Blockade of the C5a–C5aR axis alleviates lung damage in hDPP4-transgenic mice infected with MERS-CoV

Jiang, Yuting; Zhao, Guangyu; Song, Nianping; Li, Pei; Chen, Yuehong; Guo, Yan; Li, Junfeng; Du, Lanying; Jiang, Shibo; Guo, Renfeng; Sun, Shihui; Zhou, Yusen

In our study, increased numbers of macrophages in splenic red pulp and decreased IL-12 concentrations in sera were observed in the treatment group compared to Fig. 6 C5a-C5aR blockade in hDPP4-transgenic mice increases splenic cell regeneration and decreases splenic cell apoptosis. a, b Apoptosis of splenic cells was assessed by immunohistochemical staining of cleaved caspase-3 in spleen tissues 7 days after challenge. c, d Apoptosis of splenic cells was detected using a DAB TUNEL-based apoptosis detection assay in spleen tissue 7 days after challenge. e, f Representative images of regenerated splenic cells detected by IHC staining of PCNA 7 days after challenge. g Apoptosis index of splenocytes was assessed according to TUNEL-based apoptosis detection in spleen sections 7 days after challenge. h Semi-quantitative analysis of PCNA-positive cells in spleen sections 7 days after challenge (n = 5 per group) the sham treatment group, indicating that the anti-C5aR Ab treatment may decrease the excessive complement immune response induced by MERS-CoV infection.