Figure 2. Effects of FRG on G614, alpha, beta, gamma, and delta pseudovirus infection.

Calu-3 cells were incubated with rhCHI3L1 (CHI3L1, 250 ng/ml) or vehicle control for 48 hr in the presence of anti-CHI3L1 (FRG) or its isotype control (IgG). Pseudoviruses (PS) that contain S proteins with the (A) G614, (B) alpha, (C) beta, (D) gamma, or (E) delta mutations were added, and GFP was quantitated by fluorescence-activated cell sorting (FACS). The percentage of GFP-positive cells was evaluated by flow cytometry. The noted values are representative of a minimum of three similar evaluations.