Abstract
Psoriasis is classically considered a chronic inflammatory skin disorder, however the identification of autoantigens in its pathogenesis established it as a T cell mediated autoimmune disease. As such professional antigen-presenting cells (APCs) are key players in the development of lesions. APCs in the skin include dendritic cells, Langerhans cells and monocytes/macrophages. In addition, epidermal keratinocytes and dermal mast cells are also endowed with antigen-presenting capacity. Skin APCs have central role in the maintenance of cutaneous immune homeostasis, as well as in initiating and sustaining inflammation under pathologic conditions. In this review we discuss the functional specialization of human skin APCs that promote T cell activation and adaptive immune response during psoriasis initiation and onset.
Highlights
A recent immune cell infiltrate analysis of psoriatic lesional skin revealed that receptor tyrosine kinase (c-Kit) and tryptase double-positive, activated Mast cells (MCs) are enriched in psoriatic skin, and their number gradually decreases upon clinical treatment, supporting an important role of MC activation in the progression of psoriasis [88]
It is of note though, that LL37, which may act as an autoantigen in psoriasis, can directly induce pro-inflammatory cytokine synthesis in MCs [91]
Our perception of antigen-presenting cells (APCs) in pathological skin conditions has greatly improved in the past decade, owing, in part, to a more accurate definition of surface markers of different
Summary
Other genes involved in antigen presentation were identified as psoriasis genetic risk factors, such as the ERAP1 and ERAP2, which encode amino-peptidase enzymes that can cleave peptide antigens before presentation to T cells [8]. Epidermal keratinocytes and mast cells are capable to antigen presentation by expressing MHC class I [20], and under certain conditions even MHC class II [21,22,23] molecules. This concise review will consider only human data regarding the functional role of APCs in psoriasis.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
