Involvement of ICAM-1, actin and VCAM-1 in the binding of IRBCs on HBECs.

HBECs D3 were grown to confluence, incubated overnight with 10 ng/ml TNF and co-cultured with IRBCs for 90 min before processing and labelling with anti-ICAM-1, phalloidin or anti-VCAM-1.. Bar: 20µm (A, B, E–G), 10µm (C–D). A–B) show PKH-labelled IRBC stacked onto the HBECs and colocalized with ICAM-1 labelling. ICAM-1 was both detected on the surface of the HBECs and in the engulfing cup of the IRBCs, C–D) show engulfment of an IRBC by HBEC. ICAM-1 and actin are co-localized in the engulfing cup (arrow). E) shows stress actin fibres in HBECs (arrow) and accumulation of actin in the engulfing cup (arrow) of PKH-labelled IRBCs. F) same as A–B but with VCAM1 detection in the engulfing cup (arrow). G) same as A–B with control mouse IgG1 isotype labelling showing no signal.