What is the primary target of HIV within the host immune system?

HIV primarily targets T cells, specifically CD4+ T cells, which are crucial components of the immune system. These cells play a vital role in orchestrating the immune response by activating other immune cells, including B cells that produce antibodies, and cytotoxic T cells that kill infected cells.

When HIV infects CD4+ T cells, it uses them to replicate and spread throughout the body, leading to the gradual decline in the immune system's ability to respond to infections and diseases. The loss of these T cells is a central factor in the progression of HIV infection to AIDS, as individuals become increasingly vulnerable to opportunistic infections and malignancies that a healthy immune system would typically control.

While other immune cells such as B cells, macrophages, and natural killer cells are affected by the overall immune dysfunction caused by HIV, they are not the primary targets of the virus. The primary focus on CD4+ T cells is what distinguishes HIV's mechanism of pathogenesis and underscores the importance of these cells in maintaining immune health.