title: CD57 expression and cytokine production by T cells in lesional and unaffected skin from patients with psoriasis.
abstract: BACKGROUND
  The immunopathogenic mechanisms leading to psoriasis remain unresolved. CD57 is a marker of replicative inability and immunosenescence on CD8+ T cells and the proportion of CD57 expressing CD8+ T cells is increased in a number of inflammatory conditions.
  
  
  METHODS
  We examined the expression of CD57 on T cells in the skin of patients affected with psoriasis, comparing lesional and unaffected skin. We also assessed functionality of the T cells by evaluating the secretion of several inflammatory cytokines (IL-17A, IFN-gamma, IL-2, IL-33, TNF-alpha, IL-21, IL-22, and IL-27), from cell-sorted purified CD4+ and CD8+ T cells isolated from lesional and unaffected skin biopsies of psoriasis patients.
  
  
  RESULTS
  We observed that the frequency of CD57+CD4+ and CD57+CD8+ T cells was significantly higher in unaffected skin of psoriasis patients compared to lesional skin. Sorted CD4+ T cells from psoriatic lesional skin produced higher levels of IL-17A, IL-22, and IFN-gamma compared to unaffected skin, while sorted CD8+ T cells from lesional skin produced higher levels of IL-17, IL-22, IFN-gamma, TNF-alpha, and IL-2 compared to unaffected skin.
  
  
  CONCLUSIONS
  These findings suggest that T cells in unaffected skin from psoriasis patients exhibit a phenotype compatible with replicative inability. As they have a lower replicative capacity, CD57+ T cells are less frequent in lesional tissue due to the high cellular turnover.
authors.affiliation: Division of Experimental Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, USA. maridiasbatista@gmail.com
authors.forename: Mariana D
authors.initials: MD
authors.lastname: Batista
authors.forename: Camilla
authors.initials: C
authors.lastname: Tincati
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Milush
authors.forename: Emily L
authors.initials: EL
authors.lastname: Ho
authors.forename: Lishomwa C
authors.initials: LC
authors.lastname: Ndhlovu
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: York
authors.forename: Esper G
authors.initials: EG
authors.lastname: Kallas
authors.forename: Jorge
authors.initials: J
authors.lastname: Kalil
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Keating
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Norris
authors.forename: David
authors.initials: D
authors.lastname: Chang
authors.forename: Patrick
authors.initials: P
authors.lastname: Unemori
authors.forename: Kieron S
authors.initials: KS
authors.lastname: Leslie
authors.forename: Toby
authors.initials: T
authors.lastname: Maurer
authors.forename: Wilson
authors.initials: W
authors.lastname: Liao
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Nixon
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018959:CD57 Antigens / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000276:immunology / Q000378:metabolism*; D012867:Skin / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
chemical_list: D018959:CD57 Antigens; D016207:Cytokines