The control of antibody diversity during IgM and IgG anti-sheep red cell responses in mice.

The isoelectric heterogeneity of both IgM and IgG murine anti-sheep red cell serum antibodies has been examined using an adaptation of published methods. It was found that the IgM spectra were restricted in a characteristic manner, implying oligoclonality. In cell transfer experiments, the T cell dependency of the IgM responses was confirmed. Further, helper cells appeared to switch on IgG antibody production and, simultaneously, recruit many novel IgG-forming clones into the response. The pattern of the IgM oligoclonality was attributed in part t o the inheritance of genes at, or closely linked to, the Ig1 heavy chain locus. These findings are discussed in relation to current research on the regulation of diversity. [ABSTRACT FROM AUTHOR]