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Hehle V, Fraser LD, Tahir R, Kipling D, Wu YC, Lutalo PM, Cason J, Choong L, D’Cruz DP, Cope AP, Dunn-Walters DK, Spencer J. Immunoglobulin kappa variable region gene selection during early human B cell development in health and systemic lupus erythematosus. Mol Immunol 2015; 65:215-23. [DOI: 10.1016/j.molimm.2015.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 01/29/2023]
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2
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Abstract
Background LEA (late embryogenesis abundant) proteins encode conserved N-terminal mitochondrial signal domains and C-terminal (A/TAEKAK) motif repeats, long-presumed to confer cell resistance to stress and death cues. This prompted the hypothesis that LEA proteins are central to mitochondria mechanisms that connect bioenergetics with cell responses to stress and death signaling. In support of this hypothesis, recent studies have demonstrated that mammalian LEA protein PRELI can act as a biochemical hub, which upholds mitochondria energy metabolism, while concomitantly promoting B cell resistance to stress and induced death. Hence, it is important to define in vivo the physiological relevance of PRELI expression. Methods and Findings Given the ubiquitous PRELI expression during mouse development, embryo lethality could be anticipated. Thus, conditional gene targeting was engineered by insertion of flanking loxP (flox)/Cre recognition sites on PRELI chromosome 13 (Chr 13) locus to abort its expression in a tissue-specific manner. After obtaining mouse lines with homozygous PRELI floxed alleles (PRELIf/f), the animals were crossed with CD19-driven Cre-recombinase transgenic mice to investigate whether PRELI inactivation could affect B-lymphocyte physiology and survival. Mice with homozygous B cell-specific PRELI deletion (CD19-Cre/Chr13 PRELI−/−) bred normally and did not show any signs of morbidity. Histopathology and flow cytometry analyses revealed that cell lineage identity, morphology, and viability were indistinguishable between wild type CD19-Cre/Chr13 PRELI+/+ and CD19-Cre/Chr13 PRELI−/− deficient mice. Furthermore, B cell PRELI gene expression seemed unaffected by Chr13 PRELI gene targeting. However, identification of additional PRELI loci in mouse Chr1 and Chr5 provided an explanation for the paradox between LEA-dependent cytoprotection and the seemingly futile consequences of Chr 13 PRELI gene inactivation. Importantly, PRELI expression from spare gene loci appeared ample to surmount Chr 13 PRELI gene deficiency. Conclusions These findings suggest that PRELI is a vital LEA B cell protein with failsafe genetics.
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3
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Belessi C, Stamatopoulos K, Hadzidimitriou A, Hatzi K, Smilevska T, Stavroyianni N, Marantidou F, Paterakis G, Fassas A, Anagnostopoulos A, Laoutaris N. Analysis of expressed and non-expressed IGK locus rearrangements in chronic lymphocytic leukemia. Mol Med 2009; 11:52-8. [PMID: 16622520 PMCID: PMC1449522 DOI: 10.2119/2005-00044.belessi] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2005] [Accepted: 03/05/2006] [Indexed: 11/06/2022] Open
Abstract
Immunoglobulin kappa (IGK) locus rearrangements were analyzed in parallel on cDNA/genomic DNA in 188 kappa- and 103 lambda-chronic lymphocytic leukemia (CLL) cases. IGKV-KDE and IGKJ-C-intron-KDE rearrangements were also analyzed on genomic DNA. In kappa-CLL, only 3 of 188 cases carried double in-frame IGKV-J transcripts: in such cases, the possibility that leukemic cells expressed more than one kappa chain cannot be excluded. Twenty-eight kappa-CLL cases also carried nonexpressed (nontranscribed and/or out-of-frame) IGKV-J rearrangements. Taking IGKV-J, IGKV-KDE, and IGKJ-C-intron-KDE rearrangements together, 38% of kappa-CLL cases carried biallelic IGK locus rearrangements. In lambda-CLL, 69 IGKV-J rearrangements were detected in 64 of 103 cases (62%); 24 rearrangements (38.2%) were in-frame. Four cases carried in-frame IGKV-J transcripts but retained monotypic light-chain expression, suggesting posttranscriptional regulation of allelic exclusion. In all, taking IGKV-J, IGKV-KDE, and IGKJ-C-intron-KDE rearrangements together, 97% of lambda-CLL cases had at least 1 rearranged IGK allele, in keeping with normal cells. IG repertoire comparisons in kappa- versus lambda-CLL revealed that CLL precursor cells tried many rearrangements on the same IGK allele before they became lambda producers. Thirteen of 28 and 26 of 69 non-expressed sequences in, respectively, kappa- or lambda-CLL had < 100% homology to germline. This finding might be considered as evidence for secondary rearrangements occurring after the onset of somatic hypermutation, at least in some cases. The inactivation of potentially functional IGKV-J joints by secondary rearrangements indicates active receptor editing in CLL and provides further evidence for the role of antigen in CLL immunopathogenesis.
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MESH Headings
- Adult
- Aged
- Amino Acid Sequence
- Cells, Cultured
- Female
- Gene Expression Regulation, Neoplastic/immunology
- Gene Rearrangement, B-Lymphocyte/immunology
- Humans
- Immunoglobulin Joining Region/biosynthesis
- Immunoglobulin Joining Region/genetics
- Immunoglobulin Variable Region/biosynthesis
- Immunoglobulin Variable Region/genetics
- Immunoglobulin kappa-Chains/biosynthesis
- Immunoglobulin kappa-Chains/genetics
- Immunoglobulin kappa-Chains/metabolism
- Immunoglobulin lambda-Chains/biosynthesis
- Immunoglobulin lambda-Chains/genetics
- Immunoglobulin lambda-Chains/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Male
- Middle Aged
- Molecular Sequence Data
- RNA Editing/immunology
- Receptors, Antigen, B-Cell/genetics
- Recombination, Genetic/immunology
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4
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Rangel R, McKeller MR, Sims-Mourtada JC, Kashi C, Cain K, Wieder ED, Molldrem JJ, Pham LV, Ford RJ, Yotnda P, Guret C, Francés V, Martinez-Valdez H. Assembly of the kappa preB receptor requires a V kappa-like protein encoded by a germline transcript. J Biol Chem 2005; 280:17807-14. [PMID: 15757909 DOI: 10.1074/jbc.m409479200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By confining germline transcription as a byproduct of the mechanisms inherent to genetic rearrangements, the translation of respective mRNAs and their biological relevance might have been overlooked. Here we report the identification, cloning, and biochemical characterization of a human Vkappa-like protein that is encoded by a germline transcript. This surrogate protein assembles with the immunoglobulin mu heavy chain at the surface of B cell progenitors and precursors to form a kappa-like antigen receptor. These findings support the notion that germline transcription is not futile and stress the flexibility in eukaryotic gene usage and expression. In addition, the present study confirms the co-existence of surrogate lambda and kappa receptors that are proposed to work in concert to promote B lymphocyte maturation.
