Figure 3.

Intimate relationship between Fcγbp and mucin on the bronchial mucosa. IgG-SARS-CoV-2 immune complex is bound to Fcγbp through the Fc portion of IgG. Fcγbp is attached tightly to mucin, and SARS-CoV-2 can be eliminated by mucin secretion. (a) and (b) illustrate situations without Fcγbp production: (a) Fcγbp (–), IgG (–); (b) Fcγbp (–), IgG (+). (c) and (d) indicate situations with secretion of Fcγbp attached to the mucin flow: (c) Fcγbp (+), IgG (–); (d) Fcγbp (+), IgG (+). When IgG trapping SARS-CoV-2 is bound to Fcγbp (d), SARS-CoV-2 is effectively eliminated by Fcγbp on the mucin molecules.

SARS-CoV-2: severe acute respiratory syndrome coronavirus-2.