Pan/E2A expression precedes immunoglobulin heavy-chain expression during B lymphopoiesis in nontransformed cells, and Pan/E2A proteins are not detected in myeloid cells

1994 ◽  
Vol 14 (6) ◽  
pp. 4087-4096
Author(s):  
Y Jacobs ◽  
X Q Xin ◽  
K Dorshkind ◽  
C Nelson
Keyword(s):  
B Cell ◽  
Cell Line ◽  
Heavy Chain ◽  
B Lymphocyte ◽  
Myeloid Cells ◽  
Immunoglobulin Heavy Chain ◽  
Cell Development ◽  
B Cell Development ◽  
Chain Gene ◽  
Enhancer Element

A newly developed rat long-term bone marrow culture system was used to study the role of Pan/E2A basic helix-loop-helix transcription factors during B-cell development. In this system, B-lymphocyte progenitors actively differentiate into mature B cells. Monoclonal (Yae) and polyclonal (anti-Pan) antibodies were employed to characterize the expression of Pan proteins by Western blot assay during hematopoiesis and to examine the components of immunoglobulin heavy-chain gene enhancer element-binding species by electrophoretic mobility shift assay. During B-cell development, the appearance of Pan/E2A proteins preceded the expression of immunoglobulin heavy-chain protein. A Pan-containing immunoglobulin heavy-chain enhancer element (mu E5)-binding species (BCF1), composed of immunoreactive Pan-1/E47 but not Pan-2/E12, was observed concomitantly with the detection of Pan/E2A proteins. In addition to BCF1, other mu E5-binding species were detected which were not recognized by the Yae antibody. Two of these species were present in primary B-lymphocyte and myeloid cultures and were recognized by an anti-upstream stimulatory factor antiserum. Although Pan/E2A proteins have been proposed to be ubiquitous, Pan/E2A proteins were not detected in primary myeloid cultures composed mainly of granulocytes and macrophages or in the macrophage cell line J774. The absence of Pan/E2A proteins in differentiated myeloid cells correlated with low steady-state levels of Pan/E2A RNA. However, Pan/E2A proteins were present in a promyeloid cell line, 32DCL3, suggesting that extinction of Pan/E2A expression may play a role in myelopoiesis.

scholarly journals Pan/E2A expression precedes immunoglobulin heavy-chain expression during B lymphopoiesis in nontransformed cells, and Pan/E2A proteins are not detected in myeloid cells.

1994 ◽  
Vol 14 (6) ◽  
pp. 4087-4096 ◽  
Author(s):  
Y Jacobs ◽  
X Q Xin ◽  
K Dorshkind ◽  
C Nelson
Keyword(s):  
B Cell ◽  
Cell Line ◽  
Heavy Chain ◽  
B Lymphocyte ◽  
Myeloid Cells ◽  
Immunoglobulin Heavy Chain ◽  
Cell Development ◽  
B Cell Development ◽  
Chain Gene ◽  
Enhancer Element

A newly developed rat long-term bone marrow culture system was used to study the role of Pan/E2A basic helix-loop-helix transcription factors during B-cell development. In this system, B-lymphocyte progenitors actively differentiate into mature B cells. Monoclonal (Yae) and polyclonal (anti-Pan) antibodies were employed to characterize the expression of Pan proteins by Western blot assay during hematopoiesis and to examine the components of immunoglobulin heavy-chain gene enhancer element-binding species by electrophoretic mobility shift assay. During B-cell development, the appearance of Pan/E2A proteins preceded the expression of immunoglobulin heavy-chain protein. A Pan-containing immunoglobulin heavy-chain enhancer element (mu E5)-binding species (BCF1), composed of immunoreactive Pan-1/E47 but not Pan-2/E12, was observed concomitantly with the detection of Pan/E2A proteins. In addition to BCF1, other mu E5-binding species were detected which were not recognized by the Yae antibody. Two of these species were present in primary B-lymphocyte and myeloid cultures and were recognized by an anti-upstream stimulatory factor antiserum. Although Pan/E2A proteins have been proposed to be ubiquitous, Pan/E2A proteins were not detected in primary myeloid cultures composed mainly of granulocytes and macrophages or in the macrophage cell line J774. The absence of Pan/E2A proteins in differentiated myeloid cells correlated with low steady-state levels of Pan/E2A RNA. However, Pan/E2A proteins were present in a promyeloid cell line, 32DCL3, suggesting that extinction of Pan/E2A expression may play a role in myelopoiesis.

