Urocanic Acid: An Endogenous Regulator of Langerhans Cells Anika Bruhs, Leopold Eckhart, Erwin Tschachler, Thomas Schwarz, Agatha Schwarz  Journal of Investigative Dermatology  Volume 136, Issue 8, Pages 1735-1737 (August 2016) DOI: 10.1016/j.jid.2016.04.016 Copyright © 2016 The Authors Terms and Conditions

Figure 1 HIS mice are less susceptible to UVR-induced immunosuppression. (a) Mice were sensitized against 1% TNCB through UVR-exposed back skin (1.5 kJ/m2). Ears were challenged 5 days later with 0.5% TNCB, and ear swelling was measured 24 hours thereafter. (b) Lymph nodes and splenocytes were obtained from UVR-exposed WT (C57BL/6J) and HIS mice (a) and injected intravenously into naïve WT mice. Recipients were sensitized against TNCB 24 hours after injection, and ear challenge was performed 5 days later. CHS was determined as the amount of swelling of the hapten-challenged ear compared with the thickness of the vehicle-treated ear and expressed in cm × 10-3 (mean ± standard deviation). Data show one representative of three independently performed experiments with six mice per group. Differences between the means ± standard deviations and the corresponding control value with P < 0.05 were considered statistically significant. CHS, contact hypersensitivity; HIS, histidinemic; NegCo, negative control; PosCo, positive control; TNCB, 2,4,6-trinitochlorobenzene; WT, wild type. Journal of Investigative Dermatology 2016 136, 1735-1737DOI: (10.1016/j.jid.2016.04.016) Copyright © 2016 The Authors Terms and Conditions

Figure 2 Higher antigen presenting capacity of HIS-LC and lower sensitization threshold in HIS mice. (a) Freshly prepared LCs obtained from WT and HIS mice were labeled with TNBS, and 5 × 105 cells were injected subcutaneously into the naïve WT mice. Recipients were challenged after 5 days against TNCB, and ear swelling was measured 24 hours later. CHS was determined as the amount of swelling of the hapten-challenged ear compared with the thickness of the vehicle-treated ear and expressed in cm × 10–3 (mean ± standard deviation). (b) HIS and WT mice were sensitized with 1.0% or 0.5% TNCB on the back. Five days later ears were challenged with 0.5% of TNCB, and ear swelling was measured 24 hours thereafter. CHS was determined as the amount of swelling of the hapten-challenged ear compared with the thickness of the vehicle-treated ear and expressed in cm × 10–3 (mean ± standard deviation). Data show one representative of three independently performed experiments with six mice per group. Differences between the means ± standard deviations and the corresponding control value with P < 0.05 were considered statistically significant. CHS, contact hypersensitivity; HIS, histidinemic; LC, Langerhans cell; TNBS, 2,4,6-trinitrobenzenesulfonic acid; TNCB, 2,4,6-trinitrochlorobenene; WT, wild type. Journal of Investigative Dermatology 2016 136, 1735-1737DOI: (10.1016/j.jid.2016.04.016) Copyright © 2016 The Authors Terms and Conditions