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[Preprint]. 2024 Nov 21:rs.3.rs-5454588. [Version 1] doi: 10.21203/rs.3.rs-5454588/v1

Figure 2. The in vivo antiviral efficacy of prophylactic and therapeutic TMP1 treatment against SARS-CoV-2 infection.

Figure 2

(a) Pharmacokinetics of TMP1 oral delivery in mice. 8-week-old male BALB/c mice (n=3) were orally delivered with 100 mg/kg/dose TMP1, 100 mg/kg/dose nirmatrelvir (NRV) or 20 mg/kg/dose camostat. 20 mg/kg/dose ritonavir (RTV) was also included as metabolic enhancer for combined treatment. Plasma was continuously sampled for measurement of the plasma drug (or drug metabolites) concentration with liquid chromatography-mass spectrometry (LC-MS).

(b) Schematic illustration of the in vivo experiment design. 8- to 12-week-old K18-hACE2 transgenic mice were intranasally challenged with 1250 PFU SARS-CoV-2 Delta strain. Mice were orally treated with 100 mg/kg/dose TMP1 or nirmatrelvir in combination with 20 mg/kg/dose ritonavir twice per day. For prophylactic therapy (n=6), treatment onset one day prior to virus infection while therapeutic treatment (n=10) was delayed to 24 hpi. Nasal turbinate and lung tissues were harvested at 3 dpi. for virological assessment by RT-qPCR and plaque assays. For survival study, body weight and survival of the infected mice were monitored for 14 days or until death of the animal.

(c) Quantification of sgE gene of SARS-CoV-2 in the nasal turbinate and lung tissues of the infected mice with prophylactic treatment at 3 dpi by RT-qPCR analysis.

(d) Quantification of the infectious viral titres in the nasal turbinate and lung tissues of the infected mice with prophylactic treatment at 3 dpi by plaque assays.

(e) Viral antigen expression in the nasal turbinate and lung tissues of infected mice (n=3) with prophylactic treatment at 3 dpi. was quantified with ImageJ.

(f) Representative images of SARS-CoV-2 nucleocapsid (N) protein expression (black arrow) in nasal turbinate and lung tissue of the infected mice at 3 dpi. by IHC staining. Scale bar represents 100 μm.

(g) Histology analysis of the nasal turbinate and lung tissue of the infected at 3dpi. by H&E staining. Scale bar represents 100 μm. Black arrowhead, nasal epithelial desquamation; open arrowhead, alveolar collapse; dashed circle, inflammation infiltrations in alveolar septa; asterisk, bronchiolar epithelium damage.

(h) Body weight change of the female (n=6) and male (n=11–13) infected mice with or without TMP1 prophylactic treatment.

(i) Survival of the female (n=6) and male (n=11–13) infected mice with or without TMP1 prophylactic treatment.

(j) Quantification of sgE gene of SARS-CoV-2 in the nasal turbinate and lung tissues of the infected mice with delayed therapeutic treatment at 3 dpi by RT-qPCR analysis.

Each data point represents one biological repeat. Data represents mean ± SD from the indicated number of biological repeats. Statistical significances were determined using one way-ANOVA with Dunnett’s multiple comparisons test (c-e), (j) and log-rank (Mantel-Cox) tests (i). Data were obtained from three independent experiments. * represented p < 0.05 and ** represented p < 0.01. *** represented p < 0.001, **** represented p < 0.0001. ns, not statistically significant; WT, wildtype SARS-CoV-2; Veh, vehicle; PAX, Paxlovid.