Spontaneous Autoimmunity in Mice: Antibodies to Nucleoprotein in Strain A/J.

An antibody to nucleoprotein, which appears to be an autoantibody, occurs in the gamma-globulin fraction of serum from mice of the A/J strain. This antibody combines with nucleoprotein of several species but not with calf thymus DNA. The frequency of its occurrence increases with age and is greater in females. Serums that contain the antibody produce typical lupus erythematosus cells in vitro.