1
|
Palti Y, Vallejo RL, Purcell MK, Gao G, Shewbridge KL, Long RL, Setzke C, Fragomeni BO, Cheng H, Martin KE, Naish KA. Genome-wide association analysis of the resistance to infectious hematopoietic necrosis virus in two rainbow trout aquaculture lines confirms oligogenic architecture with several moderate effect quantitative trait loci. Front Genet 2024; 15:1394656. [PMID: 38854430 PMCID: PMC11162110 DOI: 10.3389/fgene.2024.1394656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 04/30/2024] [Indexed: 06/11/2024] Open
Abstract
Infectious hematopoietic necrosis (IHN) is a disease of salmonid fish that is caused by the IHN virus (IHNV), which can cause substantial mortality and economic losses in rainbow trout aquaculture and fisheries enhancement hatchery programs. In a previous study on a commercial rainbow trout breeding line that has undergone selection, we found that genetic resistance to IHNV is controlled by the oligogenic inheritance of several moderate and many small effect quantitative trait loci (QTL). Here we used genome wide association analyses in two different commercial aquaculture lines that were naïve to previous exposure to IHNV to determine whether QTL were shared across lines, and to investigate whether there were major effect loci that were still segregating in the naïve lines. A total of 1,859 and 1,768 offspring from two commercial aquaculture strains were phenotyped for resistance to IHNV and genotyped with the rainbow trout Axiom 57K SNP array. Moderate heritability values (0.15-0.25) were estimated. Two statistical methods were used for genome wide association analyses in the two populations. No major QTL were detected despite the naïve status of the two lines. Further, our analyses confirmed an oligogenic architecture for genetic resistance to IHNV in rainbow trout. Overall, 17 QTL with notable effect (≥1.9% of the additive genetic variance) were detected in at least one of the two rainbow trout lines with at least one of the two statistical methods. Five of those QTL were mapped to overlapping or adjacent chromosomal regions in both lines, suggesting that some loci may be shared across commercial lines. Although some of the loci detected in this GWAS merit further investigation to better understand the biological basis of IHNV disease resistance across populations, the overall genetic architecture of IHNV resistance in the two rainbow trout lines suggests that genomic selection may be a more effective strategy for genetic improvement in this trait.
Collapse
Affiliation(s)
- Yniv Palti
- National Center for Cool and Cold Water Aquaculture, USDA-ARS, Kearneysville, WV, United States
| | - Roger L. Vallejo
- National Center for Cool and Cold Water Aquaculture, USDA-ARS, Kearneysville, WV, United States
| | - Maureen K. Purcell
- US Geological Survey, Western Fisheries Research Center, Seattle, WA, United States
| | - Guangtu Gao
- National Center for Cool and Cold Water Aquaculture, USDA-ARS, Kearneysville, WV, United States
| | - Kristy L. Shewbridge
- National Center for Cool and Cold Water Aquaculture, USDA-ARS, Kearneysville, WV, United States
| | - Roseanna L. Long
- National Center for Cool and Cold Water Aquaculture, USDA-ARS, Kearneysville, WV, United States
| | - Christopher Setzke
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States
| | - Breno O. Fragomeni
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
| | - Hao Cheng
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | | | - Kerry A. Naish
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States
| |
Collapse
|
2
|
Rothschild SC, Lai G, Tombes RM, Clements WK. Constitutively active CaMKII Drives B lineage acute lymphoblastic leukemia/lymphoma in tp53 mutant zebrafish. PLoS Genet 2023; 19:e1011102. [PMID: 38117861 PMCID: PMC10766190 DOI: 10.1371/journal.pgen.1011102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 01/04/2024] [Accepted: 12/07/2023] [Indexed: 12/22/2023] Open
Abstract
Acute lymphoblastic leukemia/lymphoma (ALL) is the most common pediatric cancer and is a malignancy of T or B lineage lymphoblasts. Dysregulation of intracellular Ca2+ levels has been observed in patients with ALL, leading to improper activation of downstream signaling. Here we describe a new zebrafish model of B ALL, generated by expressing human constitutively active CaMKII (CA-CaMKII) in tp53 mutant lymphocytes. In this model, B cell hyperplasia in the kidney marrow and spleen progresses to overt leukemia/lymphoma, with only 29% of zebrafish surviving the first year of life. Leukemic fish have reduced productive genomic VDJ recombination in addition to reduced expression and improper splicing of ikaros1, a gene often deleted or mutated in patients with B ALL. Inhibiting CaMKII in human pre-B ALL cells induced cell death, further supporting a role for CaMKII in leukemogenesis. This research provides novel insight into the role of Ca2+-directed signaling in lymphoid malignancy and will be useful in understanding disease development and progression.
