Protein tyrosine phosphatase 1B in hematopoiesis

Protein tyrosine phosphatase 1B (PTP-1B) is a ubiquitously expressed cytosolic phosphatase best known for its role in insulin signaling. Despite the fact that it is highly expressed in hematopoietic tissues and has been shown to downregulate cytokine receptor signaling, no physiological role for PTP-1B in immune regulation had been reported. Our recent results show that the absence of PTP-1B affects murine myelopoiesis through increased phosphorylation of the CSF-1 receptor tyrosine kinase. Here we further discuss the role of PTP-1B in monocyte/macrophage differentiation as well as the implications of our findings in the context of PTP-1B inhibitors.