The initial organoid model of the human conjunctiva, a tissue involved in tear generation, was created by a Dutch scientific team.
Tears are produced by our eyes to shield them from wounds and diseases. Through the secretion of mucus, the conjunctiva, a tissue covering the inside of the eyelids and the white of the eye, contributes to the formation of these tears.
This mucus shields the ocular surface from infections and enables tears to adhere to it.
The researchers utilized human conjunctiva cells and cultured them into three-dimensional structures in a dish for their work, which was published in the journal Cell Stem Cell. These microscopic formations, which resemble actual human conjunctiva, are known as organoids.
“Once we had these functioning organoids, we wanted to know how the conjunctiva is involved in the production of tears,” said lead researcher Marie Bannier-Helaouet, from the Organoid group at the Hubrecht Institute in Netherlands.
“We discovered that the conjunctiva makes antimicrobial components and therefore contributes to tear production in more ways than by simply making mucus,” she added.
Then, in order to simulate allergies, the researchers changed the environment of the plate containing the tiny conjunctivae.
“The organoids started to produce completely different tears: There was more mucus but there were also more antimicrobial components,” said Bannier-Helaouet.
Under these conditions, they also found a new cell type in the organoids: Tuft cells.
“Similar cells have been discovered in other tissues, but not in the human conjunctiva.”
In the allergy-like environment, the number of tuft cells increased, indicating a potential involvement for these cells in the ocular response to allergens.
Conjunctiva is impacted by a number of illnesses and conditions, including infections, allergies, cancer, and dry eye syndrome. When this conjunctiva tissue malfunctions severely, blindness may also result.
The newly-developed organoid model opens the possibility for study into disorders affecting the conjunctiva.
Long-term, it might even be feasible to create new conjunctivae for patients suffering from genetic diseases, ocular burns, or ocular malignancies.
“We are now running preclinical studies in rabbits to assess whether this approach is feasible and helpful,” Bannier-Helaouet said.