Fig. 6: Hemin and chloroquine combined treatment reversed the enhanced infection promoted by hemin.

A Experimental design of murine Coronavirus infection. BALB/cJ mice were infected with 6000 PFU of MHV-A59 by intraperitoneal injection. Mice were treated with chloroquine (CQ) (four doses of 30 mg/kg, i.p.) (MHV + CQ) and/or hemin (a single dose of 10 mg/kg, i.p.) (MHV + H and MHV + H + CQ). Infected untreated mice (MHV + PBS) received 100 µL of PBS by i.p. injection. Five days post-infection (dpi), the liver, lung, brain, heart, kidney, spleen, and pancreas were dissected for RT-qPCR analyzes and viral plaque assays. B (i) Body weight pre- (empty circles) and post- (filled circles) infection of MHV + PBS, MHV + H, MHV + CQ, and MHV + H + CQ mice. (ii) Total protein (g/L) levels measured in the blood of MHV + PBS, MHV + H, MHV + CQ, and MHV + H + CQ mice, pre- (empty circles) and post- (filled circles) infection (Upper panel). Liver macroscopic appearance (Lower panel). C Viral RNA abundance (-Ct), measured by RT-qPCR, in liver, lung, brain, heart, kidney, spleen, and pancreas samples from all of the MHV + PBS (n = 6), MHV + H (n = 6), MHV + CQ (n = 6) and MHV + H + CQ (n = 6) mice (i) mean ± S.E.M of each group (ii) and bar plot for each organ depicting statistical differences between groups (iii). Each dot represents the mean value of three technical replicates (i) or biological replicates (ii). Viral RNA abundance is shown as the mean ± SEM. BDL below detection limit. Statistical significance was set at p < 0.05. *p < 0.05, **p < 0.01, ***p < 0.001.