AUTHOR=Le Stephanie T. , Merleev Alexander A. , Luxardi Guillaume , Shimoda Michiko , Adamopoulos Iannis E. , Tsoi Lam C. , Wang Jenny Z. , Alexanian Claire , Raychaudhuri Siba P. , Hwang Samuel T. , Gudjonsson Johann , Marusina Alina I. , Maverakis Emanual TITLE=2D Visualization of the Psoriasis Transcriptome Fails to Support the Existence of Dual-Secreting IL-17A/IL-22 Th17 T Cells JOURNAL=Frontiers in Immunology VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.00589 DOI=10.3389/fimmu.2019.00589 ISSN=1664-3224 ABSTRACT=

The present paradigm of psoriasis pathogenesis revolves around the IL-23/IL-17A axis. Dual-secreting Th17 T cells presumably are the predominant sources of the psoriasis phenotype-driving cytokines, IL-17A and IL-22. We thus conducted a meta-analysis of independently acquired RNA-seq psoriasis datasets to explore the relationship between the expression of IL17A and IL22. This analysis failed to support the existence of dual secreting IL-17A/IL-22 Th17 cells as a major source of these cytokines. However, variable relationships amongst the expression of psoriasis susceptibility genes and of IL17A, IL22, and IL23A were identified. Additionally, to shed light on gene expression relationships in psoriasis, we applied a machine learning nonlinear dimensionality reduction strategy (t-SNE) to display the entire psoriasis transcriptome as a 2-dimensonal image. This analysis revealed a variety of gene clusters, relevant to psoriasis pathophysiology but failed to support a relationship between IL17A and IL22. These results support existing theories on alternative sources of IL-17A and IL-22 in psoriasis such as a Th22 cells and non-T cell populations.