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Affiliation(s)
- Roberto Rangel
- Department of Immunology, M. D. Anderson Cancer Center, The University of Texas, Houston, Texas 77054, USA
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5
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Wang YH, Zhang Z, Burrows PD, Kubagawa H, Bridges SL, Findley HW, Cooper MD. V(D)J recombinatorial repertoire diversification during intraclonal pro-B to B-cell differentiation. Blood 2003; 101:1030-7. [PMID: 12393550 DOI: 10.1182/blood-2002-06-1828] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The initial B-cell repertoire is generated by combinatorial immunoglobulin V(D)J gene segment rearrangements that occur in a preferential sequence. Because cellular proliferation occurs during the course of these rearrangement events, it has been proposed that intraclonal diversification occurs during this phase of B-cell development. An opportunity to examine this hypothesis directly was provided by the identification of a human acute lymphoblastic leukemic cell line that undergoes spontaneous differentiation from pro-B cell to the pre-B and B-cell stages with concomitant changes in the gene expression profile that normally occur during B-cell differentiation. After confirming the clonality of the progressively differentiating cells, an analysis of immunoglobulin genes and transcripts indicated that pro-B cell members marked by the same DJ rearrangement generated daughter B cells with multiple V(H) and V(L) gene segment rearrangements. These findings validate the principle of intraclonal V(D)J diversification during B-cell generation and define a manipulable model of human B-cell differentiation.
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Affiliation(s)
- Yui-Hsi Wang
- Division of Developmental and Clinical Immunology, and Department of Medicine, University of Alabama at Birmingham and the Howard Hughes Medical Institute, Birmingham, AL 35294, USA
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6
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Abstract
The kappa chain repertoire of individual IgD(+) human neonatal B cells was analyzed using a single cell PCR technique. A total of 104 productive and 90 non-productive VkappaJkappa rearrangements from three cord blood B cell samples were sequenced and compared to the adult IgM(+) peripheral B cell VkappaJkappa repertoire. All six Vkappa families were present in neonatal B cells, but the distribution was not random. In the non-productive repertoire Vkappa2 and Vkappa6 families were less frequent, Vkappa1 and Vkappa3 families were as frequent, and Vkappa4 and Vkappa5 families were more frequent than expected from random chance. Notably, the Vkappa2 family was negatively selected into the productive repertoire. In contrast, the Vkappa1 family was positively selected because of positive selection of three specific genes, O12/O2, L12a and L9. B3 (Vkappa4) and B2 (Vkappa5) were over-represented in the non-productive repertoire and then were expressed less frequently in the productive repertoire. In contrast, the Vkappa3 family gene, A27, was also over-represented in the non-productive repertoire but not further selected into the productive repertoire. Compared to the adult repertoire, junctional diversity was less marked because of a diminished influence of TdT activity, whereas the mean CDR3 length was comparable to that of normal adult B cells. Comparison of the distribution of Vkappa and Jkappa genes with those found in normal adult subjects suggested that there was less receptor editing in neonatal B cells. When neonatal CD5(+) B cells were compared with CD5(-) IgD(+) B cells, it was noted that the Vkappa gene A30 was used only in CD5(+) B cells in both the productive and non-productive repertoires. The results indicate that the usage of Vkappa genes by neonatal B cells is biased by both intrinsic molecular processes and selection. The evidence of selection indicates that the Vkappa repertoire is shaped by self antigens, since exposure to exogenous antigens is limited at the time of birth.
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Affiliation(s)
- Hermann J Girschick
- Department of Internal Medicine, Harold C. Simmons Arthritis Research Center, University of Texas, Southwestern Medical Center at Dallas, Dallas, TX 75235, USA.
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7
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Bertrand FE, Vogtenhuber C, Shah N, LeBien TW. Pro-B-cell to pre-B-cell development in B-lineage acute lymphoblastic leukemia expressing the MLL/AF4 fusion protein. Blood 2001; 98:3398-405. [PMID: 11719380 DOI: 10.1182/blood.v98.12.3398] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The most common chromosomal abnormality of infant acute lymphoblastic leukemia (ALL) is the t(4;11)(q21;q23) that gives rise to the MLL/AF4 fusion gene. Leukemic blasts expressing MLL/AF4 are arrested at an early progenitor stage with lymphoid or monocytoid characteristics. A novel B-lineage ALL cell line termed B-lineage-3 (BLIN-3) requiring human bone marrow (BM) stromal cell contact and interleukin-7 (IL-7) for optimal proliferation has been established. BLIN-3 cells have a CD19(+)/CD10(-) phenotype typical of infant ALL, and they harbor the t(4;11)(q21;q23) chromosomal translocation. Reverse transcription-polymerase chain reaction and Western blot analysis confirmed the presence of the MLL/AF4 fusion mRNA and protein in BLIN-3. Initial BLIN-3 cultures had a pro-B cell phenotype and did not express cytoplasmic or surface mu heavy chain. After approximately 5 months in culture on BM stromal cells plus IL-7, BLIN-3 sublines emerged expressing mu heavy chain and VpreB on the cell surfaces (ie, pre-B-cell receptor [BCR](+)). BLIN-3 cells expressing pre-BCR had the t(4;11)(q21;q23) translocation and expressed the MLL/AF4 fusion protein. Cross-linking the BLIN-3 pre-BCR led to enhanced cell proliferation, demonstrating that BLIN-3 expressed a functional pre-BCR. Increased acquisition of surface pre-BCR in BLIN-3 sublines was associated with loss of DJ rearrangements and the appearance of VDJ rearrangements. These results indicate that expression of the MLL/AF4 fusion protein is compatible with BM stromal cell and cytokine dependency, functional immunoglobulin gene segment rearrangement, and subsequent expression of a potentially diverse antigen receptor repertoire. Thus, the expression of MLL/AF4 is compatible with the normal developmental program of human B-lineage cells.
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Affiliation(s)
- F E Bertrand
- University of Minnesota Cancer Center and the Department of Laboratory Medicine and Pathology, Minneapolis 55455, USA.
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8
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Davis RS, Wang YH, Kubagawa H, Cooper MD. Identification of a family of Fc receptor homologs with preferential B cell expression. Proc Natl Acad Sci U S A 2001; 98:9772-7. [PMID: 11493702 PMCID: PMC55528 DOI: 10.1073/pnas.171308498] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Investigation of human genome sequences with a consensus sequence derived from receptors for the Fc region of Igs (FcR) led to the identification of a subfamily of five Ig superfamily members that we term the Fc receptor homologs (FcRHs). The closely linked FcRH genes are located in a chromosome 1q21 region in the midst of previously recognized FcR genes. This report focuses on the FcRH1, FcRH2, and FcRH3 members of this gene family. Their cDNAs encode type I transmembrane glycoproteins with 3-6 Ig-like extracellular domains and cytoplasmic domains containing consensus immunoreceptor tyrosine-based activating and/or inhibitory signaling motifs. The five FcRH genes are structurally related, and their protein products share 28-60% extracellular identity with each other. They also share 15-31% identity with their closest FcR relatives. The FcRH genes are expressed primarily, although not exclusively, by mature B lineage cells. Their conserved structural features, patterns of cellular expression, and the inhibitory and activating signaling potential of their transmembrane protein products suggest that the members of this FcRH multigene family may serve important regulatory roles in normal and neoplastic B cell development.
