PRODUCTION OF ANTIBODIES TO DENATURED DEOXYRIBONUCLEIC ACID (DNA)

Abstract

Thermally denatured calf thymus DNA and T4 phage DNA act as haptens in the rabbit when injected as complexes with methylated bovine serum albumin (MBSA). The antigenic determinant groups of calf thymus DNA seem to comprise sequences of the four common deoxyribonucleotides because (1) each of the deoxyribonucleotides but not ribonucleotides, deoxyribose, or the bases, inhibits the C''-fixation reaction between antiserum and denatured calf thymus DNA; (2) the antiserum cross-reacts with denatured DNA from various mammalian and bacterial species; (3) native DNA is unreactive; (4) the reactive antigen is found in fractions of highly purified DNA and cannot be dissociated from it. The antibodies against denatured calf thymus DNA do not react with single-stranded T4 phage DNA. Similarly, anti-T4 phage DNA serum shows little cross-reactivity with heat-denatured heterologous DNA. This relative specificity of the phage DNA may be due to its unique base content. Pneumococcal polysaccharide, like denatured DNA, also becomes immunogenic in rabbits when complexed to MBSA. Thus, MBSA appears to be a suitable carrier for antigenic acidic polymers.