A Novel Anti-CEACAM5 Monoclonal Antibody, CC4, Suppresses Colorectal Tumor Growth and Enhances NK Cells-Mediated Tumor Immunity
Figure 1
Characterization of mAb CC4 and identification of mAb CC4 antigen.
MAb CC4 was used to stain LS174T cells in flow cytometry assay (A) and immunofluorescence (B). Isotype-matched murine normal IgG served as negative control. Frozen sections of normal colon and colorectal tumor tissues were stained by mAb CC4 in immunohistochemical analysis (C); and extracts from these tissues and whole cell extracts of LS174T and SW1116 were subjected to immunoblot using mAb CC4 (D, lower panels). LS174T cell lysate were immunoblotted with CC4 under reduced or non-reduced conditions (D, upper panels). Immunoprecipitation was performed using mAb CC4 or mIgG to accumulate the antigen protein and immunoprecipitates were subjected to Western blot assays (E). Four peptides were obtained from LC-MS analysis using CC4 precipitates and the antigen was identified as CEACAM5, of which partial amino acid sequence and these identified peptides were illustrated (F). Bladder cancer cells T2-4 were transfected with CEACAM5 expression plasmids and subjected to flow cytometry analysis with CC4 (G).