The pre-B cell receptor and its role in proliferation and Ig heavy chain allelic exclusion.
The pre-B cell receptor (pre-BCR) is composed of the immunoglobulin (Ig) heavy (microH) chain and the surrogate light chain encoded by VpreB and lambda5. The pre-BCR has been implicated in precursor B cell proliferation, differentiation and IgH chain allelic exclusion. B cell development in mice lacking the transmembrane form of microH chain is blocked at the precursor B cell stage: the cells cannot proliferate or differentiate further and the IgH locus is allelically included. In mice lacking lambda5, the precursor B cells, although unable to proliferate, can nonetheless differentiate, whereas the IgH locus is allelically excluded. It was, therefore, postulated that microH chain together with VpreB could form a pre-BCR-like receptor that would allow IgH allelic exclusion but not proliferation. In mice lacking both VpreB genes, precursor B cells do not proliferate but are able to differentiate. Surprisingly, the IgH locus is allelically excluded. This suggests that microH chains find other partner proteins to signal allelic exclusion.
Mårtensson
Inga-Lill
IL
The Babraham Institute, Cambridge CB2 4AT, UK. lill.martensson@bbsrc.ac.uk
Rolink
Antonius
A
Melchers
Fritz
F
Mundt
Cornelia
C
Licence
Steve
S
Shimizu
Takeyuki
T
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology*; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D020868:Gene Silencing / Q000276:immunology; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000276:immunology*; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell
D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D008562:Membrane Glycoproteins; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell