title: Siglecg limits the size of B1a B cell lineage by down-regulating NFkappaB activation.
abstract: BACKGROUND
  B1 B cells are believed to be a unique lineage with a distinct developmental pathway, function and activation requirement. How this lineage is genetically determined remained largely obscure.
  
  
  RESULTS
  Using the Siglecg-deficient mice with a knockin of green-fluorescent protein encoding sequence, we show here that, although the Siglecg gene is broadly expressed at high levels in all stages and/or lineages of B cells tested and at lower levels in other lineages, its deletion selectively expanded the B1a B cell lineages, including the frequency of the B1 cell progenitor in the bone marrow and the number of B1a cells in the peritoneal cavity, by postnatal expansion. The expansion of B1a B cells in the peritoneal correlated with enhanced activation of NFkappaB and was ablated by an IKK inhibitor.
  
  
  CONCLUSIONS
  Our data revealed a critical role for Siglec G-NFkappaB pathway in regulating B1a B cell lineage. These data lead to a novel model of B1a lineage development that explains a large array of genetic data in this field.
authors.affiliation: Division of Immunotherapy, Section of General Surgery, Department of Surgery, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ding
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Bae Keun
authors.initials: BK
authors.lastname: Park
authors.forename: Cun-Yu
authors.initials: CY
authors.lastname: Wang
authors.forename: Pan
authors.initials: P
authors.lastname: Zheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D019070:Cell Lineage; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000166:cytology; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000166:cytology; D037102:Lectins / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism*; D010537:Peritoneum / Q000473:pathology; D063265:Sialic Acid Binding Immunoglobulin-like Lectins
chemical_list: D037102:Lectins; D016328:NF-kappa B; D063265:Sialic Acid Binding Immunoglobulin-like Lectins