FIGURE 7.

GalNAc exposure is associated with ERK activation. CD4⁺ T cells were left untreated or stimulated overnight with αCD3/CD28 beads in the presence or absence of the inhibitor FK506 (calcineurin, 10 nm) and/or the MAPK kinase inhibitors U0126 (MEK/ERK, 25 mm), SB203580 (p38 MAPK, 12.5 mm), SP600125 (JNK, 25 mm), and subsequently characterized for their surface glycosylation by lectin binding. Glycan specificities of the lectins used HPA, α-GalNAc/Tn, PNA, Galβ1–3GalNAc, and SBA, α/β-GalNAc. DMSO was added as a vehicle control. All inhibitors were titrated and used at concentrations that allowed for at least 90% cell survival. 7-AAD was included to exclude dead cells. All inhibitors were tested in at least three independent donors, yielding similar results. One representative donor is shown.