Modeling trophoblast differentiation using equine chorionic girdle vesicles

Area of Science:

• Reproductive biology and immunology in equids.
• Trophoblast cell differentiation and function.

Background:

• Equine chorionic girdle cells invade the endometrium to form endometrial cups.
• Studying these cells is challenging due to invasive sampling and pregnancy termination requirements.
• Understanding trophoblast-maternal immune interactions is crucial for reproductive success.

Purpose of the Study:

• To develop an in vitro and in vivo model for studying equine trophoblast differentiation.
• To investigate trophoblast-immune interactions in equine pregnancy.
• To establish a method for analyzing chorionic girdle cells without terminating pregnancy.

Main Methods:

• Cultured equine chorionic girdle pieces in serum-free medium to form trophoblast vesicles.
• Analyzed vesicle cell morphology and equine chorionic gonadotrophin (eCG) secretion.
• Ectopically transplanted vesicles into recipient mares' vulvar mucosa and analyzed biopsies over 28 days.

Main Results:

• Cultured vesicles mimicked pre-invasion chorionic girdle cells and secreted eCG.
• Transplanted trophoblast cells survived and differentiated for at least 21 days.
• Recipient mares mounted cellular (CD4+, CD8+) and humoral immune responses to transplanted cells.

Conclusions:

• A novel in vitro and in vivo model for equine trophoblast research was successfully developed.
• This model facilitates the study of trophoblast differentiation and maternal immune responses.
• The findings pave the way for understanding key aspects of equine reproductive immunology.