Journal: Microbiology Spectrum

Article Title: SARS-CoV-2 Infection of Microglia Elicits Proinflammatory Activation and Apoptotic Cell Death

doi: 10.1128/spectrum.01091-22

Figure Lengend Snippet: Microglia of K18-hACE2 mice were infected by intranasally administered SARS-CoV-2. (A) The SARS-CoV-2 inoculum (50 μL, 100 MLD 50 ) was intranasally administered to a susceptible mouse model (K18-hACE2, n = 4). Their body weight was measured every day (Mock: black; Infected: blue). (B) At 6 d postinfection (dpi), the brain homogenates of the mock or infected mice were used to detect the viral RNA by quantitative real-time PCR (RT-qPCR), and the graph indicates viral RNA copies per microgram of total RNA. (C) The colocalization of SARS-Cov-2 spike protein and microglial Iba1 at 6 dpi in the infected mice by immunofluorescence staining. Scale bars = 50 μm. Statistically significant differences between the groups were determined by multiple Student's t test (A) and Student's t test (B); * , P < 0.05; * * , P < 0.01; ** * , P < 0.001; *** * , P < 0.0001. Symbols represent mean ± SEM.

Article Snippet: Isolated brain mononuclear cells from the mock or SARS-CoV-2-infected mice in cell staining buffer (phosphate-buffered saline [PBS] with 1% FBS and 0.09% NaN 3 ) were stained for 30 min with fluorescence-conjugated antibodies, namely, brilliant violet 421 anti-mouse/human CD11b antibody (101236, BioLegend, San Diego, CA, USA), PE/Cyanine7 anti-mouse CD45 antibody (103114, BioLegend), APC anti-mouse TNF-α antibody (506307, BioLegend), FITC anti-mouse IL-6 monoclonal antibody (MP5-20F3) (11-7061-82, eBioscience, San Diego, CA, USA), FITC anti-human ACE2 antibody (NBP2-7211F, Novus Biologicals, Centennial, CO, USA), and Alexa 647 anti-Iba1 antibody (78060S, Cell Signaling Technology, Danvers, MA, USA).

Techniques: Infection, Real-time Polymerase Chain Reaction, Quantitative RT-PCR, Immunofluorescence, Staining