What type of T cells leave secondary lymphatic organs to eliminate foreign cells?

What type of T cells leave secondary lymphatic organs to eliminate foreign cells?

• A. T helper cells
• B. B cells
• C. T cytotoxic cells
• D. NK cells

Answer: (C)

T cytotoxic cells are primarily responsible for directly eliminating foreign cells, such as virus-infected cells and tumor cells. These cells recognize antigens presented by infected or abnormal cells through Major Histocompatibility Complex (MHC) class I molecules. Once activated by interaction with antigen-presenting cells in secondary lymphatic organs, T cytotoxic cells leave these organs and travel through the bloodstream to target and destroy infected or cancerous cells.

In contrast, T helper cells play a more supportive role by activating other immune cells but do not directly kill foreign cells. B cells, which are primarily involved in antibody production, also do not leave secondary lymphatic organs specifically to eliminate foreign cells. NK cells, while capable of destroying infected cells, are part of the innate immune response rather than the adaptive immune response characterized by T cytotoxic cells. Thus, the role of T cytotoxic cells is distinct in its direct action against foreign cells, highlighting their critical function in adaptive immunity.