Inflammatory events in the blood and airways of guinea pigs immunized to toluene diisocyanate.
Toluene diisocyanate (TDI)-induced asthma is a common cause of occupational lung disease. We used a model to investigate the course of bronchopulmonary inflammation following immunization with TDI. Guinea pigs were immunized by weekly intradermal injections and challenged with TDI 7 d after the third injection. The animals were killed at different times after challenge and prepared for histologic examination of central and peripheral airways, for immunohistochemical studies of T lymphocyte and eosinophil distribution, and for hematologic and serologic investigations. Specific IgG1 against TDI were present only in immunized animals. In immunized TDI-challenged animals there was a significant increase in the number of metachromatic cells (at 24 h) and a late increase of eosinophils (at 48 h) in the peripheral blood. Mast cells and eosinophils were also increased in the submucosa of central airways of immunized TDI-challenged animals. A similar pattern was observed in the animals' peripheral airways. Additionally, a significant increase of T-lymphocytes and eosinophils was found in the lamina propria at 6 h after exposure in immunized TDI-challenged animals as compared with control animals. In these immunized animals, TDI challenge caused a significant increase of eosinophils, T-lymphocytes, and CD4+ T cells. These findings indicate that intradermal injections of TDI induced a specific antibody response as well as an inflammatory process in both central and peripheral airways. T cells, particularly CD4+ T cells and eosinophils, are the key cells in the immunopathologic alterations induced by TDI in the guinea pig lung.
Mapp
C E
CE
Institute of Occupational Medicine, University of Padova, Italy.
Lapa e Silva
J R
JR
Lucchini
R E
RE
Chitano
P
P
Rado
V
V
Saetta
M
M
Pretolani
M
M
Karol
M H
MH
Maestrelli
P
P
Fabbri
L M
LM
D000818:Animals; D000906:Antibodies / Q000032:analysis; D001249:Asthma / Q000097:blood / Q000209:etiology / Q000473:pathology*; D001772:Blood Cell Count; D001980:Bronchi / Q000473:pathology; D004804:Eosinophils / Q000473:pathology; D006168:Guinea Pigs; D007114:Immunization; D007074:Immunoglobulin G / Q000032:analysis; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D008168:Lung / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000473:pathology; D014051:Toluene 2,4-Diisocyanate / Q000276:immunology*
D000906:Antibodies; D007074:Immunoglobulin G; D014051:Toluene 2,4-Diisocyanate