Levels of selected T lymphocyte subpopulations in peripheral blood of mares which experienced early embryonic death.

This research investigates the role of specific immune cells in mares that endure early embryonic death (EED) during pregnancy. The results suggest that mares experiencing EED exhibit different immune reactions compared to normally pregnant mares, potentially triggering Th1 cell immune responses.

Methodology of the Study

• The study recruited 48 purebred Arabian mares that were fertile. They were categorized into two groups: (1) the control group, which consisted of 32 mares in the early pregnancy stages; and (2) the group of 12 mares that had suffered EED.
• The study identified specific subsets of T lymphocytes (a type of white blood cell) including cells with CD2(+), CD4(+), and CD8(+) markers through flow cytometry, a technology that allows for detailed cell analysis.
• The team also calculated the percentages of CD3(+) lymphocytes, which are made up of cells with both the CD4(+) and CD8(+) markers, and of NK cells, found by subtracting CD3(+) cells from CD2(+) lymphocytes.
• In addition, the researchers determined the levels of TGF-beta1, a protein that suppresses T lymphocytes’ functioning during pregnancy, using ELISA, a common method for measuring biological substances.

Key Findings

• The researchers discovered that mares suffering from EED presented a significantly higher number of T lymphocytes with CD2(+) and CD4(+) markers, and NK cells, between the 14th and 21st days compared to mares without EED.
• Alterations in the ratio of CD4(+)/CD8(+) cells exhibited a similar pattern, with a statistically significant increase in this value from the 96th hour to the 30th day after ovulation in the EED group compared to the healthy pregnancy group.
• Contrarily, the EED group recorded significantly lower serum levels of the protein TGF-beta1 than the control group.

Conclusion and Implications

• The research findings suggest that mares experiencing EED develop inflammatory reactions, which seems to trigger Th1 cell immune responses. Th1 cells are a type of immune cell involved in defenses against viruses and certain bacteria, and they can contribute to autoimmunity and inflammation.
• The researchers’ observations provide valuable insights into the potential immunological factors contributing to EED in mares, which is crucial for future research and the development of potential therapies and preventive measures.