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MESH Headings
- Amino Acid Sequence
- B-Lymphocytes/metabolism
- Blotting, Northern
- Chromosome Mapping
- Chromosomes, Human, Pair 1/genetics
- Chromosomes, Human, Pair 19/genetics
- Consensus Sequence
- DNA, Complementary/genetics
- Hematologic Neoplasms/genetics
- Hematologic Neoplasms/metabolism
- Humans
- Immunoglobulin Fc Fragments/metabolism
- Molecular Sequence Data
- Multigene Family
- Neoplasm Proteins/genetics
- Organ Specificity
- Phylogeny
- Protein Isoforms/biosynthesis
- Protein Isoforms/chemistry
- Protein Isoforms/genetics
- Receptors, Fc/biosynthesis
- Receptors, Fc/chemistry
- Receptors, Fc/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Alignment
- Sequence Homology, Amino Acid
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Affiliation(s)
- R S Davis
- Divisions of Hematology/Oncology, Department of Medicine, University of Alabama, Birmingham 35294-3300, USA
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9
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Schwab J, Illges H. Regulation of CD21 expression by DNA methylation and histone deacetylation. Int Immunol 2001; 13:705-10. [PMID: 11312258 DOI: 10.1093/intimm/13.5.705] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The complement receptor II (CD21) serves as a receptor for the complement component C3d of immune complexes on B lymphocytes. Expression of the CD21 gene is tightly regulated during B lymphocyte differentiation. Only mature B lymphocytes, but not pro-, pre- or plasma B lymphocytes, express CD21. There is evidence that cell type-specific expression is mediated by a silencer element located in the first intron. The CD21 promoter region contains a CpG island adjacent to the ATG start codon. We have analyzed the methylation status of this CpG island in B lymphoid cell lines representing the various differentiation stages of B lymphocyte development and primary lymphocytes. We found that the pro-, pre- and intermediate B lymphocytes contain a methylated CpG island and do not express CD21, whereas CD21-expressing mature B lymphocytes, plasma B lymphocytes and non-lymphoid cells carry a demethylated CD21 CpG island. To analyze whether the lack of CD21 expression in early B lymphocytes is due to inhibition by CpG methylation we have used 5-aza-2'-deoxycytidine to inhibit DNA methyltransferase activity. Treatment of pro-B lymphocytes with the drug resulted in expression of CD21. We have also applied Trichostatin A (TSA), an inhibitor of histone deacetylation, to determine whether the state of histone deacetylation affects the expression of CD21. We found that TSA induces expression of CD21 in early B lymphocytes. Thus CD21 expression is controlled by both methylation of the CD21 CpG island and chromatin modification through histone deacetylation in early B lymphocyte development.
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Affiliation(s)
- J Schwab
- Immunology, Department of Biology, Faculty of Sciences, University of Konstanz, M662, 78457 Konstanz, Germany
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10
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Fitzsimmons SP, Clark KJ, Mostowski HS, Shapiro MA. Underutilization of the V kappa 10C gene in the B cell repertoire is due to the loss of productive VJ rearrangements during B cell development. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:852-9. [PMID: 10878359 DOI: 10.4049/jimmunol.165.2.852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The V kappa10 family of murine light chain Ig genes is composed of three members, two of which (V kappa 10A and V kappa 10B) are well used. V kappa 10C, the third member of this family, is not detected in any expressed Abs. Our previous work showed that V kappa 10C is structurally functional and can recombine, but mRNA levels in spleen were extremely low relative to those of V kappa 10A and V kappa 10B. Furthermore, while the V kappa 10C promoter was efficient in B cells, it was shown to work inefficiently in pre-B cell lines. Here, we extend our analysis of the V kappa 10 family and examine V kappa 10 gene accessibility, their representation in V kappa cDNA phage libraries, and the frequency and nature of rearrangements during different stages of B cell development. We demonstrate that V kappa 10C is under-represented in V kappa cDNA libraries, but that the frequency of its sterile transcripts in pre-B cells surpasses both V kappa 10A and V kappa 10B, indicating that the gene is as accessible as V kappa 10A and V kappa 10B to the recombination machinery. We also demonstrate that V kappa 10C recombines at a frequency equal to that of V kappa 10A in pre-B cells and has a normal nonproductive to productive recombination ratio. As B cells develop, however, both the frequency of V kappa 10C rearrangements and the presence of productive rearrangements decline, indicating that these cells are in some fashion being eliminated.
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Affiliation(s)
- S P Fitzsimmons
- Division of Monoclonal Antibodies and Division of Cellular and Gene Therapies, Food and Drug Administration, Center for Biologics Evaluation and Research, Rockville, MD 20852, USA.
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11
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Guzman-Rojas L, Sims JC, Rangel R, Guret C, Sun Y, Alcocer JM, Martinez-Valdez H. PRELI, the human homologue of the avian px19, is expressed by germinal center B lymphocytes. Int Immunol 2000; 12:607-12. [PMID: 10784606 DOI: 10.1093/intimm/12.5.607] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the identification of a human cDNA encoding a 25 kDa protein of relevant evolutionary and lymphoid interest (PRELI). PRELI was cloned by screening a B lymphocyte-specific cDNA library with a probe generated by mRNA differential display. PRELI amino acid sequence is 85% similar to the avian px19 protein, expressed within the blood islands and in the liver during avian embryo development. PRELI and px19 contain tandem repeats (A/TAEKAK) of the late embryogenesis abundant (LEA) motif, characteristic of a group of survival molecules and originally thought to be present only in plant proteins. Interestingly, PRELI expression is high in the fetal liver, a major site for B cell lymphopoiesis, while the mRNA levels in other fetal tissues such as the brain, lung, and kidney are comparatively low. At the adult stage, PRELI expression is drastically reduced in the liver but exhibits high mRNA levels in the spleen, brain, lung and kidney tissues, suggesting that PRELI expression may be important for the development of vital and immunocompetent organs. Moreover, PRELI is also highly expressed in the adult lymph nodes and peripheral blood leukocytes, further stressing that at the adult stage, PRELI expression may be important during secondary immune responses. Consistent with this hypothesis, the expression of PRELI is predominant within germinal centers (GC), a stage in which B lymphocytes are under a stressful selection pressure. Taken together these data: (i) strongly support the notion that the conserved LEA motif represents a phylogenetic link between plants and animals, (ii) reveal a novel molecule whose expression may play a role in the maturation of distinct human tissues, and (iii) suggest that PRELI expression may be important for GC B lymphocytes.
