The full form of CD3 is Cluster of Differentiation 3.
CD3 is a protein complex and T cell co-receptor that plays a crucial role in activating T cells, which are essential components of the adaptive immune system. It's involved in activating both cytotoxic T cells (CD8+ T cells) and T helper cells (CD4+ T cells).
Key aspects of CD3:
- Protein Complex: CD3 is not a single molecule but rather a complex of several different protein chains.
- T Cell Co-Receptor: It works in conjunction with the T cell receptor (TCR) to recognize and bind to antigens presented by antigen-presenting cells.
- Activation Signal: Upon antigen binding, the CD3 complex transmits a signal into the T cell, initiating a cascade of events that lead to T cell activation, proliferation, and ultimately, an immune response.
- Targets in Therapy: Due to its importance in T cell activation, CD3 is a target for immunosuppressive drugs used in transplantation and autoimmune diseases. Some monoclonal antibodies target CD3 to deplete T cells, suppressing the immune response.
