Evidence for Non-Allergic Mast Cell Activation in Pollen-Associated Inflammation  Martin Metz, Stefanie Gilles, Astrid Geldmacher, Heidrun Behrendt, Claudia Traidl-Hoffmann, Marcus Maurer  Journal of Investigative Dermatology  Volume 131, Issue 4, Pages 987-990 (April 2011) DOI: 10.1038/jid.2010.419 Copyright © 2011 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 IgE-independent skin inflammation by aqueous pollen extracts from birch (Bet.-APEs) is associated with increased mast cell (MC) degranulation.Bet.-APE or vehicle (100μg each) was injected intradermally (in 20μl Dulbecco's phosphate buffered saline (D-PBS)) into the ears of C57BL/6 mice. MC degranulation was assessed by quantitative histomorphometry in alkaline Giemsa-stained sections. Data are derived from three independent experiments, (a) n≥11 per group, (b) n=4; ***P<0.005, *P<0.01. Images in c are representative of not degranulated, moderately degranulated, and extensively degranulated MCs; original magnification × 100, bar=20μm. Journal of Investigative Dermatology 2011 131, 987-990DOI: (10.1038/jid.2010.419) Copyright © 2011 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Aqueous pollen extracts from birch (Bet.-APEs) induce mast cell (MC)-dependent skin inflammation in mice. Ears of naïve wild-type Kit+/+ mice (a, c), MC-deficient KitW/KitW-v mice (b, c), KitW/KitW-v mice that have been locally and selectively engrafted with MCs (KitW/KitW-v+bone marrow-derived cultured mast cell (BMCMC), (c)) or C57BL/6 mice were injected intradermally with 100μg Bet.-APE or as indicated (in 20μl D-PBS). (a, b) n≥6 mice/group, (c) n≥12 , (d) n=4; ***P<0.005. Journal of Investigative Dermatology 2011 131, 987-990DOI: (10.1038/jid.2010.419) Copyright © 2011 The Society for Investigative Dermatology, Inc Terms and Conditions