hiv

             all daughter cells during subsequent cell divisions. Then in one or more of.
             these daughter cells, the virus produces RNA copies of its genetic material.
             These new HIV clones become covered with protein coats and leave the cell to.
             find other host cells where they can repeat the life cycle.
             The Body Fights Back.
             As viruses begin to invade the body, a few are consumed by macrophages,.
             which seize their antigens and display them on their own surfaces. Among.
             millions of helper T cells circulating in the bloodstream, a select few are.
             programmed to "read" that antigen. Binding the macrophage, the T cell.
             becomes activated. Once activated, helper T cells begin to multiply. They.
             then stimulate the multiplication of those few killer T cells and B cells.
             that are sensitive to the invading viruses. As the number of B cells.
             increases, helper T cells signal them to start producing antibodies.
             Meanwhile, some of the viruses have entered cells of the body - the only.
             place they are able to replicate. Killer T cells will sacrifice these cells.
             by chemically puncturing their membranes, letting the contents spill out,.
             thus disrupting the viral replication cycle. Antibodies then neutralize the.
             viruses by binding directly to their surfaces, preventing them from attacking.
             other cells. Additionally, they precipitate chemical reactions that actually.
             destroy the infected cells. As the infection is contained, suppresser T.
             cells halt the entire range of immune responses, preventing them from.
             spiraling out of control. Memory T and B cells are left in the blood and.
             lymphatic system, ready to move quickly should the same virus once again.
             invade the body.
             HIV's Life Cycle.
             In the initial stage of HIV infection, the virus colonizes helper T cells,.
             specifically CD4+ cells, and macrophages, while replicating itself relatively.
             unnoticed. As the amount of the virus soars, the number of helper cells.
             falls; macrophages die as well.