El-Nefiawy Nagwa, Abdel-Hakim Khaled, Kanayama Naohiro, Suganuma Nobuhiko, Terao Toshihiko
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Handayama, Hamamatsu, Japan.
Immunol Cell Biol. 2003 Oct;81(5):335-42. doi: 10.1046/j.1440-1711.2003.t01-1-01178.x.
Plasma cells play a pivotal role in the immune system and are responsible for the synthesis and release of immunoglobulins. Numerous in vitro culture experiments on the yolk sac demonstrated the generation of mature cells of the myeloid and lymphoid lineages under appropriate culture conditions. However, there are no reports describing the development of mature lymphoid cells in the yolk sac so far. For this reason, we undertook this study to investigate the development of antibody-containing plasma cells during early yolk sac haematopoiesis. Immunohistochemistry and immunoelectron microscopy were employed in the study. Results of this work demonstrated very weak immune staining for the intracytoplasmic IgA, IgG, and IgM at days 10 and 11 of embryonic life, while dark staining was obtained at 12 days. Positive staining was localized to the endodermal cell layer. Electron microscopic examinations revealed the existence of cells with the typical characteristics of plasma cells inside the endodermal cell layer, which may suggest their endodermal origin. To further verify the nature of these cells, intracytoplasmic immunoglobulins were demonstrated by immunoelectron microscopy. The present study demonstrated emergence of mature functioning plasma cells in early rat yolk sac. In a previous work we hypothesized the possibility of endodermal origin of yolk sac macrophages. This study adds additional evidence to support that hypothesis. The possible role of plasma cells in the yolk sac is discussed.
浆细胞在免疫系统中发挥着关键作用，负责免疫球蛋白的合成与释放。众多针对卵黄囊的体外培养实验表明，在适宜的培养条件下可生成髓系和淋巴系的成熟细胞。然而，迄今为止尚无关于卵黄囊中成熟淋巴细胞发育的报道。基于此，我们开展了这项研究，以探究早期卵黄囊造血过程中含抗体浆细胞的发育情况。本研究采用了免疫组织化学和免疫电子显微镜技术。研究结果显示，在胚胎发育第10天和第11天，胞质内IgA、IgG和IgM的免疫染色非常微弱，而在第12天则出现深染色。阳性染色定位于内胚层细胞层。电子显微镜检查发现内胚层细胞层内存在具有浆细胞典型特征的细胞，这可能提示它们起源于内胚层。为进一步验证这些细胞的性质，通过免疫电子显微镜证实了胞质内免疫球蛋白的存在。本研究证明了早期大鼠卵黄囊中成熟功能性浆细胞的出现。在之前的一项研究中，我们推测卵黄囊巨噬细胞可能起源于内胚层。本研究为支持该假说增添了更多证据。文中还讨论了浆细胞在卵黄囊中可能发挥的作用。
