T-Lymphocyte Receptors for Alloantigens

Abstract

Recent developments in research on T-cell receptors for alloantigens have been reviewed. Recognition of these antigens is T-cell dependent and, when measured in the PAR test, can be shown to take place with receptors present on T cells, with those shed spontaneously from T cells and also with “recognition structures” of as yet unknown origin and structure present in post-transplantation alloantiserum but absent from B-cell induced alloantiserum. All recognizing structures of parental T-cell origin mentioned above also induce formation of anti-T cell receptor antisera when injected into appropriate F₁ hybrid animals. The highly specific inhibitory activity of the sera can be demonstrated both in vitro and in vivo, and the most fascinating aspect constitutes cytotoxic elimination of T cells bearing receptors for a given alloantigenic specificity without harming T cells with other alloreceptors. The biochemical nature of T-cell receptors is not known and, depending on the physical form in which it is investigated, high molecular weight as well as cpnsiderably lower molecular weight structures have been found. It has, on the other hand, become quite clear that the antigen-binding region of B- and T-cell receptors shows idiotypic similarity and it is, therefore, likely that this part of the receptor molecule of both lymphocyte classes is similar if not identical (51).