title: B-1 B lymphocytes require Blimp-1 for immunoglobulin secretion.
abstract: B-1 B cells produce circulating natural antibodies that provide "innate-like" protection against bacterial and viral pathogens. They also provide adaptive responses to blood and air-borne pathogens. B lymphocyte-induced maturation protein 1 (Blimp-1) is a transcriptional repressor that is required for the formation of B-2-derived antibody-secreting plasma cells. In this study, we used mice lacking Blimp-1 in the B cell lineage to show that Blimp-1 is not necessary for the formation or self-renewal of B-1 B cells but that Blimp-1 is required for normal immunoglobulin (Ig) secretion by B-1 cells. B-1 cells lacking Blimp-1 do not repress Pax5 mRNA and do not induce X-box binding protein 1, and mu secreted mRNA normally, showing that B-1 and B-2 cells both use a common pathway for Ig secretion. Blimp-1-deficient B-1 B cells are also defective in providing early protection against influenza infection.
authors.affiliation: Department of Biological Sciences, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
authors.forename: David
authors.initials: D
authors.lastname: Savitsky
authors.forename: Kathryn
authors.initials: K
authors.lastname: Calame
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000276:immunology*; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D007136:Immunoglobulins / Q000378:metabolism*; D007150:Immunohistochemistry; D051379:Mice; D009976:Orthomyxoviridae Infections / Q000276:immunology*; D000074462:Positive Regulatory Domain I-Binding Factor 1; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D007136:Immunoglobulins; C513258:Prdm1 protein, mouse; D012097:Repressor Proteins; D014157:Transcription Factors; D000074462:Positive Regulatory Domain I-Binding Factor 1