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Affiliation(s)
- L Guzman-Rojas
- Department of Immunology, Box 178, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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12
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Romanow WJ, Langerak AW, Goebel P, Wolvers-Tettero IL, van Dongen JJ, Feeney AJ, Murre C. E2A and EBF act in synergy with the V(D)J recombinase to generate a diverse immunoglobulin repertoire in nonlymphoid cells. Mol Cell 2000; 5:343-53. [PMID: 10882075 DOI: 10.1016/s1097-2765(00)80429-3] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Immunoglobulin (Ig) and T cell receptor (TCR) genes are assembled during lymphocyte maturation through site-specific V(D)J recombination events. Here we show that E2A proteins act in concert with RAG1 and RAG2 to activate Ig VK1J but not Iglambda VlambdaIII-Jlambda1 rearrangement in an embryonic kidney cell line. In contrast, EBF, but not E2A, promotes VlambdaIII-Jlambda1 recombination. Either E2A or EBF activate IgH DH4J recombination but not V(D)J rearrangement. The Ig coding joints are diverse, contain nucleotide deletions, and lack N nucleotide additions. IgK VJ recombination requires the presence of the E2A transactivation domains. These observations indicate that in nonlymphoid cells a diverse Ig repertoire can be generated by the mere expression of the V(D)J recombinase and a transcriptional regulator.
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Affiliation(s)
- W J Romanow
- Department of Biology, University of California, San Diego, La Jolla 92093, USA
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13
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Ignatovich O, Tomlinson IM, Popov AV, Brüggemann M, Winter G. Dominance of intrinsic genetic factors in shaping the human immunoglobulin Vlambda repertoire. J Mol Biol 1999; 294:457-65. [PMID: 10610771 DOI: 10.1006/jmbi.1999.3243] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The expressed human immunoglobulin Vlambda repertoire demonstrates a strong bias in the use of individual Vlambda segments. Mechanisms that underlie such biases can be divided into two categories: intrinsic genetic processes that lead to the preferential rearrangement and/or expression of certain segments; and selection following light chain expression. Here, we have used two approaches to investigate the factors that shape the human Vlambda repertoire. Firstly, we characterised 136 Vlambda rearrangements (59 productive and 77 non-productive) amplified from the human genomic DNA of peripheral blood cells. Secondly, we analysed Vlambda segment use in a library of 2000 cDNA clones from a transgenic mouse containing a 380 kb region (including 15 functional Vlambda segments) from the human immunoglobulin lambda locus. By hybridisation and sequencing we found that the patterns of use of human Vlambda segments in the transgenic mouse were similar to those found in the expressed human peripheral blood repertoire and in productive and non-productive genomic DNA rearrangements. These data indicate the importance of intrinsic genetic factors in shaping the human Vlambda repertoire and highlight the remarkable conservation of the molecular mechanisms involved in the production of the antibody repertoire in mouse and man. Therefore, transgenic mice represent a good model for analysis of the human antibody repertoire and for the production of human antibodies.
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Affiliation(s)
- O Ignatovich
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK.
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14
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Abstract
Clonal selection, a central principle in immunology, is predicated on one lymphocyte making one kind of antibody or T cell receptor. At loci encoding antigen receptors only one allele is used, and this has been shown in normal lymphocytes from frogs to humans. Fish antibody chains, however, are encoded by multiple loci, and at some of these loci the gene segments are already rearranged in the germline. The differences in germline organization and the uncoupling of rearrangement and expression raise questions as to whether some of the early vertebrates might be an exception to the clonal selection theory.
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Affiliation(s)
- E Hsu
- Department of Physiology and Pharmacology, State University of New York, Health Science Center at Brooklyn, Brooklyn, New York 11203-2098, USA
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15
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Haruta H, Tachibana H, Yamada K. Concanavalin A stimulation enhanced secondary VlambdaJlambda rearrangement in some human plasma B cells without up-regulation of recombination-activating gene expression and Vlambda germline transcription. Immunology 1999; 97:549-57. [PMID: 10457206 PMCID: PMC2326890 DOI: 10.1046/j.1365-2567.1999.00821.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/1998] [Revised: 02/22/1999] [Accepted: 03/18/1999] [Indexed: 02/07/2023] Open
Abstract
Light chain shifting is a phenomenon that occurs in certain human antibody-producing plasma B cells which, when stimulated with concanavalin A (Con A), shift production of the original light chain to new light chains. Here we investigated the effect of Con A stimulation on these light chain shift-inducible cells. Analysis of transcripts and VJ-coding joints for new light chains revealed that a leaky amount of secondary VlambdaJlambda rearrangement occurs spontaneously, without Con A stimulation, and that Con A stimulation markedly increases VJ-coding joints and transcripts for new light chains. It was also shown that new light chain producers, which have carried out secondary rearrangement, do not further rearrange their light chain genes, even when stimulated with Con A. Recombination-activating gene (RAG) products and Vlambda germline transcription were constitutively expressed in these cell lines and their expression levels were not affected by Con A stimulation. These results suggest that Con A stimulation enhanced secondary VlambdaJlambda rearrangement, but this was not a result of the up-regulation of RAG expression and Vlambda germline transcription, which are believed to be sufficient for the process of VlambdaJlambda rearrangement.
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Affiliation(s)
- H Haruta
- Graduate School of Bioresources and Bioenvironmental Science, Kyushu University, Higashi-ku, Fukuoka, Japan
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16
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Abstract
Kappa and lambda, the two types of immunoglobulin light (L) chains present in mammals, contribute differently to the L chain pool of each species. Here we show that the extreme preponderance of kappa in the mouse results from programmed sequential activation of the kappa and lambda loci. Activation--a prerequisite of rearrangement--was monitored by analyzing transcription of unrearranged J-C clusters. Upon in vitro differentiation of a rearrangement-deficient pro/pre-B line, germ-line transcripts of the lambda J-C clusters, that are newly described here, became detectable 2 days later than their counterparts of J-C kappa. Clear differences could also be observed in vivo: germ-line transcripts of kappa were already present in large B220+ CD25+ pre B-II cells whereas germ-line lambda transcripts first became detectable at the consecutive developmental stage of small B220+ CD25+ pre-B-II cells. This activation pattern was found to be identical in mice which can not rearrange kappa due to a targeted deletion or inactivation of kappa. This suggests that pre-B-II cells follow a hit-and-run mechanism of development which includes programmed transitions and differential activation of the L chain loci, i.e. kappa first, then lambda. Thus, privileged activation of kappa might be the decisive factor in setting the 10:1 ratio of kappa to lambda present in the mouse.
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Affiliation(s)
- H Engel
- Molecular Immunology, GBF, National Research Center for Biotechnology, Braunschweig, Germany.
