Figure 2

Necrotic pneumonia and uncontrolled infection in TNF-KO mice, but not in mem-TNF mice at 30 days afterMtbinfection (100 CFU, intranasal administration). Survival (A), relative lung weights (B), macroscopic lung changes (C), and bacterial load at 30 days in the lungs (D). The results are expressed as the mean ± SD (n = 6 per group) and are representative of two independent experiments. The bacterial load at day 1 upon infection was 84 ± 28 CFU per lung (n = 6). Microscopic investigations of the lungs show confluent neutrophil and mononuclear cell inflammation with extensive, confluent necrosis and abundant bacilli in TNF-KO mice, while mem-TNF and WT mice show focal, largely perivascular mononuclear cell infiltration (E). Representative haematoxylin and eosin stained lung sections at low (50×) and high power (200×) are shown (n = 5 per group).