Investigation of physiological function of PLA2R receptor in birds and mammals: Study on prolonged antibody concentration in blood

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21369
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 42:Veterinary medical science, animal science, and related fields
• Research Institution: Nagoya University
• Principal Investigator: Atsushi Murai 名古屋大学, 生命農学研究科, 教授 (10313975)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 畜産学 / 栄養生理学 / ニワトリ / ヒト / 抗体 / 受容体

Outline of Final Research Achievements

Physiological functions of the phospholipase A2 receptor (PLA2R) differ between birds and mammals. Avian PLA2R functions as an antibody receptor, but it is unknown whether mammalian PLA2R functions as an antibody receptor or not. In this study, we investigated a potential of chicken antibody (IgY) transport by chicken PLA2R, and further investigated whether human PLA2R functions as an antibody receptor. We established a cell culture system in which chicken PLA2R was expressed, and demonstrated that chicken PLA2R is an antibody receptor and that chicken PLA2R promotes intracellular transport (transcytosis) of IgY, suggesting that PLA2R is involved in prolongation of blood IgY concentration. On the other hand, it was found that human PLA2R does not function as an antibody receptor.

Free Research Field

栄養生理学

Academic Significance and Societal Importance of the Research Achievements

鳥類と哺乳類のPLA2Rが全く異なる機能を持つことが判明した。鳥類のPLA2Rは主たる免疫グロブリンであるIgYを分解することなく細胞内を輸送する能力を持つことが判明し、PLA2Rが抗体寿命を延長させる本体であることを確信した。今後、免疫機能が増強された感染症に罹患しづらいニワトリ、抗体を大量に含む機能性卵の作出に応用が可能な成果である。
ヒトPLA2Rの生物学的存在意義は依然として不明である。しかし、ヒトPLA2Rが抗体受容体としての機能を持たないことが明確となったため、抗体受容体としての機能が腎疾患であるネフローゼ症候群の原因因子ではないことが判明した点は意義深い。