HIV that causes AIDS first starts destroying:

Explanation

The AIDS retrovirus, called human immunodeficiency virus(HIV), mounts a direct attack on CD4 + T-helper cells because it recognizes the CD4 coreceptors associated with these cells. HIV's attack on CD4 + T cells cripples the immune system in at least three ways. First, HIV-infected cells die only after releasing replicated viruses that infect other CD4 + T cells, until the entire population of CD4 + T cells is destroyed. Second, HIV causes infected CD4 + T cells, to secrete a soluble suppressing factor that blocks other T cells from responding to the HIV antigen. Finally, HIV may block transcription of MHC genes, hindering the recognition and destruction of infected CD4 + T cells, and thus protecting those cells from any remaining vestiges of the immune system. The combined effect of these responses to HIV infection is to wipe out the human immune defense.