Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: What we still don’t know about AIDS. | Journal of Biology Editorial What we still don t know about AIDS Miranda Robertson A great deal is known about the human immunodeficiency virus HIV that causes acquired immune deficiency syndrome AIDS 1 one of whose cardinal features is its exquisite adaptation to its human host. It enters the body through damaged epithelia or more insidiously through specialized cells M cells in the intestinal epithelium whose function is to deliver viruses and bacteria to waiting immune cells in the tissue below. There the virus binds to a specialized receptor on the surface of one of these cells - the dendritic cells which play a central part in activating the CD4 T lymphocytes whose destruction by the virus ultimately and lethally disables the immune system. Recognition of the bound virus causes the dendritic cell to migrate to the lymphoid tissues where it engages with the CD4 T lymphocytes that it activates. This enables the virus to bind to molecules on the surface of the T cell - a highly specific interaction involving the CD4 molecules that give CD4 T cells their name and that enables the virus to enter the cell. Once the virus is inside the cell it produces DNA copies of its genome that integrate into the host DNA where cellular transcriptional regulators specifically induced by activation of CD4 T cells are instrumental in activating transcription of the viral genome to produce more viruses. A great deal is unknown about what happens to the adaptive immune system in consequence of this fiendish and focused assault. The adaptive immune system consists of the lymphocytes that provide lasting immunity and CD4 T lymphocytes are essential to activating most of adaptive immunity. The loss of these cells in HIV infection thus punches an enormous hole in the immune defences of the host. But CD4 T cells are homeostatically selfrenewing and it is still unclear exactly why they are progressively lost in HIV infection. It is also unclear what happens to the dynamics of the immune .
