Search

Mice injected with rat erythrocytes produce erythrocyte autoantibodies and suppressor cells that specifically inhibit the autoimmune response without inhibiting the net production of antibodies against rat erythrocytes. Here it is shown that the suppressor cells bind preferentially to monolayers of rat erythrocytes rather than to erythrocytes from mice or sheep, Suppressor populations depleted of B cells, and cells that adhered to monolayers of rat erythrocytes, lost the ability to suppress the production of autoantibodies in normal mice injected with rat erythrocytes. In contrast, suppressor populations depleted of B cells and cells that adhered to sheep erythrocytes or mouse erythrocytes retained suppressor activity. From these results it is suggested that the regulation of autoantibody production by the suppressor cells in this model may be part of a normal system by which antibody responses to foreign antigens are regulated, and not a unique homeostatic mechanism by which harmful autoimmune responses are eliminated. [ABSTRACT FROM AUTHOR]

Erythrocyte autoantibodies can be elicited in mice by injections of rat RBC which are cross-reactive with mouse RBC. This report shows that reduction of autoantibodies is dependent, in part, on gene(s) outside the H-2 complex. Using CBA mice congenic for Ig allotype and the F1 and F2 hybrids, a higher incidence of autoantibody production was observed in mice bearing the Ig allotype 1b (1bb' or 1ab) in contrast to mice homozygous for the allotype Ig-1a. Serum haemagglutination titres against rat RBC were not reduced in the groups of mice with the lower incidence of autoantibody production. A probable explanation for these observations is that the change in Ig allotype is associated with some change in the variable region determining autoimmune specificity that is governed by VH genes linked to allotype genes. The transfer of 30× 106 spleen cells from Coombs' positive mice to syngeneic recipients before starting the immunization regime with rat RBC suppressed autoantibody production and enhanced antibody production against rat RBC. These suppressor cells were effective in congemic mice and in F1 hybrids, which suggest that the Ig allotype is not a crucial site for the effector stage of suppression of this autoimmune response. [ABSTRACT FROM AUTHOR]

Investigates the erythrocyte autoantibodies and autoantibody-specific suppressor cells in mice injected with rat erythrocytes. Solubilization of rat erythrocyte membranes; Preparation of hemoglobin-free membranes and soluble lysates of rat red blood cells; Adoptive transfer of spleen cells; Fractions of rat RBC membranes injected into spleen cell donors.

Examines the failure to induce autoimmunity in mice with endotoxin. Provocation of immunity against endotoxin by prolonged immunization of mice with endotoxin-coated syngeneic erythrocytes; Clearance of allogeneic erythrocytes; Response against syngeneic erythrocytes as measured by direct Coombs' tests and in vivo survival studies.