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Liu H, Duan Z, Zheng H, Hu D, Li M, Tao Y, Bode AM, Dong Z, Cao Y. EBV-encoded LMP1 upregulates Igκ 3'enhancer activity and Igκ expression in nasopharyngeal cancer cells by activating the Ets-1 through ERKs signaling. PLoS One 2012; 7:e32624. [PMID: 22396784 PMCID: PMC3291551 DOI: 10.1371/journal.pone.0032624] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 02/01/2012] [Indexed: 12/19/2022] Open
Abstract
Accumulating evidence indicates that epithelial cancer cells, including nasopharyngeal carcinoma (NPC) cells, express immunoglobulins (Igs). We previously found that the expression of the kappa light chain protein in NPC cells can be upregulated by the EBV-encoded latent membrane protein 1 (LMP1). In the present study, we used NPC cell lines as models and found that LMP1-augmented kappa production corresponds with elevations in ERKs phosphorylation. PD98059 attenuates LMP1-induced ERKs phosphorylation resulting in decreased expression of the kappa light chain. ERK-specific small interfering RNA blunts LMP1-induced kappa light chain gene expression. Luciferase reporter assays demonstrate that immunoglobulin κ 3′ enhancer (3′Eκ) is active in Igκ-expressing NPC cells and LMP1 upregulates the activity of 3′Eκ in NPC cells. Moreover, mutation analysis of the PU binding site in 3′Eκ and inhibition of the MEK/ERKs pathway by PD98059 indicate that the PU site is functional and LMP1-enhanced 3′Eκ activity is partly regulated by this site. PD98059 treatment also leads to a concentration-dependent inhibition of LMP1-induced Ets-1 expression and phosphorylation, which corresponds with a dose-dependent attenuation of LMP1-induced ERK phosphorylation and kappa light chain expression. Suppression of endogenous Ets-1 by small interfering RNA is accompanied by a decrease of Ig kappa light chain expression. Gel shift assays using nuclear extracts of NPC cells indicate that the transcription factor Ets-1 is recruited by LMP1 to the PU motif within 3′Eκin vitro. ChIP assays further demonstrate Ets-1 binding to the PU motif of 3′Eκ in cells. These results suggest that LMP1 upregulates 3′Eκ activity and kappa gene expression by activating the Ets-1 transcription factor through the ERKs signaling pathway. Our studies provide evidence for a novel regulatory mechanism of kappa expression, by which virus-encoded proteins activate the kappa 3′ enhancer through activating transcription factors in non-B epithelial cancer cells.
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Affiliation(s)
- Haidan Liu
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
- State Key Laboratory of Medical Genetics, Clinical Center for Gene Diagnosis and Therapy, Central South University, The Second Xiangya Hospital, Changsha, China
- Department of Cardiothoracic Surgery, Central South University, The Second Xiangya Hospital, Changsha, China
| | - Zhi Duan
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Hui Zheng
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Duosha Hu
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Ming Li
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yongguang Tao
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Ann M. Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota, United States of America
| | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota, United States of America
- * E-mail: (ZGD); (YC)
| | - Ya Cao
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
- * E-mail: (ZGD); (YC)
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Increased frequency of Ig heavy-chain HS1,2-A enhancer *2 allele in dermatitis herpetiformis, plaque psoriasis, and psoriatic arthritis. J Invest Dermatol 2008; 128:1920-4. [PMID: 18323783 DOI: 10.1038/jid.2008.40] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The enhancer DNase-hypersensitive region 1,2 (HS1,2), a member of the Ig heavy-chain 3' regulatory region (3'RR) cluster, is active in human B cells transfected with reporter genes and in mouse is activated in late maturation. HS1,2-A contains binding sites for several transcription factors. There are four known alleles, that is, (*)1, (*)2, (*)3, and (*)4, which differ in their lengths in transcription factor binding. We showed that in celiac disease the frequency of the (*)2 allele is increased. Both dermatitis herpetiformis (DH) and psoriasis can be associated with different frequencies with celiac disease. Thus, we further investigate the frequency of allele (*)2 in DH, plaque psoriatic, and psoriatic arthritis patients. HS1,2-A allele frequencies were investigated in 37 DH, 61 plaque psoriatic, 28 psoriatic arthritis patients, and 265 healthy donors, age- and sex-matched, from the same geographical area. The frequency of the (*)2 allele changes from 0.39 in controls to 0.63 in DH, 0.59 in plaque psoriasis and 0.75 in psoriatic arthritis (P between 10(-4)-10(-5)). Our data evidence an increased frequency of the (*)2 allele of HS1,2-A in these cutaneous immune-related disorders. We suggest a related genetic predisposition in these pathogeneses.
