title: IL-7Ralpha and E47: independent pathways required for development of multipotent lymphoid progenitors.
abstract: Mice that lack the transcription factors encoded by the E2A gene or the receptor for interleukin 7 (IL-7R) have severe overlapping defects in lymphocyte development. Here, we show that E2A proteins are required for the survival of early T-lineage cells; however, they function through a pathway that is distinct from the survival pathway initiated by IL-7R signaling. While E2A proteins are required to suppress caspase 3 activation, ectopic expression of the anti-apoptotic protein Bcl-2 is not sufficient to overcome the lymphopoietic defects observed in the absence of E2A. Remarkably, mice that lack both IL-7Ralpha and E47 display a synergistic decrease in the number of T-cell, NK-cell and multipotent progenitors in the thymus, indicating that these distinct survival pathways converge to promote the development of multipotent lymphoid progenitors.
authors.affiliation: Department of Biology, University of California San Diego, La Jolla, CA 92093, USA. bkee@bsd.uchicago.edu
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Kee
authors.forename: Gretchen
authors.initials: G
authors.lastname: Bain
authors.forename: Cornelis
authors.initials: C
authors.lastname: Murre
mesh_terms: D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D019254:Genes, bcl-2; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008954:Models, Biological; D020395:Receptors, Interleukin-7 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D020395:Receptors, Interleukin-7; D051820:TCF Transcription Factors; C544913:Tcf7l1 protein, mouse; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; C415350:interleukin-7 receptor, alpha chain