Cyclin D2 controls B cell progenitor numbers.
J Leukoc Biol
; 74(6): 1139-43, 2003 Dec.
Article
en En
| MEDLINE
| ID: mdl-14612431
ABSTRACT
Cyclin D2 affects B cell proliferation and differentiation in vivo. It is rate-limiting for B cell receptor (BCR)-dependent proliferation of B cells, and cyclin D2-/- mice lack CD5+(B1) B lymphocytes. We show here that the bone marrow (BM) of cyclin D2-/- mice contains half the numbers of Sca1+B220+ B cell progenitors but normal levels of Sca1+ progenitor cells of other lineages. In addition, clonal analysis of BM from the cyclin D2-/- and cyclin D2+/+ mice confirmed that there were fewer B cell progenitors (B220+) in the cyclin D2-/- mice. In addition, the colonies from cyclin D2-/- mice were less mature (CD19lo) than those from cyclin D2+/+ mice (CD19Hi). The number of mature B2 B cells in vivo is the same in cyclin D2-/- and cyclin D2+/+ animals. Lack of cyclin D2 protein may be compensated by cyclin D3, as cyclin-dependent kinase (cdk)6 coimmunoprecipitates with cyclin D3 but not cyclin D1 from BM mononuclear cells of cyclin D2-/- mice. It is active, as endogenous retinoblastoma protein is phosphorylated at the cdk6/4-cyclin D-specific sites, S807/811. We conclude that cyclin D2 is rate-limiting for the production of B lymphoid progenitor cells whose proliferation does not depend on BCR signaling.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Tirosina Quinasas
/
Células Madre Hematopoyéticas
/
Linfocitos B
/
Proteínas Proto-Oncogénicas
/
Ciclinas
Límite:
Animals
Idioma:
En
Revista:
J Leukoc Biol
Año:
2003
Tipo del documento:
Article
País de afiliación:
Reino Unido