School of Bioscience and Biotechnology, Kangwon National University, Chuncheon 200-701, Korea.
J Leukoc Biol. 2013 Aug;94(2):325-35. doi: 10.1189/jlb.0313128. Epub 2013 Jun 6.
The present study demonstrates that RA has activity of an IgA switch factor and is more specific than TGF-β1. RA independently caused only IgA switching, whereas TGF-β1 caused IgA and IgG2b switching. We found that RA increased IgA production and that this was a result of its ability to increase the frequency of IgA-secreting B cell clones. Increased IgA production was accompanied by an increase of GLTα. RA activity was abrogated by an antagonist of the RAR. Additionally, RA affected intestinal IgA production in mice. Surprisingly, RA, in combination with TGF-β1, notably enhanced not only IgA production and GLTα expression but also CCR9 and α4β7 expression on B cells. These results suggest that RA selectively induces IgA isotype switching through RAR and that RA and TGF-β have important effects on the overall gut IgA antibody response.
本研究表明，RA 具有 IgA 转换因子的活性，比 TGF-β1 更具特异性。RA 仅独立引起 IgA 转换，而 TGF-β1 引起 IgA 和 IgG2b 转换。我们发现 RA 增加了 IgA 的产生，这是其增加 IgA 分泌 B 细胞克隆频率的结果。IgA 产生的增加伴随着 GLTα 的增加。RAR 的拮抗剂可阻断 RA 活性。此外，RA 影响小鼠肠道 IgA 的产生。令人惊讶的是，RA 与 TGF-β1 联合使用不仅显著增强了 IgA 的产生和 GLTα 的表达，而且增强了 B 细胞上 CCR9 和 α4β7 的表达。这些结果表明，RA 通过 RAR 选择性诱导 IgA 同种型转换，RA 和 TGF-β1 对肠道 IgA 抗体的整体应答具有重要影响。
