Description
The goal of the study was to identify the genes which are regulated by Interleukin-2 in the CD4+ T cells of the scurfy mice during regulatory T-cell deficiency. Scurfy (Sf) mice bear a mutation in the forkhead box P3 (Foxp3) transcription factor, lack regulatory T-cells (Treg), develop multi-organ inflammation, and die prematurely. The major target organs affected are skin, lungs, and liver. Sf mice lacking the Il2 gene (Sf.Il2-/-), despite devoid of Treg, did not develop skin and lung inflammation, but the inflammation in liver, pancreas, submandibular gland and colon remained. Genome-wide microarray analysis revealed hundreds of genes were differentially regulated among Sf, Sf.Il2-/-, and B6 CD4+ T-cells but the most changes were those encoding receptors for trafficking/chemotaxis/retention and lymphokines. Our study suggests that IL-2 controls the skin and lung inflammation in Sf mice in an apparent "organ-specific" manner through two novel mechanisms: by regulating the expression of genes encoding receptors for T-cell trafficking/chemotaxis/retention and by regulating Th2 cell expansion and lymphokine production. Thus, IL-2 is a master regulator for multi-organ inflammation and an underlying etiological factor for various diseases associated with skin and lung inflammation.