Mi. Gilmour et al., INCREASED IMMUNE AND INFLAMMATORY RESPONSES TO DUST-MITE ANTIGEN IN RATS EXPOSED TO 5 PPM NO2, Fundamental and applied toxicology, 31(1), 1996, pp. 65-70
Immune hypersensitivity to house dust mite antigen (HDM) is a frequent
cause of respiratory allergy. The objective of this study was to dete
rmine whether exposure to NO2, a common indoor air pollutant, modulate
s immune responses to HDM and influences immune-mediated lung disease.
Brown Norway rats were immunized ip with 100 mu g semipurified antige
n and Bordetella pertussis adjuvant and challenged 2 weeks later with
an intratracheal injection of 50 mu g of a crude antigen preparation.
Exposure to 5 ppm NO2 for 3 hr after both immunization and challenge p
rocedures resulted in significantly higher levels of antigen-specific
serum IgE, local IgA, IgG, and IgE antibody than air controls, and inc
reased numbers of inflammatory cells in the lungs. Lymphocyte responsi
veness to antigen in the spleen and MLN was also significantly higher
in NO2-exposed animals. These data show that exposure to a common air
pollutant can upregulate specific immune responses and subsequent immu
ne-mediated pulmonary inflammation. (C) 1996 Society of Toxicology