PT  - JOURNAL ARTICLE
AU  - Keyna, U
AU  - Beck-Engeser, G B
AU  - Jongstra, J
AU  - Applequist, S E
AU  - Jäck, H M
TI  - Surrogate light chain-dependent selection of Ig heavy chain V regions.
DP  - 1995 Dec 15
TA  - The Journal of Immunology
PG  - 5536--5542
VI  - 155
IP  - 12
4099  - http://www.jimmunol.org/content/155/12/5536.short
4100  - http://www.jimmunol.org/content/155/12/5536.full
SO  - J. Immunol.1995 Dec 15; 155
AB  - Bone marrow B cell precursors frequently rearrange the Ig heavy chain variable (VH) gene segment VH81X. It is puzzling, therefore, that mature B cells in adult mice rarely express mu-heavy chains bearing this VH gene segment. We show in this work in transformed pre-B cell lines that two VH81X/mu-chains that differ in their VH-D-JH joining sequences are not assembled covalently with the B cell precursor-specific surrogate light (SL) chain and are not expressed on the cell surface. From these findings, we propose that a B cell precursor clonally expands and proceeds to the next developmental stage only if it expresses a mu-chain with a VH domain that, together with the SL chain, directs the formation of a signal-transducing mu/SL chain membrane complex. Therefore, a checkpoint exists early in B cell development, at which SL chain not only screens B cell precursors for the presence of a full-length mu-chain, but also for a VH domain that promotes the assembly of a mu/SL chain complex.