Synopsis:
In this study, we observed an increased frequency of functional CD4+ T cells secreting IL-17 or IL-22 in the blood of patients with HS compared with healthy donors (HD). However, we did not observe an increased frequency of infiltrating CD4+ T cells secreting IL-22 in HS skin lesions, but we found an increased frequency of infiltrating CD4+ T cells secreting both IL-17 and IFN-γ compared with healthy skin. Transcriptome analysis performed on whole lesional skin confirmed these results. We showed that keratinocytes isolated from HFs of patients with HS presented a distinctive pattern of AMP expression. They constitutively exhibit an inflammatory profile. After pattern recognition receptor stimulation, these cells produced higher amount of IL-1β leading to an increased production of proinflammatory cytokines. This profile severely contrasts with keratinocytes from HD. Globally, these results point out a primary dysfunction of keratinocytes from patients with HS characterized by a defect in enhancing a tissue protective response, but rather a chronic inflammatory response, to microbial products leading to a perpetual inflammation at sites of infection in skin lesions.
Full study:
https://www.jidonline.org/article/S0022-202X(16)31247-7/fulltext