Fig. 3.

The eNAMPT-neutralizing mAb reduces pristane-induced murine vasculitis and alveolar hemorrhage. A/B. Alveolar hemorrhage was absent in control mice that were not exposed to pristane challenge. All pristane-exposed mice receiving either PBS or IgG (controls) survived to Day 10 and exhibited varying degrees of alveolar hemorrhage (mild to severe) by gross whole lung pathology. Representative lung samples are depicted. In contrast, mice receiving the eNAMPT-neutralizing ALT-100 mAb (1 mg/kg) beginning on Day 1 showed substantial reduction in the severity of DAH by gross examination compared with PBS or IgG mice. C. Quantification of the extent of lung involvement with alveolar hemorrhage demonstrated similar severity in both the PBS- and IgG-treated pristane-challenged groups with each groups exhibiting comparable (30%) incidence of mild DAH and severe DAH. In contrast, only 10% of ALT-100 mAb-treated mice exhibited evidence of severe lung hemorrhage compared to 30% of PBS- or IgG-challenged mice. D/E. Histologic examination of pristane-induced lung inflammatory injury by H&E staining (four 20X fields) was examined in randomly selected areas on the H&E sections for each mouse and representative histology images are presented. These studies revealed dramatic immune cell and leukocyte infiltration in perivascular area which was similar in both PBS- and IgG-treated mice but significantly reduced in mice treated with the ALT-100 mAb, verified by Image J quantification of randomly selected H&E areas.