Abstract
Ten guinea pigs were inoculated with porcine monocomponent insulin on days 0, 13, 22 and 58. Serial antisera obtained 22 days after the first inoculation were pooled and anti-insulin antibodies were purified by passing them through an insulin-epoxy-sepharose 6 B column. After extensive dialysis against 0.1 M NaH2PO4, pH 3.0, followed by extensive dialysis against PBS, anti-insulin antibodies were inoculated subcutaneously on days 0, 8, 15 in two Japanese white rabbits (API-1, API-2) with FCA. Antisera obtained 18 days after the first inoculation were tested for the presence of anti-insulin antibodies first. Because weak anti-insulin antibody activities were noted, both antisera were passed through insulin-epoxy-sepharose 6 B to remove anti-insulin antibody activities in them. Antisera thus obtained were examined for the presence of anti-insulin anti-idiotypic antibodies.
Antisera from API-1 and API-2 in the γ-globulin concentrations of 3 γ 10-1 mg and 6.7 γ 10-1 mg inhibited the binding of 125I-insulin with anti-insulin antibodies which had been covalently attached on sepharose 6 B up to 82.7% and 81.7%, respectively. On the other hand, rabbit antiguinea pig IgG and IgM did not interfere with the interaction between 125 I-insulin and antiinsulin antibodies. These results clearly indicate the presence of anti-insulin anti-idiotypic antibodies in the sera from both rabbits. The clinical as well as the basic usefulness of anti-insulin antiidiotypic antibodies is discussed.
