Title:Interleukin-26, a Highly Cationic T-Cell Cytokine Targeting Epithelial Cells
Volume: 11
Issue: 3
Author(s): Oliver Braum, Heide Pirzer and Helmut Fickenscher
Affiliation:
Keywords:
AK155, colon carcinoma, ICAM-1, Interleukin-26, IL-26, herpes virus saimiri, STAT, T cell, Th17
Abstract: Interleukin-26 (IL-26) is a member of the IL-10 cytokine family due to sequence homology. IL-26 was discovered,
since the gene is strongly overexpressed in T cells which are growth transformed by herpesvirus saimiri. The IL-26
gene maps to human chromosome 12q15 between the genes for two other T-cellular class-II cytokines, namely interferon-
λ (lFN-λ) and lL-22. IL-26, IL-22, and IFN-λ are co expressed by activated T cells and, especially, by Th17 cells. IL-26
forms homodimers and adheres to glycosaminoglycans on cell surfaces, presumably due to its positive charge. IL-26 specifically
targets the lL-26-specific heterodimeric receptor complex consisting of IL-20R1 and IL-10R2 which is typically
expressed on epithelial cells such as colon carcinoma cells or keratinocytes. IL-26 stimulation induces STAT1 and STAT3
phosphorylation, CD54 surface expression, and cytokine secretion as shown for IL-8 and IL-10. IL-26 seems to act as a
cell surface-associated and rather proinflammatory T-cell cytokine at the epithelial barrier, possibly linking T-cell response
with epithelial functions.
