Press C M, Reynolds J D, McClure S J, Simpson-Morgan M W, Landsverk T
Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, Oslo, Norway.
Immunology. 1996 May;88(1):28-34. doi: 10.1046/j.1365-2567.1996.d01-641.x.
B-cell depleted fetal sheep were created following a single injection of an anti-IgM monoclonal antibody early in gestation. Six sheep fetuses were given a single intraperitoneal injection of a monoclonal antibody directed against IgM at 63 days of gestation (gestation in sheep = 150 days). The fetuses were killed at 138-142 days of gestation and lymphoid tissues were collected for subsequent light microscopy and immunohistochemical examination. The ileal and jejunal Peyer's patch (PP) follicles in four of the six injected fetuses were markedly reduced in size. Cells in the rudimentary follicles of the ileal PP of these animals showed no reactivity for IgM and most were negative for CD45. The dome regions contained many T cells, which were predominantly CD8+ cells and included gamma delta T cells. The interfollicular areas of the PP of the markedly affected fetuses contained large populations of T cells. The spleen and lymph nodes were also markedly depleted of IgM+ cells and these tissues contained only a small, scattered population of weakly IgM+ cells. Follicular accumulations of IgM+ cells were absent. Large populations of T cells were present in the white pulp of the spleen and cortex of the lymph nodes. The liver did not contain IgM+ cells and the medulla of the thymus was depleted of IgM+ cells. The results of this study suggest that a surface IgM+ B-cell population is present in the sheep fetus at 63 days of gestation, which is essential for the colonization of the ileal PP and subsequent B-cell development.
在妊娠早期单次注射抗IgM单克隆抗体后，构建了B细胞耗竭的胎羊。六只胎羊在妊娠63天时（绵羊妊娠期=150天）接受了一次针对IgM的单克隆抗体腹腔注射。这些胎羊在妊娠138 - 142天时被处死，收集淋巴组织用于后续的光学显微镜检查和免疫组织化学检查。六只注射胎羊中有四只的回肠和空肠派尔集合淋巴结（PP）滤泡大小明显减小。这些动物回肠PP原始滤泡中的细胞对IgM无反应，且大多数CD45呈阴性。圆顶区域含有许多T细胞，主要是CD8 +细胞，还包括γδT细胞。受影响明显的胎羊PP滤泡间区域含有大量T细胞。脾脏和淋巴结中的IgM +细胞也明显减少，这些组织中仅含有少量散在的弱阳性IgM +细胞。不存在IgM +细胞的滤泡性聚集。脾脏白髓和淋巴结皮质中有大量T细胞。肝脏中不含IgM +细胞，胸腺髓质中的IgM +细胞耗竭。本研究结果表明，妊娠63天时绵羊胎儿体内存在表面IgM + B细胞群体，这对于回肠PP的定植和随后的B细胞发育至关重要。
