In an attempt to further define the mechanism of anti-erythrocyte autoantibody production in mice immunized with rat red blood cells (Rrbc), we have analyzed the eluted autoantibody with respect to antigenic specificity and clonal heterogeneity. The eluted autoantibody was shown to be heterogeneous with respect to class and subclass specificities as well as antigenic specificities. Moreover, cell-bound erythrocyte autoantibody included IgG1, IgG2a, IgG2b, and IgM, but only the presence of erythrocyte-bound IgG2b correlated with the hemolytic process. The other class and subclass specificities appeared to have little or no pathogenetic effect. The eluate reacted as a panagglutinin with both an allogeneic red blood cell test panel and Rrbc. Both the anti-mouse red blood cell (Mrbc) and the anti-Rrbc activities of eluted autoantibody were absorbed more efficiently by Rrbc than Mrbc, although the indirect globulin titers against both targets were similar. Finally, an expanded population of antigen-binding lymphocytes and plaque-forming cells specific for cryptic erythrocyte autoantigens was demonstrated. It is concluded that the IgG1 subclass response represents cross-reactive or "degenerative" antibody and the IgM response is directed against cryptic autoantigen on isologous erythrocytes.
ASJC Scopus subject areas
- Immunology and Allergy
- Pathology and Forensic Medicine