1 Answers
CD28 family receptors are a group of regulatory cell surface receptors expressed on immune cells. The CD28 family in turn is a subgroup of the immunoglobulin superfamily.
Two family members, CD28 and ICOS, act as positive regulators of T cell function while another three, BTLA, CTLA-4 and PD-1 act as inhibitors. Ligands for the CD28 receptor family include B7 family proteins.
CD28 receptors play a role in the development and proliferation of T cells. The CD28 receptors enhance signals from the T cell receptors in order to stimulate an immune response and an anti-inflammatory response on regulatory T cells. Through the promotion of T cell function, CD28 receptors allow effector T cells to combat regulatory T cell-mediated suppression from adaptive immunity. CD28 receptors also elicit the prevention of spontaneous autoimmunity.