Figure 4.

mc²6030-induced antituberculosis protection was retained in CD4^–/– mice that were depleted of CD8⁺, TCR-γδ⁺, and NK1.1⁺ cells. CD4^–/– mice were vaccinated with the mc²6030 vaccine strain and 60 days later were treated i.p. with 0·5 mg of a mAb against CD8 (clone 2.43), TCR-γδ (clone GL3), NK1.1 (clone PK-136) or Thy-1.2 (clone 30-H12) molecules alone or in combination twice before an Erdman aerogenic challenge and every 10 days subsequent to challenge. Mice were killed 1 month following challenge, and the lung (a) and spleen (b) bacterial CFU were determined. Flow analysis of spleen cells showed that the mAbs depleted > 95% of the target cell populations. 1, naïve; 2, mc²6030-immunized; 3–7 were vaccinated and then antibody depleted; ^**P < 0·01; ^***P < 0·001.