Carrier-specific induction of suppressor cells controlling anti-erythrocyte autoantibody production in mice

The influence of adjuvants on the generation of autoantibody and specific suppression in rat erythrocyte-immunized mice

A number of adjuvants were investigated for their ability to modulate either the autoimmune response induced in mice by immunization with rat erythrocytes (RRBC) or the ability of RRBC-primed spleen cells to suppress the induction of anti-red cell autoimmunity in recipient mice. The inability of the agents used to do so is discussed on the background of models used to explain the generation of suppression in this system.

Autoimmune response induction and regulation in rat erythrocyte-immunized mice

The process of antibody formation to self-red blood cells (RBC) has been studied in rat RBC (rRBC)-immunized mice. A positive correlation was noted between antibody production to mouse RBC (mRBC) and rRBC in some mouse strains. The low responsiveness on both indices was overcome by s.c. injections of rRBC in low doses. rRBC-tolerant mice exhibited lower levels of antibody production to mRBC. Splenocytes from rRBC-immunized donors, when transferred to irradiated recipients, revealed enhanced and accelerated anti-mRBC and anti-rRBC antibody production in response to rRBC but not to autologous mRBC. Consequently, the autoimmune process is not accompanied by disordered immunologic tolerance to self-RBC and requires participation of Th responding to foreign epitopes of rRBC antigens. Splenocytes from rRBC-immunized donors, when transferred to non-irradiated recipients, inhibited antibody production to mRBC. The suppressive effect was not abrogated by pretreating donors or recipients with low doses of cyclophosphamide (CP) or by pretreating donors with antibodies to I-J. It was abrogated by the elimination of cells of donor origin within 8-9 days after transfer. Inoculation of antibodies to rRBC in immunized mice on a schedule imitating their splenocyte transfer dynamics inhibited antibody production to mRBC. Therefore, it can be assumed that the suppressive effect of cell transfer is accounted for, not by suppressors or their inducers, but by antibodies to rRBC on the basis of feedback regulation.

Identification of an erythrocyte autoantigen using monoclonal autoantibodies induced by immunization of mice with rat erythrocyte

An erythrocyte autoantigen has been identified by means of monoclonal autoantibodies raised by immunizing mice with rat red blood cells (RBC). The autoantibodies reacted with intact rat and mouse RBC as judged by a cellular radioimmunoassay, and with a 52K band on western blots of rat and mouse RBC. They did not react with intact sheep RBC or blotted sheep erythrocyte membranes. Although anti-rat erythrocyte antibodies did react with bands in the molecular weight region of 50-55 K (on blots of rat erythrocyte membranes), these bands were susceptible to neuraminidase digestion, thus distinguishing them from the 52 K band recognized by monoclonal autoantibodies. The implications of the above results for the known autoantibody specificity of suppression is discussed, and it is suggested that they favour the existence of autoantigen-specific suppressor cells.