HIV virology: implications for the pathogenesis of HIV infection

Infection by the human immunodeficiency virus (HIV) causes a wide variety of disease ranging from positive blood tests for HIV infection without accompanying symptoms, to the extensive deterioration of the immune system. Characteristics of the HIV life cycle may influence the disease process of HIV infection. HIV specifically attacks and destroys CD4 cells, a type of immune cell. CD4 cells are involved in the production of immune proteins called antibodies, another type of immune cell. Antibodies are produced in the presence of a foreign substance such as a virus, and can specifically bind and inactivate the virus. Hence, HIV destruction of CD4 cells decrease the production of antibodies and reduce the ability of the patient to fight viral infection. The viral envelope, or outer structure of the virus, consists of antigens, components that can activate an immune response. Because the viral envelope of HIV is highly variable, the ability of the patient's immune response to control HIV infection is limited. The persistence of HIV results from the ability of the virus to integrate its genetic material into the cells of the infected individual. This viral genetic material can then be activated by cell signals that control normal immune cell activation. In this way, HIV replication is be linked with the normal cell functions of the patient. These characteristics contribute to the chronic and progressive nature of HIV infection. (Consumer Summary produced by Reliance Medical Information, Inc.)