Functional Abnormalities in Protein Tyrosine Phosphatase ε-Deficient Macrophages

Protein tyrosine phosphatase ε (PTPε)-deficient mice were generated by targeted deletion of exons 3, 4, and 5 of the Ptpre gene. Mice homozygous for this deletion (PtpreΔ3-5) were fertile, bred and developed normally and exhibited no overt phenotype. However, closer examination of the function of macrophages from these mice revealed a defect in the regulation of the respiratory burst. While bacterial lipopolysaccharide (LPS) or tumour necrosis factor α (TNFα) were able to prime bone marrow-derived macrophages (BMM) from wild type (Ptpre+) macrophages for an enhanced respiratory burst, they were unable to do so in macrophages from PTPε-deficient mice. PTPε-deficient BMM also had abnormalities in cytokine production with a reduced ability to produce TNFα and enhanced IL-10 production in response to challenge with LPS. These findings suggest an important role for PTPε in the control of macrophage function.