Cell-mediated (cellular) immunity is a type of specific defense mediated mainly by which of the following cell types?

• A. B lymphocytes (B cells)
• B. T lymphocytes (T cells)
• C. Macrophages
• D. Neutrophils

Answer: (B)

Verified step by step guidance

1. Understand that cell-mediated immunity is a branch of the adaptive immune system that does not involve antibodies but instead relies on the activation of certain immune cells to fight pathogens.
2. Recall that B lymphocytes (B cells) are primarily responsible for humoral immunity, which involves the production of antibodies to neutralize extracellular pathogens.
3. Recognize that macrophages and neutrophils are part of the innate immune system and act as phagocytes to engulf and destroy pathogens nonspecifically.
4. Identify that T lymphocytes (T cells) are the main players in cell-mediated immunity, as they can directly kill infected cells or help other immune cells respond to pathogens.
5. Conclude that the correct cell type mediating cell-mediated immunity is T lymphocytes (T cells), which include subsets such as cytotoxic T cells and helper T cells.