In vitro studies of contact hypersensitivity. The effect of the haptens 2,4-dinitrochlorobenzene (DNCB) and 2,4-dinitrofluorobenzene (DNFB) and of hapten-protein conjugates on the migration of guinea-pig peritoneal exudate cells.

The inhibition of macrophage migration test has been used to study the effect of simple chemical sensitizers, 2,4-dinitrochlorobenzene (DNCB) and 2,4-dinitrofluorobenzene (DNFB) on peritoneal exudate cells harvested from animals exhibiting contact hypersensitivity to the haptens. Specific inhibition of migration of cells from eleven out of twelve sensitized animals was achieved when cells were cultured in the presence of a dinitrophenyl-guinea-pig serum conjugate in a concentration which had no effect on cells from normal animals. The unconjugated haptens were toxic to cells and inhibited, non-specifically, the migration from capillary tubes of cells from normal guinea-pigs and from guinea-pigs sensitized to DNCB and DNFB, cultured in the presence of low concentrations of the haptens. Non-specific inhibition also occurred with high concentrations of the conjugates, dinitrophenyl-lysine and dinitrophenyl-guinea-pig erythrocyte stromata, while lower concentrations of these conjugates had little effect.