| First Author | Dingjan GM | Year | 2001 |
| Journal | J Exp Med | Volume | 193 |
| Issue | 10 | Pages | 1169-78 |
| PubMed ID | 11369788 | Mgi Jnum | J:69605 |
| Mgi Id | MGI:1934986 | Doi | 10.1084/jem.193.10.1169 |
| Citation | Dingjan GM, et al. (2001) Bruton's tyrosine kinase regulates the activation of gene rearrangements at the lambda light chain locus in precursor B cells in the mouse. J Exp Med 193(10):1169-78 |
| abstractText | Bruton's tyrosine kinase (Btk) is a nonreceptor tyrosine kinase involved in precursor B (pre-B) cell receptor signaling. Here we demonstrate that Btk-deficient mice have an approximately 50% reduction in the frequency of immunoglobulin (Ig) lambda light chain expression, already at the immature B cell stage in the bone marrow. Conversely, transgenic mice expressing the activated mutant Btk(E41K) showed increased lambda usage. As the kappa/lambda ratio is dependent on (a) the level and kinetics of kappa and lambda locus activation, (b) the life span of pre-B cells, and (c) the extent of receptor editing, we analyzed the role of Btk in these processes. Enforced expression of the Bcl-2 apoptosis inhibitor did not alter the Btk dependence of lambda usage. Crossing 3-83mudelta autoantibody transgenic mice into Btk-deficient mice showed that Btk is not essential for receptor editing. Also, Btk-deficient surface Ig(+) B cells that were generated in vitro in interleukin 7-driven bone marrow cultures manifested reduced lambda usage. An intrinsic defect in lambda locus recombination was further supported by the finding in Btk-deficient mice of reduced lambda usage in the fraction of pre-B cells that express light chains in their cytoplasm. These results implicate Btk in the regulation of the activation of the lambda locus for V(D)J recombination in pre-B cells. |
