NIAID scientists discover how HIV kills immune system

Scientists at the National Institute of Allergy and Infectious Diseases recently discovered exactly how and when HIV destroys a person's immune system, which may change the face of HIV treatment.

An HIV infection harms the immune system by killing infection-fighting cells, but the specific way in which this was done was unknown, until now. HIV replicates inside CD4+T cells, infection-fighting human immune cells, and inserts its genes into cellular DNA. During this process, scientists were surprised to find the cellular enzyme DNA-dependent protein kinase, DNA-PK, became activated.

DNA-PK usually organizes the repair of breaks in strands of molecules within DNA. As HIV breaks the DNA during the infection process, the DNA-PK performs a destructive role and signals the CD4+T cells to die. The very cells that are supposed to fight the infection are the ones signaled to die as the HIV begins its destructive process.

This discovery has the potential to change how HIV is treated. Scientists said if an HIV-infected person detects the infection early, a process to prevent the DNA-PK signal can not only prevent the destruction of the immune system but may also improve CD4+T cell and immune function.

Scientists are also hopeful this study will reveal how resting HIV-infected cells develop so these sites can be targeted in future treatment methods.