Inhibition of Local Graft-versus-Host Reaction by Anti-Alloantibodies

Abstract

THE variable part of an antibody molecule can be used as an antigen within the species that produces it. Antibodies against such variable part antigenic determinants (idiotypes) are called anti-idiotypic¹. One example of anti-idiotype antibodies is found in alloantibody systems, where A anti-B antibodies directed against histocompatibility antigens can be shown to elicit the formation of anti-alloantibodies when injected into (A×B) F₁ hybrids^2,3. That the hybrid indeed synthesises anti-alloantibodies has been demonstrated both by studies on the kinetics of formation⁴ and on the allotypic specificity⁵ of the F₁ product. Such anti-alloantibodies can be shown to react not only with humoral alloantibodies³, but also with cells carrying receptors (recognition structures) of the same idiotypic specificity². The possibility of using anti-alloantibodies for highly selective immunosuppression of transplantation reactions in vivo is of obvious importance. We have therefore attempted to prevent a local graft-versus-host (GvH) reaction in rats by anti-alloantibody.