Manor Preboards Module 6 Practice Test

HIV most affects CD4-positive T helper lymphocytes because the virus binds to the CD4 receptor on these cells (often using a co-receptor as well) to gain entry and replicate. These helper T cells are the conductors of the immune system: they activate B cells to make antibodies and help cytotoxic T cells and other immune cells respond properly. When HIV depletes these cells, the immune system loses its coordination, leading to the immunodeficiency characteristic of AIDS. Other cells aren’t the primary targets. Phagocytes can be infected to some extent, but they are not the main population HIV drives into dysfunction. B-lymphocytes aren’t the primary entry point for the virus, and cytotoxic T cells (CD8+ cells) are more affected indirectly through the loss of helper signals rather than being the main initial targets.