Mycobacterium avium subspecies paratuberculosis (Map) genomic library expressed in Escherichia coli was screened for the identification of novel interferon-gamma (IFN-γ) inducing antigens by the use of peripheral blood mononuclear cells (PBMC) from experimentally-infected cattle. Two recombinant proteins, Map39 and Map41, were produced that were based on nucleotide sequences obtained from two positive clones induced by IFN-γ in PBMC. These recombinant proteins significantly elicited IFN-γ production in PBMC from cattle infected with Map. The addition of anti-bovine interleukin10 monoclonal antibody enhanced the IFN-γ response against the recombinant proteins. Map39 and Map41 are members of the PPE protein family of Map. The PCR cross-reaction test indicated that M. avium subsp. avium also possessed similar PPE family protein genes, but no cross-reactions were observed in the other mycobacterial species tested. Map39 and Map41 may be useful as diagnostic antigens for Map infections.
(Research Team for Paratuberculosis, TEL +81-29-838-7857)
Reference:
Nagata et al. (2005). Infect. Immun. 73:3778-3782.