I L Mårtensson

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The surrogate light chain is composed of two polypeptides, VpreB and lambda 5. In the mouse there are two VpreB genes which are 99% identical within the coding regions. Extensive restriction enzyme mapping and sequencing of these two genes showed that only the coding region and immediate 5' and 3' flanking sequences exhibited such high homology. More distal(More)
The lambda 5 gene is expressed specifically in pre-B cells; during B lymphocyte differentiation the expression of the lambda 5 gene is turned on in pre-B cells and turned off again at the mature B cell stage. No other cell type has yet been found to express the lambda 5 gene. The pre-B cell-specific expression of the lambda 5 gene is regulated at the level(More)
The two tyrosine kinase receptors, c-kit and flt3, and their respective ligands KL and FL, have been demonstrated to play key and nonredundant roles in regulating the earliest events in hematopoiesis. However, their precise roles and potential interactions in promoting early lymphoid commitment and development remain unclear. Here we show that most if not(More)
The antibody responses against empty polyacryl starch microparticles and the corresponding human serum albumin (HSA)-containing microparticles were followed in mice for 30 weeks. Empty polyacryl starch microparticles were nonimmunogenic as determined by a direct, enzyme-linked immunosorbent assay (ELISA). However, when the previously nonimmunogenic particle(More)
The surrogate light chain (SL) is composed of two polypeptides, Vpre-B and lambda5. In large pre-BII cells the SL chain associates with Ig mu heavy chain (muH) to form the pre-B cell receptor (pre-BCR). In mice there are two Vpre-B genes which are 98% identical within the coding regions. The two genes are co-expressed at the RNA level and encode functional(More)
The pre-B cell-specific expression of the lambda5 gene is regulated at the level of transcription. The 5' region of the lambda5 gene has been shown to contain an enhancer that activates heterologous promoters. Here, we show that this enhancer, B(lambda5), also acts as a lineage- and tissue-restricted enhancer on its own promoter. We define the enhancer(More)
The chicken Ig lambda light chain locus is composed of a single V gene closely linked (1.8 kb) to a single J-C unit in its natural configuration. In mice transgenic for this locus, the transgene becomes rearranged in B cells and to a much lesser extent in T cells. Modifications were introduced in the transgene in order to characterize elements which target(More)
Conditions for transfection of normal, freshly isolated and mitogen-stimulated spleen cells were established. A sharp optimum of plasmid at 10 micrograms per 1.5 X 10(7) transfected spleen cells per transfection was observed. The Ig promoter and the IgH enhancer activity was found to be restricted to cells of the B lineage also in normal, freshly isolated(More)
The lambda5 gene is expressed exclusively in precursor (pre-) B cells where its gene product, as part of the pre-B cell receptor, is crucial for the proliferation of these cells. Several DNA regions regulate the activity and expression pattern of the lambda5 gene. Amongst these is an enhancer, B(lambda5), located 5' of the gene. Here we analyze the lambda5(More)