Anti-tumor necrosis factor-alpha antibody treatment reduces pulmonary inflammation and methacholine hyper-responsiveness in a murine asthma model induced by house dust.
OBJECTIVE
Recent studies documented that sensitization and exposure to cockroach allergens significantly increase children's asthma morbidity as well as severity, especially among inner city children. TNF-alpha has been postulated to be a critical mediator directly contributing to the bronchopulmonary inflammation and airway hyper-responsiveness in asthma. This study investigated whether an anti-TNF-alpha antibody would inhibit pulmonary inflammation and methacholine (Mch) hyper-responsiveness in a mouse model of asthma induced by a house dust extract containing both endotoxin and cockroach allergens.


METHODS
A house dust sample was extracted with phosphate-buffered saline and then used for immunization and two additional pulmonary challenges of BALB/c mice. Mice were treated with an intravenous injection of anti-TNF-alpha antibody or control antibody 1 h before each pulmonary challenge.


RESULTS
In a kinetic study, TNF-alpha levels within the bronchoalveolar lavage (BAL) fluid increased quickly peaking at 2 h while BAL levels of IL-4, IL-5, and IL-13 peaked at later time-points. Mch hyper-responsiveness was measured 24 h after the last challenge, and mice were killed 24 h later. TNF inhibition resulted in an augmentation of these Th2 cytokines. However, the allergic pulmonary inflammation was significantly reduced by anti-TNF-alpha antibody treatment as demonstrated by a substantial reduction in the number of BAL eosinophils, lymphocytes, macrophages, and neutrophils compared with rat IgG-treated mice. Mch hyper-responsiveness was also significantly reduced in anti-TNF-alpha antibody-treated mice and the pulmonary histology was also significantly improved. Inhibition of TNF significantly reduced eotaxin levels within the lung, suggesting a potential mechanism for the beneficial effects. These data indicate that anti-TNF-alpha antibody can reduce the inflammation and pathophysiology of asthma in a murine model of asthma induced by a house dust extract.
Kim
J
J
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA. jiyoukim@umich.edu
McKinley
L
L
Natarajan
S
S
Bolgos
G L
GL
Siddiqui
J
J
Copeland
S
S
Remick
D G
DG
D000485:Allergens / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D001249:Asthma / Q000276:immunology / Q000628:therapy*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D016085:Bronchoconstrictor Agents; D003058:Cockroaches; D016207:Cytokines / Q000097:blood; D004391:Dust; D004731:Endotoxins; D005260:Female; D008168:Lung / Q000276:immunology*; D016210:Methacholine Chloride; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D000485:Allergens; D000911:Antibodies, Monoclonal; D016085:Bronchoconstrictor Agents; D016207:Cytokines; D004391:Dust; D004731:Endotoxins; D014409:Tumor Necrosis Factor-alpha; D016210:Methacholine Chloride