摘要
Regulatory T cells （Tregs） are critical for the peripheral maintenance of the autoreactive T cells in autoimmune disorders such as type 1 diabetes （TID）. Pharmacological inhibition of Janus tyrosine kinase 3 （JAK3） has been proposed as a basis for new treatment modalities against autoimmunity and allogeneic responses. Targeting JAK3 with an inhibitor has previously been shown to exhibit protective action against the development of T 1D in non-obese diabetic （NOD） mice. As the mechanism of such preventative action has been unknown, we hypothesized that JAK3 inhibition induces generation of Tregs. Here, we show that the JAK3 inhibitor 4-（4＇-hydroxyphenyl）-amino-6,7-dimethoxyquinazoline （WHI-P131） suppresses proliferation of short-term cultured NOD CD4＋ T cells through induction of apoptosis, while promoting survival of a particular population of long-term cultured cells. It was found that the surviving cells were not of the CD4＋CD25＋FoxP3＋ phenotype. They secreted decreased amounts of IL-IO, IL-4 and interferon （IFN）-y compared to the cells not exposed to the optimal concentrations of JAK3 inhibitor. However, an elevated transforming growth factor （TGF）-β secretion was detected in their supernatants. In vivo treatment of prediabetic NOD mice with WHI-P131 did not affect the frequency and number of splenic and pancreatic lymph node CD4＋FoxP3＋ Tregs, while generating an elevated numbers of CD4＋FoxP3- TGF-β-secreting T cells. In conclusion, our data suggest an induction of TGF-β-secreting CD4＋ T cells as the underlying mechanism for antidiabetogenic effects obtained by the treatment with a JAK3 inhibitor. To our knowledge, this is the first report of the JAK3 inhibitor activity in the context of the murine Tregs.
Regulatory T cells （Tregs） are critical for the peripheral maintenance of the autoreactive T cells in autoimmune disorders such as type 1 diabetes （TID）. Pharmacological inhibition of Janus tyrosine kinase 3 （JAK3） has been proposed as a basis for new treatment modalities against autoimmunity and allogeneic responses. Targeting JAK3 with an inhibitor has previously been shown to exhibit protective action against the development of T 1D in non-obese diabetic （NOD） mice. As the mechanism of such preventative action has been unknown, we hypothesized that JAK3 inhibition induces generation of Tregs. Here, we show that the JAK3 inhibitor 4-（4＇-hydroxyphenyl）-amino-6,7-dimethoxyquinazoline （WHI-P131） suppresses proliferation of short-term cultured NOD CD4＋ T cells through induction of apoptosis, while promoting survival of a particular population of long-term cultured cells. It was found that the surviving cells were not of the CD4＋CD25＋FoxP3＋ phenotype. They secreted decreased amounts of IL-IO, IL-4 and interferon （IFN）-y compared to the cells not exposed to the optimal concentrations of JAK3 inhibitor. However, an elevated transforming growth factor （TGF）-β secretion was detected in their supernatants. In vivo treatment of prediabetic NOD mice with WHI-P131 did not affect the frequency and number of splenic and pancreatic lymph node CD4＋FoxP3＋ Tregs, while generating an elevated numbers of CD4＋FoxP3- TGF-β-secreting T cells. In conclusion, our data suggest an induction of TGF-β-secreting CD4＋ T cells as the underlying mechanism for antidiabetogenic effects obtained by the treatment with a JAK3 inhibitor. To our knowledge, this is the first report of the JAK3 inhibitor activity in the context of the murine Tregs.
