Transplantation Research Center, Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.
China Pharmaceutical University, Nanjing, China.
Front Immunol. 2022 Aug 11;13:801945. doi: 10.3389/fimmu.2022.801945. eCollection 2022.
Lymph nodes (LNs) are the critical sites of immunity, and the stromal cells of LNs are crucial to their function. Our understanding of the stromal compartment of the LN has deepened recently with the characterization of nontraditional stromal cells. CD41 (integrin αIIb) is known to be expressed by platelets and hematolymphoid cells. We identified two distinct populations of CD41Lyve1 and CD41Lyve1 cells in the LNs. CD41Lyve1 cells appear in the LN mostly at the later stages of the lives of mice. We identified CD41 cells in human LNs as well. We demonstrated that murine CD41 cells express mesodermal markers, such as Sca-1, CD105 and CD29, but lack platelet markers. We did not observe the presence of platelets around the HEVs or within proximity to fibroblastic reticular cells of the LN. Examination of thoracic duct lymph fluid showed the presence of CD41Lyve1 cells, suggesting that these cells recirculate throughout the body. FTY720 reduced their trafficking to lymph fluid, suggesting that their egress is controlled by the S1P1 pathway. CD41Lyve1 cells of the LNs were sensitive to radiation, suggestive of their replicative nature. Single cell RNA sequencing data showed that the CD41 cell population in naïve mouse LNs expressed largely stromal cell markers. Further studies are required to examine more deeply the role of CD41 cells in the function of LNs.
淋巴结 (LNs) 是免疫的关键部位，而 LNs 的基质细胞对其功能至关重要。随着对非传统基质细胞的特征描述，我们最近对 LN 的基质区室有了更深入的了解。CD41（整合素 αIIb）已知表达于血小板和造血淋巴样细胞。我们在 LN 中鉴定出两种不同的 CD41Lyve1 和 CD41Lyve1 细胞群。CD41Lyve1 细胞在 LN 中的出现主要发生在小鼠生命的后期阶段。我们在人类 LN 中也鉴定出 CD41 细胞。我们证明了小鼠 CD41 细胞表达中胚层标记物，如 Sca-1、CD105 和 CD29，但缺乏血小板标记物。我们没有观察到血小板存在于 HEV 周围或接近 LN 的纤维母细胞网状细胞附近。对胸导管淋巴液的检查显示存在 CD41Lyve1 细胞，表明这些细胞在全身循环。FTY720 减少了它们向淋巴液的转移，表明它们的移出受 S1P1 途径控制。LN 中的 CD41Lyve1 细胞对辐射敏感，提示其具有复制性。单细胞 RNA 测序数据显示，幼稚小鼠 LN 中的 CD41 细胞群主要表达基质细胞标记物。需要进一步研究以更深入地研究 CD41 细胞在 LN 功能中的作用。