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17
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Haruta H, Tachibana H, Yamada K. Serum starvation induced secondary V lambda J lambda rearrangement in a human plasma B cell line. Mol Immunol 1999; 36:177-85. [PMID: 10403483 DOI: 10.1016/s0161-5890(99)00028-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
HB4C5 is a human antibody producing plasma B cell line that expresses the recombination activating gene-1 (RAG-1) and RAG-2 constitutively, but undergoes few secondary immunoglobulin gene rearrangements when cultured in fetal bovine serum-containing medium. Here, we found that depletion of serum from the culture media induces secondary VlambdaJlambda rearrangement in this cell line. To investigate the induction mechanism of secondary VlambdaJlambda rearrangement, we assessed the expression levels of RAG-1 and RAG-2 products, Vlambda germline transcription level and the amount of Vlambda signal broken ends (SBE) in HB4C5 cells cultured in serum-supplemented or serum-free medium. Western-blot analysis showed that the expression level for the RAG-1 and RAG-2 proteins was not affected by the serum depletion. Vlambda germline transcript was found to be constitutively expressed in HB4C5 cell line and this transcription level was not affected by the lack of serum. On the other hand, the amount of Vlambda SBE was shown to be increased in HB4C5 cells cultured in serum-free medium, suggesting that this increased formation of Vlambda SBE at least partly contributed to the enhanced occurrence of secondary VlambdaJlambda rearrangement in HB4C5 cells cultured in the serum-free condition. These results indicate that expression of RAG proteins and Vlambda germline transcription is not enough to undergo secondary VlambdaJlambda rearrangement in this cell line.
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Affiliation(s)
- H Haruta
- Graduate School of Bioresources and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
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18
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Bain G, Romanow WJ, Albers K, Havran WL, Murre C. Positive and negative regulation of V(D)J recombination by the E2A proteins. J Exp Med 1999; 189:289-300. [PMID: 9892611 PMCID: PMC2192990 DOI: 10.1084/jem.189.2.289] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/1998] [Revised: 11/06/1998] [Indexed: 01/29/2023] Open
Abstract
A key feature of B and T lymphocyte development is the generation of antigen receptors through the rearrangement and assembly of the germline variable (V), diversity (D), and joining (J) gene segments. However, the mechanisms responsible for regulating developmentally ordered gene rearrangements are largely unknown. Here we show that the E2A gene products are essential for the proper coordinated temporal regulation of V(D)J rearrangements within the T cell receptor (TCR) gamma and delta loci. Specifically, we show that E2A is required during adult thymocyte development to inhibit rearrangements to the gamma and delta V regions that normally recombine almost exclusively during fetal thymocyte development. The continued rearrangement of the fetal Vgamma3 gene segment in E2A-deficient adult thymocytes correlates with increased levels of Vgamma3 germline transcripts and increased levels of double-stranded DNA breaks at the recombination signal sequence bordering Vgamma3. Additionally, rearrangements to a number of Vgamma and Vdelta gene segments used predominantly during adult development are significantly reduced in E2A-deficient thymocytes. Interestingly, at distinct stages of T lineage development, both the increased and decreased rearrangement of particular Vdelta gene segments is highly sensitive to the dosage of the E2A gene products, suggesting that the concentration of the E2A proteins is rate limiting for the recombination reaction involving these Vdelta regions.
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MESH Headings
- Animals
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/immunology
- Flow Cytometry
- Gene Expression Regulation/immunology
- Gene Rearrangement, T-Lymphocyte/genetics
- Gene Rearrangement, T-Lymphocyte/immunology
- Helix-Loop-Helix Motifs/genetics
- Helix-Loop-Helix Motifs/immunology
- Mice
- Mice, Knockout
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Recombination, Genetic/genetics
- Recombination, Genetic/immunology
- T-Lymphocytes/immunology
- TCF Transcription Factors
- Thymus Gland/immunology
- Transcription Factor 7-Like 1 Protein
- Transcription Factors
- Transcription, Genetic/genetics
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Affiliation(s)
- G Bain
- Department of Biology, University of California San Diego, La Jolla, California 92093, USA
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19
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Light Chain Shifting: Identification of a Human Plasma Cell Line Actively Undergoing Light Chain Replacement. Blood 1999. [DOI: 10.1182/blood.v93.1.198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractWe identified an antibody-secreting human B-cell line (HTD8), which actively replaces the production of the original λ light chain with a new λ chain (light chain shifting) at a high rate. Loss of the original rearranged λ light chain occurs by significantly reducing the amount of transcript expressed. Expression of the new λ chain, which replaces the original λ chain, occurs by rearranging new VJ segments on a previously excluded allele. V λ gene usage of these new rearrangements are biased toward Vλ4, Vλ6, and Vλ10 families, which are known to be the least frequently used. In striking contrast to the plasma cell phenotype, recombination activating genes, RAG-1 and RAG-2, were expressed in the HTD8 cells and were shown to be necessary, but insufficient for inducing expression of the new λ chain. These results suggest that human plasma cells have the potential to actively undergo light chain replacement.
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20
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Light Chain Shifting: Identification of a Human Plasma Cell Line Actively Undergoing Light Chain Replacement. Blood 1999. [DOI: 10.1182/blood.v93.1.198.401k11_198_207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified an antibody-secreting human B-cell line (HTD8), which actively replaces the production of the original λ light chain with a new λ chain (light chain shifting) at a high rate. Loss of the original rearranged λ light chain occurs by significantly reducing the amount of transcript expressed. Expression of the new λ chain, which replaces the original λ chain, occurs by rearranging new VJ segments on a previously excluded allele. V λ gene usage of these new rearrangements are biased toward Vλ4, Vλ6, and Vλ10 families, which are known to be the least frequently used. In striking contrast to the plasma cell phenotype, recombination activating genes, RAG-1 and RAG-2, were expressed in the HTD8 cells and were shown to be necessary, but insufficient for inducing expression of the new λ chain. These results suggest that human plasma cells have the potential to actively undergo light chain replacement.
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21
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Yu CCK, Larijani M, Miljanic IN, Wu GE. Differential Usage of VH Gene Segments Is Mediated by cis Elements. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.7.3444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
Ig diversity is generated in large part by the combinatorial joining of the Ig gene segments, VH, D, and JH, that together encode the variable domain of Ig. The final Ig repertoire, however, not only reflects the diversity generated through V(D)J recombinatorial joining, but it is also the product of a number of developmental restraints and selections. To avoid such restrictions and assess the recombination potential of individual Ig gene segments, we constructed Ig heavy (H) chain microlocus plasmids, each of which contain germline coding, recombination signal, and flanking sequences of a VH, D, and JH gene segment. These plasmids allow us to assess the recombination potential of the segments in the context of their natural flanking DNA sequences, but in the absence of any higher order chromatin structure or cellular selection. We found that the frequency and extent of deletions and additions at the recombination breakpoints are similar to those observed at rearranged Ig H chain loci in intact animals. The relative frequencies of the types of rearrangements—VD-J, V-DJ, VinvD-J (invD = inverted D), and VDJ—however, differ strongly. Moreover, V81x, the most used VH gene segment in intact mice, also is overused in this plasmid assay, 15 to 30 times that of another VH segment. This result indicates that the overuse of V81x in the early B cell repertoire can be a consequence of its DNA sequence and not of cellular activities.
