Monoclonal antibodies against two human lung carcinoma cell lines

Monoclonal antibodies against 2 human lung carcinoma cell lines (E14 and BEN) were prepared by production and cloning of somatic cell hybrids between the murine myeloma NS1, and spleens from E14- and BEN-immune BALB/c mice. Approximately 2000 hybrid culture supernatants were screened for antibody simultaneously against the immunizing cell line and lung fibroblasts (573 Lu) using a radiolabelled Protein A binding assay. Although the vast majority secreted antibodies which recognized species-specific antigens, a few supernatants showed marked differential reactivity against E14 or BEN. These were cloned and subsequently tested against a panel of up to 25 human cell lines originating from different neoplastic and non-neoplastic tissues. Two anti-E14 clones (3E19.8 and 4EAB3.7) displayed preferential activity against lung cancer cell lines, but a low level of reactivity was also detectable with cell lines of different tissue provenance. The antibodies of 3 anti-BEN clones (7B3.5, 7B5.4, 7B17.7) likewise recognized antigens present to a higher density on lung cancer cell lines but were also reactive (to a variable extent for the different clones) with a diversity of other tumour cell lines. The antibodies of 2 further clones were exceptional in so far as one (7BC9.1) reacted only with BEN and WIDR (colorectal cancer) cells, while another (7B24.4) reacted, with apparent exclusivity, against BEN cells. With the exception of the latter, the distinction in antigen expression between many of the cell lines was quantitative rather than qualitative and the emergent picture is one of random expression of individual determinants on several disparate types of cancer cells, rather than restriction to cells of a given morphological type or histogenic derivation.