De Petris S, Takacs B
Eur J Immunol. 1983 Oct;13(10):831-40. doi: 10.1002/eji.1830131010.
The relationship between mouse lymphocyte receptors for peanut agglutinin (PNA) and Helix pomatia agglutinin (HPA) has been investigated by immunofluorescence (cocapping) and radiolabeling. In neuraminidase-treated and untreated thymocytes there are two groups of glycoproteins which bind roughly equivalent amounts of PNA. One group also carries all the detectable receptors for HPA, the other binds only PNA. Binding inhibition experiments suggest that PNA and HPA receptors are in close proximity on the shared glycoproteins. The same two groups of receptors are present on 35-40% of neuraminidase-treated spleen lymphoid cells, mainly immunoglobulin (Ig)-negative lymphocytes. Almost all B cells have only PNA-specific receptors. Five-12% of the untreated spleen cells appreciably bind PNA and only a few bind HPA. Solubilized glycoproteins specific for PNA or HPA were compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. The major PNA-specific radioiodinated glycoproteins of neuraminidase-treated thymocytes, as isolated by affinity chromatography, consist of the 185-kDa and 195-kDa components of the T200 antigen and of two (diffuse) components of about 140 and 120-125 kDa. All these molecules also bind to HPA-Sepharose, with the exception of the 185 kDa component, which is probably the main constituent of the "pure" PNA receptors on the intact thymocytes. In gels directly labeled with radioactive lectins, the only band strongly labeled by PNA and HPA is the diffuse 140-kDa band. The band at 120 kDa is well labeled by PNA, but all the other components are weakly labeled. The mobility of the 140- and 120-kDa bands depends strongly on neuraminidase-treatment. These bands cannot be detected in gels of untreated thymocytes, but a major HPA-and PNA-specific band of lower molecular weight can be labeled after treating the gels with neuraminidase. The factors determining the differences in labeling pattern obtained by different methods as well as the nature of PNA and HPA binding sites are discussed. The same major PNA- and HPA-binding glycoproteins (apart from minor differences) are present on neuraminidase-treated Ig-negative spleen lymphocytes. The major PNA-binding protein of B lymphocytes appears to correspond to the 225-kDa ("B220") antigen specific for these cells.
已通过免疫荧光（共帽法）和放射性标记研究了小鼠淋巴细胞上花生凝集素（PNA）受体与苹果蜗牛凝集素（HPA）受体之间的关系。在经神经氨酸酶处理和未经处理的胸腺细胞中，有两组糖蛋白，它们结合的PNA量大致相等。一组还携带所有可检测到的HPA受体，另一组仅结合PNA。结合抑制实验表明，PNA和HPA受体在共享的糖蛋白上紧密相邻。在35%-40%的经神经氨酸酶处理的脾脏淋巴样细胞上存在相同的两组受体，主要是免疫球蛋白（Ig）阴性淋巴细胞。几乎所有B细胞仅具有PNA特异性受体。5%-12%的未经处理的脾脏细胞能明显结合PNA，只有少数能结合HPA。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳和放射自显影比较了PNA或HPA特异性的可溶性糖蛋白。经亲和层析分离的经神经氨酸酶处理的胸腺细胞的主要PNA特异性放射性碘化糖蛋白由T200抗原的185 kDa和195 kDa成分以及约140 kDa和120-125 kDa的两种（弥散）成分组成。除185 kDa成分外，所有这些分子也与HPA-琼脂糖结合，185 kDa成分可能是完整胸腺细胞上“纯”PNA受体 的主要成分。在直接用放射性凝集素标记的凝胶中，唯一被PNA和HPA强烈标记的条带是弥散的140 kDa条带。120 kDa处的条带被PNA很好地标记，但所有其他成分被弱标记。140 kDa和120 kDa条带的迁移率强烈依赖于神经氨酸酶处理。在未经处理的胸腺细胞的凝胶中无法检测到这些条带，但在用神经氨酸酶处理凝胶后，可以标记一条较低分子量的主要HPA和PNA特异性条带。讨论了决定通过不同方法获得的标记模式差异的因素以及PNA和HPA结合位点的性质。在经神经氨酸酶处理的Ig阴性脾脏淋巴细胞上存在相同的主要PNA和HPA结合糖蛋白（除了微小差异）。B淋巴细胞的主要PNA结合蛋白似乎对应于这些细胞特有的225 kDa（“B220”）抗原。
