Regulation of immune responses to protein therapeutics by transplacental induction of T cell tolerance

Sci Transl Med. 2015 Feb 18;7(275):275ra21. doi: 10.1126/scitranslmed.aaa1957.


Central tolerance plays a key role in modulating immune responses to self and exogenous antigens. The absence of self-antigen expression, as in patients with genetic deficiencies, prevents the development of antigen-specific immune tolerance. Hence, a substantial number of patients develop neutralizing antibodies to the corresponding protein therapeutics after replacement treatment. In this context, the administration of missing antigens during fetal development, a key period for self-tolerance establishment, should confer early and long-lasting antigen-specific tolerance. To this end, we exploited the physiological pathway of the neonatal Fc receptor (FcRn) through which maternal immunoglobulins are transplacentally transferred to fetuses. We demonstrate that Fc-fused antigens administered to pregnant mice reach fetal lymphoid organs in an FcRn-dependent manner, accumulate in antigen-presenting cells of myeloid origin, and promote the generation of both thymic and peripheral antigen-specific regulatory T cells. This strategy was successfully pursued in a mouse model of hemophilia A, where maternofetal transfer of the Fc-fused immunodominant domains of coagulation factor VIII conferred antigen-specific tolerance. Transplacental tolerance induction with Fc-fused proteins may thus prove valuable to prevent alloimmunization after replacement protein therapy for congenital deficiencies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / immunology
  • Antigen-Presenting Cells / immunology
  • Endocytosis
  • Factor VIII / immunology
  • Factor VIII / therapeutic use*
  • Female
  • Hemophilia A / therapy
  • Immune Tolerance*
  • Maternal-Fetal Exchange
  • Mice
  • Placenta / immunology*
  • Pregnancy
  • T-Lymphocytes / immunology*


  • Antibodies, Neutralizing
  • F8 protein, human
  • Factor VIII