Cellular and Humoral Immunogenicity Investigation of Single and Repeated Allogeneic Tenogenic Primed Mesenchymal Stem Cell Treatments in Horses Suffering From Tendon Injuries.

This research studies the safety of using mesenchymal stem cells (MSCs) for the treatment of tendon injuries in horses. In particular, it examines whether administering these stem cells at various intervals ignites an immune response in the horses.

Research Objectives and Methodology

• The primary objective was to understand if the single and multiple introduction of tenogenic primed MSCs (tpMSCs), stem cells specialised for repairing tendons, would trigger an immune reaction in horses with tendon injuries.
• To investigate this, two studies were conducted. In the first study, eight horses with surgically induced tendon injuries were treated with tpMSCs. In the second study, six horses with natural tendon wounds were treated twice with tpMSCs.
• The researchers assessed the cellular immune reaction by studying lymphocyte reactions before and after treatment. The lymphocyte reaction helps illustrate how the body reacts to foreign entities. They also measured the humoral immune response using a crossmatch assay, which detects antibodies.
• The presence of anti-bovine serum albumin (BSA) antibodies was observed through an enzyme lined immunosorbent assay (ELISA), a test that measures immune responses in the blood.

Research Findings

• The research found no cellular immune response in any of the horses, indicating that the tpMSCs were not viewed as intruders by the horses’ bodies.
• One horse among the first study group, and none in the second study group, developed antibodies against tpMSCs. Interestingly, the horse that did present antibodies had equine sarcoid, a common skin tumor in horses. Further testing revealed that this horse also developed increased antibodies against the cancer cells after treatment, suggesting a nonspecific immune response originating after therapy.
• Some horses also showed antibody formation against BSA which is further evidence of a nonspecific immune response.
• However, no such antibody formation was found in other horses’ serum.

Conclusions and Recommendations

• Overall, the studies concluded that using tpMSCs to treat horses with tendon injuries didn’t provoke a cellular or humoral immune response after single or double application treatments.
• The only exception was a horse with a pre-existing condition (equine sarcoid), and this requires further study.
• The researchers recommend a larger field study to confirm these findings and ensure the safe use of tpMSCs for further application in treating horses with tendon injuries.