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

For mechanistic analysis, we evaluated expression levels of the cytokines IFN-γ, IP-10, MCP-1, IL-12, IL-6, and TNF-α in the lungs of infected mice administered NPs using qPCR ( Figure 5A ). Compared with the glucose group, the mRNA levels of mice in the ZrO 2 group were reduced, and those in the 100 mg/kg ZrO 2 group showed significantly lower expression levels (P < 0.05). Combined with histopathological analyses and the detection of HA copy numbers, these results confirm that NPs can alleviate pathological injury and reduce viral levels in the lungs through degradation of the cytokine storm. The cytokine storm occurs when excessive levels of pro-inflammatory cytokines induce an acute mononuclear and neutrophilic inflammatory response. 44 ELISA results also showed significantly lower protein expression levels of cytokines in the 100 mg/kg ZrO 2 group compared with the other groups at 6 days post-infection, consistent with the results of qPCR ( Figure 5B ). In the present study, we found that positively-charged ZrO 2 at 200 nm can reduce the production of cytokines involved in the cytokine storm and consequently protect animals from viral infection.