Major anti-paternal alloantibody induced by murine pregnancy is non-complement-fixing IgG1

Abstract

In the mouse, females of certain inbred strains mated repeatedly with an allogeneic male produce antibody directed against paternally inherited fetal histocompatibility antigens. Four IgG isotypes (IgG1, IgG2a, IgG2b and IgG3) occur in the serum of normal animals. The availability of Ig-secreting plasmacytomas made possible the preparation of isotype-specific antisera. Using these antisera in a modified hemadsorption assay, it was demonstrated that the major alloantibody response induced by murine pregnancy involves the non-complement-fixing IgG1 subclass. This is a noncytotoxic antibody with potentially protective (enhancing) properties.