Restricted heterogeneity of antibodies to idiotypes of isologous immunoglobulins

Abstract

To determine whether isologous anti-idiotypic antibody responses are degenerate, the antibodies made by BALB/c mice to the idiotype of M167, an IgA,k myeloma protein of BALB/c origin, were tested for: (a) homogeneity with respect to affinity, (b) immunoglobulin class, and (c) polydispersity in isoelectric focussing. The results showed that the anti-idiotypic antibodies to M167 belonged to the IgGl class, were essentially homogeneous in affinity for the 125I-Fab fragment of M167, and displayed little polydispersity by isoelectric focussing. The relative homogeneity of these isologous anti-idiotypic molecules is particularly notable because they were elicited by an immunization procedure that, with conventional antigens, usually evokes highly heterogeneous antibody responses.