HIV. Computer artwork of HIV (human immunodeficiency virus), the virus that causes AIDS (acquired immune deficiency syndrome). HIV features an outer lipid membrane which encases the RNA-containing protein (genetic component) capsid of the virus. Globular structures protruding from the outer layer represent surface glycoproteins. The virus enters CD4+ T-lymphocytes (white blood cells) and hijacks the host cell's machinery to copy itself. The cell dies when the virus clones burst from it, weakening the immune system and causing AIDS.