Unexpected Support

Your throat’s sore, your head hurts, and you feel absolutely miserable. Upon hearing this, the first thing your doctor will probably do is check your lymph nodes [glands]. These little oval-shaped organs are the immune system’s ‘military bases’ distributed throughout our body. They’re jam-packed with T cells in the core, with B cells surrounding them, both of which are crucial in fighting off disease. When viruses or bacteria enter a lymph node, it gets activated and can grow up to three times its original size – which the doctor can feel. To better understand how this growth is orchestrated scientists labelled cells that support B cells orange. Or so they thought. In fact, orange-stained cells were also found between the T cells in the core (pictured). Further tests showed that this newly discovered cell type is crucial for keeping a growing lymph node in shape, and hence for keeping us healthy.

Written by Emma Bornebroek

• Image by Cyrille Mionnet and colleagues
• Aix-Marseille University, France
• Originally published under a Creative Commons Attribution Licence
• Research published in PLOS Biology, October 2013