Meyer & Kofler, 2018. Cellular and Molecular Immunology.
BACKGROUND: The scavenger-like lymphocyte receptor CD6 is a regulator of T cell functions, and is associated with autoimmune diseases. However, the specific contribution of CD6 to autoimmunity remains unknown. Under physiological conditions, CD6 associates with the T cell antigen receptor (TCR)/CD3 complex at the center of the immunological synapse and regulates T cell responses through activation-dependent recruitment of the positive regulator SLP-76 and other downstream signaling effectors.1,2 In recent years, immune-activating and immune-inhibiting functions of CD6 have been reported, indicating a dual role of CD6 in T cell activation.1 It has been postulated that the strength of TCR activation determines whether CD6 enhances or inhibits TCR signaling. This possible counter-regulatory role of CD6 may contribute to the control of T cell responses.