And class two is used for communicating between different types of white blood cells. So AlphaBeta T cells can only interact with these antigen presenting cells. Now, what about the other category of T cells known as the gamma delta T cells? So the gamma delta T cells contain T cell receptors that are slightly different. Instead of having an alpha and a basic polypeptide submune we have a gamma and a delta polypeptide subune as shown in the following diagram. So the purple is our gamma and the blue is our delta.