In AIDS, the HIV virus destroys which of the cells involved in the immune response?

• A. B cells and T cells
• B. T cells and dendritic cells
• C. T helper cells and macrophages
• D. Null cells and dendritic cells

Answer: (C)

HIV attacks cells that coordinate and amplify the immune response. It binds to the CD4 receptor on helper T cells, and over time these T helper cells are depleted. Since they guide both antibody production by B cells and the activation of other immune cells, their loss weakens the whole immune system and sets the stage for AIDS.

Macrophages can also be infected because they express CD4 and the appropriate co-receptors. When macrophages are compromised, their ability to engulf pathogens and present antigens is reduced, and they can act as reservoirs for ongoing HIV replication, further weakening immune defenses.

B cells, dendritic cells, and NK cells aren’t the primary targets of destruction in HIV infection, so the most accurate pairing is the loss or dysfunction of T helper cells and macrophages.