HIV-1 selectively kills regulatory T cells for the efficient propagation

HIV-1 selectively kills regulatory T cells (Treg). Treg are the lymphocytes that suppress the activity of other lymphocytes. HIV-1 fundamentally kills activated lymphocytes selectively, because HIV-1 uses CCR5 molecules, which are expressed on the surface of activated lymphocytes, for viral invasion into the target cells. In addition, since the HIV-1 growth is dependent on the host cellular transcription, the active cellular transcription hastens the viral growth. Treg also highly express CCR5 molecules, moreover Treg themselves are replication-active lymphocytes. Accordingly, Treg are the perfect targets for HIV-1 infection. Depletion of Treg after HIV-1 infection enhances the other lymphocyte’s activation, which results in making of the suitable environment for HIV-1 proliferation. This is the clever strategy of HIV-1.