Studies of Allospecific Suppressor Cells in Culture

Abstract

Suppressor T lymphocytes are presumed to constitute an important regulatory mechanism of immune responses and a considerable body of information has been gathered concerning their role in humoral and cellular immunity, as well as in immune tolerance. However, very little is known as to the mechanism of suppressor cell induction on the cellular level, as well as to the cellular parameters of their function. The present study was undertaken in order to gain some insight into the respective cellular mechanisms, particularly concerning allospecific cellular responses. For a critical analysis of the relevant parameters, an experimental model was developed in which both the generation of suppressor cells and the assay of their subsequent suppressive function were studied in culture. We have reported on this in a previous publication (1), showing that allospecific suppressor T lymphocytes could be induced in vitro by stimulation of mouse thymus cells with allogeneic irradiated spleen cells. When this primary culture was harvested at an appropriate stage and transferred to a one-way mixed lymphocyte reaction, a significant suppression of thymidine incorporation could be demonstrated, as compared with control MLR.