IMMUNOPROPHYLACTIC STUDIES ON CELL-WALL ASSOCIATED PROTEINS OF MYCOBACTERIUM-TUBERCULOSIS H37RA

The cell wall protein peptidoglycan complex (CW-PPC) of Mycobacterium tuberculosis H37Ra was isolated through sequential extraction of lipid s, carbohydrates and soluble proteins, CW-PPC emulsified in FIA was fo und to induce significant protection in mice against challenge with LD 50 dose of M. tuberculosis H(37)Rv. To identify the immunoprotective c omponents of CW-PPC, the proteins in avid association with peptidoglca n were dissociated by chemical treatment with trifluoromethanesulthoni c acid (CF3CO3H): anisole (2:1), Immunoreactivity of total (CW-Pr) as, yell as its component proteins i.e., 71, 60 and 45 kDa proteins of cel l wall was studied in animals immunized with CW-Pr-FIA, The 71 kDa pro tein was found to be most immunoreactive giving higher T-cell sensitiz ation and humoral responses, Further, immunization of mice with 71 kDa -FIA demonstrated enhanced T- and B-cell responses, Mice immunized wit h 71 kDa-FIA gave significantly higher protection (P less than or equa l to 0.05) against intravenous challenge with LD50 dose of M. tubercul osis H37RV, than BCG immunized animals, The results indicate the poten tial of 71 kDa cell wall protein as a suitable candidate for Cthe subu nit vaccine.