Comparative studies on antibody and antibody production to poly(ADP-ribose) in mice

Antibodies to poly(ADP-ribose) were produced in C3H/He mice by injection of poly(ADP-ribose) in Freund's incomplete adjuvant or its complexes with methylated bovine serum albumin in Freund's incomplete adjuvant. Titres of the antibody obtained from the latter were about 50-fold higher than those from the former. Thus, the effect of methylated bovine serum albumin on the antibody production to poly(ADP-ribose) resembled the case of poly(I).poly(C) and was different from the case of single stranded DNA. The class of the antibodies obtained from these two different procedures mainly consists of 7S antibodies, and the specificity of these antibodies was independent of their titres. It was also found that antibodies to poly(ADP-ribose) were most reactive to poly(ADP-ribose) with 20 repeating ADP-ribose units. The reactivity of the antibody was dependent on the chain length of the polymer. Neither the complex in Freund's incomplete adjuvant nor poly(ADP-ribose) alone in Freund's imcomplete adjuvant could induce an immune response to poly(ADP-ribose) in athymic nude mice. Therefore, the immune response to poly(ADP-ribose) may occur through a thymus function.