Expression and regulation of erythrocyte auto-antibodies in mice following immunization with rat erythrocytes.

Mice immunized with intact rat red blood cells (RBC) developed serum auto-antibodies (some of which were mouse specific) to the RBC membrane components spectrin and antigens of 100 and 81 kDa as shown by Western blotting and enzyme-linked immunosorbent assay as well as RBC surface-bound autoantibodies detected by the Coombs' test. In order to discover whether these autoantibodies were induced and controlled in similar or different ways, mice were challenged with a variety of rat and mouse RBC preparations. In addition, the ability of recipients given spleen cells from the above donors to generate autoantibody responses to intact rat RBC was measured. It was found that all the autoantibodies were induced in mice challenged with rat RBC ghosts but none following immunization with butanol-extracted rat RBC ghosts or intact mouse RBC. By contrast, mice injected with mouse RBC ghosts made autoantibodies to spectrin and to the 100-kDa band. Spleen cells from mice primed with intact rat RBC, rat RBC ghosts or butanol-extracted rat RBC ghosts curtailed Coombs' autoantibody production of recipient mice challenged with intact rat RBC. Serum from recipients of spleen cells primed with intact rat RBC or the butanol extract generally failed to react with rat or mouse spectrin or with the 81-kDa band, although antibody was detected to the rat 100-kDa band. Recipients of rat RBC ghost-primed spleen cells produced antibody to rat and mouse spectrin and to rat 100-kDa band but not to mouse 100-kDa or rat or mouse 81-kDa bands. Occasionally, suppression of antibody to the rat-specific 38-kDa band was observed in recipients of intact rat RBC-primed spleen cells. It is therefore suggested that regulation of cross-reactive and mouse-specific autoantibodies as well as rat-specific antibodies occurs in an independent, determinant-specific manner.