Department of Molecular Immunology, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
J Dent Res. 2014 Mar;93(3):288-93. doi: 10.1177/0022034513518223. Epub 2013 Dec 30.
Dendritic cell (DC) migration to regional lymph nodes (RLNs) is an essential step in adaptive immunity, and cell-surface antigens on migrating DCs greatly affect the quality and quantity of subsequent immune responses. Although MHC class II(+) DC-like cells exist in the dental pulp, the lineage and function of these cells remain unknown. Here, we identified migratory DCs from the dental pulp after cusp trimming and acid etching in KikGR mice, in which the photoconvertible fluorescent protein changed from green to red upon violet light exposure. Two major cell fractions from the dental pulp had migrated to the RLNs at 16 hrs after cusp treatment, which showed the following lineage markers in the main and second fractions: CD11c(high)CD11b(++)Ly6C(low) Ly6G(low) F4/80(+) and CD11c(med)CD11b(+++)Ly6C(++)Ly6G(+++)F4/80(-), respectively. These lineage markers indicate that the former cells were DCs that had migrated through afferent lymphoid vessels, and the latter were granulocytes recruited via blood circulation. Migratory dental pulp DCs were mature, expressing the highest levels of CD273 (B7-DC) and CD86 co-stimulators and MHC class II. Our results suggest that cariogenic-bacteria-exposed dental pulp DCs migrate to RLNs and there trigger adaptive immune responses.
树突状细胞（DC）向区域性淋巴结（RLNs）的迁移是适应性免疫的一个重要步骤，而迁移 DC 表面的抗原极大地影响了随后免疫反应的质量和数量。尽管牙髓中存在 MHC Ⅱ类阳性（+）DC 样细胞，但这些细胞的谱系和功能仍不清楚。在这里，我们在 KikGR 小鼠的牙尖修剪和酸蚀后，从牙髓中鉴定出迁移的 DC，其中光可转换的荧光蛋白在暴露于紫光时从绿色变为红色。在牙尖处理后 16 小时，牙髓中的两个主要细胞群已经迁移到 RLNs，它们在主群和第二群中显示出以下谱系标记：CD11c（高）CD11b（++）Ly6C（低）Ly6G（低）F4/80（+）和 CD11c（中）CD11b（+++）Ly6C（++）Ly6G（+++）F4/80（-）。这些谱系标记表明，前一群细胞是通过输入淋巴管迁移的 DC，后一群细胞是通过血液循环募集的粒细胞。迁移的牙髓 DC 是成熟的，表达最高水平的 CD273（B7-DC）和 CD86 共刺激物以及 MHC Ⅱ类。我们的结果表明，龋病细菌暴露的牙髓 DC 迁移到 RLNs，并在那里触发适应性免疫反应。
