Definition for Clonal expansion
From Biology Forums Dictionary
Once displayed on the surface of the antigen-presenting cell, the foreign antigen-MHC complex is scanned by the millions of T cells present in the lymph nodes. If the T cell is able to bind to this complex, the T cell becomes activated and begins to go through a number of mitotic divisions. This is referred to as clonal expansion and enables a significant increase in the number of T cells that recognize the antigen.
