title: Identification of CD4int progenitors in mouse fetal spleen, a source of resident lymphoid cells.
abstract: Hematopoiesis occurs in different tissues during adult and fetal life. Splenic hematopoiesis arises in the fetal period until the first weeks of life. We have analyzed the hematopoietic progenitor content of the fetal spleen (FS) at the embryonic days 14.5-15.5. We first demonstrate that the hematopoietic content of the FS differs largely from its fetal liver (FL) counterpart. The difference mainly concerns the distribution of the different pool of progenitors, as most of the splenic progenitors are comprised in the lineage(-)Sca1(-)cKit(lo) contrary to the FL. We have divided the fetal hematopoietic pool into smaller fractions to enable characterization of the earliest lymphoid progenitors. Among the lymphoid progenitors that already represent a rare population, we were able to separate a population, respectively, enriched in B or T/NK progenitors. Lineage restriction of the different developmental intermediates was tested by clonal assays. We propose a model for fetal splenic hematopoietic progenitors and their distribution.
authors.affiliation: Unité du Développement des Lymphocytes, INSERM U668, Institut Pasteur, Paris Cedex, France.
authors.forename: Guillaume E
authors.initials: GE
authors.lastname: Desanti
authors.forename: Ana
authors.initials: A
authors.lastname: Cumano
authors.forename: Rachel
authors.initials: R
authors.lastname: Golub
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000172:deficiency; D005260:Female; D005333:Fetus; D005434:Flow Cytometry; D006410:Hematopoiesis; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008819:Mice, Nude; D011247:Pregnancy; D013154:Spleen / Q000166:cytology / Q000276:immunology*
chemical_list: D004268:DNA-Binding Proteins; C499308:Rag2 protein, mouse