Accelerated expansion of antibody heterogeneity by complete Freund's adjuvant during the response to bacterial alpha-amylase.

Changes in the isoelectric focusing (IEF) spectra of specific antibodies were followed during the response of individual mice to bacterial alpha-amylase (B alpha A) in either incomplete or complete Freund's adjuvant (IFA or CFA). The response to a suboptimal dose of B alpha A was maximally enhanced by employing CFA at an optimal dose of Mycobacterium tuberculosis. Regardless of the strain difference in responsiveness to B alpha A between C3H/He (C3) and C57B1/6 (B6) mice, the enhancing effect of CFA was characterized by an accelerated expansion of IEF spectra and by the intensified stain of focused antibody, compared with the response of mice immunized with the same antigen dose in IFA. The manner and the rate of heterogeneity expansion during the enhanced antibody response to a low dose in CFA were quite similar to the strictly restricted expansion of spectra during a response of a high dose of B alpha A in IFA, although each mouse showed an individual banding pattern with a different degree of heterogeneity, depending on the antibody titre. Thus, CFA accelerated the expansion of IEF spectra during the response to B alpha A without affecting the general manner of sequential expansion of anti-B alpha A antibody heterogeneity.