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Affiliation(s)
| | - Mani Larijani
- †Ontario Cancer Institute, and
- ‡Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | | | - Gillian E. Wu
- †Ontario Cancer Institute, and
- ‡Department of Immunology, University of Toronto, Toronto, Ontario, Canada
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22
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Fitzsimmons SP, Rotz BT, Shapiro MA. Asymmetric Contribution to Ig Repertoire Diversity by Vκ Exons: Differences in the Utilization of Vκ10 Exons. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.5.2290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The mouse has approximately 140 germline Vκ genes, and functional Vκ exons are expressed at roughly equivalent levels in the preimmune repertoire. We have examined the expression of individual members of the Vκ10 family. Vκ10A and Vκ10B genes have been utilized in numerous hybridomas and myelomas, while Vκ10C has not. In this study, we have cloned the Vκ10C gene and shown that it is structurally functional, has the expected promoter elements and recombination signal sequences, and that it is capable of recombination. Vκ10C mRNA, however, is present at levels at least 1000-fold lower than Vκ10A and Vκ10B in adult spleens. While there are no sequence differences in the octamer or TATA box between Vκ10C and Vκ10A, there are three nucleotide changes in the promoter region. These promoters equally drive the expression of a reporter gene in B cells or plasma cells, but the Vκ10A promoter is able to drive expression in pre-B cell lines significantly better than the Vκ10C promoter (p < 0.05). Vκ10C rearrangements can be detected in bone marrow and splenic DNA. Therefore, the lack of Vκ10C expression may reflect the inability of Vκ10C-rearranged cells to undergo positive or negative selection. Our results suggest that the available Ab repertoire is shaped not only by the number of structurally functional genes, but also by the ability of assembled genes to be expressed at critical points during B cell maturation.
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Affiliation(s)
- Sean P. Fitzsimmons
- Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20892
| | - Benjamin T. Rotz
- Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20892
| | - Marjorie A. Shapiro
- Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20892
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23
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Wang YH, Nomura J, Faye-Petersen OM, Cooper MD. Surrogate Light Chain Production During B Cell Differentiation: Differential Intracellular Versus Cell Surface Expression. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.3.1132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Expression of the surrogate light (ψL) chain genes encoding the VpreB and λ5/14.1 proteins is restricted to B-lineage cells. Pro-B and pre-B cells produce ψL chains, but whether both employ these as cell surface receptor components remains enigmatic. Recombinant human VpreB protein was used to generate a large panel of monoclonal anti-VpreB Abs to examine this issue. Native ψL chain proteins within pro-B cells as well as those serving as receptor components on pre-B cells were precipitated by 16 of the 26 anti-VpreB Abs. Surrogate light chains were easily detected on pre-B cell lines, whereas these anti-VpreB Abs reacted with pro-B cell lines only after plasma membrane permeabilization. The subpopulation of normal bone marrow cells bearing pre-B receptors included large and small pre-B cells exclusively, although pro-B cells also contained intracellular VpreB. VpreB proteins were not detected on or within B cells in bone marrow or the circulation, but a subpopulation of B cells in germinal centers was found to express the VpreB proteins intracellularly. Surrogate L chains are thus intermittently produced during human B-lineage differentiation, while their role as receptor components appears limited to the pre-B cell stage.
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Affiliation(s)
- Yui-Hsi Wang
- *Division of Developmental and Clinical Immunology; Departments of Medicine, Pediatrics, Microbiology, and
| | - Jun Nomura
- *Division of Developmental and Clinical Immunology; Departments of Medicine, Pediatrics, Microbiology, and
- ‡Howard Hughes Medical Institute, University of Alabama, Birmingham, AL 35924
| | | | - Max D. Cooper
- *Division of Developmental and Clinical Immunology; Departments of Medicine, Pediatrics, Microbiology, and
- †Pathology; and
- ‡Howard Hughes Medical Institute, University of Alabama, Birmingham, AL 35924
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24
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Affiliation(s)
- J R Gorman
- Howard Hughes Medical Institute, Children's Hospital, Boston, Massachusetts 02115, USA
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25
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Ignatovich O, Tomlinson IM, Jones PT, Winter G. The creation of diversity in the human immunoglobulin V(lambda) repertoire. J Mol Biol 1997; 268:69-77. [PMID: 9149142 DOI: 10.1006/jmbi.1997.0956] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sequence diversity in the human antibody repertoire is generated in two steps: by the combinatorial assembly of V gene segments and by somatic hypermutation. Here, we have characterised these processes for the lambda (lambda) light chain using a library of 7600 lambda cDNA clones from peripheral blood lymphocytes. By hybridisation and sequencing we found that most lambda chains are derived from the cluster of V(lambda) segments closest to the J(lambda)-C(lambda) pairs and that there is considerable variation in the use of individual V(lambda) segments (ranging from 0.02% to 27%): three of the 30 functional V(lambda) segments encode half the expressed V(lambda) repertoire. As a result of these biases, sequence diversity in the primary repertoire is focused at the centre of the antigen binding site. By contrast, somatic hypermutation spreads diversity to the periphery. Comparison with the human kappa (kappa) light chain indicates that both kappa and lambda use the same strategy for searching sequence space and have almost identical patterns of diversity in the mature antibody repertoire.
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Affiliation(s)
- O Ignatovich
- MRC Centre for Protein Engineering, Cambridge, UK
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26
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Foster SJ, Brezinschek HP, Brezinschek RI, Lipsky PE. Molecular mechanisms and selective influences that shape the kappa gene repertoire of IgM+ B cells. J Clin Invest 1997; 99:1614-27. [PMID: 9120005 PMCID: PMC507981 DOI: 10.1172/jci119324] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To analyze the human kappa chain repertoire and the influences that shape it, a single cell PCR technique was used that amplified Vkappa Jkappa rearrangements from genomic DNA of individual human B cells. More than 350 productive and 250 nonproductive Vkappa Jkappa rearrangements were sequenced. Nearly every functional Vkappa gene segment was used in rearrangements, although six Vkappa gene segments, A27, L2, L6, L12a, A17, and O12/O2 were used preferentially. Of these, A27, L2, L6, and L12a showed evidence of positive selection based on the variable region and not CDR3, whereas A17 was overrepresented because of a rearrangement bias based on molecular mechanisms. Utilization of Jkappa segments was also nonrandom, with Jkappa1 and Jkappa2 being overrepresented and Jkappa3 and Jkappa5 underrepresented in the nonproductive repertoire, implying a molecular basis for the bias. In B cells with two Vkappa Jkappa rearrangements, marked differences were noted in the Vkappa segments used for the initial and subsequent rearrangements, whereas Jkappa segments were used comparably. Junctional diversity was generated by n-nucleotide addition in 60% and by exonuclease trimming in 75% of the Vkappa Jkappa rearrangements analyzed. Despite this large degree of diversity, a strict CDR3 length was maintained in both productive and nonproductive rearrangements. More than 23% of the productive rearrangements, but only 7% of the nonproductive rearrangements contained somatic hypermutations. Mutations were significantly more frequent in Vkappa sequences derived from CD5- as compared with CD5+ B cells. These results document that the gene segment utilization within the Vkappa repertoire is biased by both intrinsic molecular processes as well as selection after light chain expression. Moreover, IgM+ memory cells with highly mutated kappa genes reside within the CD5- but not the CD5+ B cell compartment.
