Regulators of Immunity

What am I looking at?

This is a colored scanning electron microscopy image of human dendritic cells interacting with regulatory T cells. The dendritic cells are blue (1), and the T cells are red (2).

Biology in the background

There are several types of T cells that each carry out a different function. Those pictured here do the opposite of what most other cells in the immune system do: They suppress the immune response instead of activating it. While this may seem counterintuitive for a cell within the immune system, it is essential to protect our bodies from glitches in our own immune response.

If you have ever had an allergic reaction to something, you know how strongly our immune systems can influence how we feel. Allergies are an overreaction of the immune system to something not dangerous to us, such as dust, pollen, or even a medication. The regulatory T cells are involved in controlling these inappropriate reactions and are also essential for tamping down the immune system once it has eliminated an actual infection, helping the system return to its baseline status.

A regulatory T cell can grow up to 10 micrometers across, about 7.5 times smaller than the width of a human hair.

Technique

This image was created using electron microscopy.