Qiao Shuo-Wang, Kobayashi Kanna, Johansen Finn-Eirik, Sollid Ludvig M, Andersen Jan Terje, Milford Edgar, Roopenian Derry C, Lencer Wayne I, Blumberg Richard S
Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Proc Natl Acad Sci U S A. 2008 Jul 8;105(27):9337-42. doi: 10.1073/pnas.0801717105. Epub 2008 Jul 1.
The neonatal Fc receptor for IgG (FcRn) is a distant member of the MHC class I protein family. It binds IgG and albumin in a pH-dependent manner and protects these from catabolism by diverting them from a degradative fate in lysosomes. In addition, FcRn-mediated IgG transport across epithelial barriers is responsible for the transmission of IgG from mother to infant and can also enhance IgG-mediated antigen uptake across mucosal epithelia. We now show a previously undescribed role for FcRn in mediating the presentation of antigens by dendritic cells when antigens are present as a complex with antibody by uniquely directing multimeric immune complexes, but not monomeric IgG, to lysosomes.
新生儿IgG的Fc受体（FcRn）是MHC I类蛋白家族的远亲成员。它以pH依赖的方式结合IgG和白蛋白，并通过将它们从溶酶体中的降解途径转移来保护它们免受分解代谢。此外，FcRn介导的IgG跨上皮屏障转运负责IgG从母体到婴儿的传递，还可增强IgG介导的抗原跨粘膜上皮摄取。我们现在发现，当抗原与抗体形成复合物时，FcRn在介导树突状细胞呈递抗原方面具有以前未描述的作用，它通过独特地将多聚体免疫复合物而非单体IgG导向溶酶体来实现。