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Affiliation(s)
- S J Foster
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8884, USA
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27
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Abstract
Biosynthesis of the immunoglobulin (Ig) receptor components and their assembly were examined in cell lines representative of early stages in human B lineage development. In pro-B cells, the nascent surrogate light chain proteins form a complex that transiently associates in the endoplasmic reticulum with a spectrum of unidentified proteins (40, 60, and 98 kD) and Bip, a heat shock protein family member. Lacking companion heavy chains, the surrogate light chains in pro-B cells do not associate with either the Ig(alpha) or Ig(beta) signal transduction units, undergo rapid degradation, and fail to reach the pro-B cell surface. In pre-B cells, by contrast, a significant portion of the surrogate light chain proteins associate with mu heavy chains, Ig(alpha), and Ig(beta) to form a stable receptor complex with a relatively long half-life. Early in this assembly process, Bip/GRP78, calnexin, GRP94, and a protein of approximately 17 kD differentially bind to the nascent mu heavy chains. The 17-kD intermediate is gradually replaced by the surrogate light chain protein complex, and the Ig(alpha) and Ig(beta) chains bind progressively to the mu heavy chains during the complex and relatively inefficient process of pre-B receptor assembly. The results suggest that, in humans, heavy chain association is essential for surrogate light chain survival and transport to the cell surface as an integral receptor component.
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Affiliation(s)
- K Lassoued
- Department of Medicine, University of Alabama at Birmingham, 35294, USA
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28
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Stiernholm BJ, Berinstein NL. Mutations in immunoglobulin V gene promoters may cause reduced germline transcription and diminished recombination frequencies. Ann N Y Acad Sci 1995; 764:116-20. [PMID: 7486509 DOI: 10.1111/j.1749-6632.1995.tb55813.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- B J Stiernholm
- Department of Immunology, University of Toronto, Ontario, Canada
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29
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Parolini O, Rohrer J, Shapiro LH, Conley ME. B-cell-specific demethylation of BTK, the defective gene in X-linked agammaglobulinemia. Immunogenetics 1995; 42:129-35. [PMID: 7541776 DOI: 10.1007/bf00178587] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BTK, the gene that is defective in X-linked agammaglobulinemia, encodes a cytoplasmic tyrosine kinase that is critical for B-cell proliferation, or survival. To identify regulatory elements that control the expression of BTK we evaluated the methylation pattern of this gene in cell lines and in freshly isolated cells. An Hpa II site that was specifically demethylated in mature B cells but not in pre-B cells, T cells, neutrophils, or nonhematopoietic cells was identified in the tenth intron of BTK. In a 40 kilobase (kb) segment of DNA spanning the entire coding region of BTK plus 3 kb upstream of the first exon there were no other sites that demonstrated lineage-specific demethylation. The B-cell-specific demethylation site in intron 10, which falls within the SH2 domain, 26 kb distal to the first exon, occurs in a region rich in regulatory elements including two E2 boxes, two AP-2 sites, and a cAMP response element. It is likely that this site plays a role in maintaining BTK transcription in mature B cells.
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Affiliation(s)
- O Parolini
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38101, USA
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30
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Genevier HC, Hinshelwood S, Gaspar HB, Rigley KP, Brown D, Saeland S, Rousset F, Levinsky RJ, Callard RE, Kinnon C. Expression of Bruton's tyrosine kinase protein within the B cell lineage. Eur J Immunol 1994; 24:3100-5. [PMID: 7805739 DOI: 10.1002/eji.1830241228] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Defects in the gene encoding Bruton's tyrosine kinase (Btk), normally expressed in B cells, cause X-linked agammaglobulinemia (XLA). The phenotype of XLA is characterized by a lack of circulating B cells and immunoglobulin. It has been suggested that B cell maturation from the pre-B cell stage to more mature stages is dependent on the appropriate expression of this gene. The Btk mRNA is expressed in B cells and myeloid cells, but protein expression in relation to B cell maturation has not been determined. Moreover, expression of the Btk protein has so far only been investigated in human Epstein-Barr virus-transformed B cell lines, and in murine splenocytes and B cell lines. We have developed an antiserum which recognizes the human Btk protein and shown that normal human tonsillar B cells, peripheral blood monocytes and myeloid cells express the protein, whereas tonsil-derived T cells do not. We also show that the protein is present in early and mature human B cell lines, but is absent in terminally differentiated plasma cell lines. Furthermore, expression is reduced or absent in three B lineage cell lines derived from two patients with defined genetic mutations in Btk and suffering from XLA.
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Affiliation(s)
- H C Genevier
- Cellular Immunology Unit, Institute of Child Health, London
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31
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Lewis SM. The mechanism of V(D)J joining: lessons from molecular, immunological, and comparative analyses. Adv Immunol 1994; 56:27-150. [PMID: 8073949 DOI: 10.1016/s0065-2776(08)60450-2] [Citation(s) in RCA: 482] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- S M Lewis
- Division of Biology, California Institute of Technology, Pasadena 91125
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32
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Fulton R, Van Ness B. Kappa immunoglobulin promoters and enhancers display developmentally controlled interactions. Nucleic Acids Res 1993; 21:4941-7. [PMID: 8177743 PMCID: PMC311410 DOI: 10.1093/nar/21.21.4941] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We have investigated the interaction of the kappa immunoglobulin light chain intron and 3' enhancers with two different kappa promoters at distinct stages of B-cell development. We find that transiently transfected reporter gene constructs driven by either the kappa V-region promoter, or the kappa germline promoter, are controlled by the known enhancers of the locus in a developmentally regulated fashion. We have, however, observed differences in promoter activation by each enhancer. Moreover, constructs controlled by a combination of both enhancers are synergistically activated at the B-cell and plasma cell stages as compared with constructs containing either enhancer alone. This synergy is not observed early in development, at the pre-B cell stage. The pattern of enhancer and promoter interactions is discussed in the context of the known developmental regulation of the locus.
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Affiliation(s)
- R Fulton
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455
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33
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Kallenbach S, Babinet C, Pournin S, Cavelier P, Goodhardt M, Rougeon F. The intronic immunoglobulin kappa gene enhancer acts independently on rearrangement and on transcription. Eur J Immunol 1993; 23:1917-21. [PMID: 8344354 DOI: 10.1002/eji.1830230828] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It is not known which cis-acting elements regulate kappa gene rearrangement. However, the onset of rearrangement coincides with the onset of transcription suggesting that common regulatory elements are used. We have investigated the role of the intronic enhancer on rearrangement using mice transgenic for kappa minigenes. The rabbit kappa enhancer, which is defective in activation of transcription in mouse cells, allows a high level of rearrangement. However, transgenes which possess no enhancer region at all are rearranged a hundred times less compared to transgenes which possess the rabbit enhancer. Our results suggest that while the enhancer region can activate rearrangement as well as transcription, its action on both phenomena can be uncoupled.
