A comparison of irradiation and mitomycin as blocking agents in the mixed lymphocyte reaction

In comparison with administration of mitomycin, lethal irradiation (2,000 rad) of the stimulator cells in a one-way mixed leukocyte culture results in a reduced response due at least in part to the release of inhibitory materials by the irradiated cells. These inhibitory molecules may be partially removed by washing and possess differential reactivity with respect to phytohemagglutinin, concanavalin A, lipopolysaccharide, and pokeweed mitogen.