Changes in asparagine-linked sugar chains of human promyelocytic leukemic cells (HL-60) during monocytoid differentiation and myeloid differentiation. Appearance of high mannose-type oligosaccharides in neutral fraction

Abstract

Structural changes in the asparagine-linked sugar chains of plasma membrane glycoproteins during myeloid and monocytoid differentiation were investigated by the use of an in vitro differentiation system for human promyelocytic leukemic cells (HL-60), which can be induced to more mature myeloid cells by exposure to dimethyl sulfoxide and to macrophage-like cells by a phorbol ester. The asparagine-linked sugar chains released from their plasma membranes by hydrazinolysis were separated into a neutral fraction and an acidic fraction composed of over ten components. The content of neutral oligosaccharides, which accounted for 8% of the total asparagine-linked sugar chains in HL-60 cells, increased slightly to 13% in dimethyl sulfoxide-induced cells and markedly to 33% in phorbol ester-induced cells. Structural analyses revealed that the neutral oligosaccharides of HL-60 cells are all of the complex type with a variety of Gal beta 1----4GlcNAc beta 1----units in their outer chain moieties and the following core structure: (sequence; see text) After myeloid and monocytoid differentiation, the total amount of neutral complex-type sugar chains did not change significantly, but newly found high mannose-type sugar chains contributed up to 3% and 24% of the total sugar chains, respectively.