Collapse
Affiliation(s)
- Sarah C. Rothschild
- Life Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Guanhua Lai
- Pathology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Robert M. Tombes
- Life Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Wilson K. Clements
- Experimental Hematology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| |
Collapse
|
3
|
Identification and Validation of Ikaros (IKZF1) as a Cancer Driver Gene for Marek’s Disease Virus-Induced Lymphomas. Microorganisms 2022; 10:microorganisms10020401. [PMID: 35208856 PMCID: PMC8877892 DOI: 10.3390/microorganisms10020401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 12/29/2022] Open
Abstract
Marek’s disease virus (MDV) is the causative agent for Marek’s disease (MD), which is characterized by T-cell lymphomas in chickens. While the viral Meq oncogene is necessary for transformation, it is insufficient, as not every bird infected with virulent MDV goes on to develop a gross tumor. Thus, we postulated that the chicken genome contains cancer driver genes; i.e., ones with somatic mutations that promote tumors, as is the case for most human cancers. To test this hypothesis, MD tumors and matching control tissues were sequenced. Using a custom bioinformatics pipeline, 9 of the 22 tumors analyzed contained one or more somatic mutation in Ikaros (IKFZ1), a transcription factor that acts as the master regulator of lymphocyte development. The mutations found were in key Zn-finger DNA-binding domains that also commonly occur in human cancers such as B-cell acute lymphoblastic leukemia (B-ALL). To validate that IKFZ1 was a cancer driver gene, recombinant MDVs that expressed either wild-type or a mutated Ikaros allele were used to infect chickens. As predicted, birds infected with MDV expressing the mutant Ikaros allele had high tumor incidences (~90%), while there were only a few minute tumors (~12%) produced in birds infected with the virus expressing wild-type Ikaros. Thus, in addition to Meq, key somatic mutations in Ikaros or other potential cancer driver genes in the chicken genome are necessary for MDV to induce lymphomas.
Collapse
|
4
|
Stosik MP, Tokarz-Deptuła B, Deptuła W. Specific humoral immunity in Osteichthyes. Cent Eur J Immunol 2018; 43:335-340. [PMID: 30588178 PMCID: PMC6305611 DOI: 10.5114/ceji.2018.80054] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/12/2017] [Indexed: 12/12/2022] Open
Abstract
The fish immune system is extremely complex and has considerable adaptive potential. In Osteichthyes, the system is formed by lymphopoietic organs which are important for the differentiation and maturation of the immune system cells. These organs include the anterior kidney (phronephros), the thymus, the spleen, the posterior kidney (mesonephros), and mucosa-associated lymphoid tissues (MALT). Apart from the lymphocytic organs and the MALT system, the immune system components include defensive cells and their products. Those identified in fish include, inter alia, monocytes/macrophages, melanomacrophages, neutrophilic granulocytes, thrombocytes, B cells, plasma cells, and T cells. The roles of the individual components of the organisation of the immune system, the organs, and lymphoid tissue as well as the constituents conditioning the innate and adaptive immunity mechanisms are considered equally important, especially in the context of functional interdependence. The progress in the exploration of the processes of specific humoral immunity in Osteichthyes and the possibilities of their practical application is increasingly promising in view of the expected need for protection of fish against diseases. The paper discusses selected issues concerning recent knowledge about haematopoiesis of B cells, plasmablasts, plasma cells, and immunoglobulins (IgM, IgD, IgT/IgZ).
