FIG 1.

SARS-CoV-2 infection of human bronchial epithelial cells grown at an air-liquid interface identifies donor-dependent variation in infection levels. (A) Schematic of experimental design (created with BioRender.com). Air-liquid interface (ALI) cultures of human bronchial epithelial cells (HBECs) were generated, differentiated in vitro, and infected apically with SARS-CoV-2, and the infection was monitored over time. (B) HBEC ALI cultures fixed at 96 h postinfection were stained for viral nucleocapsid protein (NP), α-tubulin (ciliated cells), muc5AC (goblet cells), and DAPI (nuclei) and imaged at 60× on a confocal microscope. Scale bar = 20 μm. Infected cells showing costaining with either α-tubulin (1) or muc5AC (2) are shown in greater magnification. (C) Time kinetics of HBEC ALI cultures (n = 2) from three different donors (1, 2, and 3) infected with SARS-CoV-2 at an MOI of 0.05; (D) time kinetics for donor 1 and 3 at an MOI of 0.5. Infection was analyzed by qPCR of both apical (viral release during 1 h) and basolateral samples collected at the indicated time points.