What type of B cell daughter cell is specifically responsible for producing antibodies against the activating antigen?

The type of B cell daughter cell that is specifically responsible for producing antibodies against the activating antigen is the plasma cell. When naive B cells are activated by an antigen, they undergo a process of proliferation and differentiation. Some of these activated B cells will become memory cells, which are important for long-term immunity, but it is the plasma cells that are primarily responsible for the immediate production of antibodies.

Plasma cells are specialized for this purpose; they are essentially the effector form of B cells that have undergone clonal selection and expansion. Once differentiated into plasma cells, they secrete large amounts of antibodies specific to the antigen that triggered their activation. These antibodies play a critical role in the immune response by neutralizing pathogens or marking them for destruction by other immune cells.

Memory cells, while important for the secondary immune response, do not produce antibodies directly; instead, they are responsible for long-term immunity by quickly responding to future exposures to the same antigen. Regulatory cells, on the other hand, are involved in maintaining tolerance and preventing autoimmune reactions, not in antibody production. Naive cells refer to B cells that have not yet encountered their specific antigen and are not involved in any active response at that point.