Early immunomodulatory effects of dermal triclosan exposure in mice.
Marshall NB; Anderson SE; Anderson KL; Long CM; Lukomska E; Meade BJ
Toxicologist 2014 Mar; 138(1):34
It has recently been shown that dermal application of the commonly used antimicrobial compound triclosan, enhanced allergic responses in a mouse asthma model. To help elucidate the mechanisms of this augmented allergic response, we investigated the early immune-related effects of dermal triclosan exposure in mice. Triclosan was applied daily to the dorsal surface of the ears of BALB/c mice at concentrations ranging from 0%-3%, and leukocytes were examined in different organs over time using flow cytometry. Examination of the draining lymph nodes revealed a dose-dependent increase in cell numbers and enhanced GATA-3, IL-4, IL-21 and IL-17 expression suggesting enhanced Th2- and Th17-like effector T cell polarization. Effects on antigen presenting cells were also observed including increased expression of MHC class II, CD80 and CD86. In mice sensitized to ovalbumin (OVA) and subsequently challenged with OVA through pharyngeal aspiration on day 7, mice exposed to triclosan had increased cell numbers in the bronchoalveolar lavage and mediastinal LN by 24 hours compared to vehicle-treated mice. Interestingly, the introduction of OVA into the airway of triclosan-exposed mice was associated with increased swelling of the ear tissue along with an influx of CD11b+ cells and dramatic increase in TSLP and TNF-alpha expression. Taken together, the early immunomodulatory effects of triclosan suggest an adjuvancy- type effect that involves CD4 T cells and antigen presenting cells which may contribute to the augmentation of allergic responses
Toxicology; Animals; Laboratory-animals; Allergic-reactions; Allergens; Exposure-levels; Risk-factors; Cell-function; Cellular-function
The Toxicologist. Society of Toxicology 53rd Annual Meeting and ToxExpo, March 23-27, 2014, Phonex, Arizona