Temporal dependence of the inhibition by cytochalasin B of antigen initiated migration inhibition factor production

The effects of cytochalasin B on the antigen recognition process have been examined using an in vitro assay of macrophage inhibition factor (MIF) production by activated guinea pig T lymphocyte enriched populations. The data indicate that cytochalasin B inhibits MIF production if added at the initiation of culture but not if added 2 hr after antigen. These data are interpreted as consistent with either an inhibition by cytochalasin B of the physical association of antigen bearing macrophage and lymphocytes or with an inhibition of the access of antigen to the T lymphocyte receptor.