, produced based on nucleotide sequences obtained from the screening of Mycobacterium avium subsp. paratuberculosis genomic library expressed in Escherichia coli significantly elicited gamma interferon production in peripheral blood mononuclear cells from infected cattle. Two of these proteins were members of the PPE protein family.
Insights
Three novel recombinant proteins from Mycobacterium avium subsp. paratuberculosis stimulated immune responses in cattle. These proteins, including two PPE family members, show potential for diagnosing Johne's disease.
Area of Science:
- Veterinary immunology
- Bacteriology
- Molecular biology
Background:
- Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in cattle, leading to significant economic losses in the dairy industry.
- Current diagnostic methods for Johne's disease have limitations in sensitivity and specificity.
- Identifying novel MAP antigens is crucial for developing improved diagnostic tools and potential vaccines.
Purpose of the Study:
- To identify and characterize novel recombinant proteins from MAP that can elicit an immune response in infected cattle.
- To evaluate the diagnostic potential of these proteins by measuring their ability to stimulate gamma interferon production.
Main Methods:
- Screening of a MAP genomic library to identify potential protein-coding sequences.
- Expression of selected nucleotide sequences as recombinant proteins (Map10, Map39, Map41) in Escherichia coli.
- Incubation of recombinant proteins with peripheral blood mononuclear cells (PBMCs) from cattle infected with MAP.
- Quantification of gamma interferon (IFN-γ) production as a measure of cellular immune response.
Main Results:
- Three recombinant proteins, Map10, Map39, and Map41, were successfully produced.
- All three proteins significantly elicited gamma interferon production in PBMCs from MAP-infected cattle.
- Two of the identified proteins, Map39 and Map41, belong to the PPE protein family, known for their immunomodulatory roles.
Conclusions:
- The recombinant proteins Map10, Map39, and Map41 are immunogenic in cattle infected with MAP.
- These proteins, particularly the PPE family members, show promise as diagnostic antigens for Johne's disease.
- Further research into these MAP antigens could lead to the development of more effective diagnostic assays.
