Herranz-Jusdado J Germán, Morel Esther, Simón Rocío, Díaz-Rosales Patricia, Tafalla Carolina
Animal Health Research Center (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Valdeolmos 28130 Madrid, Spain.
iScience. 2023 Jul 20;26(8):107434. doi: 10.1016/j.isci.2023.107434. eCollection 2023 Aug 18.
Although most B cells in teleost systemic compartments co-express IgM and IgD on the surface, cells exclusively expressing either of the two Igs are common in fish mucosal tissues, providing us with a unique opportunity to further characterize IgDIgM B cells, an intriguing B cell subset. Hence, we compared the phenotype of IgDIgM cells to that of IgMIgD B cells in rainbow trout gills and skin, also establishing the response of these subsets to immune stimulation. The transcriptional profile and secreting capacity of IgDIgM B cells corresponded to that of cells that have started a differentiation program toward plasmablasts, similarly to IgMIgD B cells. Yet, IgMIgD B cells retained high levels of surface MHC II and antigen-processing abilities, while these were much lower in IgDIgM cells, suggesting important differences in their antigen-presenting capacities. Our findings contribute to a deeper understanding of the enigmatic role of IgD in mucosal surfaces.
虽然硬骨鱼全身各腔室中的大多数B细胞在表面共表达IgM和IgD，但仅表达这两种免疫球蛋白之一的细胞在鱼类黏膜组织中很常见，这为我们提供了一个独特的机会来进一步表征IgD⁺IgM⁻ B细胞，这是一个有趣的B细胞亚群。因此，我们比较了虹鳟鱼鳃和皮肤中IgD⁺IgM⁻细胞与IgM⁺IgD⁻ B细胞的表型，还确定了这些亚群对免疫刺激的反应。IgD⁺IgM⁻ B细胞的转录谱和分泌能力与已开始向浆母细胞分化程序的细胞相似，与IgM⁺IgD⁻ B细胞相同。然而，IgM⁺IgD⁻ B细胞保留了高水平的表面MHC II和抗原加工能力，而这些在IgD⁺IgM⁻细胞中要低得多，这表明它们在抗原呈递能力方面存在重要差异。我们的研究结果有助于更深入地了解IgD在黏膜表面的神秘作用。
