Figure 2.

Adoptive transfer of protective immunity against tuberculosis by bulk transfer of CD4⁺CD8⁻ or CD8⁺CD4⁻ T cells to naive mice. T-cell subsets were obtained by negative selection from lymph nodes of DNA-immunized or BCG-vaccinated mice. Recipient mice were γ-irradiated then injected intravenously with 5×10⁶ T cells and 1×10⁵M. tuberculosis cells. The number of live bacteria in the lungs was determined 4 weeks after infection. Control mice were either untreated or were irradiated and reconstituted with non-specific lymph node T cells enriched from normal mice. Results are shown as mean CFU±SD from groups of five animals. Asterisks indicate a significant difference from vaccinated (DNA- or BCG-) and control group. *P <0·01 and **P <0·001 and 2 logs difference.