Project description:IKKα kinase is essential for the B cell maturation and secondary lymphoid organ development. In the current study, we evaluated the role of IKKα in the marginal zone and follicular B lymphocyte development by genetically deleting IKKα from the B cell lineage using CD19-Cre mice. The loss of IKKα did not affect the normal development of early B cell progenitors. However, a significant decline was observed in the percentage of immature B lymphocytes, mature marginal zone and follicular B cells along with a severe disruption of splenic marginal and follicular B cell zones. A gene expression analysis performed on the RNA extracted from the newly formed B cells (B220+IgMhi) revealed that IKKα deficiency produces significant changes in the expression of genes involved in MZ and FO B lymphocyte survival, homing and migration. And several among those genes identified belong to G protein family. Specifically, we validated the upregulated expression of regulator of G protein signaling 13 (RGS13), which is a GTPase activating protein (GAP) that negatively regulates G protein signaling and impede B cell migration. Likewise, promigratory B lymphocyte receptor, the sphingosine-1-phosphate receptor 3 (SIPR3) that couple to Gαi showed significantly reduced expression. In addition, an in silico analysis of gene product interactions revealed NF-κB signaling pathways to be a major gene regulating networks perturbed with IKKα deletion. Taken together, this study reveals IKKαNF-κB and G protein signaling axis to be central for the MZ and FO B cells survival, maintenance, homing and migration.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:The transcription factor EBF1 is essential for lineage specification in early B cell development. Here we demonstrate by conditional mutagenesis that EBF1 was required for B cell commitment, pro-B cell development and subsequent transition to pre-B cells. Later in B cell development, EBF1 was essential for the generation and maintenance of distinct mature B cell types. Marginal zone and B-1 B cells were lost, whereas follicular and germinal center B cells were reduced in the absence of EBF1. Activation of the B cell receptor resulted in impaired intracellular signaling, proliferation and survival of EBF1-deficient follicular B cells. Immune responses were severely reduced upon Ebf1 inactivation, as germinal centers were formed but not maintained. ChIP- and RNA-sequencing of follicular B cells identified EBF1-activated genes that code for receptors, signal transducers and transcriptional regulators implicated in B cell signaling. Notably, ectopic expression of EBF1 efficiently induced the development of B-1 cells at the expense of conventional B cells. These gain- and loss-of-function analyses uncovered novel important functions of EBF1 in controlling B cell immunity. 29 samples (4 ChIP-seq,16 input, 9 RNA-seq), All ChIP-seq in 2 biological replicates, but EBF1 ChIP-seq Pro-B in 2 technical replicates; All RNA-seq in 2 biological replicates but RNA-seq mature B_FO B_Cd23-Cre Ebf1(fl/–). WT and experimental samples are provided.
Project description:The transcription factor EBF1 is essential for lineage specification in early B cell development. Here we demonstrate by conditional mutagenesis that EBF1 was required for B cell commitment, pro-B cell development and subsequent transition to pre-B cells. Later in B cell development, EBF1 was essential for the generation and maintenance of distinct mature B cell types. Marginal zone and B-1 B cells were lost, whereas follicular and germinal center B cells were reduced in the absence of EBF1. Activation of the B cell receptor resulted in impaired intracellular signaling, proliferation and survival of EBF1-deficient follicular B cells. Immune responses were severely reduced upon Ebf1 inactivation, as germinal centers were formed but not maintained. ChIP- and RNA-sequencing of follicular B cells identified EBF1-activated genes that code for receptors, signal transducers and transcriptional regulators implicated in B cell signaling. Notably, ectopic expression of EBF1 efficiently induced the development of B-1 cells at the expense of conventional B cells. These gain- and loss-of-function analyses uncovered novel important functions of EBF1 in controlling B cell immunity.
Project description:Nodal marginal zone lymphoma is a poorly defined entity in the WHO classification, largely based on criteria by exclusion and the diagnosis often remains subjective. Follicular Lymphoma lacking t(14;18), have similar characteristics which results in a major potential diagnostic overlap which this study aims to dissect. Four subgroups of lymphoma samples (n=56) were analyzed with high-resolution arrayCGH; Nodal marginal zone lymphoma, t(14;18)-negative Follicular Lymphoma, localized t(14:18)-positive Follicular Lymphoma and disseminated t(14;18)-positive Follicular Lymphoma. Gains on chromosomes 7, 8 and 12 were observed in all subgroups. The mean number of aberrations was higher in disseminated t(14;18)-positive Follicular Lymphoma compared to localized t(14:18)-positive Follicular Lymphoma (p<0.01) and the majority of alterations in localized t(14:18)-positive Follicular Lymphoma were also found in disseminated t(14;18)-positive Follicular Lymphoma. Nodal marginal zone lymphoma was marked by 3q gains with amplifications of four genes. A different overall pattern of aberrations was seen in t(14;18)-negative Follicular Lymphoma compared to t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma is marked by specific (focal) gains on chromosome 3 as observed in Nodal marginal zone lymphoma. Our results support the notion that localized t(14:18)-positive Follicular Lymphoma represents an early phase of disseminated t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma bears aberrations that are more alike Nodal marginal zone lymphoma, suggesting a relation between these groups. Four subgroups of follicular lymphoma were analyzed: NMZL (n=14), t-FL (n=12), LOC t+FL (n=16), DIS t+FL (n=14).
Project description:Marginal zone B cells which make rapid mitosis-independent plasma cell responses are dependent on Notch2 signaling for their generation and maintenance. In order to determine the effect of ongoing Notch signaling on the maintenance of the MZ transcriptome, we performed RNA-seq on MZ and follicular B cells after 12, 24 and 48 hours of in vivo Notch2 antibody blockade
Project description:Nodal marginal zone lymphoma is a poorly defined entity in the WHO classification, largely based on criteria by exclusion and the diagnosis often remains subjective. Follicular Lymphoma lacking t(14;18), have similar characteristics which results in a major potential diagnostic overlap which this study aims to dissect. Four subgroups of lymphoma samples (n=56) were analyzed with high-resolution arrayCGH; Nodal marginal zone lymphoma, t(14;18)-negative Follicular Lymphoma, localized t(14:18)-positive Follicular Lymphoma and disseminated t(14;18)-positive Follicular Lymphoma. Gains on chromosomes 7, 8 and 12 were observed in all subgroups. The mean number of aberrations was higher in disseminated t(14;18)-positive Follicular Lymphoma compared to localized t(14:18)-positive Follicular Lymphoma (p<0.01) and the majority of alterations in localized t(14:18)-positive Follicular Lymphoma were also found in disseminated t(14;18)-positive Follicular Lymphoma. Nodal marginal zone lymphoma was marked by 3q gains with amplifications of four genes. A different overall pattern of aberrations was seen in t(14;18)-negative Follicular Lymphoma compared to t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma is marked by specific (focal) gains on chromosome 3 as observed in Nodal marginal zone lymphoma. Our results support the notion that localized t(14:18)-positive Follicular Lymphoma represents an early phase of disseminated t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma bears aberrations that are more alike Nodal marginal zone lymphoma, suggesting a relation between these groups.