Monoclonal anti-erythrocyte auto-antibodies from unimmunized NZB mice

In order to study the heterogeneity of the anti-erythrocyte auto-antibody response in NZB mice, we have developed hybridomas producing monoclonal auto-antibodies with anti-erythrocyte activity. These monoclonals were prepared by fusion of NZB splenocytes with the P3 X 63.Ag8 myeloma and were screened for activity by indirect immunofluorescence using flow cytometry. We have produced a variety of monoclonal anti-red cell auto-antibodies that have differing antigenic reactivities and immunoglobulin isotypes. Eleven monoclonal antibodies extensively studied thus far react with intact mouse erythrocytes, whereas only two of the eleven also cross react with sheep erythrocytes and bromelain treated mouse erythrocytes. These results suggest that the fusion pattern may represent the range of anti-red cell auto-antibodies found in the intact NZB mouse, with the exception of monoclonal auto-antibodies against cryptic red cell auto-antigens, which were not demonstrated in this initial fusion study.