Four
monoclonal antibodies (MAbs) from hybridoma obtained by in vitro stimulation of regional lymph node lymphocytes from
lung cancer patients and electrofusion of the stimulated cells with murine or human-mouse myeloma cells were reactive to
lung cancer cells in
enzyme-linked immunoabsorbent assay, and to
lung cancer tissue in immunohistochemical analysis using
acetone-
methyl benzoate-
xylene (AMeX) fixed tissue and in immunofluorescence analysis. Three of the MAbs (designated ZLG40, 27D57 and 28K29) recognised
cell-surface antigens of the
lung adenocarcinoma cell line A549 and the remaining one (designated 29D38) recognised nuclear membrane
antigens of the same cell line. The three surface-binding MAbs showed a significant
complement-dependent cytotoxicity (CDC) to the A549 cells, but the membrane-binding 29D38 showed no CDC to the A549 cells. Western blotting of the extracts of the A549 or
PC6 (
small-cell lung cancer) cell lines by the four MAbs showed a 28K29
antigen band at M(r) of approximately 600,000 (+/- 2-ME), a ZLG40
antigen band at M(r) 50,000 (+/- 2-ME), and one 29D38
antigen band at M(r) of more than 1,000,000 (-2-ME) and M(r) between 20,000 and 80,000 (+2-ME), but no detectable band for 27D57
antigen.