Fig. 3.

Intercellular protein transfer is regulated by membrane properties. (A) The representative phase-contrast image showing tunneling nanotubes connecting a HUVEC and a 1205Lu cell; scale bar = 5 μm. (B) Average GFP intensity in HUVECs when co-cultured with 1205Lu-GFP cells in the presence of cytochalasin B for 7 days with an initial seeding. (C) Computational model simulation of a patterned co-culture set-up without, and with decreased nanotube stability (or the average nanotube length decreased by 50%), causing high diffusion of cytosolic proteins due to enhanced formation of transient heterotypic cell–cell bonds. Time lapse acquirement of GFP levels is shown in HUVECs at various distances from the 1205Lu-GFP cells; the distance is shown in units of HUVEC cell lengths. (D) Flow cytometry analysis of co-culture of HUVECs and 1205Lu-GFP cells with a 1 : 3 ratio at an initial total density of 100 000 cm⁻² for 7 days in the presence of DMSO (Cntrl), Cyclodextrin (CycloD), and Linoleic Acid (LA). In the panels above, *, P < 0.05, ***, P < 0.001; error bars represent the standard error of mean (s.e.m.).