Chicken BAFF--a highly conserved cytokine that mediates B cell survival.
Members of the tumor necrosis factor (TNF) family play key roles in the regulation of inflammation, immune responses and tissue homeostasis. Here we describe the identification of the chicken homologue of mammalian B cell activating factor of the TNF family (BAFF/BLyS). By searching a chicken EST database we identified two overlapping cDNA clones that code for the entire open reading frame of chicken BAFF (chBAFF), which contains a predicted transmembrane domain and a putative furin protease cleavage site like its mammalian counterparts. The amino acid identity between soluble chicken and human BAFF is 76%, considerably higher than for most other known cytokines. The chBAFF gene is most strongly expressed in the bursa of Fabricius. Soluble recombinant chBAFF produced by human 293T cells interacted with the mammalian cell-surface receptors TACI, BCMA and BAFF-R. It bound to chicken B cells, but not to other lymphocytes, and it promoted the survival of splenic chicken B cells in culture. Furthermore, bacterially expressed chBAFF induced the selective expansion of B cells in the spleen and cecal tonsils when administered to young chicks. Our results suggest that like its mammalian counterpart, chBAFF plays an important role in survival and/or proliferation of chicken B cells.
Schneider
Kirsten
K
Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, University of Freiburg, 79104 Freiburg, Germany.
Kothlow
Sonja
S
Schneider
Pascal
P
Tardivel
Aubry
A
Göbel
Thomas
T
Kaspers
Bernd
B
Staeheli
Peter
P
D000595:Amino Acid Sequence; D000818:Animals; D053264:B-Cell Activating Factor; D001402:B-Lymphocytes / Q000276:immunology*; D015152:Blotting, Northern; D015153:Blotting, Western; D002060:Bursa of Fabricius / Q000276:immunology; D002470:Cell Survival; D002478:Cells, Cultured; D002645:Chickens / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology*; D008969:Molecular Sequence Data; D014066:Palatine Tonsil / Q000276:immunology; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000276:immunology; D017385:Sequence Homology; D013045:Species Specificity; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000276:immunology*
D053264:B-Cell Activating Factor; D008565:Membrane Proteins; D011994:Recombinant Proteins; C505719:TNFSF13B protein, human; D014409:Tumor Necrosis Factor-alpha