Involvement of IL-16 in the induction of airway hyper-responsiveness and up-regulation of IgE in a murine model of allergic asthma.
Experiments were designed to investigate the role of IL-16 in a mouse model of allergic asthma. OVA-sensitized mice were repeatedly exposed to OVA or saline aerosols. Bronchoalveolar lavage fluid (BALF) was collected after the last aerosol, and the presence of IL-16 was evaluated using a migration assay with human lymphocytes. Migration of lymphocytes was significantly increased in the presence of cell-free BALF from OVA-challenged mice compared with BALF from saline-challenged controls. This response was significantly inhibited after addition of antibodies to IL-16, demonstrating the presence of IL-16 in BALF of OVA-challenged animals. Immunohistochemistry was performed and revealed IL-16 immunoreactivity particularly in airway epithelial cells but also in cellular infiltrates in OVA-challenged mice. IL-16 immunoreactivity was absent in nonsensitized animals; however, some reactivity was detected in epithelial cells of sensitized but saline-challenged mice, suggesting that sensitization induced IL-16 expression in airway epithelium. Treatment of mice with antibodies to IL-16 during the challenge period significantly suppressed up-regulation of OVA-specific IgE in OVA-challenged animals. Furthermore, antibodies to IL-16 significantly inhibited the development of airway hyper-responsiveness after repeated OVA inhalations, whereas the number of eosinophils in bronchoalveolar lavage or airway tissue was not affected. In conclusion, IL-16 immunoreactivity is present in the airways after sensitization. After repeated OVA inhalation, IL-16 immunoreactivity is markedly increased and IL-16 is detectable in BALF. Furthermore, IL-16 plays an important role in airway hyper-responsiveness and up-regulation of IgE but is not important for eosinophil accumulation in a mouse model of allergic asthma.
Hessel
E M
EM
Department of Pharmacology and Pathophysiology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands. E.M.Hessel@FAR.RUU.NL
Cruikshank
W W
WW
Van Ark
I
I
De Bie
J J
JJ
Van Esch
B
B
Hofman
G
G
Nijkamp
F P
FP
Center
D M
DM
Van Oosterhout
A J
AJ
D000818:Animals; D001249:Asthma / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000209:etiology*; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D004804:Eosinophils / Q000502:physiology; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007371:Interferon-gamma / Q000502:physiology; D019410:Interleukin-16 / Q000032:analysis / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D015854:Up-Regulation
D019410:Interleukin-16; D007073:Immunoglobulin E; D007371:Interferon-gamma; D010047:Ovalbumin