Collapse
Affiliation(s)
- Michał P. Stosik
- Department of Microbiology and Genetics, Faculty of Biological Sciences, University of Zielona Gora, Zielona Gora, Poland
| | - Beata Tokarz-Deptuła
- Department of Immunology, Faculty of Biology, University of Szczecin, Szczecin, Poland
| | - Wiesław Deptuła
- Department of Microbiology, Faculty of Biology, University of Szczecin, Szczecin, Poland
| |
Collapse
|
5
|
Tafalla C, Granja AG. Novel Insights on the Regulation of B Cell Functionality by Members of the Tumor Necrosis Factor Superfamily in Jawed Fish. Front Immunol 2018; 9:1285. [PMID: 29930556 PMCID: PMC6001812 DOI: 10.3389/fimmu.2018.01285] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/22/2018] [Indexed: 12/12/2022] Open
Abstract
Most ligands and receptors from the tumor necrosis factor (TNF) superfamily play very important roles in the immune system. In particular, many of these molecules are essential in the regulation of B cell biology and B cell-mediated immune responses. Hence, in mammals, it is known that many TNF family members play a key role on B cell development, maturation, homeostasis, activation, and differentiation, also influencing the ability of B cells to present antigens or act as regulators of immune responses. Evolutionarily, jawed fish (including cartilaginous and bony fish) constitute the first animal group in which an adaptive immune response based on B cells and immunoglobulins is present. However, until recently, not much was known about the expression of TNF ligands and receptors in these species. The sequences of many members of the TNF superfamily have been recently identified in different species of jawed fish, thus allowing posterior analysis on the role that these ligands and receptors have on B cell functionality. In this review, we summarize the current knowledge on the impact that the TNF family members have in different aspects of B cell functionality in fish, also providing an in depth comparison with functional aspects of TNF members in mammals, that will permit a further understanding of how B cell functionality is regulated in these distant animal groups.
Collapse
Affiliation(s)
| | - Aitor G Granja
- Animal Health Research Center (CISA-INIA), Madrid, Spain
| |
Collapse
|
6
|
Zwollo P. Dissecting teleost B cell differentiation using transcription factors. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:898-905. [PMID: 21251922 PMCID: PMC3107362 DOI: 10.1016/j.dci.2011.01.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/08/2011] [Accepted: 01/11/2011] [Indexed: 05/07/2023]
Abstract
B cell developmental pathways in teleost fishes are poorly understood. In the absence of serological reagents, an alternative approach to dissecting teleost B cell development is to use transcription factors that are differentially expressed during B cell development. This review discusses the structure and function of six transcription factors that play essential roles during teleost B cell development: Ikaros, E2A, EBF, Pax5, Blimp1, and XbpI. Research on alternative splicing of both the Ikaros and Pax5 genes in rainbow trout is presented, including their functional significance. An application is discussed that should aid in elucidating teleost B cell development and activation, by using transcription factors as developmental markers in flow cytometric analysis. Possible future studies in teleost B cell development are suggested in the context of gene regulation. Lastly, broader impacts and practical applications are discussed.
Collapse
Affiliation(s)
- Patty Zwollo
- The College of William and Mary, Department of Biology, Williamsburg, VA 23187, USA.
| |
Collapse
|
7
|
John LB, Ward AC. The Ikaros gene family: transcriptional regulators of hematopoiesis and immunity. Mol Immunol 2011; 48:1272-8. [PMID: 21477865 DOI: 10.1016/j.molimm.2011.03.006] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/07/2011] [Accepted: 03/08/2011] [Indexed: 01/10/2023]
Abstract
The Ikaros family of proteins - comprising Ikaros, Aiolos, Helios, Eos and Pegasus - are zinc finger transcription factors. These proteins participate in a complex network of interactions with gene regulatory elements, other family members and a raft of other transcriptional regulators to control gene expression including via chromatin remodelling. In this way, Ikaros family members regulate important cell-fate decisions during hematopoiesis, particularly in the development of the adaptive immune system. Mutation of several family members results in hematological malignancies,especially those of a lymphoid nature. This review describes the key roles of Ikaros proteins in development and disease, their mechanisms of action and gene targets, as well as explaining their evolutionary origins and role in the emergence of adaptive immunity.
