Progress on research of chicken IgY antibody-FcRY receptor combination and transfer

Abstract

The transfer of maternal immunoglobulins (Igs) plays a significant role in fetal initial humoral immunity, of which process has changed and diversified during the evolution of vertebrates. IgY is a key molecular in antibody evolution which links ancient Igs and mammalian Igs such as IgG and IgE. IgY’s transfer to the embryo is a two-step receptor-mediated process, including the transfer from the maternal bloodstream to the yolk sac, and from the yolk sac to the embryo. IgY’s neonatal Fc receptor (FcRY) mainly functions in the second process. This article reviews IgY’s status in antibody evolution and IgY’s structure and application. Furthermore, this review compares the binding and transferring mechanism between mammalian IgG, and IgG’s neonatal Fc receptor and chicken IgY–FcRY. Details of IgY–FcRY combination, such as combining conditions required, IgY–FcRY binding stoichiometry and exact binding sites on both FcRY and IgY are discussed. Likewise, the endocytosis, the main mechanism of IgY–FcRY transfer and recycling mechanism are analyzed. Related knowledge might be important for better understanding antibody and receptor evolution, antibody–receptor interaction and antibody function. Furthermore, such kind of knowledge might be useful for antibody drug research and development.

Keywords::

• Antibody transfer
• chicken IgY
• chicken IgY’s neonatal Fc receptor (FcRY)
• IgG’s neonatal Fc receptor (FcRn)
• antibody evolution

Acknowledgments

The authors thank Prof. Dr. Rüdiger Schade from Institute of Pharmacology, Charité Medical School Berlin, Germany, for his comments.

Declaration of interest

This study was supported by Research Fund for the Doctoral Program of Higher Education (20100204120019), Fund of State Key Laboratory of Veterinary Biotechnology (SKLVBF201106), the Fundamental Research Funds for the Central Universities (Z109021003, Northwest A & F University) and grants from Returned Oversee Chinese Scholar (01140407) of Northwest A & F University, China.