Evaluation of equine xenogeneic mixed lymphocyte reactions using 5-ethynyl-2′-deoxyuridine (EdU).

The research article discusses a study that investigated the use of a particular method, using a substance called 5-ethynyl-2′-deoxyuridine (EdU), for evaluating immune response between different species, specifically between horses and pigs. The study found that enriched T-cells from horses showed a greater immune response than unmodified cells, suggesting their use may be preferable in determining suitability for organ transplants between different species.

Objectives and Background of the Research

• The study was conducted in light of the necessity for more donor organs for allogeneic solid organ transplantation, the currently available treatment option for patients suffering from end stage organ disease.
• Considering the shortage of donor organs, the potential of xenogeneic organ transplantation, where organs are transferred between different species, is being explored.
• The researchers aimed to utilize a cost-effective and speedy in vitro method to examine the compatibility of the immune system prior to undertaking expensive and comprehensive live animal studies.
• The substance, 5-ethynyl-2′-deoxyuridine (EdU), an analog of the DNA base thymidine, was a focal point of the study, purposed for assessing cell proliferation using flow cytometry in particular.

Design and Hypothesis of the Study

• The study was strategized to optimize and test the use of EdU for assessing a specific type of immune response, the one-way mixed lymphocyte reaction (MLR), using horses’ immune cells in response to pig stimulator cells.
• The researchers hypothesized that an enriched population of T-lymphocytes (T-cells) in horses would produce a higher proliferative response to stimulation, and more cytokine production compared to unfractionated peripheral blood mononuclear cells (PBMCs).

Research Procedure and Findings

• PBMCs and T-cells were isolated from 3 horses and 4 pigs for the experiment.
• For comparison, the researchers established equine xenogeneic MLRs using porcine allogeneic MLRs, monitoring for clinically acceptable levels of cell proliferation.
• The results suggest that equine T-cells showed a significantly greater EdU incorporation in one-way xenogeneic MLRs, compared to equine PBMCs. However, there was no significant contrast in cell proliferation between porcine T-cell and PBMC as responders in allogenic one-way MLR.

Conclusion and Recommendations

• Concluding from the obtained results, the study suggests that enriched equine T-cells should be used over unfractionated PBMCs when evaluating the equine xenogeneic response with the EdU assay. This recommendation is based on better assessment of suitability for xenogeneic transplants in living organisms.