Infection of C3HeB/FeJ mice with the docile strain of lymphocytic choriomeningitis virus induces autoantibodies specific for erythrocyte Band 3.

C3HeB/FeJ mice infected with the docile strain of lymphocytic choriomeningitis virus (LCMV-d) develop a persistent infection with a transient haemolytic anaemia. Immunoglobulin can be eluted from the red blood cells (RBC) of these mice but it cannot be detected on the RBC by a conventional antiglobulin test. The present study demonstrates that RBC from such mice bear erythrocyte autoantibodies which are predominantly of the IgG2a subclass, with lower levels of autoantibodies of the IgG1, IgG2b and IgG3 subclasses. To identify the target antigen the autoantibodies were eluted from the RBC of LCMV-infected mice. The eluted autoantibody bound to intact normal RBC and precipitated a 105000 MW component that corresponds to murine Band 3 protein. A monoclonal antibody derived from mice infected with LCMV-d also precipitated mouse Band 3, and reacted specifically by enzyme-linked immunosorbent assay against a purified preparation of Band 3. This study has shown that in C3H mice infected with LCMV-d which develop autoimmune haemolytic anaemia, the target autoantigen is erythrocyte membrane Band 3.