Collapse
Affiliation(s)
- Liza B John
- School of Medicine, Deakin University, Waurn Ponds, Victoria 3217, Australia
| | | |
Collapse
|
8
|
Zwollo P, Mott K, Barr M. Comparative analyses of B cell populations in trout kidney and mouse bone marrow: establishing "B cell signatures". DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2010; 34:1291-9. [PMID: 20705088 PMCID: PMC2945407 DOI: 10.1016/j.dci.2010.08.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 08/01/2010] [Accepted: 08/02/2010] [Indexed: 05/07/2023]
Abstract
This study aimed to identify the frequency and distribution of developing B cell populations in the kidney of the rainbow trout, using four molecular B cell markers that are highly conserved between species, including two transcription factors, Pax5 and EBF1, recombination-activating gene RAG1, and the immunoglobulin heavy chain mu. Three distinct B cell stages were defined: early developing B cells (CLP, pro-B, and early pre-B cells), late developing B cell (late pre-B, immature B, and mature B cells), and IgM-secreting cells. Developmental stage-specific, combinatorial expression of Pax5, EBF1, RAG1 and immunoglobulin mu was determined in trout anterior kidney cells by flow cytometry. Trout staining patterns were compared to a well-defined primary immune tissue, mouse bone marrow, and using mouse surface markers B220 and CD43. A remarkable level of similarity was uncovered between the primary immune tissues of both species. Subsequent analysis of the entire trout kidney, divided into five contiguous segments K1-K5, revealed a complex pattern of early developing, late developing, and IgM-secreting B cells. Patterns in anterior kidney segment K1 were most similar to those of mouse bone marrow, while the most posterior part of the kidney, K5, had many IgM-secreting cells, but lacked early developing B cells. A potential second B lymphopoiesis site was uncovered in segment K4 of the kidney. The B cell patterns, or "B cell signatures" described here provide information on the relative abundance of distinct developing B cell populations in the trout kidney, and can be used in future studies on B cell development in other vertebrate species.
Collapse
Affiliation(s)
- Patty Zwollo
- Department of Biology, The College of William and Mary, Williamsburg, VA 23188, FAX: 757-221-6483, Phone: 757-221-1969,
| | - Katrina Mott
- Department of Biology, The College of William and Mary, Williamsburg, VA 23188, FAX: 757-221-6483, Phone: 757-221-1969,
| | - Maggie Barr
- Department of Biology, The College of William and Mary, Williamsburg, VA 23188, FAX: 757-221-6483, Phone: 757-221-1969,
| |
Collapse
|
9
|
Ikaros expression in tongue sole macrophages: a marker for lipopolysaccharide- and lipoteichoic acid-induced inflammatory responses. Mol Biol Rep 2010; 38:2273-9. [PMID: 21069465 DOI: 10.1007/s11033-010-0358-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 10/21/2010] [Indexed: 12/30/2022]
Abstract
Ikaros, an important transcription factor plays a role in the development of hemato-lymphoid system, yet its functional importance in fish macrophages remains unknown. In this study, an Ikaros cDNA was cloned from the half-smooth tongue sole Cynoglossus semilaevis. The cDNA contained an open reading frame of 1,290 nucleotides that encoded a 430 amino acid protein. The deduced protein is structurally similar to dul from other species, for example human, axolotl, and possesses 3-zinc finger and 2-zinc finger domains at its N- and C-termini, respectively. Phylogenetic analysis revealed C. semilaevis Ikaros to be grouped with all the fish Ikaros, but branching from other Ikaros family members. Both semi-quantitative PCR and quantitative real-time PCR indicated Ikaros to be predominantly expressed in the immune-relevant tissues such as kidney, thymus, spleen and liver. In the macrophages cultured from C. semilaevis head kidney and challenged with lipopolysaccharide and lipoteichoic acid not only induced expression of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin 1-beta but also caused up-regulation of Ikaros in a dose- and time-dependent fashions. All these data suggest that Ikaros might be a useful marker for inflammatory responses in C. semilaevis.
Collapse
|
10
|
Abstract
Xenopus laevis is the model of choice for evolutionary, comparative, and developmental studies of immunity, and invaluable research tools including MHC-defined clones, inbred strains, cell lines, and monoclonal antibodies are available for these studies. Recent efforts to use Silurana (Xenopus) tropicalis for genetic analyses have led to the sequencing of the whole genome. Ongoing genome mapping and mutagenesis studies will provide a new dimension to the study of immunity. Here we review what is known about the immune system of X. laevis integrated with available genomic information from S. tropicalis. This review provides compelling evidence for the high degree of similarity and evolutionary conservation between Xenopus and mammalian immune systems. We propose to build a powerful and innovative comparative biomedical model based on modern genetic technologies that takes take advantage of X. laevis and S. tropicalis, as well as the whole Xenopus genus. Developmental Dynamics 238:1249-1270, 2009. (c) 2009 Wiley-Liss, Inc.
