Case Study Argumentative Essay Example

and command the immune system while instructing Killer T cells and B cells. However, HIV targets Helper T cells by binding its gp120 protein to the CD4 protein on their surface.

HIV does not target B Cells that lack the CD4 protein because this protein is necessary for virus binding and cell entry. If some Helper T cells remain functional, they will instruct killer T cells to eliminate infected cells. However, over time, cytotoxic cells stop responding to HIV because all Helper T cells become infected. As a result, they can no longer guide killer T cells and B cells. Furthermore, killer T cells no longer recognize HIV as foreign since it is present in all cells rather than just a few. Once the immune system becomes infected with HIV, it actively fights against the virus but cannot completely eliminate it. Instead of producing more antibodies against HIV, helper T cells – which coordinate defenses against the virus – end up serving as factories for generating more copies of the virus (source: http://www.thebody.com/h/what-happens-when-the-immune-system-is-weakened-by-hiv-infection.html).

The immune system responds to HIV infection by increasing the production of T cells, some of which develop into helper T cells. Nevertheless, as time goes on, the virus specifically attacks and infects these helper T cells, leading to their destruction. Despite continuous attempts to combat the infection and generate more T cells, there comes a stage when the body is no longer able to produce sufficient T cells. Consequently, this decrease in helper T cells leaves the body susceptible to typically harmless microorganisms like bacteria and viruses (excluding HIV).

This acquired condition of immunodeficiency is known as AIDS

(http://people. u. edu/~jbrown/hiv. html) F HIV manages to evade the immune system. HIV is gp120, a protein that recognizes and binds to a protein called CD4 present on the surface of Helper T cells. Once the virus is docked, its lipid membrane fuses with the human cell, or HIV is taken into the cell through endocytosis. Some individuals may have protection against HIV due to the presence of HLA (Human Leukocyte Antigen). If a person has HLA, their cells are especially effective at displaying fragments of HIV in a binding groove that enables killer T cells to identify and eliminate infected cells before they can act as virus replication centers.