Lectin activity as a marker for Hodgkin disease cells

Area of Science:

• Biochemistry
• Cell Biology
• Immunology

Background:

• Hodgkin disease (HD) cells display reduced VIM-D5 antibody reactivity due to neuraminidase treatment, affecting the X hapten (fucosyl-N-acetyllactosamine).
• HD cells characteristically express high levels of ectosialyltransferase activity.

Purpose of the Study:

• To investigate the cause-effect relationship between ectosialyltransferase activity and VIM-D5 antigenicity in HD cells.
• To explore the potential lectin activity of ectosialyltransferase and its role in antigen recognition.
• To establish a relationship between HD cell surface lectin activity and the hepatic binding protein (HBP).

Main Methods:

• Neuraminidase treatment of cultured HD cells.
• Modulation of ectosialyltransferase activity to restore VIM-D5 antigenicity.
• Utilizing antiserum to hepatic binding protein (HBP) to inhibit VIM-D5 antigen loss.
• Assessing asialoglycoprotein binding to hepatocytes after HD cell interaction.
• Confirming lectin activity through erythrocyte agglutination by HD cells.

Main Results:

• Restoration of VIM-D5 antigenicity on neuraminidase-treated HD cells by modulating transferase activity.
• Evidence of ectosialyltransferase exhibiting lectin activity, binding desialylated galactosyl residues and hindering VIM-D5 recognition.
• Antiserum to HBP inhibited neuraminidase-induced VIM-D5 antigen loss and blocked asialoglycoprotein binding.
• HD cells demonstrated erythrocyte-agglutinating ability, confirming surface lectin activity.

Conclusions:

• Ectosialyltransferase on HD cells possesses lectin activity that influences VIM-D5 antigenicity, potentially through autoinhibition similar to HBP.
• A strong relationship exists between the HD cell galactophilic binding site and HBP.
• The lectin activity associated with HD cell ectosialyltransferase may function as a specific marker for abnormal Hodgkin disease cells.