Resident skin cells in psoriasis: a special look at the pathogenetic functions of keratinocytes.
Psoriasis is a chronic inflammatory skin disease characterized by exaggerated keratinocyte proliferation. Current paradigm indicates that psoriasis is driven by T cell-mediated immune responses targeting keratinocytes. However, psoriasis cannot be explained solely on the basis of T-cell activation, and it is likely that intrinsic alterations in epidermal keratinocytes play a very relevant role in disease expression. In particular, keratinocytes may be important in initiating, sustaining, and amplifying the inflammatory responses by expressing molecules involved in T-cell recruitment, retention, and activation. Keratinocytes are also a relevant source of growth factors for angiogenesis. Finally, intrinsic defects in cytokine and growth factor signaling in keratinocytes may be responsible for their aberrant hyperproliferation and differentiation to T cell-derived signals. Other skin resident cells such as fibroblasts, mast cells, and endothelial cells also contribute to psoriasis pathogenesis by expressing molecules involved in T-cell recruitment and activation.
Albanesi
Cristina
C
Laboratory of Immunology and Allergology, Istituto Dermopatico dell'Immacolata (IDI)-IRCCS, Rome, Italy. c.albanesi@idi.it
De Pità
Ornella
O
Girolomoni
Giampiero
G
D000938:Antigen-Presenting Cells / Q000276:immunology; D002454:Cell Differentiation; D049109:Cell Proliferation; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D004817:Epidermis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D007249:Inflammation; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism; D015603:Keratinocytes / Q000473:pathology / Q000502:physiology*; D008213:Lymphocyte Activation; D011565:Psoriasis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology*
D016207:Cytokines; D018836:Inflammation Mediators