Which MHC class is primarily involved in signaling and communication rather than antigen binding?

MHC class III is primarily involved in signaling and communication rather than directly participating in antigen presentation. While MHC class I and MHC class II molecules are typically recognized for their roles in binding and presenting peptides to T cells, MHC class III molecules contribute to the immune response through the production of various cytokines and complement proteins, which are essential for cell signaling and communication between immune cells.

This functional distinction highlights the importance of MHC class III in modulating immune reactions, even though it does not bind antigens in the manner that MHC class I and MHC class II molecules do. Understanding this division helps clarify the roles of different molecules in the immune response and their mechanisms of action, illustrating that MHC class III is more about facilitating communication within the immune system rather than presenting specific antigens to T cells.