IBT/07 Proteomic analysis of Cytosolic proteins of Mycobacterium leprae

Antigen which could preferentially recognized by antibodies may play an integral role in the modulation of host-parasite interactions and also may be used as important potential vaccinogens. Since evidence exists implicating vaccine is a protection from invasive disease, the potential peptide antigens for vaccine development should be studied to find logical candidates. We studied the association between human immune responses and cytosolic antigens of M leprae. Two dimensional gel electrophoresis (2DE) separated proteins of various fractions were immuno-blotted with antihuman IgA/IgM/IgG to immunogenic antigen of M leprae in sera of leprosy patients, tuberculosis patients and healthy individuals. The majority of antigens which can recognize antibodies in sera are found to be in cytsolic fraction. In all 18 (4 with anti-IgA, 3 with anti-IgM and 11 with IgG) immunoreactive spots were observed with sera from leprosy patients. Of these only 9 spots were identified by MALDI and MASCOT search which revealed significantly scored for homology with other bacterial proteins from Tryopherma whipplei (five proteins), Corynibacterium jeikeium (two proteins), Corynibacterium glutamicum (one protein), and Streptomyces griseus (one protein). Cytosolic fraction of M. leprae have cross reactive antigens identified as homologue of Chorismate synthase (EC 4.2.3.5) (5-enolpyruvylshikimate-3-phosphate phospholyase) of Corynebacterium jeikeium (designated here as CyGL2 and CyGL4) may be used as a considerable candidate antigen for polypeptide vaccine.