FIG. 5.

Transwell assay of in vitro transepithelial neutralization. An epithelial monolayer was preincubated with the antibodies from the basal side before HIV-infected PBMCs were added from the apical side. After 3 h of coincubation, p24 levels on both sides of the transwell were determined by ELISA. The reduction is presented as the percentage of p24 found in the basal medium when incubated with the antibodies compared to p24 levels in the basal medium of the isotype control, representing uninhibited transcytosis of the virus.