Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus

Huo, Caiyun; Xiao, Jin; Xiao, Kai; Zou, Shumei; Wang, Ming; Qi, Peng; Liu, Tianlong; Hu, Yanxin

In the glucose group, IAV antigen was observed in mucosal epithelium cells, deciduous alveolar cells, and the lamina propria of bronchioles in the lungs of mice through IHC analysis, while the presence of antigens in the ZrO 2 groups was sporadic ( Figure 3B ). In the 25 mg/kg ZrO 2 and 50 mg/kg ZrO 2 groups, low levels of positive signals were observed in alveolar cells and the lamina propria of bronchioles. Furthermore, few positive signals, which were only distributed in the lamina propria of bronchioles, were detected in the 100 mg/kg ZrO 2 group. No positive cells were observed in the control group. The scores of IAV antigens in the lungs of H5N1-infected mice were determined. To investigate the influence of ZrO 2 on replication of IAV in vivo, the viral load in the lung tissues of virusinfected mice was examined. As shown in Figure 3C , HA copy numbers and PFU values in the ZrO 2 groups at day 6 post-infection were lower than those of glucose-treated mice, with the 100 mg/kg ZrO 2 group showing a significant difference (P < 0.05). At day 6 post-infection, the pulmonary viral titers of ZrO 2 groups were significantly lower than those of glucose-treated mice, with extremely significant differences found for both the 50 mg/kg ZrO 2 and 100 mg/kg ZrO 2 groups (P < 0.001). These viral titer results were in accordance with the results of IHC staining. Taken together, ZrO 2 reduces lung injury and viral replication in H5N1infected mice.