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Affiliation(s)
- S Kallenbach
- Unité de Génétique et Biochimie du Développement, CNRS URA 361, Institut Pasteur, Paris, France
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34
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Goldman JP, Spencer DM, Raulet DH. Ordered rearrangement of variable region genes of the T cell receptor gamma locus correlates with transcription of the unrearranged genes. J Exp Med 1993; 177:729-39. [PMID: 8382255 PMCID: PMC2190937 DOI: 10.1084/jem.177.3.729] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
T cell receptor V gamma genes rearrange to the J gamma 1 gene segment in a highly ordered fashion during development. We demonstrate a striking correlation between the pattern of expression of unrearranged V gamma genes and the timing of their rearrangement. Thus, the increases in V gamma 2 rearrangements, and decreases in V gamma 3 and V gamma 4 rearrangements observed during development are paralleled by increasing or decreasing levels of the corresponding unrearranged V gene transcript. We also provide evidence that both the V gamma 3 and V gamma 4 genes are accessible in mature V gamma 3+ cells, but that the V gamma 4 gene may be inaccessible in the progenitors of V gamma 3 cells. The results suggest that regulated local accessibility of the chromatin surrounding V gamma genes is responsible for ordered V gamma gene rearrangement during development.
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Affiliation(s)
- J P Goldman
- Department of Molecular and Cell Biology, University of California, Berkeley 94720
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35
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Thompson A, Timmers E, Kenter MJ, Kraakman ME, Hendriks RW, Schuurman RK. Immunoglobulin kappa light chain germ-line transcripts in human precursor B lymphocytes. Eur J Immunol 1992; 22:3167-71. [PMID: 1446707 DOI: 10.1002/eji.1830221221] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
B lymphoblastoid cell lines (BLCL), established from bone marrow and peripheral blood mononuclear cells from two severe combined immunodeficiency (SCID) patients, manifested a complete absence of genomic rearrangements of the immunoglobulin (Ig) heavy (H) and light (L) chain loci. The BLCL contained germ-line transcripts of the Ig kappa region locus of approximately 1.2 kilobase (kb). By cDNA cloning and sequence analysis the transcripts were shown to consist of a C kappa segment, a J kappa 1 gene segment, 160 base pairs (bp) of J kappa 1 5' intervening sequence, containing the heptamer/nonamer recombination recognition sequences and at the 5' end a 523-bp segment designated human kappa zero, The first 206 bp of this 5' segment were homologous to the reported murine kappa zero region. Genomic restriction mapping and DNA sequence analysis demonstrated that the human kappa zero segment is located approximately 4 kb upstream of J kappa 1. The kappa zero segment contains a putative promoter region with an OCT2 binding site, and has a splice donor site to accomplish splicing to an acceptor site 160 bp upstream of J kappa 1. Expression of the kappa zero gene segment was found in BLCL derived from normal fetal bone marrow, in which both Ig kappa loci were in the germ-line configuration. These findings indicate that the described transcripts are not only present in SCID, but also in normal developing pre-B lymphocytes. The expression of germ-line Ig kappa L chain transcripts may be associated with the locus becoming accessible to gene rearrangement.
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Affiliation(s)
- A Thompson
- Department of Immunohaematology, University Hospital, Leiden, The Netherlands
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36
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Transcription of germ line V alpha segments correlates with ongoing T-cell receptor alpha-chain rearrangement. Mol Cell Biol 1992. [PMID: 1312664 DOI: 10.1128/mcb.12.4.1480] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
M14T is a virally transformed immature T-cell line which continues to rearrange its T-cell antigen receptor (TCR) alpha-chain genes in vitro and thus represents a dynamic system for studying TCR assembly. In an effort to investigate whether the TCR alpha locus is accessible for V(D)J rearrangement events, we examined M14T cells for the presence of germ line TCR alpha transcripts. Several unrearranged V alpha segments were found to be transcriptionally active in M14T cells. By comparison, germ line V alpha transcripts are absent in nonlymphoid and pro-T-cell lines and barely detectable in mature T-cell lines, suggesting that this phenomenon is likely stage and tissue specific. We demonstrate a perfect correlation between transcriptionally active V alpha segments and their involvement in ongoing V alpha-to-J alpha rearrangements. In addition, data suggesting that the unrearranged J alpha locus is also transcriptionally active in the M14T line are presented. Furthermore, the recombination-activating genes RAG-1 and RAG-2 are differentially expressed, with RAG-2 detectable only by polymerase chain reaction, implying that very low levels of one of these gene products are sufficient to complement the other to facilitate VJ rearrangements. These findings provide the first direct evidence for an accessibility model of antigen receptor rearrangement in T cells.
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Fondell JD, Marcu KB. Transcription of germ line V alpha segments correlates with ongoing T-cell receptor alpha-chain rearrangement. Mol Cell Biol 1992; 12:1480-9. [PMID: 1312664 PMCID: PMC369589 DOI: 10.1128/mcb.12.4.1480-1489.1992] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
M14T is a virally transformed immature T-cell line which continues to rearrange its T-cell antigen receptor (TCR) alpha-chain genes in vitro and thus represents a dynamic system for studying TCR assembly. In an effort to investigate whether the TCR alpha locus is accessible for V(D)J rearrangement events, we examined M14T cells for the presence of germ line TCR alpha transcripts. Several unrearranged V alpha segments were found to be transcriptionally active in M14T cells. By comparison, germ line V alpha transcripts are absent in nonlymphoid and pro-T-cell lines and barely detectable in mature T-cell lines, suggesting that this phenomenon is likely stage and tissue specific. We demonstrate a perfect correlation between transcriptionally active V alpha segments and their involvement in ongoing V alpha-to-J alpha rearrangements. In addition, data suggesting that the unrearranged J alpha locus is also transcriptionally active in the M14T line are presented. Furthermore, the recombination-activating genes RAG-1 and RAG-2 are differentially expressed, with RAG-2 detectable only by polymerase chain reaction, implying that very low levels of one of these gene products are sufficient to complement the other to facilitate VJ rearrangements. These findings provide the first direct evidence for an accessibility model of antigen receptor rearrangement in T cells.
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Affiliation(s)
- J D Fondell
- Genetics Graduate Program, State University of New York, Stony Brook 11794-5215
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Ricken G, Pluschke G, Krawinkel U. T cell receptor alpha-chain germ line transcripts from activated lymphocytes. Immunol Lett 1992; 32:97-8. [PMID: 1339407 DOI: 10.1016/0165-2478(92)90206-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- G Ricken
- Klinische Forschergruppe für Rheumatologie, Universitätsklinikum Freiburg, Germany
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Hsieh CL, Gauss G, Lieber MR. Replication, transcription, CpG methylation and DNA topology in V(D)J recombination. Curr Top Microbiol Immunol 1992; 182:125-35. [PMID: 1490346 DOI: 10.1007/978-3-642-77633-5_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- C L Hsieh
- Department of Pathology, Stanford University School of Medicine, CA 94305-5324
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