VLA receptors, short for very late antigen receptors, are a group of cell surface proteins that are primarily found on white blood cells known as leukocytes. They belong to the integrin family of adhesion molecules and play a crucial role in cell adhesion and migration processes during immune responses.
VLA receptors are heterodimeric molecules composed of different combinations of α and β subunits. The most well-known VLA receptors are α4β1 (also known as very late antigen-4 or VLA-4), α5β1 (VLA-5), and αVβ3 (VLA-6). These receptors are expressed on various leukocyte subsets including lymphocytes, monocytes, and granulocytes.
Their main function is to mediate cell-to-cell and cell-to-extracellular matrix interactions by binding to specific ligands such as fibronectin, laminin, and VCAM-1 (vascular cell adhesion molecule-1). Through these interactions, VLA receptors facilitate leukocyte migration and trafficking to sites of inflammation or infection.
VLA receptors are crucial for immune cell recruitment, as they help leukocytes adhere to the inner lining of blood vessels and traverse the vascular endothelium to reach the inflamed tissues. Additionally, VLA receptors are involved in the regulation of immune cell activation and survival signals.
Given their significance in immune responses, VLA receptors have emerged as promising targets for therapeutic interventions in various pathological conditions such as autoimmune diseases, inflammatory disorders, and certain cancers. Modulating VLA receptor activity and interactions have the potential to regulate leukocyte trafficking and dampen excessive immune responses, leading to improved disease outcomes.
