Barrier function of the Vero E6 cell monolayer.

Vero E6 cells are a standard model in virology research because of their broad susceptibility to viral infection. However, their ability to form functional barrier layers has received less attention. Here, we show that Vero E6 cells cultured on transwell inserts develop continuous monolayers with moderate transepithelial electrical resistance (TEER), reaching approximately 30 Ω·cm2 in serum-containing medium and 45 Ω·cm2 in virus production medium. The permeability coefficient (Papp) for 4 kDa FITC-dextran, a common measure for paracellular transport, is 3.7 × 10-6 cm/s, comparable to established endothelial models such as HUVEC or corneal endothelium. Immunofluorescence confirms the presence of tight junction (ZO-1) and adherens junction (β-catenin) proteins. Chelation of calcium with EGTA causes a dose-dependent, reversible decrease in TEER and a marked increase in permeability, confirming the calcium sensitivity of the barrier. These findings suggest that Vero E6 cells serve as a valuable epithelial barrier model, facilitating studies on viral entry, immune evasion, and drug delivery.