Effect of progesterone on the in vitro response of peripheral blood mononuclear cells stimulated by Escherichia coli in mares.

This study investigates the impact of the hormone progesterone on the immune responses of horses to the bacteria Escherichia coli. The results display that progesterone significantly reduces the immune cells’ reaction to the bacteria.

Study Objective and Method

• The research intended to assess how progesterone influences the immune responses of horses reacting to an Escherichia coli (E. coli) attack. E. coli is a bacterium typically found in the intestinal tract. It’s primarily harmless, but some strains can cause serious illness.
• The bacteria used in the study were isolated from the uterus of a Thoroughbred mare suffering from bacterial endometritis, an inflammation of the uterus lining.
• The effect of progesterone, a hormone that prepares the uterus for pregnancy and maintains pregnancy, was evaluated using peripheral blood mononuclear cells (PBMCs) from ten non-pregnant, clinically healthy adult horses of diverse breeds and ages.

Investigation and Findings

• The research explored whether progesterone influences the proliferation (increase in number) of cells and the expression of cytokine messenger RNA from cells in response to E. coli stimulation.
• Cytokines are small proteins that play crucial roles in cell signalling, which can stimulate immune responses. Here, the study focused on interferon (IFN)-γ, tumour necrosis factor (TNF)-α, and interleukin (IL)-10.
• The findings revealed that progesterone notably inhibited the proliferation of PBMCs and the expression of IFN-γ when stimulated with E. coli.

Conclusion

• The research concluded that progesterone disrupts the immune response to E. coli in mares. This implies that it might lower the horse’s ability to fight off bacterial infections, potentially affecting the health and reproductive ability of the horse.
• The ways hormones manipulate immunity could be significant in understanding and treating bacterial diseases in mares.