Rabbit anti human il 6 antibody

A549 cells that were regularly maintained in F12K medium (Thermo Fisher, Waltham, MA, USA) containing 10% FBS, 1× P/S solution (Corning, Glendale, AZ, USA), 1× MEM-Eagle (Biological Industries, Cromwell, CT, USA), and 1× L-glutamine at 37 °C in a 5% CO₂ incubator were used for cytokine expression. A549 cells were seeded at a density of 5 × 104 cells per well in a 4-well chambered slide overnight. Following the infection and treatments of Aβ_1-42 at 50 µg/mL similar to the procedure described above, cells were fixed in 4% paraformaldehyde in 1× PBS 17 h after infection with the SARS-CoV-2 pseudovirus. To detect the intracellular IL-6 levels, immuno-fluorescence confocal microscopy using rabbit anti-human IL-6 antibody (Abcam, Cambridge, MA, USA) and Alexa Fluo 594-conjugated donkey anti-rabbit antibody was performed. Semi-quantification of IL-6 immuno-reactivity was measured by total fluorescent area of Alexa Fluo 594 per DAPI-positive cell for the control (including 1016 cells from 3 wells), Aβ_1-42 alone at 50 µg/mL (including 778 cells from 2 wells), SARS-CoV-2 pseudovirus-infected group (868 cells from 3 wells), and SARS-CoV-2 pseudovirus infection in the presence of Aβ_1-42 at 50 µg/mL (including 861 cells from 3 wells).