Interleukin-19 upregulates keratinocyte growth factor and is associated with psoriasis

Br J Dermatol. 2005 Sep;153(3):591-5. doi: 10.1111/j.1365-2133.2005.06665.x.


Background: Interleukin (IL)-19, a member of the IL-10 family, signals through the IL-20R1/IL-20R2 heterodimer, which is shown to be involved in abnormal keratinocyte differentiation and proliferation. Little is known about its in vitro biological functions or its role in psoriasis.

Objectives: To investigate the role of IL-19 in the psoriatic process.

Methods: The expression of keratinocyte growth factor (KGF) transcripts was measured by polymerase chain reaction in CD8+ T cells treated with IL-19. Next, we developed monoclonal and polyclonal antibodies to measure the levels of IL-19 in the sera of patients with psoriasis and healthy volunteers using an enzyme-linked immunosorbent assay. In addition, we performed immunohistochemical staining on psoriatic skin and normal controls.

Results: We found that IL-19 upregulated KGF transcripts on CD8+ T cells. Patients with psoriasis had a lower level of IL-19 in serum than healthy volunteers. The difference between these two groups was statistically significant (P < 0.05). IL-19 expression was seen in basal and suprabasal keratinocytes in a continuous pattern, and was increased in psoriatic epidermis.

Conclusions: These results suggest that IL-19 plays a role in the complex pathological cytokine network in psoriasis.

MeSH terms

  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / metabolism*
  • Case-Control Studies
  • Enzyme-Linked Immunosorbent Assay / methods
  • Epidermis / immunology*
  • Epidermis / metabolism
  • Fibroblast Growth Factor 7
  • Fibroblast Growth Factors / genetics*
  • Fibroblast Growth Factors / metabolism
  • Humans
  • Immunohistochemistry / methods
  • Interleukin-10 / blood
  • Interleukin-10 / pharmacology
  • Interleukin-10 / physiology*
  • Interleukins
  • Keratinocytes / chemistry
  • Polymerase Chain Reaction / methods
  • Psoriasis / immunology*
  • Psoriasis / metabolism
  • RNA, Messenger / analysis
  • Up-Regulation


  • FGF7 protein, human
  • IL19 protein, human
  • Interleukins
  • RNA, Messenger
  • Fibroblast Growth Factor 7
  • Interleukin-10
  • Fibroblast Growth Factors