Researchers from Japan have found that treatment with mesenchymal stromal cells (MSCs) increased regulatory T cells while decreasing inflammatory TH1 and TH17 cells, highlighting MSCs’ potential as a novel treatment to prevent ocular complications associated with GVHD. Credit: Lone Primate on Open Verse. CC BY-NC-SA.

A new study has found mesenchymal stem cells injected into periocular tissue effectively reduce inflammation in the eyes without harmful side effects.

Graft-versus-host disease (GVHD) is a common and severe complication that occurs after stem cell transplantation, where the donor’s immune cells attack the recipient’s tissues.

Ocular manifestation of GVHD is among the most challenging to treat, often leading to chronic inflammation and corneal tissue damage, which can result in loss of vision.

Conventional treatments, including corticosteroids, are frequently used to manage ocular inflammation associated with GVHD.

However, these therapies come with significant side effects, including the risk of glaucoma and other ocular complications.

Properties

Mesenchymal stromal cells (MSCs), a heterogeneous population of cells present in various tissues of the body, are known to possess immunoregulatory and modulatory properties.

Their ability to navigate to sites that have suffered injury and inflammation in the body makes them highly sought after for the development of regenerative treatments and pharmaceuticals.

In fact, several studies have explored the potential of human-derived MSCs for treating such conditions.

However, much remains to be known about their true potential for the treatment of ocular GVHD and advancing their clinical application.

Now, in a new study conducted by Dr Shigeto Shimmura and Robert M Rusch from Fujita Health University and Keio University, Japan, researchers have proposed a novel therapy for ocular GVHD involving MSCs.

The team explored the potential of regenerative mesenchymal stem cells in reducing ocular inflammation in GVHD-infected mice.

Their study explores the potential of adipose-derived MSCs (adMSCs) to reduce inflammation and promote tissue repair​.

Elaborating on the rationale behind this study, Shimmura said: “adMSCs are easy to obtain and have demonstrated benefits in corneal tissue regeneration.

“Moreover, we injected adMSCs after the onset of GVHD and also monitored them over an extended period of time, helping us verify their therapeutic applicability.”

Regenerative capacity

Using mice that had been induced with chronic GVHD, researchers administered adMSCs into the eyes via a single injection.

Over three weeks, the researchers found that the adMSC treatment increased regulatory T cells while reducing inflammation in the mice.

Further, adMSC-conditioned media enhanced cell migration and proliferation in laboratory scratch tests, showcasing the regenerative capacity of the cells.

Importantly, the injected cells disappeared within a week, minimising the risk of long-term complications such as tumour formation.

Shimmura added: “Our findings highlight the dual benefits of adMSCs: they suppress inflammation and enhance tissue healing.

“This makes them a promising candidate for treating immune-related ocular disorders without systemic side effects.”

These observations point to the potential of adMSCs as a targeted, localised therapy for immune-related eye conditions.

Unlike systemic treatments, these local injections ensured the therapeutic effects remained localised to the ocular surface. 

Shimmura advised: “Our work underscores the safety and efficacy of adMSCs, paving the way for clinical trials in humans.”

With their immunoregulatory and regenerative properties, adMSCs may offer a lifeline to patients suffering from chronic ocular GVHD and related inflammatory diseases.

Future studies, however, need to focus on dose optimisation and delivery methods to maximise therapeutic outcomes.

In summary, these results offer hope for a future where innovative, stem cell-based therapies can transform the way we manage autoimmune diseases, offering patients better outcomes and improved quality of life.

The study is published in The Ocular Surface.