Suppressor of Cytokine Signaling 3 Promotes Bone Marrow Cells to Differentiate into CD8+ T Lymphocytes in Lung Tissue via Up-Regulating Notch1 Expression

Suppressor of cytokine signaling 3 (SOCS3) expression in bone marrow cells (BMC) was up-regulated upon exposure to interleukin 6, lipopolysaccharide, or tumor-associated factors. But, how the up-regulated SOCS3 affects differentiation of BMCs is incompletely characterized. Here, we showed that SOCS3 promoted BMCs to intently differentiate into CD8 T cells. Importantly, lung can be as one athymus tissue for the BMCs to differentiate into CD8(+) T cells. Notch I plays a critical role in the differentiation from SOCS3-transfected BMCs to CD8(+) T cells. We conclude that the up-regulated SOCS3 in some pathologic conditions, such as tumor and inflammation, might promote BMCs to differentiate into CD8(+) T lymphocytes in lung tissue via up-regulating Notch1 expression. This may represent a new mechanism against diseases such as tumor. [Cancer Res 2009;69(4):1578-86]