Problem: Maternal immune response to fetal tissues is modified in such way that it favors the development of pregnancy. Human leukocyte antigen (HLA)-G, progesterone and mesenchymal stem cells (MSCs) have been identified as potent immunomodulatory agents in different experimental systems and the interactions between these three factors are studies in this paper.
Method of study: Human MSCs are isolated from human adipose tissue, bone marrow and decidua are cultured in the presence of progesterone and the expression of HLA-G is followed-up at protein and mRNA levels.
Results: The MSCs cultured in the presence of progesterone express increased levels of both cell surface and cytoplasmic HLA-G when compared with the control MSCs.
Conclusion: Progesterone up-regulates the expression by MSCs of HLA-G which is a major player in maintenance of the immune balance between the mother and the fetus. MSCs are newly detected targets of progesterone with well documented immunomodulatory activity.