Expression of intercellular adhesion molecule-1 (ICAM-1) on human thyroid cells lines correlated with their binding...

Area of Science:

• Immunology
• Cell Biology
• Endocrinology

Background:

• Intercellular adhesion molecule-1 (ICAM-1) plays a role in immune cell interactions.
• Thyroid cells' immune response mechanisms are not fully understood.
• Novel human thyroid cell lines (SGHTL) provide a model for studying thyroid cell behavior.

Purpose of the Study:

• To investigate ICAM-1 expression in human thyroid cells.
• To determine the role of ICAM-1 in lymphocyte adhesion to thyroid cells.
• To elucidate the molecular pathways involved in thyroid cell-lymphocyte interactions.

Main Methods:

• Utilized novel functional human thyroid cell lines (SGHTL).
• Analyzed ICAM-1 expression using cytokine stimulation (gamma-interferon, interleukin-1, tumor necrosis factor).
• Assessed lymphocyte binding to thyroid cells and inhibition using monoclonal antibodies against ICAM-1, LFA-1, CD2, and MHC class II antigens.

Main Results:

• ICAM-1 is constitutively expressed on SGHTL cells and rapidly upregulated by recombinant cytokines.
• Major histocompatibility complex (MHC) class II antigens showed slower upregulation by gamma-interferon.
• Activated lymphocyte binding to SGHTL cells increased after cytokine treatment and was inhibited by anti-ICAM-1 and anti-LFA-1 antibodies.

Conclusions:

• Thyroid cell binding of lymphocytes involves an LFA-1 and ICAM-1 dependent pathway.
• Cytokine-induced upregulation of ICAM-1 enhances lymphocyte adhesion.
• The interaction does not appear to involve MHC class II antigens or CD2.