Final answer:
The area of contact between membranes of a T cell and an antigen-presenting cell where a clustering of protein-protein interactions occur is called an immunological synapse.
Step-by-step explanation:
The area of contact between membranes of a T cell and an antigen-presenting cell where a clustering of protein-protein interactions occur is called an immunological synapse. During this process, the antigens are processed and presented by the antigen-presenting cell, and the T cell receptor recognizes and binds to the antigen presented on the major histocompatibility complex (MHC) molecule.