CD antigens related to cell receptor

We know that there are at least three cell types required for cell receptors, namely the T-cell, B-cell and macrophage. Different classes of cells can readily be distinguished, however, by virtue of the fact that they express unique combinations of molecules in their membranes. Our knowledge of the different cell types involved in cell receptors is a direct result of the development of reagents to distinguish these various cells by their cell surface markers. We will see that such markers include molecules distinguished either by antibodies directed against them, or else by their ability to bind various other molecules or cells.