Fig. 3: CB6 can effectively reduce viral load and alleviated infection-related lung damage in rhesus macaques.
From: A human neutralizing antibody targets the receptor-binding site of SARS-CoV-2
a, Nine rhesus macaques (6 males and 3 females) were divided into pre-exposure (prophylactic), post-exposure (treatment) and control groups with three macaques (2 males and 1 female) in each group. Before infection, the macaques in the pre-exposure group were infused with 50 mg kg−1 body weight CB6(LALA) intravenously. One day later, all macaques were inoculated with 1 × 105 TCID50 SARS-CoV-2 via intratracheal intubation. The post-exposure group were also infused with 50 mg kg−1 CB6(LALA) on days 1 and 3 after exposure, and the three macaques in the control group were given PBS as a control. Viral RNA loads in throat swabs, determined by RT–qPCR, were monitored for 7 days. Data are average values from 3 macaques for the first 5 days, from 2 macaques at 6 dpi, and from 1 macaque at 7 dpi. To evaluate the viral loads for each macaque at the indicated time point, RT–qPCR were performed with two replicates. b–d, Histopathology and immunohistochemical examination of lung tissues from pre-exposure, post-exposure and control macaques. One macaque from each group was euthanized and necropsied at 5 dpi. Samples for histological examination were stored in formalin for 7 days, embedded in paraffin, sectioned and stained before examination by light microscopy. Haematoxylin and eosin (H&E) sections exhibited the interstitial pneumonia and inflammatory-factor infiltration in tissues. Masson’s trichrome showed lung tissue fibrosis. Scale bar, 200 μm.
