DIFFERENCES IN MIGRATION-INHIBITORY FACTOR PRODUCTION BY C57B1/6 AND BALB/C MICE IN ALLERGIC AND IRRITANT CONTACT-DERMATITIS

Two strains of mice, BALB/c and C57B1/6, which are known to differ in their inflammatory responsiveness to allergens, were analyzed regarding their expression of macrophage migration inhibitory factor (MIF). Allergic contact dermatitis to 2,4-dinitro-1-fluorobenzene and irritant contact dermatitis to croton oil were studied immunohistologically at designated time intervals after elicitation. BALB/c mice presented a significantly more intense ear swelling response than C57B1/6 mice and showed a strong endothelial MIF expression in the early phase of inflammation in both allergic and irritant contact dermatitis. Endothelial MIF expression was much weaker in C57B1/6 mice. Furthermore, the infiltration rate of inflammatory cells (MIF+ and BM8+ macrophages, Lyt2+ and L3T4+ T cells) was significantly higher in BALB/c than in C57B1/6 mice. We conclude that genetically determined differences of susceptibility to allergens and irritants in BALB/c and C57B1/6 mice are reflected by the intensity of MIF expression in the microvascular endothelium and immigrating inflammatory cells. MIF seems to appear as first molecular equivalent of developing inflammation and probably determines the degree of cellular infiltration.