What is a key function of CD-4 T cells?

• A. Killing infected cells
• B. Activating B cells
• C. Generating antibodies
• D. Producing cytokines

Answer: (B)

CD-4 T cells, also known as helper T cells, play a crucial role in the immune response by activating other immune cells, particularly B cells. When CD-4 T cells recognize antigens presented by antigen-presenting cells (APCs), they release various cytokines that enhance the activity of B cells and stimulate their differentiation into plasma cells, which are responsible for producing antibodies. This activation leads to a more robust and effective immune response against pathogens.

The ability of CD-4 T cells to activate B cells is vital for coordinating the adaptive immune response, leading to the production of specific antibodies that can neutralize pathogens or mark them for destruction by other immune cells. Thus, their primary role is centered around supporting and activating other elements of the immune system, particularly in the context of humoral immunity.