EXPRESSION OF BETA-1-6-BRANCHED N-LINKED OLIGOSACCHARIDES IS ASSOCIATED WITH ACTIVATION IN HUMAN T4 AND T8 CELL-POPULATIONS

Activation of human T lymphocytes by phorbol 12-myristate 13-acetate a nd leukoagglutinin from Phaseolus vulgaris (L PHA) results in importan t changes in N-glycosylation. The most important event is the increase , in both T4 and T8 cells (especially the latter), of L-PHA(+) structu res characterized by beta 1-6-branching of complex-type oligosaccharid es. Moreover, the existence of a CD4-mediated increase of these beta 1 -6-branched structures on positively selected T4 cells, as compared wi th the negatively selected ones, suggests that the presence of these s tructures, not detectable on T8 resting cells, could be related to sti mulation events triggered by both selection methods. This beta 1-6-bra nching on N-glycans, strongly associated with a metastatic phenotype i n human and rodent tumors, is exhibited by numerous glycoproteins on s timulated cells, as shown by blot analysis.