Abstract:

“The paradox of acquisition humoral immunity” was propased in the book-food immunity published in 2008. This review summarizes the current understanding of the FcRn-mediated IgG metabolism and transport. Based on the results, the acquisition of the humoral immunity, especially Fc binding with Fc receptors is able to mediate the humoral immunity through maternofetal transmission of immunogolubins and antibody-dependent cellular cytotoxicity (ADCC), but also establish an essential association from acquisition immunity to innate immunity. One of the important Fc receptors, FcRn, is involved in transferring maternal immunity and protecting IgG from fast degradation throughout life. FcRn also mediates bidirectional transport of IgG across mucosal, the intestinal epithelial and placenta barriers. All the data have presented a good answer to the “paradox of acquisition humoral immunity”, and meanwhile provided the scientific bases for food immunity and infant formula milk powder.

Key words: FcRn, ADCC, Fc receptor, the paradox of acquisition humoral immunity, food immunity