Analysis of B lymphocyte activation and differentiation by expression profiling
type: CreativeWork
description: B cell development is severely impaired in the absence of SLP65 adaptor protein. SLP65-deficient B cells are arrested at the large cycling pre-B cell stage in the bone marrow and transitional B cell stages in the spleen of mice. The zinc-finger transcription factor EGR1 is an immediate early gene induced upon Ag-binding and BCR engagement in B cells. EGR1 promotes B cell differentiation and maturation at the progression from pro-B to pre-B and into the mature B cell stages. The main hypothesis of this study was that EGR1 expression is regulated through a SLP65-dependent signaling chain and therefore, EGR1 overexpression in SLP65-/- mice could restore or at least partially rescue developmental blocks caused by the absence of SLP65 in B cells. The results revealed that both EGRxSLP65-/- and SLP65-/- B cells appear to be arrested at the same developmental (large pre-B cell) stage, suggesting that in the absence of SLP65, EGR1 activity alone is not sufficient to rescue the developmental block in the bone marrow. However, independent of this developmental arrest EGR1 overexpression mediates downregulation of IL-2R alpha chain in B cells. Further analysis showed that although EGR1 could not completely rescue the developmental arrest at the transitional B cells stages in EGRxSLP65-/- mice, splenic B cells from EGRxSLP65-/- mice have a more mature phenotype compared to splenic B cells from SLP65-/- animals. In order to determine the underlying molecular basis of these EGR1-mediated phenotypic changes in EGRxSLP65-/- B cells as well as to identify additional EGR1 target genes in B cells, gene expression profiling experiments were performed. By microarray hybridizations and several validation methods at least nine genes were found to be differentially regulated in EGRxSLP65-/- B cells. Inspection of the promoter sequences suggests that seven genes: Ly-6A/E, TAF10, SLFN1, SLFN2, CalA, CCR2 and Oct1 might be potential EGR1 target genes in B cells. Ly-6D and Ly-6E are upregulate…
abstract: B cell development is severely impaired in the absence of SLP65 adaptor protein. SLP65-deficient B cells are arrested at the large cycling pre-B cell stage in the bone marrow and transitional B cell stages in the spleen of mice. The zinc-finger transcription factor EGR1 is an immediate early gene induced upon Ag-binding and BCR engagement in B cells. EGR1 promotes B cell differentiation and maturation at the progression from pro-B to pre-B and into the mature B cell stages. The main hypothesis of this study was that EGR1 expression is regulated through a SLP65-dependent signaling chain and therefore, EGR1 overexpression in SLP65-/- mice could restore or at least partially rescue developmental blocks caused by the absence of SLP65 in B cells. The results revealed that both EGRxSLP65-/- and SLP65-/- B cells appear to be arrested at the same developmental (large pre-B cell) stage, suggesting that in the absence of SLP65, EGR1 activity alone is not sufficient to rescue the developmental block in the bone marrow. However, independent of this developmental arrest EGR1 overexpression mediates downregulation of IL-2R alpha chain in B cells. Further analysis showed that although EGR1 could not completely rescue the developmental arrest at the transitional B cells stages in EGRxSLP65-/- mice, splenic B cells from EGRxSLP65-/- mice have a more mature phenotype compared to splenic B cells from SLP65-/- animals. In order to determine the underlying molecular basis of these EGR1-mediated phenotypic changes in EGRxSLP65-/- B cells as well as to identify additional EGR1 target genes in B cells, gene expression profiling experiments were performed. By microarray hybridizations and several validation methods at least nine genes were found to be differentially regulated in EGRxSLP65-/- B cells. Inspection of the promoter sequences suggests that seven genes: Ly-6A/E, TAF10, SLFN1, SLFN2, CalA, CCR2 and Oct1 might be potential EGR1 target genes in B cells. Ly-6D and Ly-6E are upregulate…
author: Rakhmanov, Mirzokhid
keywords: B Cell Differentiation, microarrays, EGR1 target genes, pre-B ALL
date modified: 2026-07-24T02:22:28Z
provider: University of Freiburg
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Freiburg