Bruton's tyrosine kinase is required for signaling the CD79b-mediated pro-B to pre-B cell transition

Citation
T. Kouro et al., Bruton's tyrosine kinase is required for signaling the CD79b-mediated pro-B to pre-B cell transition, INT IMMUNOL, 13(4), 2001, pp. 485-493
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Immunology
Journal title
INTERNATIONAL IMMUNOLOGY
ISSN journal
0953-8178 → ACNP
Volume
13
Issue
4
Year of publication
2001
Pages
485 - 493
Database
ISI
SICI code
0953-8178(200104)13:4<485:BTKIRF>2.0.ZU;2-#
Abstract
Formation of the pre-BCR complex is a critical check point during B cell de velopment and induces the transition of pro-B to pre-B cells. CD79b (Ig bet a) is a signaling component in the pre-BCR complex, since differentiation t o the pre-B phenotype is induced by cross-linking the CD79b expressed on de velopmentally arrested pro-B cells from recombination-activating gene (RAG) -2-deficient mice. Bruton's tyrosine kinase (BTK) plays important roles in B cell development. However, its molecular mechanisms In early B cell devel opment are not fully understood. To examine whether BTK functions in CD79b- mediated signaling for the pro-B/pre-B transition, we utilized RAG2/BTK dou ble-knockout (DKO) mice. Pro-B cells from RAG2/BTK-DKO mice did not differe ntiate Into pre-B cells following CD79b cross-linking, although tyrosine ph osphorylation of cellular proteins including Erk1/2 and phospholipase C-gam ma2 was induced in the same manner as RAG2-KO mice. BTK is phosphorylated a fter cross-linking of CD79b on RAG2-deficient pro-B cells. These findings s uggest that BTK-dependent pathways downstream of CD79b are critical for the pro-B/pre-B transition and BTK-independent signaling pathways are also act ivated via the pre-BCR complex.