Mycobacterium avium subsp.
paratuberculosis (Map) contains PPE family
antigens which are
Proline and
glutamic acid rich and may play important role as T cell
antigens. Hence the identification and generation of
antigens are necessary for immunological characterization. In the present study, the
epitopic region of a unique PPE gene encoding 34.9 kDa
protein from Map was amplified by polymerase chain reaction. The gene was cloned into Escherichia coli vector pQE30 UA. The recombinant plasmid designated as pQPPE was transformed into E. coli
M15 and induced with
IPTG revealed the high level expression of 37.1 kDa His-fusion
protein (34.9 kDa PPE and 2.2 kDa His-tag), which was confirmed by immunoblotting. Recombinant PPE
protein was then purified by Ni-NTA
agarose chromatography. The polyclonal antiserum raised against purified recombinant PPE
protein reacted with expressed 37.1 kDa His-fusion
protein as well as with Map sonicate. The
protein elicited significant delayed type
hypersensitivity (DTH) skin reaction in mice sensitized with Map. The results indicated that the recombinant PPE
protein of Map was associated with cellular immune response.