Restriction in IgM expression-II. The V_H regions of murine anti-lactose antibodies

Abstract

A comparison of the anti-lactose IgM response among individual animals of five inbred strains of mice has been made with a view to possible germ-line restriction in IgM diversity. The _VH regions of the antibodies were isolated and the individual preparations examined by isoelectrical focusing (IEF) in 7 M urea. The main findings were the complexity of the IEF patterns as well as their similarity among individuals of the same strain and their near-identity to the patterns for the V_H regions derived from normal IgM. These observations parallel results found earlier with V_H preparations of equine anti-lactose IgM. This homology of behavior between the two systems suggests a cautious generalization about IgM responses to the effect that limited longevity of the B cell clones and germ-line restriction of V_H in IgM expression remain tenable notions.