Adhesion molecules controlling lymphocyte migration.

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• Circulating lymphoid cells interact with the vessel wall via adhesion molecules.
• Integrin and immunoglobulin supergene families are known mediators of this interaction.

Purpose of the Study:

• To characterize newly identified structural families of adhesion molecules.
• To investigate their role in lymphocyte recirculation and adhesion events.

Main Methods:

• Structural analysis of adhesion molecule families (Hermes/CD44, Mel-14).
• Sequence homology comparisons to known protein structures (cartilage link proteins, lectins, EGF, complement binding proteins).

Main Results:

• Identified Hermes/CD44 family with homology to cartilage link proteins, involved in attachment to vascular beds.
• Characterized Mel-14 receptor with lectin, EGF, and complement binding protein domains, supporting lectin-carbohydrate interactions in lymphocyte homing.
• Extended this structural family to ELAM-1 and GMP-140, implicating them in leukocyte and platelet adhesion.

Conclusions:

• Two novel adhesion molecule families play critical roles in leukocyte-vessel wall interactions.
• Lectin-carbohydrate interactions are significant in lymphocyte recirculation.
• The findings expand the understanding of adhesion mechanisms in immune cell trafficking.