title: Characterization of a B cell progenitor present in neonatal bone marrow and spleen but not in adult bone marrow and spleen.
abstract: The neonatal period marks an important time in mammalian immunologic development, yet it is often ignored in studies of lymphocyte development. We identified a cell population with the phenotype heat stable Ag (HSA)low lin- CD43low that contained B cell progenitors at a high frequency in the neonatal bone marrow and spleen. Although cells with a similar phenotype can be identified in the bone marrow and spleen of adult animals, these populations showed a greatly reduced frequency of B cell progenitors. B lineage cells were detected after 7 days in culture at a frequency of 1:15 when HSAlow lin- CD43low cells from neonatal bone marrow were cultured on stromal cells and IL-7 under limiting dilution conditions. Under similar conditions, the equivalent population in adult bone marrow had a frequency of B cell progenitors that was less than 1:2000. The expression of terminal deoxynucleotidyl transferase in freshly sorted neonatal HSAlow lin- CD43low cells suggested that cells committed to the lymphocyte lineage were present in this population. These data suggested that the HSAlow lin- CD43low population of cells represents a pool of B lineage precursors that may be responsible for filling the immune compartment early in neonatal life.
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Medical Center, Shreveport 71130, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Moscatello
authors.forename: K L
authors.initials: KL
authors.lastname: Biber
authors.forename: D C
authors.initials: DC
authors.lastname: Dempsey
authors.forename: R
authors.initials: R
authors.lastname: Chervenak
authors.forename: R M
authors.initials: RM
authors.lastname: Wolcott
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D015703:Antigens, CD / Q000096:biosynthesis; D016175:B-Lymphocyte Subsets / Q000201:enzymology / Q000276:immunology*; D001854:Bone Marrow Cells / Q000201:enzymology / Q000276:immunology*; D051927:CD24 Antigen; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D019070:Cell Lineage / Q000276:immunology; D004253:DNA Nucleotidylexotransferase / Q000096:biosynthesis; D005260:Female; D016130:Immunophenotyping; D051917:Leukosialin; D018655:Lymphocyte Count; D008297:Male; D008562:Membrane Glycoproteins; D051379:Mice; D008810:Mice, Inbred C57BL; D012795:Sialoglycoproteins / Q000096:biosynthesis; D013154:Spleen / Q000166:cytology / Q000201:enzymology / Q000276:immunology*; D013234:Stem Cells / Q000201:enzymology / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D051927:CD24 Antigen; C497890:Cd24a protein, mouse; D051917:Leukosialin; D008562:Membrane Glycoproteins; D012795:Sialoglycoproteins; C497863:Spn protein, mouse; D004253:DNA Nucleotidylexotransferase