The Role of Antigen-Presenting Cells (AQA A Level Biology)

The Role of Antigen-Presenting Cells

• T-lymphocytes produce an immune response when they are exposed to a specific antigen

• T cells will only bind to an antigen if it is present on the surface of an antigen-presenting cell

What is an antigen-presenting cell?

• An antigen-presenting cell is one of the host's cells that has been invaded by a pathogen and is displaying the antigen on its cell surface membrane

What does an antigen-presenting cell do?

• These cells present the antigens from toxins, foreign cells and ingested pathogens

• They help to recruit other cells of the immune system to produce a specific immune response

• Once the surface receptor of the T cell binds to the specific complementary antigen (on the antigen-presenting cell) it becomes sensitised and starts dividing to produce a clone of cells

What are the antigen-presenting cells?

• Several different immune system cells can present antigens

• The most common types are macrophages and dendritic cells

• Although less common, neutrophils can also act as antigen-presenting cells