Fetomaternal Immune Tolerance: Crucial Mechanisms of Tolerance for Successful Pregnancy in Humans

ABSTRACT

For many years, the question of how the maternal immune system tolerates the foreign fetus has remained unanswered, and numerous studies have considerably attempted to elucidate underlying mechanisms for fetomaternal tolerance. This review aimed at discussing various significant mechanisms in fetomaternal compatibility. At the fetomaternal interface, in addition to having efficient control against infections, innate and adaptive maternal immune systems selectively prevent fetal rejection. In general, understanding the complex mechanisms of fetomaternal tolerance is critical for immunologic tolerance induction and spontaneous abortion prevention in high-risk populations. Different cells and molecules, such as regulatory T-cells, dendritic cells, decidua cells, IDO, Class I HLA molecules, TGF-β, and IL-10, induce maternal immune tolerance in the fetus in numerous ways. The findings on fetomaternal immune tolerance have remained controversial and require further research.

KEYWORDS:

• Abortion
• fetomaternal tolerance
• fetomaternal interface
• fetus
• pregnancy

Acknowledgments

This study has been done as part of the Ph.D. thesis for Yousef Yousefzadeh.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Yousef Yousefzadeh and Mohammad Sadegh Soltani-Zangbar: wrote the manuscript and contributed to prepare the manuscript in journal format. Navid Shomali: helped in reference finding. Maryam Hemmatzadeh: draw the figures. Ata Mahmoodpoor and Javad Ahmadian Heris: helped in editing the manuscript. Mehdi Yousefi: principal investigator and supervised the study.

Additional information

Funding

This study was supported by the Stem Cell Research Center at Tabriz University of Medical Sciences, Iran [Grant No 65106].