Which cell type is not typically part of the adaptive immune response?

• A. B cells
• B. Dendritic cells
• C. Polymorphonuclear cells
• D. Cytotoxic T lymphocytes

Answer: (C)

Distinguishing innate from adaptive immunity helps answer this. Polymorphonuclear cells, especially neutrophils, are frontline players of the innate immune system. They respond quickly to general infection signals, perform phagocytosis, and release antimicrobial substances, but they do not have antigen-specific receptors or long-term memory. The adaptive immune response, on the other hand, relies on lymphocytes with specific antigen receptors—B cells producing antibodies and cytotoxic T cells targeting infected cells—often with help from dendritic cells that present antigens to T cells to initiate the response. So the cell type not typically part of adaptive immunity is polymorphonuclear cells.