Siglec-G regulates B1 cell survival and selection.
Siglec-G is a negative regulator of BCR-mediated signaling in B1a cells. This population of B cells is highly increased in Siglec-G-deficient mice, but the mechanism of this expansion is not known so far. In this study, we demonstrate that Siglecg(-/-) B1a cells show a lower level of spontaneous apoptosis and a prolonged life span. Mechanistically, the lower apoptosis could result from higher expression levels of the transcription factor NFATc1 in Siglec-G-deficient B1a cells. Interestingly, Siglecg(-/-) B1a cells display an altered BCR repertoire compared with wild-type B1a cells. As the BCR repertoire and the VDJ composition of Igs of Siglecg(-/-) B1a cells resembles more the Abs produced by adult bone marrow-derived B cells rather than canonical fetal liver-derived B1a cells, this suggest that the selection into the B1a cell population is altered in Siglec-G-deficient mice.
Jellusova
Julia
J
Department of Genetics, University of Erlangen, Erlangen, Germany.
Düber
Sandra
S
Gückel
Eva
E
Binder
Christoph J
CJ
Weiss
Siegfried
S
Voll
Reinhard
R
Nitschke
Lars
L
D019264:Adoptive Transfer; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000637:transplantation; D002451:Cell Compartmentation / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics / Q000276:immunology*; D002478:Cells, Cultured; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D037102:Lectins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D050778:NFATC Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D010537:Peritoneum / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
D018398:Homeodomain Proteins; D037102:Lectins; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D011947:Receptors, Antigen, B-Cell; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; C522403:Siglecg protein, mouse; C064658:RAG-1 protein; D017493:Leukocyte Common Antigens; C516770:Ptprc protein, mouse