Mutations in the gene for Bruton's tyrosine kinase result in the B cell differentiation defects X-linked agammaglobulinemia in man and X-linked immunodeficiency in mice. Here we describ the generation of two yeast artificial chromesome (YAC)-transgenic mouse strains in which high-level expression of human Btk is provided by endogenous regulatory cis-acting elements that are present on a 340-kb transgene, Yc34O-hBtk. The expression pattern of the transgenic human Btk was found to parallel that of the endogenous murine gene. When the Yc340-hBtk-transgenic mice were mated onto a Btk-deficient background, the xid B cell defects were fully corrected: conventional and CD5+ B-1 B cells were present in normal numbers, serum IgM and IgG3 levels as well as responses to T cell-independent type II antigens were in the normal ranges. In vivo competition experiments in Btk(+/-) female mice demonstrated that in the conventional B cell population the Yc340-hBtk transgene could fully compensate the absence of expression of endogenous murine Btk. We conclude that in the YAC-transgenic mice Btk is appropriately expressed in the context of native regulatory sequences.

dx.doi.org/10.1002/eji.1830270910, hdl.handle.net/1765/2548
European Journal of Immunology
Erasmus MC: University Medical Center Rotterdam

Maas, A, Dingjan, G.M, Savelkoul, H.F.J, Kinnon, C, Grosveld, F.G, & Hendriks, R.W. (1997). The X-linked immunodeficiency defect in the mouse is corrected by expression of human Bruton's tyrosine kinase from a yeast artificial chromosome transgene. European Journal of Immunology, 27(9), 2180–2187. doi:10.1002/eji.1830270910