Collapse
Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA.
| | | |
Collapse
|
11
|
John LB, Yoong S, Ward AC. Evolution of the Ikaros gene family: implications for the origins of adaptive immunity. THE JOURNAL OF IMMUNOLOGY 2009; 182:4792-9. [PMID: 19342657 DOI: 10.4049/jimmunol.0802372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Members of the Ikaros family of transcription factors are important for immune system development. Analysis of Ikaros-related genes from a range of species suggests the Ikaros family derived from a primordial gene, possibly related to the present-day protostome Hunchback genes. This duplicated before the divergence of urochordates to produce two distinct lineages: one that generated the Ikaros factor-like (IFL) 2 genes of urochordates/lower vertebrates and the Pegasus genes of higher vertebrates, and one that generated the IFL1 genes of urochordates/lower vertebrates, the IKFL1 and IKFL2 genes of agnathans and the remaining four Ikaros members of higher vertebrates. Expansion of the IFL1 lineage most likely occurred via the two intervening rounds of whole genome duplication. A proposed third whole genome duplication in teleost fish produced a further increase in complexity of the gene family with additional Pegasus and Eos members. These findings question the use of IFL sequences as evidence for the existence of adaptive immunity in early chordates and vertebrates. Instead, this study is consistent with a later emergence of adaptive immunity coincident with the appearance of the definitive lymphoid markers Ikaros, Aiolos, and Helios.
Collapse
Affiliation(s)
- Liza B John
- Center for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
| | | | | |
Collapse
|
12
|
Laing KJ, Dutton S, Hansen JD. Molecular and biochemical analysis of rainbow trout LCK suggests a conserved mechanism for T-cell signaling in gnathostomes. Mol Immunol 2007; 44:2737-48. [PMID: 17178421 DOI: 10.1016/j.molimm.2006.11.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 11/16/2006] [Accepted: 11/18/2006] [Indexed: 11/23/2022]
Abstract
Two genes were identified in rainbow trout that display high sequence identity to vertebrate Lck. Both of the trout Lck transcripts are associated with lymphoid tissues and were found to be highly expressed in IgM-negative lymphocytes. In vitro analysis of trout lymphocytes indicates that trout Lck mRNA is up-regulated by T-cell mitogens, supporting an evolutionarily conserved function for Lck in the signaling pathways of T-lymphocytes. Here, we describe the generation and characterization of a specific monoclonal antibody raised against the N-terminal domains of recombinant trout Lck that can recognize Lck protein(s) from trout thymocyte lysates that are similar in size ( approximately 57kDa) to mammalian Lck. This antibody also reacted with permeabilized lymphocytes during FACS analysis, indicating its potential usage for cellular analyses of trout lymphocytes, thus representing an important tool for investigations of salmonid T-cell function.
Collapse
Affiliation(s)
- Kerry J Laing
- Department of Pathobiology, University of Washington, Seattle, WA 98195, USA
| | | | | |
Collapse
|
13
|
Solem ST, Stenvik J. Antibody repertoire development in teleosts--a review with emphasis on salmonids and Gadus morhua L. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2006; 30:57-76. [PMID: 16084588 DOI: 10.1016/j.dci.2005.06.007] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The group of teleosts is highly diverse, comprising more than 23000 extant species. Studies of the teleost antibody repertoire have been conducted in many different species within different orders, though some species and families have been better characterised than others. The Atlantic cod (Gadus morhua L.) and several species within the Salmoninae (e.g. Salmo salar and Oncorynchus mykiss) are among the best-studied teleosts in terms of the antibody repertoire. The estimated size of the repertoire, the organisation of immunoglobulin (IG) gene segments, the expressed IG repertoire, the IgM serum concentration, and the serum antibody responses reveal some fundamental differences between these species. The serum IgM concentration of G. morhua is some ten times higher than that of S. salar, though G. morhua is characterised as a 'low' (or 'non') responder in terms of specific antibody production. In contrast, an antibody response is readily induced in S. salar, although the response is strongly regulated by antigen induced suppression. The IGHD gene of G. morhua has a unique structure, while the IGHM and IGHD genes of S. salar have a characteristic genomic organisation in two parallel loci. In addition, salmonids, express a broad repertoire of IGH and IGI V-region gene segments, while a single V gene family dominates the expressed heavy and light chain repertoire of G. morhua. Little is known about the developing antibody repertoire during ontogeny, in different stages of B-cell maturation, or in separate B-cell subsets. Information on the establishment of the preimmune repertoire, and the possible role of environmental antigens is also sparse.
