Monoclonal antibodies were obtained after fusion of mouse P3 x 63 myeloma cells with spleen cells isolated from BALB/c mice that had been immunized with aflatoxin B 1-adducted DNA complexed with methylated bovine serum albumin. Selected hybridomas were found to produce monoclonal antibodies specific for aflatoxin B 1-modified DNA containing both the 2,3-dihydro-2-(N 7-guanyl)-3-hydroxyaflatoxin B 1 and the putative 2,3-dihydro-2-(N 5-formyl-2',5',6'-triamino-4' oxo-N 5-pyrimidyl)-3-hydroxyaflatoxin B 1, suggesting that these DNA adducts share a common antigenic determinant. The monoclonal antibody was not reactive towards the free aflatoxin B 1-guanine adducts in solution, seven other aflatoxin derivatives, or benzo[a]pyrene-adducted DNA. A noncompetitive ultrasensitive enzyme radioimmunoasay could measure 15 fmol of aflatoxin B 1-DNA adducts in 10 ng of DNA and was at least 100-fold more sensitive than the standard enzyme-linked immunosorbent assay. Competitive enzyme-linked immunosorbent assay with these monoclonal antibodies reliably quantitated aflatoxin B 1 adducted in vivo to rat liver DNA at adduct levels of one aflatoxin B 1 residue per 250,000 nucleotides. The competitive ultrasensitive enzyme radioimmunoassay was determined to be at least 6-fold more sensitive than the competitive enzyme-linked immunosorbent assay in analysis of aflatoxin B 1-adducted DNA. Therefore, enzyme immunoassay using monoclonal antibodies will be useful analytical tools for studying both the moleculalr interactions of aflatoxin B 1 with DNA and the occurrence of aflatoxin B 1-DNA adducts in biological specimens from people exposed to this environmental carcinogen.
|Original language||English (US)|
|Number of pages||4|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Issue number||7 I|
|State||Published - Dec 1 1981|
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