Chin N W, Zhang R, Nostro D C, Lanks K W
Laboratory Service, Veterans Affairs Medical Center, Brooklyn, New York.
Am J Pathol. 1992 May;140(5):1061-9.
Antibodies to cytokeratins (CKs) have found extensive application in the differential diagnosis of epithelial tumors. The chain-specific anti-CK reagents appear to be of practical value for further subtyping of carcinomas. The authors have produced a novel anti-CK 18 monoclonal antibody (ACK-156) using a modified immunization procedure that included sequential injections of human epidermal keratin, cyclophosphamide, and enriched cytoskeletal extracts from a human lung carcinoma cell line. This protocol effectively amplified clones with reactivity toward CK epitopes not present in epidermal keratin. Monospecificity of the antibody was confirmed by immunoblot analysis using both total cell lysates and cytoskeletal extracts as antigens. Immunoperoxidase staining of adenocarcinomas from a variety of sites, including lung, was strongly positive. Squamous cell carcinomas of lung were also strongly stained whereas squamous cell carcinomas of head and neck origin were stained focally or not at all. In contrast, several commercially available anti-CK 18 monoclonal antibodies did not distinguish squamous cell carcinomas of lung from those of head and neck origin. Immunoblot analysis of tumor lysates corroborated the tissue staining results and revealed that the commercially available antibodies that were tested recognize at least one other low molecular weight peptide in addition to the CK 18 peptide recognized by ACK-156.
细胞角蛋白（CKs）抗体已在上皮性肿瘤的鉴别诊断中得到广泛应用。链特异性抗CK试剂对于进一步区分癌的亚型似乎具有实用价值。作者采用改良的免疫程序制备了一种新型抗CK 18单克隆抗体（ACK-156），该程序包括依次注射人表皮角蛋白、环磷酰胺以及来自人肺癌细胞系的富集细胞骨架提取物。此方案有效地扩增了对表皮角蛋白中不存在的CK表位具有反应性的克隆。通过使用全细胞裂解物和细胞骨架提取物作为抗原的免疫印迹分析证实了该抗体的单特异性。对包括肺在内的多种部位腺癌的免疫过氧化物酶染色呈强阳性。肺鳞状细胞癌也呈强染色，而头颈部来源的鳞状细胞癌则呈局灶性染色或根本不染色。相比之下，几种市售的抗CK 18单克隆抗体无法区分肺鳞状细胞癌和头颈部来源的鳞状细胞癌。肿瘤裂解物的免疫印迹分析证实了组织染色结果，并显示所测试的市售抗体除了识别ACK-156所识别的CK 18肽外，还识别至少一种其他低分子量肽。
