The composition of the skin microbiota is altered in pemphigoid diseases (PDs). How this affects specific immune reactions and potentially contributes to skin inflammation is still unknown. We hypothesize that dysregulated microbe-reactive CD4+ T cells driven by an altered skin microbiome may contribute to the pathogenesis of PDs. We will characterize skin microbe-specific T cell responses and correlate these responses with microbial dysbiosis patterns. This will provide knowledge about the contribution of the microbiome and microbe-reactive T cells to PD pathogenesis, instrumental to develop specific therapeutic interventions.