Requirement of Shp-2 tyrosine phosphatase in lymphoid and hematopoietic cell development

Shp-1 and Shp-2 are cytoplasmic phosphotyrosine phosphatases with similar s tructures. Mice deficient in Shp-2 die at midgestation with defects in meso dermal patterning, and a hypomorphic mutation at the Shp-1 locus results in the moth-eaten viable (me(v)) phenotype. Previously, a critical role of Sh p-2 in mediating erythroid/myeloid cell development was demonstrated. By us ing the RAG-2-deficient blastocyst complementation, the role of Shp-2 in ly mphopoiesis has been determined. Chimeric mice generated by injecting Shp-2 (-/-) embryonic stem cells into Rag-2-deficient blastocysts had no detectab le mature T and B cells, serum immunoglobulin M, or even Thy-1(+) and B220( +) precursor lymphocytes. Collectively, these results suggest a positive ro le of Shp-2 in the development of all blood cell lineages, in contrast to t he negative effect of Shp-1 in this process. To determine whether Shp-1 and Shp-2 interact in hematopoiesis, Shp-2(-/-):me(v)/me(v) double-mutant embr yos were generated and the hematopoietic cell development in the yolk sacs was examined. More hematopoietic stem/progenitor cells were detected in Shp -2(-/-):me(v)/me(v) embryos than in Shp-2(-/-) littermates. The partial res cue by Shp-1 deficiency of the defective hematopolesis caused by the Shp-2 mutation suggests that Shp-1 and Shp-2 have antagonistic effects in hematop oiesis, possibly through a bidirectional modulation of the same signaling p athway(s). (C) 2001 by The American Society of Hematology.