Interactions of lectins and monoclonal antibodies with human mononuclear cells. I. Specific inhibition of OKT4 and OKT8 binding by Ricinus communis agglutinin and wheat germ agglutinin.
Interactions of lectins and monoclonal antibodies with human mononuclear cells. I. Specific inhibition of OKT4 and OKT8 binding by Ricinus communis agglutinin and wheat germ agglutinin.
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凝集素和单克隆抗体与人单核细胞的相互作用。
DOI：
10.4049/jimmunol.130.4.1646
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发表时间：
1983
影响因子：
4.4
通讯作者：
S. A. Dorsey
中科院分区：
文献类型：
--
作者：
D. Boldt;S. A. Dorsey
我们使用流式细胞术检查凝集素对人淋巴细胞与抗 T 细胞单克隆试剂 OKT4（T 辅助细胞特异性）和 OKT8（T 抑制蛋白特异性）之间相互作用的影响。小麦胚芽凝集素 (WGA) 平均抑制 OKT8 与淋巴细胞的结合 77%，蓖麻凝集素 (RCA-I) 抑制 OKT4 结合 66%。在每种情况下，适当的凝集素结合碳水化合物半抗原抑制剂都消除了抑制作用，表明它是由凝集素糖结合位点介导的。 WGA 和 RCA-I 均不抑制泛 T 细胞单克隆试剂 OKT3 的结合。此外，一组具有多种标称碳水化合物特异性的其他凝集素不会抑制 OKT4 或 OKT8 结合。预孵育实验和凝胶过滤表明，每种情况下的抑制是由于凝集素和单克隆抗体之间对与细胞表面的结合的竞争，而不是直接的凝集素-单克隆抗体相互作用。用 OKT8 和补体处理淋巴细胞同时减少 OKT8 和 WGA 结合细胞，而用 OKT4 和补体处理不会减少任一类型细胞的百分比。同样，OKT8 结合细胞的特异性去除消除了对 WGA 的促有丝分裂反应，但不能消除对 PHA 的促有丝分裂反应。通过流式细胞术和细胞分选制备的 WGA 结合细胞富集的细胞群证明了 OKT8 结合细胞的平行富集和 OKT4 结合细胞的耗尽。因此，这些数据证明了凝集素、RCA-I和WGA分别对OKT4和OKT8结合的特异性抑制。抑制作用是通过凝集素与淋巴样细胞表面（可能直接与 T4 或 T8 抗原）结合介导的。这些观察结果表明，凝集素可能有助于研究某些免疫细胞表面标记的结构特征。此外，它们还表明凝集素对免疫功能的某些体外影响可能是由于它们与 T4 和 T8 抗原等分子的相互作用所致。
We used flow cytometry to examine effects of lectins on interactions between human lymphocytes and the anti-T cell monoclonal reagents OKT4 (T helper-specific) and OKT8 (T suppressor-specific). Wheat germ agglutinin (WGA) inhibited OKT8 binding to lymphocytes by a mean 77% and Ricinus communis agglutinin (RCA-I) inhibited OKT4 binding by 66%. Inhibition was abolished in each case by appropriate carbohydrate hapten inhibitors of lectin binding, indicating it was mediated by the lectin saccharide combining sites. Neither WGA nor RCA-I inhibited binding of OKT3, a pan-T cell monoclonal reagent. In addition, a group of other lectins with a variety of nominal carbohydrate specificities did not inhibit OKT4 or OKT8 binding. Preincubation experiments and gel filtration indicated that inhibition in each case was due to competition between lectin and monoclonal for binding to cell surfaces, not to direct lectin-monoclonal antibody interactions. Treatment of lymphoid cells with OKT8 and complement reduced OKT8- and WGA-binding cells concurrently, whereas treatment with OKT4 and complement did not reduce percentages of either type of cell. Similarly, specific depletion of OKT8-binding cells abolished the mitogenic response to WGA but not that to PHA. Cell populations enriched for WGA-binding cells prepared by flow cytometry and cell sorting demonstrated parallel enrichment for OKT8-binding and depletion of OKT4-binding cells. Therefore, these data demonstrate specific inhibition of OKT4 and OKT8 binding by the lectins, RCA-I and WGA, respectively. Inhibition was mediated by lectin binding to lymphoid cell surfaces, perhaps directly to the T4 or T8 antigens. The observations indicate that lectins may prove useful for investigating structural features of some immunologic cell surface markers. Furthermore, they provide the possibility that certain in vitro effects of lectins on immune function may result from their interactions with molecules such as the T4 and T8 antigens.