title: Protein Tyrosine Phosphatase Gamma (PTPgamma) is a Novel Leukocyte Marker Highly Expressed by CD34 Precursors.
abstract: Protein Tyrosine Phosphatase gamma (PTPgamma) is a receptor-like transmembrane protein belonging to the family of classical protein tyrosine phosphatases. PTPgamma is known to regulate haematopoietic differentiation in a murine embryonic stem cells model. We have recently demonstrated that PTPgamma mRNA is expressed in monocytes, tissue-localized myeloid dendritic cells and in both myeloid and plasmacytoid dendritic cells in peripheral blood. We now developed a PTPgamma specific antibody that recognizes the protein by flow cytometry. PTPgamma expression was detected in monocytes and both myeloid and plasmacytoid dendritic cells, while PMN showed a low but consistent staining in contrast with previous mRNA data. B cells were found to express the phosphatase while T cells were negative. In keeping with RNA data, PTPgamma was detected in monocyte-derived dendritic cells and its expression rose upon LPS stimulation. Finally, we discovered that CD34(+) haematopoietic precursors express high PTPgamma level that drops during in vitro expansion induced by IL-3 and SCF growth factors. We therefore propose PTPgamma as a new functionally regulated leukocyte marker whose role in normal and pathological context deserve further investigation.
authors: Department of Pathology, University of Verona, Italy.
authors: Andrea
authors: A
authors: Mafficini
authors: Marzia
authors: M
authors: Vezzalini
authors: Loris
authors: L
authors: Zamai
authors: Laura
authors: L
authors: Galeotti
authors: Gabriella
authors: G
authors: Bergamini
authors: Marco
authors: M
authors: Della Peruta
authors: Paola
authors: P
authors: Melotti
authors: Claudio
authors: C
authors: Sorio