Journal: bioRxiv
Article Title: TMEM106B mediates ACE2-independent replication of the SARS-CoV-2 S-E484D variant in airway-derived cell models
doi: 10.64898/2026.03.14.711762
Figure Lengend Snippet: (A) H522 TMEM106B KO cell derivatives stably transduced with an empty vector (EV), and HA-tagged full length TMEM106B (FL), TMEM106BΔCTD, TMEM106BΔNTD were subjected to immunofluorescence microscopy. Detection of TMEM106B variants (anti-HA, green), Rab7a (lysosome marker, in red), wheat germ agglutinin (membrane, cyan), and cellular nuclei (DAPI, blue). Scale bar=10μM. (B, C) BHK-21 cells stably expressing CD71-TMEM106B-CTD-HA (CD71-CTD-HA) chimeric protein were subjected to western blotting ( B ) or surface staining and flow cytometry ( C ) using an anti-HA antibody. (D, E) BHK21-CD71-TMEM106B-CTD-HA cells were inoculated with SARS-CoV-2 mNG S E484D at a MOI of 1. Infected cells were subjected to FACS to enumerate mNG positive cells at 48 h post-infection (D) or RT-qPCR analysis to analyze cell-associated SARS-CoV-2 RNA at 48 h post infection (E). ( F ) BHK21-CD71-TMEM106B-CTD cells were infected as in (D, E) but in the presence of 50 mM ammonium chloride as in . Cell-associated SARS-CoV-2 RNA levels were assessed by RT-qPCR at 48 h post infection. ( G, H ) SARS-CoV-2 S E484D (MOI=2 equivalent) was pre-incubated with the indicated concentrations of Fc-TMEM106B-LD in SF-DMEM at 37°C for 30 min. Fc decoy-virus mixture was added on H522 (G) and H661 (H) cells and incubated at 37°C for 2h. Virus inoculum was removed and cells were replenished with complete culture media. Cell-associated viral RNA was analyzed by RT-qPCR at 72 h post infection. Data in E-H show the average of three independent replicates with error bars displaying the SEM. ** P < 0.01; *** P < 0.001; *** P < 0.0001 by two-tailed unpaired t -test or one-way ANOVA with Dunnett’s correction for multiple comparisons.
Article Snippet: After permeabilization, cells were incubated in 1% bovine serum albumin (BSA) and 10% FBS in PBS containing 0.1% Tween-20 (PBST) at room temperature for 1 h. Samples were then incubated in primary mouse monoclonal anti-HA (Biolegend, clone 16B12, 1:500) and rabbit polyclonal anti Rab7a (Novus Biologicals #NBP1-87174, 1:500) antibodies at 4 °C overnight.
Techniques: Stable Transfection, Transduction, Plasmid Preparation, Immunofluorescence, Microscopy, Marker, Membrane, Expressing, Western Blot, Staining, Flow Cytometry, Infection, Quantitative RT-PCR, Incubation, Virus, Two Tailed Test