Characterization of the B lymphocyte populations in Lyn-deficient mice and the role of Lyn in signal initiation and down-regulation

Immunity. 1997 Jul;7(1):69-81. doi: 10.1016/s1074-7613(00)80511-7.


Lyn-deficient mice were generated to analyze the role of Lyn in B cell antigen receptor (BCR) signaling. These mice had a reduced number of peripheral B cells with a greater proportion of immature cells and a higher than normal turnover rate. Aged lyn-/- mice developed splenomegaly, produced autoantibodies, and had an expanded population of B lymphoblasts of the B1 lineage. Splenic B cells from young lyn-/- mice initiated early BCR signaling events, although in a delayed fashion. Unexpectedly, lyn-/- B cells exhibited an enhanced MAP kinase activation and an increased proliferative response to BCR engagement. Stimulation of lyn-/- B cells with intact and F(ab')2 anti-IgM revealed defects in at least two mechanisms that negatively regulate BCR signaling, one of which involves Fc gammaRIIb1.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / genetics
  • Aging / immunology
  • Animals
  • Antibodies, Anti-Idiotypic / metabolism
  • Antigens, CD / biosynthesis
  • Autoantibodies / metabolism
  • B-Lymphocytes / cytology
  • B-Lymphocytes / enzymology*
  • B-Lymphocytes / metabolism
  • B7-2 Antigen
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Chickens
  • Down-Regulation*
  • Lipopolysaccharides / pharmacology
  • Membrane Glycoproteins / biosynthesis
  • Mice
  • Phenotype
  • Phosphorylation
  • Pseudogenes
  • Receptors, IgG / metabolism
  • Signal Transduction*
  • Surface Properties
  • Tyrosine / metabolism
  • src-Family Kinases / deficiency
  • src-Family Kinases / genetics
  • src-Family Kinases / metabolism*


  • Antibodies, Anti-Idiotypic
  • Antigens, CD
  • Autoantibodies
  • B7-2 Antigen
  • Cd86 protein, mouse
  • Lipopolysaccharides
  • Membrane Glycoproteins
  • Receptors, IgG
  • anti-IgM
  • Tyrosine
  • lyn protein-tyrosine kinase
  • src-Family Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases