TY - JOUR
T1 - Deviation of the B cell pathway in senescent mice is associated with reduced surrogate light chain expression and altered immature B cell generation, phenotype, and light chain expression
AU - Alter-Wolf, Sarah
AU - Blomberg, Bonnie B.
AU - Riley, Richard L.
PY - 2009/1/1
Y1 - 2009/1/1
N2 - B lymphopoiesis in aged mice is characterized by reduced B cell precursors and an altered Ab repertoire. This likely results, in part, from reduced surrogate L chains in senescent B cell precursors and compromised pre-BCR checkpoints. Herein, we show that aged mice maintain an ordinarily minor pool of early c-kit+ pre-B cells, indicative of poor pre-BCR expression, even as pre-BCR competent early pre-B cells are significantly reduced. Therefore, in aged mice, B2 B lymphopoiesis shifts from dependency on pre-BCR expansion and selection to more pre-BCR-deficient pathways. B2 c-kit+ B cell precursors, from either young or aged mice, generate new B cells in vitro that are biased to larger size, higher levels of CD43, and decreased κ L chain expression. Notably, immature B cells in aged bone marrow exhibit a similar phenotype in vivo. We hypothesize that reduced surrogate L chain expression contributes to decreased pre-B cells in aged mice. The B2 pathway is partially blocked with limited B cell development and reduced pre-BCR expression and signaling. In old age, B2 pathways have limited surrogate L chain and increasingly generate new B cells with altered phenotype and L chain expression.
AB - B lymphopoiesis in aged mice is characterized by reduced B cell precursors and an altered Ab repertoire. This likely results, in part, from reduced surrogate L chains in senescent B cell precursors and compromised pre-BCR checkpoints. Herein, we show that aged mice maintain an ordinarily minor pool of early c-kit+ pre-B cells, indicative of poor pre-BCR expression, even as pre-BCR competent early pre-B cells are significantly reduced. Therefore, in aged mice, B2 B lymphopoiesis shifts from dependency on pre-BCR expansion and selection to more pre-BCR-deficient pathways. B2 c-kit+ B cell precursors, from either young or aged mice, generate new B cells in vitro that are biased to larger size, higher levels of CD43, and decreased κ L chain expression. Notably, immature B cells in aged bone marrow exhibit a similar phenotype in vivo. We hypothesize that reduced surrogate L chain expression contributes to decreased pre-B cells in aged mice. The B2 pathway is partially blocked with limited B cell development and reduced pre-BCR expression and signaling. In old age, B2 pathways have limited surrogate L chain and increasingly generate new B cells with altered phenotype and L chain expression.
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U2 - 10.4049/jimmunol.182.1.138
DO - 10.4049/jimmunol.182.1.138
M3 - Article
C2 - 19109144
AN - SCOPUS:59849105341
VL - 182
SP - 138
EP - 147
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 1
ER -