What term is used to describe cells that present antigens to other immune cells?

• A. Antigen-Presenting Cells
• B. Killer Cells
• C. Null Cells
• D. Plasma Cells

Answer: (A)

Antigen presentation is the process by which certain immune cells display fragments of pathogens on their surface to help activate T cells and coordinate the immune response. Cells that perform this role are antigen-presenting cells, including dendritic cells, macrophages, and B cells. They present processed antigen with MHC molecules, enabling T cells to recognize the threat and become activated. Plasma cells, derived from B cells, primarily secrete antibodies and do not present antigens to other immune cells. Killer cells target and kill infected cells directly, not present antigens to other immune cells. Null cells is an older term often associated with NK cells and also does not describe antigen presentation.