Laure Migayron, Ribal Merhi, C Avril, Simon Léonard, Atika Zouine, Fanélie Jouenne, Sophie Gilardeau, Claire Drullion, Denis Thiolat, Emilian Mertinaj, Mélanie Humeau, Adèle Mauroux, Jean‐Philippe Guégan, Xavier Gauthereau, Samia Mourah, Thomas Darde, Sylvie Bordes, Brigitte Closs-Gonthier, Julien Sénéschal, Katia Boniface
Emerging evidence demonstrates that self-reactive CD8 + T resident memory cells (T RM cells) may already populate the never-lesional (NL) skin of patients with chronic inflammatory conditions, including vitiligo. However, their functional activity and regulation remain unknown. By combining cellular and transcriptomic approaches, we show that common CD8 + T cell clusters with a similar transcriptional profile infiltrate NL and peri-lesional (PL) skin of patients with vitiligo. Pathways related to immune activation were more active in T cells from PL skin, while those related to immune regulation were enriched in NL skin T cells, also evidenced by the stronger infiltration of regulatory T cells and the higher expression of programmed cell death protein 1 (PD-1) by CD8 + T cells in NL skin. Treatment of patients with baricitinib led to an increase in regulatory T cells and CD8 + T cells expressing PD-1 in repigmented skin. These findings suggest that functional T cells populate pigmented skin in vitiligo and highlight the importance of regulatory mechanisms to restrain their activation and prevent depigmentation.