چکیده (انگلیسی):

Background: Thymic stromal lymphopoietin (TSLP) plays critical roles in the induction and exacerbation of allergic
diseases. We tested various chemicals in the environment and found that xylene and 1,2,4-
trimethylbenzene induced the production of TSLP in vivo. These findings prompted us to search for additional
chemicals that induce TSLP production. In this study, we examined whether fatty acids could induce the production
of TSLP in vivo and exacerbate allergic inflammation.
Methods: Various fatty acids and related compounds were painted on the ear lobes of mice and the amount of
TSLP in the homogenate of ear lobe tissue was determined. The effects of nonanoic acid on allergic inflammation
were also examined.
Results: Octanoic acid, nonanoic acid, and decanoic acid markedly induced TSLP production, while a
medium-chain aldehyde and alcohol showed only weak activity. Nonanoic acid induced the production of TSLP
with a maximum at 24 h. TSLP production was even observed in nonanoic acid-treated C3HHeJ mice that
lacked functional toll-like receptor 4. The aryl hydrocarbon receptor agonist β-naphthoflavone did not induce
TSLP production. Nonanoic acid promoted sensitization to ovalbumin, resulting in an enhancement in the cutaneous
anaphylactic response. In addition, painting of nonanoic acid after the sensitization augmented picryl
chloride-induced thickening of the ear, which was reversed in TSLP receptor-deficient mice.
Conclusions: Nonanoic acid and certain fatty acids induced TSLP production, resulting in the exacerbation of
allergic inflammation. We propose that TSLP-inducing chemical compounds such as nonanoic acid be recognized
as chemical allergo-accelerators.