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
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.