Demonstration of lymphocyte surface lectins that recognize sulphated polysaccharides

Area of Science:

• Immunology
• Cell Biology

Background:

• Lymphocytes interact with autologous erythrocytes through a process called autorosetting.
• This interaction involves the recognition of carbohydrate structures on erythrocytes by lymphocytes.

Purpose of the Study:

• To identify the haemagglutinin found in murine lymphocyte extracts.
• To elucidate the role of carbohydrate structures in lymphocyte-erythrocyte interactions.
• To investigate the potential involvement of these interactions in lymphocyte homing and recirculation.

Main Methods:

• Extraction of haemagglutinating activity from murine lymphocytes.
• Species specificity and sugar inhibition assays.
• Experiments with autorosette inhibition factor.
• Detailed sugar inhibition studies using sulphated polysaccharides.

Main Results:

• Murine lymphocyte extracts possess haemagglutinating activity against autologous erythrocytes.
• The haemagglutinin's specificity mirrors that of autorosetting.
• Autorosette inhibition factor blocks both haemagglutination and autorosetting.
• Receptors show high affinity for sulphated polysaccharides like heparin and dextran sulphate.

Conclusions:

• The haemagglutinin and autorosetting receptors are likely the same entity.
• These receptors recognize specific carbohydrate structures, particularly sulphated polysaccharides.
• The findings suggest a role for these receptors in lymphocyte homing and recirculation, potentially via interaction with cell surface carbohydrates.