Harvey Bohdan P, Gee Renelle J, Haberman Ann M, Shlomchik Mark J, Mamula Mark J
Section of Rheumatology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
Eur J Immunol. 2007 Jul;37(7):1739-51. doi: 10.1002/eji.200636452.
B cells play an active role in directing immunity against specific proteins in part because of their capacity to sequester antigen via B cell receptor (BCR). Our prior findings indicate that B cells can initiate an immune response in vivo to self proteins independent of other antigen-presenting cells (APC). However, these studies also demonstrated that both dendritic cells and macrophages are important in the ongoing immune response. The present work illustrates a mechanism by which antigen acquired by B cells through BCR is specifically transferred to other APC, in particular, macrophages. The transfer of antigen is dependent on the specificity of BCR and requires direct contact between the cells, but does not require MHC compatibility between the cells and is independent of the activation state of macrophages. Antigen transfer is functional, in that macrophages, which received B cell derived-antigen, can activate CD4 T cells. Overall, these results define a novel mechanism by which B cells can focus immunity toward a specific antigen and transfer the ability to activate CD4 T cells to other APC.
B细胞在针对特定蛋白质的免疫导向中发挥着积极作用，部分原因在于它们能够通过B细胞受体（BCR）隔离抗原。我们之前的研究结果表明，B细胞能够在体内独立于其他抗原呈递细胞（APC）对自身蛋白质启动免疫反应。然而，这些研究也证明，树突状细胞和巨噬细胞在持续的免疫反应中都很重要。目前的工作阐明了一种机制，即B细胞通过BCR获取的抗原会特异性地转移到其他APC，特别是巨噬细胞。抗原的转移依赖于BCR的特异性，需要细胞之间的直接接触，但不需要细胞之间的MHC相容性，并且独立于巨噬细胞的激活状态。抗原转移具有功能性，因为接收B细胞衍生抗原的巨噬细胞能够激活CD4 T细胞。总体而言，这些结果定义了一种新机制，通过该机制B细胞能够将免疫聚焦于特定抗原，并将激活CD4 T细胞的能力转移给其他APC。
