[VIII-29-26_28] 形態・生理（VIII-午後）

[VIII29-26E] Identification of the origin and specificity of maternal IgA antibodies produced in the mammary gland

^○Usami Katsuki, Niimi Kanae, Sasaki Shiho, Furukawa Mutsumi, Ito Shun, Banba Yuri, Yamauchi Shinya, Watanabe Koichi, Aso Hisashi, Nochi Tomonori (Graduate School of Agriculture Science, Tohoku Univ.)

Maternal IgA antibodies produced by plasma cells in the mammary gland plays a pivotal role in protecting infant gut from various pathogens. It is well known that the migration of plasma cells into the mammary gland depends on CCL28/CCR10-mediated chemotaxis; however, the origin and specificity have not yet been identified. To address the questions, we firstly performed an adaptive transfer analysis using SCID mice that lack B and T cells. When the cells isolated from the Peyer’s patches (PPs) of the wild type mice were transferred intravenously into SCID mice, IgA-producing plasma cells were found in the mammary gland of recipient SCID mice. Confirming the importance of PPs on maternal IgA production, we next generated PPs null mice and found that the number of IgA-producing plasma cells in the mammary glands decreased significantly when compared with that of PP-intact mice. Furthermore, we found that the maternal IgA antibodies bind to intestinal microorganisms. These results indicate that PPs might involve in the induction of maternal IgA antibodies to react to microorganisms that cohabit in the gut.