PGE2-independent immunosuppressive activity of horse trophoblast tissue.

The research study investigates whether a substance called PGE2 produced by horse trophoblast tissue is responsible for suppressing immune responses during pregnancy. The research finds that even when PGE2 production is inhibited, the suppression of the immune response still occurs, suggesting that PGE2 is not the primary factor responsible for this process.

Objective and Methodology of the Research

• The research aimed to understand if PGE2, a possible immunosuppressant, produced by horse trophoblast tissue is the primary factor causing immune suppression during pregnancy.
• To achieve this, the researchers cultured horse trophoblast tissue in two conditions: one with a prostaglandin inhibitor called indomethacin present, and one without.
• The purpose of using indomethacin was to inhibit the production of PGE2 in the cultures and then compare the differences between the cultures with and without PGE2 production.

Process and Measurements

• After trophoblast tissue was cultured, the researchers measured the concentration of PGE2 and the level of immunosuppressive activity in both types of culture mediums: horse-trophoblast conditioned medium (HTCM) and HTCM treated with indomethacin (I-HTCM).
• The researchers identified the level of immunosuppressive activity by conducting lymphocyte proliferation assays, where reduced uptake of a substance called [3H]thymidine by horse lymphocytes indicated immune suppression.
• The concentration of PGE2 in the cultures was measured using a radioimmunoassay method.

Results of the Research

• The results of the study showed that cultures treated with indomethacin had a significant reduction in PGE2 production. This confirms that indomethacin effectively inhibits PGE2.
• However, despite the lower PGE2 levels, the trophoblast-derived immunosuppressive activity in the cultures was not affected.
• Therefore, these findings suggest that while PGE2 may play a role in immunity suppression during pregnancy, it is not the primary immunosuppressant produced by horse trophoblast tissue.