Suppression of migration inhibition factor (MIF) production by mitomycins in vitro

The effects of a series of mitomycins in a modified version of the Migration Inhibition Factor (MIF) test were investigated. This modified assay, which uses monocytes of the mouse cell line WEHI3 as target cells for MIF, discriminates between effects on the migrating monocytes, the production of MIF by lymphocytes and the activity of the produced MIF. The 7-methoxy mitomycins were found to be more active than the 7-amino and 7-hydroxy derivatives in suppressing both the spontaneous migration of target monocytes and the MIF production by lymphocytes. Neither of the compounds had a significant effect on the activity of produced MIF. A relationship between the activities of the mitomycins and their lipophilicity and polarographic half-wave potential is discussed. Further attention is paid to the stability of the mitomycins under the test conditions and additional advantages of the modified MIF assay over related in vitro tests for cell-mediated immunity.