CD4 T cells

Definition

CD4 T cells are a type of white blood cell that play a crucial role in the immune system by helping to coordinate the body's response to infections. They are also known as helper T cells and are essential in fighting off both viral and bacterial infections.

5 Must Know Facts For Your Next Test

1. CD4 T cells are targeted and destroyed by HIV, leading to weakened immune function.
2. They assist other immune cells by releasing cytokines, which help direct the immune response.
3. A healthy CD4 count ranges from 500 to 1,500 cells per cubic millimeter of blood.
4. Low CD4 counts increase susceptibility to opportunistic infections.
5. Antiretroviral therapy (ART) can help maintain higher levels of CD4 T cells in HIV-positive individuals.

Review Questions

• What role do CD4 T cells play in coordinating the immune response?
• How does HIV infection affect CD4 T cell counts?
• Why is monitoring CD4 counts important for individuals with compromised immune systems?

Related terms

Cytokines: Signaling proteins released by cells, particularly those in the immune system, that affect the behavior of other cells.

Antiretroviral Therapy (ART): Treatment for HIV/AIDS that helps keep the virus at bay and maintains higher levels of CD4 T cells.

Opportunistic Infections: Infections caused by pathogens that take advantage of an individual's weakened immune system.