Immunological aspect of CD4+ cells
CD4+ cells are a type of white blood cell. These cells are part of the immune system . White blood cells protect the body against infection. CD4+ cells are also called T-lymphocytes, T-cells, or T-helper cells. There are two main types of CD4 cells. T-4 cells, also called CD4+, are “helper” cells. They lead the attack against infections. T-8 cells (CD8+) are “suppressor” cells that end the immune response. CD8 cells can also be “killer” cells that kill cancer cells and cells infected with a virus.
HIV most often infects CD4 cells. The virus becomes part of the cells, and when they multiply to fight an infection, they make more copies of HIV. HIV invades and destroys CD4+ cells. But the body continues to produce new CD4+ cells to fight the HIV infection. If the infection is not treated with medicines, the body gradually loses the ability to produce enough CD4+ cells to replace the number that are being destroyed by HIV. When someone is infected with HIV but has not started treatment, the number of CD4 cells stands go to down. This is a sign that the immune system is being weakened. The lower the CD4 cell count, the more likely the person will get sick. There are millions of different families of CD4 cells. Each family is designed to fight a specific type of germ. CD4+ counts are measured every 3 to 4 months in people who are infected with HIV. The CD4+ count is an important measurement of how HIV is affecting your immune system and can help you decide when to begin treatment for HIV or when you need to try a different combination of medicines.