Scientists create organoid that produces tears in a dish

Researchers have developed the first 3D organoid model of the human conjunctiva – the thin, clear membrane that lines the inside of the eyelid and covers the sclera, the white of the eye.

Until now, a lack of good models has limited research into the function of the human conjunctiva. The new organoid can now be used to test drugs for several diseases that affect the tissue, such as dry eye disease, cancer, allergies, and infections.

“Once we had these functioning organoids, we wanted to know how the conjunctiva is involved in the production of tears,” says Marie Bannier-Hélaouët, a PhD student at the Hubrecht Institute in the Netherlands and lead author of a new paper on the findings in Cell Stem Cell.

“We discovered that the conjunctiva makes antimicrobial components and therefore contributes to tear production in more ways than by simply making mucus.”

Stem cell-derived organoids are miniature human organs in a dish, used to mimic disease and test treatments. Using their new model, the team studied the human conjunctiva under allergy-like conditions.

“The organoids started to produce completely different tears: there was more mucus but there were also more antimicrobial components,” Bannier-Hélaouët.

They also discovered that a rare cell type, called tuft cells, become more abundant, suggesting they likely play a role in allergy response.

“Similar cells have been discovered in other tissues, but not in the human conjunctiva,” says Bannier-Hélaouët.

In the long term, the researchers believe that it may even be possible to make replacement conjunctivae for people with ocular burns, ocular cancers, or perhaps even genetic disorders.

“We are now running preclinical studies in rabbits to assess whether this approach is feasible and helpful,” says Bannier-Hélaouët.