Final answer:
T cell-dependent activation of B cells requires two signals, recognition of native antigen by the B cell's surface immunoglobulin and activation of T helper cells, which secrete cytokines to fully activate the B cell.
Step-by-step explanation:
T cell-dependent activation of B cells requires two signals for activation. T cell-dependent activation of B cells requires two signals, recognition of native antigen by the B cell's surface immunoglobulin and activation of T helper cells, which secrete cytokines to fully activate the B cell. The first signal is when the B cell's surface immunoglobulin recognizes the native antigen.
The second signal occurs when some of the antigen is internalized, processed, and presented to T helper cells on a class II MHC molecule. The T helper cell binds to the B cell using its antigen receptor and is activated to secrete cytokines that diffuse to the B cell, fully activating it. This process allows the B cell to differentiate into antibody-secreting plasma cells.