Evaluation of the cutaneous microbiome in psoriasis
Psoriasis, a highly prevalent disease of humans of unknown cause, although it is considered to be a T cell-mediated autoimmune disease, and is characterized primarily by chronic inflammation primarily involving skin, with distinctive clinical characteristics. With the newly developed tools that facilitate microbiome research, it now is possible to assess whether the cutaneous microbiome plays a role in the pathogenesis of this complex disorder. To better elucidate this complexity, this study seeks to examine the cutaneous microbiome in relation to psoriasis with explorations at several taxonomic and informatic levels. Our overall objective is to examine how changes in the normal cutaneous microbiome contribute to the pathogenesis of psoriasis. Initial studies are focusing on taxonomic characterization of bacteria (using 16S rRNA) and fungi (using ITS sequences) in affected and uninvolved skin from hosts who have had extensive phenotypic analysis and from controls. Prokaryotic diversity is being screened using massively parallel DNA sequencing, exploiting a multiplexing technique to generate 16S rRNA and ITS sequence tags, followed by analyses (statistical, clustering, and phylogenetic) to estimate the distribution of phylotypes, differential abundance, and the relative contributions between phylotypes and community dissimilarities to the overall diversity in individuals and lesions.