Search

Background Plasmacytoid dendritic cells (pDCs) are a subset of dendritic cells specialized in the production of type I interferon (IFN-α/β) and involved in various cutaneous inflammatory and autoimmune disorders, such as cutaneous lupus erythematosus (CLE) and vitiligo. Heat shock proteins (HSPs) are molecular chaperones essential for maintaining cellular functions, but they can act as a danger signal during inflammation. Objectives To decipher the role of HSP70 in the production of IFN-α by pDCs in CLE and vitiligo. Methods Expression of HSP70 and CD123+ pDCs was analysed by immunohistochemistry or immunofluorescence in CLE and vitiligo skin samples. Flow cytometry was performed to analyse expression of HSP70 receptors, activation markers on pDCs and DNA uptake by pDCs in the presence of HSP70. The impact of HSP70 on DNA-induced IFN-α secretion by pDCs was evaluated by enzyme-linked immunosorbent assay (ELISA). The effect of IFN-α on chemokine (C-X-C motif) ligand 9 (CXCL9)/10 gene and protein expression by keratinocytes was determined by real-time polymerase chain reaction and ELISA. Results Infiltration of pDCs in CLE and progressive vitiligo was primarily located in the epidermis, close to keratinocytes expressing HSP70. In vitro experiments revealed that the pDCs expressing HSP70 receptor Lox-1 (lectin-like oxidized low-density lipoprotein-receptor-1) were able to aggregate HSP70. Exogenous HSP70 induced activation of pDCs and increased the uptake of exogenous DNA. Furthermore, HSP70 potentiated DNA-induced IFN-α production by pDCs. Finally, IFN-α induced expression of CXCL9 and CXCL10 by keratinocytes. Conclusions These data demonstrate that interaction between HSP70 and pDCs in CLE and vitiligo is a prerequisite for the enhancement of IFN-α production, and could be an interesting target. [ABSTRACT FROM AUTHOR]

The article discusses a study related to evaluation of paradoxical psoriasiform skin reactions among patients with hidradenitis suppurativa (HS) exposed to antitumour necrosis factor (anti-TNF)-#208;&#945 agents. Topics discussed include association between HS and psoriasis as well as and Crohn disease (CD), patients with a medical history of psoriasis developed a paradoxical reaction, and production of the MxA protein.

A letter to the editor is presented regarding the case of a 44-year-old black man with acute sunburn and was diagnosed with amyloidogenic transthyretin (ATTR) familial amyloid polyneuropathy.