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Qin X, Tang H. Differential regulation of chromatin structure of the murine 3′ IgH enhancer and IgG2b germline promoter in response to lipopolysaccharide and CD40 signaling. Mol Immunol 2006; 43:1211-20. [PMID: 16099047 DOI: 10.1016/j.molimm.2005.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Indexed: 11/22/2022]
Abstract
Class switch recombination (CSR) of murine immunoglobulin heavy chain (IgH) is controlled by germline transcription-coupled modification of the accessibility of the highly repetitive switch regions (S) located upstream of the constant region genes. Activation of the 3' IgH enhancer (3'E) is believed to regulate CSR during B cell terminal differentiation, although the detailed molecular mechanism remains unclear. Here, we show that BAF57 and BRG1, two essential subunits of murine SWI/SNF complex, differentially associate with the DNase I hypersensitive region HS1/2 of 3'E and the IgG2b germline promoter in response to LPS activation or CD40 engagement. Both LPS and CD40 signaling cause SWI/SNF complex to dissociate from HS1/2 and associate with their responsive IgG2b germline promoter, suggesting the potential fluidity of chromatin structure and specific regulatory mode for the ATP-dependent chromatin remodeler during CSR. More interesting, increase in histone acetylation is either inverse or parallel with the action of SWI/SNF complex at HS1/2 enhancer or IgG2b germline promoter, respectively. Chromatin immunoprecipitation experiments show that alteration of histone H3 and H4 acetylation has overall similarities in response to LPS and CD40 signaling, with H3 hyperacetylated and H4 hypoacetylated at the HS1/2 enhancer and reversed modification patterns at the IgG2b germline promoter. Finally, the specificity of LPS and CD40 signaling in control of CSR could be partially coded by the specific acetylation marking of H3 and H4. Our results further strengthen the notion that chromatin remodeling plays a critical role in CSR.
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Affiliation(s)
- Xincheng Qin
- The Center for Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, China
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Abstract
Plasma cells are the terminally differentiated, non-dividing effector cells of the B-cell lineage. They are cellular factories devoted to the task of synthesizing and secreting thousands of molecules of clonospecific antibody each second. To respond to microbial pathogens with the necessary specificity and rapidity, B cells are exquisitely regulated with respect to both development in the bone marrow and activation in the periphery. This review focuses on the terminal differentiation of B cells into plasma cells, including the different subsets of B cells that become plasma cells, the mechanism of regulation of this transition, the transcription factors that control each developmental stage and the characteristics of long-lived plasma cells.
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Affiliation(s)
- Miriam Shapiro-Shelef
- Departments of Microbiology, and Biochemistry and Molecular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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Giambra V, Fruscalzo A, Giufre' M, Martinez-Labarga C, Favaro M, Rocchi M, Frezza D. Evolution of human IgH3'EC duplicated structures: both enhancers HS1,2 are polymorphic with variation of transcription factor's consensus sites. Gene 2004; 346:105-14. [PMID: 15716094 DOI: 10.1016/j.gene.2004.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Revised: 09/20/2004] [Accepted: 10/05/2004] [Indexed: 11/29/2022]
Abstract
The enhancer complex regulatory region at the 3' of the immunoglobulin heavy cluster (IgH3'EC) is duplicated in apes along with four constant genes and the region is highly conserved throughout humans. Both human IgH3'ECs consist of three loci high sensitive (HS) to DNAse I with enhancer activity. It is thus possible that the presence of structural divergences between the two IgH3'ECs and of relative polymorphisms correspond to functional regulatory changes. To analyse the polymorphisms of these almost identical regions, it resulted mandatory to identify the presence of divergent sequences, in order to select distinctive primers for specific PCR genomic amplifications. To this aim, we first compared the two entire IgH3'ECs in silicio, utilising the updated GenBank (GB) contigs, then we analysed the two IgH3'ECs by cloning and sequencing amplicons from independent genomes. In silicio analysis showed that several inversions, deletions and short insertions had occurred after the duplication. We analysed in detail, by sequencing specific regions, the polymorphisms occurring in enhancer HS1,2-A (which lies in IgH3'EC-1, 3' to the Calpha-1 gene) and in enhancer HS1,2-B (which lies in IgH3'EC-2, 3' to Calpha-2). Polymorphisms are due to the repetition (occurring one to four times) of a 38-bp sequence present at the 3' of the core of enhancers HS1,2. The structure of both human HS1,2 enhancers has revealed not yet described polymorphic features due to the presence of variable spacer elements separating the 38-bp repetitions and to variable external elements bordering the repetition cluster. We found that one of the external elements gave rise to a divergent allele 3 in the two clusters. The frequency of the different alleles of the two loci varies in the Italian population and allele 3 of both loci are very rare. The analysis of the Callicebus moloch, Gorilla gorilla and Pan troglodytes HS1,2 enhancers showed the transformation from the ancestral structure with the 31- to the 17-bp external element in hominids. The relevance of the polymorphisms in the HS1,2 enhancers is due to the variable number of binding sites for the transcription factors: NF-kappaB, CMYB, BSAP1/2, AP1/4, E47, MyoD and muE5 and thus to the possible influence of these variations on switch, production of Ig and on maturation of B cells.
