T - Lymphocytic Leukemia Expresses Complex , Branched 0 - Linked Oligosaccharides on a Major Sialoglycoprotein

Leukocytes express a major sialoglycoprotein, leukosialin, of which the apparent molecular weight (mol wt) can be variable according to the differences in 0-glycans attached to this molecule. In the present study, we analyzed the structures of 0-glycans attached to leukosialin present in various T-lymphocytic leukemia cells. T-lymphoid cells from patients with acute T-lymphocytic leukemia express a large amount of the branched hexasaccharides, NeuNAca2 -+ 3Galp1 -+ 3(NeuNAcaZ + 3Galpl -+ 4GlcNAcpl -+ 6)GalNAc. which are also expressed in activated normal T lymphocytes, but that are almost absent in resting normal T lymphocytes. T-lymphoid cells from patients with chronic T-lymphocytic leukemia, on the other hand. mainly express the tetrasaccharides