K18-hACE2 mice develop respiratory disease resembling severe COVID-19
This article has been Reviewed by the following groups
Listed in
- Evaluated articles (ScreenIT)
Abstract
SARS-CoV-2 emerged in late 2019 and resulted in the ongoing COVID-19 pandemic. Several animal models have been rapidly developed that recapitulate the asymptomatic to moderate disease spectrum. Now, there is a direct need for additional small animal models to study the pathogenesis of severe COVID-19 and for fast-tracked medical countermeasure development. Here, we show that transgenic mice expressing the human SARS-CoV-2 receptor (angiotensin-converting enzyme 2 [hACE2]) under a cytokeratin 18 promoter (K18) are susceptible to SARS-CoV-2 and that infection resulted in a dose-dependent lethal disease course. After inoculation with either 10 4 TCID 50 or 10 5 TCID 50 , the SARS-CoV-2 infection resulted in rapid weight loss in both groups and uniform lethality in the 10 5 TCID 50 group. High levels of viral RNA shedding were observed from the upper and lower respiratory tract and intermittent shedding was observed from the intestinal tract. Inoculation with SARS-CoV-2 resulted in upper and lower respiratory tract infection with high infectious virus titers in nasal turbinates, trachea and lungs. The observed interstitial pneumonia and pulmonary pathology, with SARS-CoV-2 replication evident in pneumocytes, were similar to that reported in severe cases of COVID-19. SARS-CoV-2 infection resulted in macrophage and lymphocyte infiltration in the lungs and upregulation of Th1 and proinflammatory cytokines/chemokines. Extrapulmonary replication of SARS-CoV-2 was observed in the cerebral cortex and hippocampus of several animals at 7 DPI but not at 3 DPI. The rapid inflammatory response and observed pathology bears resemblance to COVID-19. Additionally, we demonstrate that a mild disease course can be simulated by low dose infection with 10 2 TCID 50 SARS-CoV-2, resulting in minimal clinical manifestation and near uniform survival. Taken together, these data support future application of this model to studies of pathogenesis and medical countermeasure development.
Article activity feed
-
-
SciScore for 10.1101/2020.08.11.246314: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Institutional Review Board Statement IACUC: Ethics Statement: Animal experiment approval was provided by the Institutional Animal Care and Use Committee (IACUC) at Rocky Mountain Laboratories. Randomization not detected. Blinding All tissue slides were evaluated by a board-certified veterinary anatomic pathologist blinded to study group allocations. Power Analysis not detected. Sex as a biological variable Animal experiments: Four to six week-old male and female (15 animals each) transgenic K18-hACE2 mice expressing hACE2 (Jackson laboratories, USA, (20)) were inoculated intranasally (I.N.) with 25 µL sterile Dulbecco’s Modified Eagle Medium (DMEM) containing either 104 TCID50 (low dose group, n = 14), 105 … SciScore for 10.1101/2020.08.11.246314: (What is this?)
Please note, not all rigor criteria are appropriate for all manuscripts.
Table 1: Rigor
Institutional Review Board Statement IACUC: Ethics Statement: Animal experiment approval was provided by the Institutional Animal Care and Use Committee (IACUC) at Rocky Mountain Laboratories. Randomization not detected. Blinding All tissue slides were evaluated by a board-certified veterinary anatomic pathologist blinded to study group allocations. Power Analysis not detected. Sex as a biological variable Animal experiments: Four to six week-old male and female (15 animals each) transgenic K18-hACE2 mice expressing hACE2 (Jackson laboratories, USA, (20)) were inoculated intranasally (I.N.) with 25 µL sterile Dulbecco’s Modified Eagle Medium (DMEM) containing either 104 TCID50 (low dose group, n = 14), 105 TCID50 (high dose group, n = 14) or 105 TCID50 γ-irradiate (45) (control group, n = 2) SARS-CoV-2. Cell Line Authentication not detected. Table 2: Resources
Antibodies Sentences Resources Spike-specific antibodies were detected with goat anti-mouse IgM or IgG Fc (horseradish peroxidase (HRP)-conjugated, Abcam) for 1 h at RT and visualized with KPL TMB 2-component peroxidase substrate kit (SeraCare, 5120-0047). anti-mouse IgMsuggested: NoneSpecific anti-CoV immunoreactivity was detected using an in-house SARS-CoV-2 nucleocapsid protein rabbit antibody at a 1:1000 dilution. SARS-CoV-2 nucleocapsid proteinsuggested: (Bioss Cat# bsm-41414M, RRID:AB_2848129)Macrophage (CD68) and T-cell (CD3) immunoreactivities were detected using CD68 rabbit polyclonal antibody (Abcam) at a 1:250 dilution and prediluted CD3 rabbit monoclonal antibody (2GV6, Roche Tissue Diagnostics), respectively. CD3suggested: NoneCD68suggested: None, ImmPRESS-VR Horse anti-rabbit polymer was used as the secondary antibody (Vector Laboratories). anti-rabbitsuggested: NoneB-cell (CD45) immunoreactivity was detected using anti CD45R rat monoclonal antibody (Abcam) at a 1:500 dilution and ImmPRESS goat anti-rat polymer (Vector Laboratories) as secondary antibody. CD45suggested: Noneanti CD45Rsuggested: Noneanti-rat polymersuggested: NoneExperimental Models: Cell Lines Sentences Resources VeroE6 cells were maintained in DMEM supplemented with 10% fetal bovine serum, 1 mM L-glutamine, 50 U/mL penicillin and 50 μg/mL streptomycin. VeroE6suggested: JCRB Cat# JCRB1819, RRID:CVCL_YQ49)Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).
Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.Results from TrialIdentifier: No clinical trial numbers were referenced.
Results from Barzooka: We did not find any issues relating to the usage of bar graphs.
Results from JetFighter: We did not find any issues relating to colormaps.
Results from rtransparent:- Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
- Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
- No protocol registration statement was detected.
-
