Fig 6. PLGA particulate vaccination failed to induce protection against M. tuberculosis infection.
C57BL/6 mice were immunised three times at two-weekly intervals with PLGA particles (n = 6) or DDA liposomes (n = 3–6), containing MPT83 adjuvanted with TDB, (A) lungs and (B) spleen, or adjuvanted with MPL, (C) lungs and (D) spleen. Six weeks following the final vaccination, mice were challenged with a low-dose aerosol of M. tuberculosis H37Rv (100 CFU). Additional mice (n = 6) were immunised with 5×105 CFU BCG once by s.c injection 12 weeks before challenge. After 4 weeks the bacterial loads were enumerated in mice immunised either i.n or s.c as indicated. The data are the means ± SEM. Statistical significance was determined by Student’s t-test, comparing the vaccinated group to the relevant unimmunised/adjuvant only control (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).