3 years ago

Oxidative stress drives CD8+ T-cell skin trafficking in patients with vitiligo through CXCL16 upregulation by activating the unfolded protein response in keratinocytes

In patients with vitiligo, an increased reactive oxygen species (ROS) level has been proved to be a key player during disease initiation and progression in melanocytes. Nevertheless, little is known about the effects of ROS on other cells involved in the aberrant microenvironment, such as keratinocytes and the following immune events. CXCL16 is constitutively expressed in keratinocytes and was recently found to mediate homing of CD8+ T cells in human skin. Objective We sought to explicate the effect of oxidative stress on human keratinocytes and its capacity to drive CD8+ T-cell trafficking through CXCL16 regulation. Methods We first detected putative T-cell skin-homing chemokines and ROS in serum and lesions of patients with vitiligo. The production of candidate chemokines was detected by using quantitative real-time PCR and ELISA in keratinocytes exposed to H2O2. Furthermore, the involved mediators were analyzed by using quantitative real-time PCR, Western blotting, ELISA, and immunofluorescence. Next, we tested the chemotactic migration of CD8+ T cells from patients with vitiligo mediated by the CXCL16-CXCR6 pair using the transwell assay. Results CXCL16 expression increased and showed a positive correlation with oxidative stress levels in serum and lesions of patients with vitiligo. The H2O2-induced CXCL16 expression was due to the activation of 2 unfolded protein response pathways: kinase RNA (PKR)–like ER kinase–eukaryotic initiation factor 2α and inositol-requiring enzyme 1α–X-box binding protein 1. CXCL16 produced by stressed keratinocytes induced migration of CXCR6+CD8+ T cells derived from patients with vitiligo. CXCR6+CD8+ T-cell skin infiltration is accompanied by melanocyte loss in lesions of patients with vitiligo. Conclusion Our study demonstrated that CXCL16-CXCR6 mediates CD8+ T-cell skin trafficking under oxidative stress in patients with vitiligo. The CXCL16 expression in human keratinocytes induced by ROS is, at least in part, caused by unfolded protein response activation.

Publisher URL: www.sciencedirect.com/science

DOI: S0091674916312775

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.