Triclosan has had widespread use in the general population as an antimicrobial agent and is commonly found in consumer products such as soaps, deodorants, toothpastes, shaving creams, mouth washes, and cleaning supplies. Triclosan has recently attracted the attention of the scientific community, regulatory agencies and the general public because of its high production volume, widespread applications and reports of endocrine-disrupting effects. A positive association between urinary levels of triclosan and diagnosis of allergies, hay fever, and sensitization to aeroallergens and foods has been identified. While not generally considered to be a sensitizing chemical, work by our group has recently shown that dermal exposure to triclosan at concentrations similar to those in consumer products augmented the allergic response to a known allergen in a mouse asthma model. However, the specific mechanism of this augmentation has yet to be elucidated. These studies were conducted to investigate the mechanism responsible for the augmented allergic response following dermal triclosan exposure. BALB/c mice were exposed dermally on the ears to concentrations of triclosan ranging from 0.75-3% (0.375-1.5mg/ mouse/day) for up to 9 consecutive days. Expression of immune genes in the ears and lymph nodes of mice following exposure was analyzed using quantitative polymerase chain reaction. Robust thymic stromal lymphopoietin (TSLP), IL-1 beta, TNF-alpha increases and modest CCL22 & IL-22 dose responsive increases in gene expression were observed in the ears. In the lymph node draining the exposure site, dose responsive increases in CCL22 & IL-4 and decreases in T-bet, IFN-gamma, TNF-alpha & IL-1beta gene expression were observed. A decrease in expression of RORgammat was observed in both the ear and lymph nodes following exposure to 3% triclosan. These results suggest that triclosan may augment allergic responses by modulating both innate and adaptive genes.
Toxicology; Exposure-levels; Chemical-composition; Chemical-properties; Cell-biology; Cell-function; Cellular-function; Animals; Laboratory-animals; Endocrine-system; Endocrine-system-disorders; Endocrinology; Urinalysis; Allergens; Allergic-reactions; Allergic-dermatitis; Sensitization; Skin-irritants; Skin; Skin-exposure; Genes; Lymph-nodes
The Toxicologist. Society of Toxicology 53rd Annual Meeting and ToxExpo, March 23-27, 2014, Phonex, Arizona