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Amelioration of epidermal hyperplasia by TNF inhibition is associated with reduced Th17 responses

Rockefeller University Press
Journal of Experimental Medicine (JEM)
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The Journal of Experimental Medicine
CORRECTION
The Journal of Experimental Medicine
Amelioration of epidermal hyperplasia by TNF inhibition is associated with reduced Th17 responses
Lisa C. Zaba, Irma Cardinale, Patricia Gilleaudeau, Mary Sullivan-Whalen, Mayte Suárez-Fariñas, Judilyn Fuentes-Duculan, Inna Novitskaya,
Artemis Khatcherian, Mark J. Bluth, Michelle A. Lowes, and James G. Krueger
Vol. 204, No. 13, December 24, 2007. Pages 3183–3194.
Please note that Mayte Suárez-Fariñas’s name appeared incorrectly in the author line as Mayte Suárez Fariñas. The
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Published July 28, 2008
... DCs in psoriatic lesions are divided into two main groups-CD11c + BDCA-1 + resident DCs that are found also in healthy skin, and CD11c + BDCA-1 − inflammatory DCs that are more common in psoriasis lesional skin and are immature DCs that produce inflammatory cytokines [178]. These inflammatory DCs also include TNF-inducible NO synthase (iNOS)-producing DCs (TipDCs) [53,179]. Tip-DCs are greatly increased in the lesional psoriatic skin [104,180]. ...
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... Psoriasis is typically accompanied by an increase in different types of DCs, in particular CD1a ? , cDC1 and pDCs, in the lesional dermis [21,[38][39][40][41][42]. Interestingly, we discovered that the number of DCs in the non-lesional skin was significantly lower, even compared to healthy donors (Fig. 4). ...
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... Levels of activated mast cells are reduced after psoriasis treatment, while numbers of resting mast cells are increased Previous work indicated that a small molecular scar remains after effective systemic anti-psoriatic treatment (37)(38)(39). To validate our ndings on MCs after topical and systemic treatment we compared ndings from dithranol-treated patients with previously published data from psoriasis patients treated with the anti-IL-17A antibody secukinumab. ...
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Little is known about IL-17 expression in psoriasis and the actual cellular source of IL-17 remains incompletely defined. We show that high numbers of IL-17 + mast cells persisted in resolved lesions after treatment (anti-IL-17A, anti-IL-23, UVB or topical dithranol) and correlated inversely with the time span in remission. IL-17 + mast cells were found in T cell-rich areas and often close to resident memory T cells (T RM ) in active psoriasis and resolved lesional skin. Digital cytometry by deconvolution of RNA-seq data showed that activated mast cells were increased in psoriatic skin, while resting mast cells were almost absent and both returned to normal levels after treatment. When primary human skin mast cells were stimulated with T cell cytokines (TNFα, IL-22 and IFNγ), they responded by releasing more IL-17A, as measured by ELISA. In situ mRNA detection using padlock probes specific for transcript variants of IL17A, IL17F , and RORC (encoding the Th17 transcription factor RORγt) revealed positive mRNA signals for IL17A , IL17F , and RORC in tryptase + cells, demonstrating that mast cells have the transcriptional machinery to actively produce IL-17. Mast cells thus belong to the center of the IL-23/IL-17 axis and high numbers of IL-17 + mast cells predict an earlier disease recurrence.
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Plaque psoriasis is a chronic inflammatory dermatosis characterized by a tendency to recur in the same locations after discontinuation of treatment. The implementation of therapy with drugs targeting cytokines like interleukin (IL) 17A (IL-17A) and IL-23 has revolutionized the treatment of psoriasis and enabled the achievement of skin without lesions. However, despite the clinical resolution of psoriatic eruptions, cells that maintain the local memory of the disease remain in the dermis and epidermis, constituting a kind of molecular scar. The cells responsible for maintaining memory in the skin of patients and influencing the rapid relapse of the disease after the triggering factor are primarily tissue resident memory T cells (TRM), but it seems that regulatory T lymphocytes (Treg), dendritic cells (DC), and Langerhans cells (LC) may also play an important role in this process. We reviewed the literature to explain the concept of molecular scarring in psoriasis, and to assess the effect of various therapies on immune memory.
... The efficacy of TNFα inhibitors is primarily due to their role in preventing the activation of dendritic cells, which produce IL23 and activation of Th17 lineage and its effector molecules (IL17 & IL22). These actions further prevent the interactions between T cells, dendritic cells, and keratinocytes (Zaba et al., 2008). ...
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