The severity of irritant contact dermatitis in various strains of mice correlates with endothelial expression of migration inhibitory factor (MIF).

Irritant contact dermatitis to croton oil in BALB/cByJ, C57Bl/6J and six recombinant inbred CxB strains of mice was investigated in relation to variations in endothelial migration inhibitory factor (MIF) reactivity. MIF has been shown to be a mediator of cellular immunity and operates as a differentiation signal inducing an inflammatory type of macrophage. The intensity of the ear swelling response reached a maximum 8 h after induction of contact dermatitis, with highest values in BALB/cByJ and CxB4/ByAH mice and weak reactions in CxB2/ByAE, CxB7/ByAK, C57Bl/6J and CxB1/ByAD mice. After the same time period (8 h) cryostat sections were immunostained for capillary endothelium expressing MIF. The most pronounced MIF expression was observed in BALB/cByJ mice, and CxB4/ByAH mice showed intermediate reactions and the other strains weak reactions. Endothelial MIF expression correlated well with the intensity of ear swelling (Pearson's correlation coefficient 0.82). Patterns of endothelial MIF expression in recombinant inbred strains suggest that endothelial MIF expression is not under the control of a single gene. Our data support the hypothesis that endothelial MIF expression plays a prominent role in inflammatory events and correlates with the severity of inflammation.