Figure 7.

GlcNAc and lactose treatments stimulate CIE in Beas2b cells via alternate routes. Antibody internalization for 30 min at 37 °C in Beas2b cells after 48-h incubation with or without 10 mm GlcNAc and in the presence or absence of 100 mm lactose (after a 1-h pretreatment) for MHCI (A) and CD59 (B) shows that increased glycan branching (due to GlcNAc treatment) leads to an increase in CIE for both cargos. Surprisingly, lactose treatment also led to an increase in CIE for both cargos. C, representative images of CD59 internalization with and without lactose treatment. The increase in internalization observed with lactose corresponds to an increase in fraction of cells performing macropinocytosis (D) and an increase in the number of macropinosomes/cell (E). Scale bars, 20 μm. At least three experiments were carried out with data expressed as mean ± S.D. (error bars). *, p < 0.05.