Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Seeing and Remembering

The immune system's resident memory T cells patrol the eye's cornea protecting against infection

01 July 2022

Seeing and Remembering

In the eye, immunity means a delicate balance between fighting pathogens and avoiding any excess inflammation, that could impede vision. This is especially critical in the outermost layer, the transparent cornea, which must remain clear but is also the front line for infections. Unlike most tissues, the central cornea was thought to be devoid of resident memory T cells, immune cells that recognise previously-encountered pathogens and can quickly respond to infection. Yet new research has overturned that view: sophisticated microscopy techniques revealed that, in mice, infecting the cornea (pictured) with herpes simplex virus (in cyan) leads to recruitment of T cells (in green), which then give rise to more persistent memory T cells. Evidence of similar-looking cells moving around in the corneas of healthy human volunteers suggests our eyes may also have some form of immune memory, with implications for the treatment of chronic dry eye and other eye diseases.

Written by Emmanuelle Briolat

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.