What is HIV known for doing in the body?

HIV, or Human Immunodeficiency Virus, is primarily known for its ability to infect and kill immune cells, particularly CD4+ T cells, which are crucial for a healthy immune response. When HIV enters the body, it targets these cells, using them to replicate and spread the virus further. As the virus continues to multiply and destroy these immune cells, it severely weakens the immune system over time, leading to a higher susceptibility to opportunistic infections and diseases.

This characteristic of HIV is fundamental to understanding the progression of the disease. Without sufficient CD4+ T cells, the body loses its ability to fight off infections and diseases effectively, which ultimately can lead to acquired immunodeficiency syndrome (AIDS). The correct answer emphasizes the harmful impact of HIV on the immune system, distinguishing this virus from others that may have different roles or effects on human health.