Figure 6

T lymphocyte [helper]_B lymphocyte [APC] as an instance of the "Cell_Cell_Interaction" concept. This instance is shown as Th_B in Fig. 2. Note that the interaction between the T cell receptor (TR), on the surface of the T lymphocyte [helper], and the pMHC-II, on the surface of the B lymphocyte (as antigen presenting cell or [APC]), is also an instance of the "Molecule_Molecule_Interaction". This example illustrates, as Fig. 4, how the IMGT-ONTOLOGY concepts of interactions allow to bridge the gap between the cell and molecule levels.