What are T Cells?

About T Cells

• T cell is a type of white blood cell.
• It is also called T lymphocyte and thymocyte.
• T cells are part of the immune system and develop from stem cells in the bone marrow.
• They help protect the body from infection and may help fight cancer.
• There are two main types:
  • Cytotoxic T-cells: Destroy infected cells.
  • Helper T-cells: Send signals that direct other immune cells to fight infection.
• Rather than generically attack any antigens, T cells circulate until they encounter their specific antigen.
• T-cells have many identical T-cell receptors that cover their surfaces and can only bind to one shape of antigen.
• When a T-cell receptor fits with its viral antigen on an infected cell, the Killer T-cell releases cytotoxins to kill that cell.

Q1: What are antigens?

An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off. An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.