Cell surface glycoprotein changes in Epstein-Barr virus-positive and -negative human hematopoietic cell lines

Area of Science:

• Glycobiology
• Cell Biology
• Oncology

Background:

• Tumor cells exhibit altered fucosyl glycopeptides compared to normal cells.
• Previous studies indicated increased fast-eluting glycopeptides in tumor cells after fucose labeling and enzymatic degradation.

Purpose of the Study:

• To investigate alterations in cell-surface fucosyl glycopeptides of human hematopoietic cell lines.
• To compare these alterations in normal lymphocytes, Epstein-Barr virus (EBV)-carrying lymphoblastoid cells, and various malignant cell lines.

Main Methods:

• Differential fucose labeling of cell-surface glycoproteins.
• Proteolytic release and degradation of labeled glycopeptides.
• Gel filtration chromatography to analyze glycopeptide elution profiles.
• Treatment with neuraminidase or mild acid to further characterize glycopeptides.

Main Results:

• Both EBV-carrying lymphoblastoid cells and malignant hematopoietic cell lines showed an increase in fast-eluting fucosyl glycopeptides compared to normal lymphocytes.
• These alterations were observed in most malignant and lymphoblastoid cell lines, suggesting a common change associated with malignant conversion or EBV infection.
• Neuraminidase or mild acid pretreatment allowed for the categorization of different hematopoietic cell lines based on their glycopeptide behavior.

Conclusions:

• Malignant transformation of human lymphoid cells in vivo is frequently associated with specific changes in fucosyl glycopeptide composition.
• EBV infection of B lymphocytes not only causes immortalization but also induces alterations in fucosyl glycopeptides similar to those in neoplastic cells.