Fig. 8

Recombinant ACE2 protein decreased the inflammation induced by coexposed to SARS-CoV-2 spike RBD and LPS. The proinflammatory cytokines A TNF-α, B IL-1β and C IL-6 in the BALF were determined by ELISA (n = 5–6 for each group). D The concentrations of MPO in the BALF were determined by ELISA (n = 5 for each group). N.D. indicates not detectable. E The protein expression levels of MPO were determined by western blot analysis, and the representative results were shown. F The macrophage infiltration in the lung tissues was determined by IHC, and the representative images were shown. CD68 was used as the maker for the staining of macrophage. The left panel, 100×, scale bar = 100 μm; the right panel, 400×, scale bar = 100 μm. Data are shown as mean ± S.D., *P < 0.05 and **P < 0.01