Torimoto Y, Kinebuchi M, Matsuura A, Kikuchi K, Uede T
Department of Pathology, Sapparo Medical College, Japan.
J Exp Med. 1990 Nov 1;172(5):1315-23. doi: 10.1084/jem.172.5.1315.
A murine monoclonal antibody, designated 8H3, recognizes a cell surface antigen expressed exclusively on rat T lineage cells. 8H3 antibody immunoprecipitated 180-, 120-, and 90-kD components from rat thymocytes as well as splenic T cells under nonreducing conditions. 8H3 antibody specifically inhibited the binding of thymocytes to fibronectin. Furthermore, binding of rat thymocytes to immobilized synthetic peptide Gly-Arg-Gly-Asp-Ser-Pro-Cys-BSA was inhibited by 8H3 antibody as was Gly-Arg-Gly-Asp-Ser-Pro-Cys, but not by Gly-Arg-Ala-Asp-Ser-Pro-Lys or Gly-Arg-Gly-Glu-Ser-Pro. Crosslinking of 8H3 antigen on double-negative thymocytes and adult thymocytes, as well as splenic T lymphocytes by 8H3 antibody and F(ab')2 fragments of goat antibodies to mouse immunoglobulin, led to an increase in the concentration of cytoplasmic free Ca2+ due to the release of Ca2+ from intracellular stores as well as the influx of Ca2+ from extracellular sources. Expression of interleukin 2 receptor and subsequently cell proliferation was observed upon incubation of thymocytes and splenic T cells with 8H3 antibody. Furthermore, 8H3 antibody induced the proliferation of double-negative thymocytes. These data collectively indicated that a cell surface antigen, 8H3, is involved in not only cell adhesion but also involved in the expression of immature as well as mature thymocytes.
一种名为8H3的鼠单克隆抗体可识别仅在大鼠T淋巴细胞系细胞上表达的细胞表面抗原。在非还原条件下，8H3抗体可从大鼠胸腺细胞以及脾T细胞中免疫沉淀出180kD、120kD和90kD的成分。8H3抗体特异性抑制胸腺细胞与纤连蛋白的结合。此外，8H3抗体可抑制大鼠胸腺细胞与固定化合成肽Gly-Arg-Gly-Asp-Ser-Pro-Cys-BSA的结合，Gly-Arg-Gly-Asp-Ser-Pro-Cys也有此作用，但Gly-Arg-Ala-Asp-Ser-Pro-Lys或Gly-Arg-Gly-Glu-Ser-Pro则无此作用。8H3抗体和山羊抗小鼠免疫球蛋白的F(ab')2片段对双阴性胸腺细胞、成年胸腺细胞以及脾T淋巴细胞上的8H3抗原进行交联，由于细胞内储存的Ca2+释放以及细胞外Ca2+内流，导致细胞质游离Ca2+浓度增加。用8H3抗体孵育胸腺细胞和脾T细胞后，可观察到白细胞介素2受体的表达以及随后的细胞增殖。此外，8H3抗体可诱导双阴性胸腺细胞增殖。这些数据共同表明，细胞表面抗原8H3不仅参与细胞黏附，还参与未成熟和成熟胸腺细胞的表达。
