T Cells Flashcards
What is a T Cell?
A type of white blood cell called a lymphocyte. T cells are direct fighters of pathogens and also produce cytokines, which are biological substances that help activate other parts of the immune system.
Describe how T Cells bind to antigens.
T cells recognize antigens within a complex of cell surface proteins called the major histocompatibility complex (MHC) on the surface of antigen-presenting cells. Antigens bind to the end of the variable regions.
Where are T Cells in the body?
They are in bone marrow and travel to the thymus to mature (why they are called T Cells!)
What are cytotoxic T Cells?
Cytotoxic T-cells are part of your adaptive immune response also called “Killer T Cells.” When they find a cell in the body that’s been infected by a virus, they latch onto it and release toxic substances that destroy the infected cell.
What is the difference between a cytotoxic T Cell and helper T Cell?
Cytotoxic T Cells are killer cells that attack the pathogens. The cytokines released by helper T-cells help activate cytotoxic T-cells.
How does a helper T Cell work?
Cells in the body, such as dendritic cells or macrophages, encounter foreign invaders like bacteria or viruses. These cells “digest” the invaders and display pieces of them, called antigens, on their surface.
Helper T cells have receptors on their surface that can recognize these antigens. When a helper T cell encounters an antigen that matches its receptors, it becomes activated.