Pi, a pre-B-cell-specific enhancer element in the immunoglobulin heavy-chain enhancer

1993 ◽  
Vol 13 (10) ◽  
pp. 5957-5969
Author(s):  
T A Libermann ◽  
D Baltimore
Keyword(s):  
B Cell ◽  
Heavy Chain ◽  
Mutational Analysis ◽  
Protein S ◽  
Immunoglobulin Heavy Chain ◽  
Chain Gene ◽  
Cell Stage ◽  
Enhancer Activity ◽  
Enhancer Element ◽  
Light Chain Gene

We have identified a new immunoglobulin heavy-chain enhancer element, designated pi, between the microE2 and microE3 elements. The pi enhancer element is transcriptionally active primarily during early stages of B-cell development but becomes virtually inactive during B-cell maturation at about the stage of immunoglobulin kappa light-chain gene rearrangement. Mutational analysis suggests that the pi element is crucial for immunoglobulin heavy-chain enhancer activity at the pre-B-cell stage but is almost irrelevant for enhancer activity at the mature B-cell or plasma-cell stage. The activity of the pi enhancer element correlates with the presence of an apparently pre-B-cell-specific protein-DNA complex. The similarity of the pi site to recognition sequences for members of the ets gene family suggests that the protein(s) interacting with the pi site most likely are ets-related transcription factors.

scholarly journals Changes in Locus-specific V(D)J Recombinase Activity Induced by Immunoglobulin Gene Products during B Cell Development

1997 ◽  
Vol 185 (4) ◽  
pp. 609-620 ◽  
Author(s):  
Andrei Constantinescu ◽  
Mark S. Schlissel
Keyword(s):  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Light Chain ◽  
Immunoglobulin Heavy Chain ◽  
Cell Development ◽  
B Cell Development ◽  
Allelic Exclusion ◽  
Chain Locus ◽  
Heavy Chain Locus

The process of V(D)J recombination is crucial for regulating the development of B cells and for determining their eventual antigen specificity. Here we assess the developmental regulation of the V(D)J recombinase directly, by monitoring the double-stranded DNA breaks produced in the process of V(D)J recombination. This analysis provides a measure of recombinase activity at immunoglobulin heavy and light chain loci across defined developmental stages spanning the process of B cell development. We find that expression of a complete immunoglobulin heavy chain protein is accompanied by a drastic change in the targeting of V(D)J recombinase activity, from being predominantly active at the heavy chain locus in pro-B cells to being exclusively restricted to the light chain loci in pre-B cells. This switch in locus-specific recombinase activity results in allelic exclusion at the immunoglobulin heavy chain locus. Allelic exclusion is maintained by a different mechanism at the light chain locus. We find that immature, but not mature, B cells that already express a functional light chain protein can undergo continued light chain gene rearrangement, by replacement of the original rearrangement on the same allele. Finally, we find that the developmentally regulated targeting of V(D)J recombination is unaffected by enforced rapid transit through the cell cycle induced by an Eμ-myc transgene.

scholarly journals The B29 (Immunoglobulin β-Chain) Gene Is a Genetic Target for Early B-Cell Factor

1999 ◽  
Vol 19 (1) ◽  
pp. 392-401 ◽  
Author(s):  
Peter Åkerblad ◽  
Maria Rosberg ◽  
Tomas Leanderson ◽  
Mikael Sigvardsson
Keyword(s):  
Transcription Factor ◽  
B Cells ◽  
B Cell ◽  
B Lymphocyte ◽  
Ectopic Expression ◽  
Cell Receptor ◽  
Cell Development ◽  
B Cell Development ◽  
Chain Gene ◽  
Early B Cell Factor

ABSTRACT Early B-cell factor (EBF) is a transcription factor suggested as essential for early B-lymphocyte development by findings in mice where the coding gene has been inactivated by homologous disruption. This makes the identification of genetic targets for this transcription factor pertinent for the understanding of early B-cell development. The lack of B29 transcripts, coding for the β subunit of the B-cell receptor complex, in pro-B cells from EBF-deficient mice suggested that B29 might be a genetic target for EBF. We here present data suggesting that EBF interacts with three independent sites within the mouse B29 promoter. Furthermore, ectopic expression of EBF in HeLa cells activated a B29promoter-controlled reporter construct 13-fold and induced a low level of expression from the endogenous B29 gene. Finally, mutations in the EBF binding sites diminished B29 promoter activity in pre-B cells while the same mutations did not have as striking an effect on the promoter function in B-cell lines of later differentiation stages. These data suggest that the B29gene is a genetic target for EBF in early B-cell development.

scholarly journals CLASS II-RESTRICTED PRESENTATION OF AN IMMUNOGLOBULIN HEAVY-CHAIN-GENE PRODUCT BY A GENE-TRANSFECTED B-CELL LINE

1994 ◽  
Vol 47 (4) ◽  
pp. 195-210
Author(s):  
Yasushi MATSUURA ◽  
Saburo ONISHI ◽  
Yasutake YAMAMOTO ◽  
Taketoshi TANIGUCHI ◽  
Satoshi OBANA ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Line ◽  
Gene Product ◽  
Heavy Chain ◽  
Immunoglobulin Heavy Chain ◽  
Class Ii ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Immunoglobulin Heavy Chain Gene
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