Immunology Research Group of Hungarian Academy of Sciences at Eotvos Lorand University, Budapest, Hungary.
Immunol Lett. 2010 May 4;130(1-2):89-96. doi: 10.1016/j.imlet.2009.12.008. Epub 2010 Jan 6.
The GL7 epitope was originally described as part of a late lymphocyte activation antigen expressed in mouse and widely used since then as a marker of germinal center. Here we report on its differential expression by rat and human immune cells and lymphoid organs. Expression pattern of the GL7 epitope in rats is similar to that described earlier in mice, namely that GL7 antigen appears only on lymphocytes after 48h activation. In humans lymphocytes, but not the differentiated cells of myeloid origin, express this epitope. The GL7 epitope is up-regulated upon in vitro activation of primary T cells, while a slightly decreased expression is found on B lymphocytes. Fluorescent immunohistochemistry shows discrete location of GL7(hi) cells in human tonsil. GL7 antibody intensely stains CD19(+), IgD(+), IgM(low) B lymphocytes found at the margin of B cell follicles. The GL7 epitope is constitutively and highly raft-associated in human lymphoid cells. Strong neuraminidase- and partial papain-sensitivity of the GL7 epitope on human lymphocytes indicates a sialic acid-containing epitope linked either to one (or more) membrane protein(s) or to lipids. The lymphocyte-restricted GL7 epitope expression and the activation-dependent bi-directional change in the amount of the epitope suggest a functional role for GL7 epitope linked to carbohydrate-based immunoregulation.
GL7 表位最初被描述为小鼠中晚期淋巴细胞激活抗原的一部分，此后被广泛用作生发中心的标志物。在这里，我们报告了其在大鼠和人类免疫细胞和淋巴器官中的差异表达。大鼠 GL7 表位的表达模式与之前在小鼠中描述的相似，即 GL7 抗原仅在淋巴细胞激活 48 小时后出现。在人类中，只有淋巴细胞表达该表位，而不是髓系来源的分化细胞。该表位在体外激活原代 T 细胞时上调，而在 B 淋巴细胞中表达略有下降。荧光免疫组织化学显示 GL7(hi)细胞在人扁桃体中的离散位置。GL7 抗体强烈染色在 B 细胞滤泡边缘发现的 CD19(+)、IgD(+)、IgM(低)B 淋巴细胞。GL7 表位在人类淋巴细胞中持续且高度与筏相关。人淋巴细胞上 GL7 表位对神经氨酸酶和部分木瓜蛋白酶具有高度敏感性，表明其是一种含有唾液酸的表位，与一种（或多种）膜蛋白或脂质相连。淋巴细胞受限的 GL7 表位表达和数量的激活依赖性双向变化表明 GL7 表位与基于碳水化合物的免疫调节有关的功能作用。
