MURINE STRAIN DIFFERENCES IN AIRWAY INFLAMMATION CAUSED BY DIESEL EXHAUST PARTICLES

To elucidate whether immunoglobulin (Ig) E or IgG are involved in the murine asthma model, we compared the pathogenic features of mice that were high IgG responders (C3H/He) with mice that were high IgE respond ers (BALB/c) after intratracheal instillation of diesel exhaust partic les (DEP) and ovalbumin sensitization. Both mouse strains received DEP intratracheally once a week for 5 weeks, After the second injection o f DEP, ovalbumin and aluminium hydroxide mere injected intraperitoneal ly. After the last DEP administration, the mice were challenged by exp osure to an aerosol of ovalbumin. DEP caused increased IgG1 production and airway hyperresponsiveness after ovalbumin sensitization in C3H/H e mice, although IgE production did not change in either strain, Furth ermore, in C3H/He mice, the number of eosinophils and goblet cells in the bronchial epithelium, and the expression of interleukin-5 and inte rleukin-2 were increased by DEP and ovalbumin treatments. In contrast, the pathogenic changes in BALB/c mice were weak, even though the same protocol was used. In conclusion, murine strain differences in respon se to air pollutants and allergens seem to be related to antigen-speci fic immunoglobulin G1 production and cytokine expression in the lungs.