Dynamic alteration of spleen dendritic cells in acute lung injury mice

Abstract

Objective To investigate the kinetics and phenotype of spleen dendritic cells (DC) in lipopolysaccharide (LPS) -induced acute lung injury (ALI) mice. Methods Thirty-six C57BL/6 mice were randomly (random number) divided into two groups: control group and ALI group. Spleens were harvested at the following intervals of 6, 12, and 24 h after LPS or PBS administration. Lung wet weight/body weight ratio (LW/BW) was recorded to assess lung injury. Meanwhile, pathological changes were examined under optical microscope. The IL-6 level in the lung was measured by using ELISA (enzyme-linked immuno sorbent assay) . The DC in the spleen was measured by flow cytometry (FCM) . Results (1) LPS-ALI resulted in a significant increase in LW/BW ratio. (2) Histologically, extensive alveolar wall thickening resulted from edema, severe hemorrhage in the interstitium and alveolus, and marked and diffuse interstitial infiltration with inflammatory cells were observed in the ALI group. (3) Meanwhile, the levels of IL-6 in lung tissue were significantly increased in the LPS-induced ALI mice. (4) LPS-induced ALI led to divergent kinetics of spleen DC in ALI mice. In ALI mice, spleen DC only showed a transient increase at 12 h. (5) All DC within spleens had a modest maturation in ALI mice. Conclusions LPS-induced ALI provokes a transient increase as well as modest maturation of spleen DC. Key words: Acute lung injury; Acuet respiratory distress syndrome; Dendritic cells; Spleen; Inflammation