Ikewaki N
Department of Microbiology, Kitasato University School of Nursing, Kanagawa, Japan.
J Clin Immunol. 1997 Mar;17(2):127-39. doi: 10.1023/a:1027374331094.
A human monoclonal antibody (mAb), designated mNKES, was generated by fusing B cells isolated from an enlarged cervical lymph node of a patient with a carotid body tumor (CBT), with human myeloma cell line KR-12 (6TG). The reactivity of mNKES was tested by the indirect immunofluorescence method. The antigen defined by mNKES was expressed on Burkitt's lymphoma cell lines Raji, Daudi, and Ramos and on B lymphoblastoid cell line IM-9. In addition, mNKES reacted with T cells stimulated with recombinant interleukin-2 (rIL-2) obtained from normal healthy donors. However, mNKES did not react with normal resting human T, B, or adherent cells (monocytes/macrophages). When the reactivity of mNKES and mouse mAbs recognizing the human adhesion-associated antigen (CD10, CD11a, CD11b, CD11c, CD14, CD16, CD18, CD23, CD28, CD29, CD31, CD43, CD44, CD45RA, CD50, CD54, CD58, CD80, CD102, CD106, and HLA class I, and HLA class II antigen) with various cell lines was compared, mNKES reactivity was found to be unique, not resembling that of any of these mouse mAbs. Interestingly, mNKES specifically and rapidly (within 2 hr) induced homotypic cell aggregation of IM-9 cells. This mNKES-induced cell aggregation was completely blocked by the addition of EDTA and when incubated at 4 degrees C. The mAbs reactive with CD11a/CD18 (leukocyte function-associated antigen-1; LFA-1) and CD54 (intercellular adhesion molecule-1; ICAM-1) completely blocked the IM-9 cell aggregation induced by mNKES, and induction of IM-9 cell aggregation by mNKES was significantly blocked in the presence of the protein kinase C inhibitors sphingosine and H-7 and completely blocked by cytochalasin B and cytochalasin D, which inhibit microfilament formation. Regarding biological function, IM-9 cells bearing surface IgG (sIgG) effectively promoted IgG-secreting activity underlying the homotypic cell aggregation induced by mNKES. The surface antigen recognized by mNKES has a molecular size of about 55 kDa, as determined by immunoblotting analysis. These findings indicate that mNKES recognizes a novel adhesion-associated antigen distinct from any previously reported adhesion-associated antigens in terms of pattern of cellular distribution and biological function and that mNKES is the first human mAb found that rapidly induces homotypic cell aggregation and effectively promotes the IgG-secreting activity of human B lymphoblastoid cell line IM-9.
一种名为mNKES的人源单克隆抗体（mAb），是通过将从一名患有颈动脉体瘤（CBT）患者的肿大颈部淋巴结中分离出的B细胞与人类骨髓瘤细胞系KR - 12（6TG）融合而产生的。采用间接免疫荧光法检测了mNKES的反应性。mNKES所定义的抗原在伯基特淋巴瘤细胞系Raji、Daudi和Ramos以及B淋巴母细胞系IM - 9上表达。此外，mNKES与用从正常健康供体获得的重组白细胞介素 - 2（rIL - 2）刺激的T细胞发生反应。然而，mNKES与正常静息的人T细胞、B细胞或黏附细胞（单核细胞/巨噬细胞）不发生反应。当比较mNKES和识别人类黏附相关抗原（CD10、CD11a、CD11b、CD11c、CD14、CD16、CD18、CD23、CD28、CD29、CD31、CD43、CD44、CD45RA、CD50、CD54、CD58、CD80、CD102、CD106以及HLA I类和HLA II类抗原）的小鼠单克隆抗体与各种细胞系的反应性时，发现mNKES的反应性是独特的，与这些小鼠单克隆抗体中的任何一种都不同。有趣的是，mNKES特异性且快速地（在2小时内）诱导IM - 9细胞的同型细胞聚集。添加EDTA并在4℃孵育时，这种mNKES诱导的细胞聚集被完全阻断。与CD11a/CD18（白细胞功能相关抗原-1；LFA - 1）和CD54（细胞间黏附分子-1；ICAM - 1）反应的单克隆抗体完全阻断了mNKES诱导的IM - 9细胞聚集，并且在蛋白激酶C抑制剂鞘氨醇和H - 7存在的情况下，mNKES对IM - 9细胞聚集的诱导作用被显著阻断，而细胞松弛素B和细胞松弛素D抑制微丝形成，则完全阻断了这种诱导作用。关于生物学功能，携带表面IgG（sIgG）的IM - 9细胞有效地促进了mNKES诱导的同型细胞聚集中潜在的IgG分泌活性。通过免疫印迹分析确定，mNKES识别的表面抗原的分子大小约为55 kDa。这些发现表明，mNKES识别一种新型的黏附相关抗原，在细胞分布模式和生物学功能方面不同于任何先前报道的黏附相关抗原，并且mNKES是发现的第一种能快速诱导同型细胞聚集并有效促进人B淋巴母细胞系IM - 9的IgG分泌活性的人源单克隆抗体。