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Affiliation(s)
- Vincenzo Giambra
- Dipartimento di Biologia Enrico Calef, Universita' degli Studi TorVergata, Viale della ricerca scientifica, 00133 Roma, Italy
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Shaffer AL, Shapiro-Shelef M, Iwakoshi NN, Lee AH, Qian SB, Zhao H, Yu X, Yang L, Tan BK, Rosenwald A, Hurt EM, Petroulakis E, Sonenberg N, Yewdell JW, Calame K, Glimcher LH, Staudt LM. XBP1, downstream of Blimp-1, expands the secretory apparatus and other organelles, and increases protein synthesis in plasma cell differentiation. Immunity 2004; 21:81-93. [PMID: 15345222 DOI: 10.1016/j.immuni.2004.06.010] [Citation(s) in RCA: 750] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Revised: 04/23/2004] [Accepted: 05/19/2004] [Indexed: 11/27/2022]
Abstract
The differentiation of B cells into immunoglobulin-secreting plasma cells is controlled by two transcription factors, Blimp-1 and XBP1. By gene expression profiling, we defined a set of genes whose induction during mouse plasmacytic differentiation is dependent on Blimp-1 and/or XBP1. Blimp-1-deficient B cells failed to upregulate most plasma cell-specific genes, including xbp1. Differentiating xbp1-deficient B cells induced Blimp-1 normally but failed to upregulate genes encoding many secretory pathway components. Conversely, ectopic expression of XBP1 induced a wide spectrum of secretory pathway genes and physically expanded the endoplasmic reticulum. In addition, XBP1 increased cell size, lysosome content, mitochondrial mass and function, ribosome numbers, and total protein synthesis. Thus, XBP1 coordinates diverse changes in cellular structure and function resulting in the characteristic phenotype of professional secretory cells.
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Affiliation(s)
- A L Shaffer
- Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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Abstract
The transcriptional co-activator OCA-B [for Oct co-activator from B cells, also known as OBF-1 (OCT-binding factor-1) and Bob1] is not required for B-cell genesis but does regulate subsequent B-cell development and function. OCA-B deficient mice show strain-specific, partial blocks at multiple stages of B-cell maturation and a complete disruption of germinal center formation in all strains, causing humoral immune deficiency and susceptibility to infection. OCA-B probably exerts its effects through the regulation of octamer-motif controlled gene expression. The OCA-B gene encodes two proteins of distinct molecular weight, designated p34 and p35. The p34 isoform localizes in the nucleus, whereas the p35 isoform is myristoylated and is bound to the cytoplasmic membrane. p35 can traffic to the nucleus and probably activates octamer-dependent transcription, although this OCA-B isoform might regulate B cells through membrane-related signal transduction.
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Affiliation(s)
- Michael A Teitell
- Departments of Pathology and Pediatrics, David Geffen School of Medicine at UCLA, University of California-Los Angeles, 675 Charles Young Drive South, Los Angeles, CA 90095, USA.
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Kim U, Siegel R, Ren X, Gunther CS, Gaasterland T, Roeder RG. Identification of transcription coactivator OCA-B-dependent genes involved in antigen-dependent B cell differentiation by cDNA array analyses. Proc Natl Acad Sci U S A 2003; 100:8868-73. [PMID: 12857960 PMCID: PMC166405 DOI: 10.1073/pnas.1033108100] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The tissue-specific transcriptional coactivator OCA-B is required for antigen-dependent B cell differentiation events, including germinal center formation. However, the identity of OCA-B target genes involved in this process is unknown. This study has used large-scale cDNA arrays to monitor changes in gene expression patterns that accompany mature B cell differentiation. B cell receptor ligation alone induces many genes involved in B cell expansion, whereas B cell receptor and helper T cell costimulation induce genes associated with B cell effector function. OCA-B expression is induced by both B cell receptor ligation alone and helper T cell costimulation, suggesting that OCA-B is involved in B cell expansion as well as B cell function. Accordingly, several genes involved in cell proliferation and signaling, such as Lck, Kcnn4, Cdc37, cyclin D3, B4galt1, and Ms4a11, have been identified as OCA-B-dependent genes. Further studies on the roles played by these genes in B cells will contribute to an understanding of B cell differentiation.
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Affiliation(s)
- Unkyu Kim
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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