Understanding the migration of lymphocytes to nonintestinal mucosal sites is fundamental to developing mucosal vaccination strategies. Studies have shown that nasal and oral immunization with cholera toxin (CT) stimulates, in addition to α4β7⁺, the induction of αE (CD103)β7⁺ B cells. To determine the extent to which αE‐associated β7 contributes to antigen (Ag)‐specific immunoglobulin (Ig)A responses in the upper respiratory tract, nasal CT vaccination was performed in wild‐type (wt) and β7^−/− mice. At 16 days postprimary immunization, upper respiratory tract IgA responses were greater in β7^−/− mice than in wt mice. IgA induction by distal β7^−/− Peyer’s patches, mesenteric lymph nodes and small intestinal lamina propria was minimal, in contrast to elevated gut IgA responses in wt mice. By 42 days postprimary immunization, β7^−/− gut IgA responses were restored, and upper respiratory tract Ag‐specific IgA responses were equivalent to those of wt mice. Examination of homing receptor expression and cell‐sorting experiments revealed that β7^−/− mice have increased usage of β1 and αE integrins by upper respiratory tract B cells, suggesting that alternative integrins can facilitate lymphocyte migration to the upper respiratory tract, especially in the absence of β7.

中文翻译：

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β7 整合素缺陷小鼠的鼻腔疫苗接种可保持升高的 IgA 免疫力。

了解淋巴细胞向非肠道粘膜部位的迁移是制定粘膜疫苗接种策略的基础。研究表明，除 α4β7 ⁺外，用霍乱毒素 (CT) 进行鼻腔和口腔免疫还可以刺激 αE (CD103)β7 ⁺ B 细胞的诱导。为了确定 αE 相关的 β7 对上呼吸道抗原 (Ag) 特异性免疫球蛋白 (Ig)A 反应的贡献程度，在野生型 (wt) 和 β7 ^-/-小鼠中进行鼻 CT 疫苗接种。^{在初次免疫后 16 天，β7 -/-}小鼠的上呼吸道 IgA 反应高于 wt 小鼠。远端 β7 诱导 IgA ^-/-Peyer 斑、肠系膜淋巴结和小肠固有层极少，这与 wt 小鼠的肠道 IgA 反应升高形成对比。初次免疫后 42 天，β7 ^-/-肠道 IgA 反应恢复，上呼吸道 Ag 特异性 IgA 反应与 wt 小鼠相当。检查归巢受体表达和细胞分选实验表明，β7 ^-/-小鼠增加了上呼吸道 B 细胞对 β1 和 αE 整合素的使用，这表明替代整合素可以促进淋巴细胞向上呼吸道迁移，尤其是在没有β7。