| First Author | Li XJ | Year | 2015 |
| Journal | J Biol Chem | Volume | 290 |
| Issue | 7 | Pages | 3894-909 |
| PubMed ID | 25538234 | Mgi Jnum | J:232693 |
| Mgi Id | MGI:5779801 | Doi | 10.1074/jbc.M114.614057 |
| Citation | Li XJ, et al. (2015) Protein-tyrosine phosphatase Shp2 positively regulates macrophage oxidative burst. J Biol Chem 290(7):3894-909 |
| abstractText | Macrophages are vital to innate immunity and express pattern recognition receptors and integrins for the rapid detection of invading pathogens. Stimulation of Dectin-1 and complement receptor 3 (CR3) activates Erk- and Akt-dependent production of reactive oxygen species (ROS). Shp2, a protein-tyrosine phosphatase encoded by Ptpn11, promotes activation of Ras-Erk and PI3K-Akt and is crucial for hematopoietic cell function; however, no studies have examined Shp2 function in particulate-stimulated ROS production. Maximal Dectin-1-stimulated ROS production corresponded kinetically to maximal Shp2 and Erk phosphorylation. Bone marrow-derived macrophages (BMMs) from mice with a conditionally deleted allele of Ptpn11 (Shp2(flox/flox);Mx1Cre+) produced significantly lower ROS levels compared with control BMMs. Although YFP-tagged phosphatase dead Shp2-C463A was strongly recruited to the early phagosome, its expression inhibited Dectin-1- and CR3-stimulated phospho-Erk and ROS levels, placing Shp2 phosphatase function and Erk activation upstream of ROS production. Further, BMMs expressing gain of function Shp2-D61Y or Shp2-E76K and peritoneal exudate macrophages from Shp2D61Y/+;Mx1Cre+ mice produced significantly elevated levels of Dectin-1- and CR3-stimulated ROS, which was reduced by pharmacologic inhibition of Erk. SIRPalpha (signal regulatory protein alpha) is a myeloid inhibitory immunoreceptor that requires tyrosine phosphorylation to exert its inhibitory effect. YFP-Shp2C463A-expressing cells have elevated phospho-SIRPalpha levels and an increased Shp2-SIRPalpha interaction compared with YFP-WT Shp2-expressing cells. Collectively, these findings indicate that Shp2 phosphatase function positively regulates Dectin-1- and CR3-stimulated ROS production in macrophages by dephosphorylating and thus mitigating the inhibitory function of SIRPalpha and by promoting Erk activation. |
