TY - JOUR T1 - Mast cells and γδ T cells are largely dispensable for adaptive immune responses after laser-mediated epicutaneous immunization JF - bioRxiv DO - 10.1101/774323 SP - 774323 AU - Isabella Joubert AU - Daniel Kovacs AU - Sandra Scheiblhofer AU - Petra Winter AU - Evgeniia Korotchenko AU - Helen Strandt AU - Richard Weiss Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/09/19/774323.abstract N2 - Background The skin resembles an attractive target for vaccination due to its accessibility and abundance of resident immune cells. Cells like γδ T cells and mast cells (MCs) are part of the first line of defence against exogenous threats. Despite being important mediators for eliciting TH2 immune responses after epithelial stress, γδ T cell and MC function still remains to be completely understood. Here, we aimed to characterize their roles in shaping adaptive immune responses after laser-mediated epicutaneous immunization (EPI).Methods γδ T cell knock out, MC depleted, and wildtype control mice were immunized with mannan-conjugated grass pollen allergen Phl p 5 (P5-MN) by laser-mediated EPI. After 2-3 immunizations, cytokine expression, T helper polarization, and antigen-specific IgG1/IgE levels were analysed. The local cytokine/chemokine milieu after laser microporation was determined.Results While the majority of inflammatory chemokines and cytokines induced by laser treatment was not affected by the presence of γδ T cells or MCs, RANTES, was elevated in γδ T cell knock out mice, and GROα and TSLP, were significantly decreased after MC depletion. However, absence of γδ T cells or depletion of MC had no substantial effect on adaptive humoral or cellular immune responses after laser-mediated EPI, except for slightly reduced IgG1 and effector T cell levels in MC depleted mice.Conclusions γδ T cells did not play a pivotal role in shaping the humoral and cellular adaptive immune response after laser-mediated EPI, whereas MC depletion decreased numbers of effector T cells, indicating a potential role of MCs in the activation and maturation of T cells after EPI.HighlightsLaser microporation induces an inflammatory chemokine milieu at the site of immunizationγδ T cells and mast cells contribute to the steady-state or damage-induced cytokine milieu in the skinγδ T cells and mast cells are dispensable for adaptive immunity after laser-mediated immunization ER -