A reevaluation of the concanavalin A induced suppressor cell assay in man

Several methods are used to evaluate the in vitro suppressor function of human peripheral blood lymphocytes (PBL). Recently however, the validity of these assays has been questioned, because possible artefacts may lead to misinterpretation of the results. A reevaluation of these assays has been performed, and a simple and reproducible technique necessitating only one bleeding has been developed. Pretreatment of human PBL with concanavalin A (ConA) results in an inhibition of 3H-thymidine incorporation after ConA stimulation by cocultured untreated autologous or allogeneic PBL collected at the same time and incubated under the same conditions as the inhibitory PBL. It is concluded that true suppression is responsible for the observed inhibition of the response to ConA and that this assay can be used to assess the functional ability of suppressor cells in different clinical situations.