Collapse
Affiliation(s)
- Stein Tore Solem
- Department of Marine Biotechnology, Norwegian College of Fishery Science, Breivika, N-9037 Tromsø, Norway.
| | | |
Collapse
|
14
|
Cobb BS, Smale ST. Ikaros-family proteins: in search of molecular functions during lymphocyte development. Curr Top Microbiol Immunol 2005; 290:29-47. [PMID: 16480038 DOI: 10.1007/3-540-26363-2_3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The regulatory steps that lead to the differentiation of hematopoietic cells from a multipotential stem cell remain largely unknown. A beginning to the understanding of these steps has come from the study of DNA-binding proteins that are thought to regulate the expression of genes required for specific developmental events. Ikaros is the founding member of a small family of DNA-binding proteins required for lymphocyte development, but the members of this family differ from other key regulators of lymphopoiesis in that direct target genes have not been conclusively identified, and reasonable support has been presented for only a few potential targets. Therefore, the molecular mechanisms that Ikaros uses for regulating lymphocyte development remain largely unknown. Current data suggest that, in some instances, Ikaros may function as a typical transcription factor. However, recent results suggest that it may function more broadly, perhaps in the formation of silent and active chromatin structures. In this review, our current knowledge of the molecular functions of Ikaros will be discussed.
Collapse
Affiliation(s)
- B S Cobb
- Department of Microbiology, Immunology and Molecular Genetics, Howard Hughes Medical Institute, University of California, Los Angeles 90095-1662, USA
| | | |
Collapse
|
15
|
Zwollo P, Cole S, Bromage E, Kaattari S. B cell heterogeneity in the teleost kidney: evidence for a maturation gradient from anterior to posterior kidney. THE JOURNAL OF IMMUNOLOGY 2005; 174:6608-16. [PMID: 15905499 DOI: 10.4049/jimmunol.174.11.6608] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The fish immune system is quite different from the mammalian system because the anterior kidney forms the main site for hematopoiesis in this species. Using transcription factor-specific Abs derived from the murine system, together with anti-trout Ig Abs and Percoll gradient separation, we analyzed B cells from trout kidney sections and compared them to those from spleen and blood. For this study, immune cells were separated by Percoll gradients, and the resulting subpopulations were defined based on expression of B cell-specific transcription factors Pax-5 and B lymphocyte-induced maturation protein-1, as well as proliferative and Ig-secreting properties. Comparison of kidney, blood, and spleen B cell subsets suggest that 1) the anterior kidney contains mostly proliferating B cell precursors and plasma cells; 2) posterior kidney houses significant populations of (partially) activated B cells and plasmablasts; and 3) trout blood contains resting, non-Ig-secreting cells and lacks plasma cells. After LPS induction of resting B cells in vitro, the kidney and spleen have a high capacity for the generation of plasma cells, whereas the blood has virtually none. Our results indicate that trout B cell subsets are profoundly different among blood, anterior kidney, posterior kidney, and spleen. We hypothesize that developing B cells mature in the anterior side of the kidney and then migrate to sites of activation, either the spleen or the posterior kidney. Lastly, our data support the notion that the trout kidney is a complex, multifunctional immune organ with the potential to support both hemopoiesis as well as humoral immune activation.
Collapse
Affiliation(s)
- Patty Zwollo
- Department of Biology, The College of William and Mary, Virginia Institute of Marine Science, The College of William and Mary, 23185, USA.
| | | | | | | |
Collapse
|
16
|
Bromage ES, Kaattari IM, Zwollo P, Kaattari SL. Plasmablast and Plasma Cell Production and Distribution in Trout Immune Tissues. THE JOURNAL OF IMMUNOLOGY 2004; 173:7317-23. [PMID: 15585855 DOI: 10.4049/jimmunol.173.12.7317] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
These studies describe the in vitro and ex vivo generation of plasmablasts and plasma cells in trout (Oncorhynchus mykiss) peripheral blood and splenic and anterior kidney tissues. Cells were derived either from naive trout and cultured with the polyclonal activator, Escherichia coli LPS, or from trout that had been immunized with trinitrophenyl-keyhole limpet hemocyanin. Hydroxyurea was used to resolve populations of replicating (plasmablast) and nonreplicating (plasma cell) Ab-secreting cells (ASC). Complete inhibition of Ig secretion was only observed within the PBL. Both anterior kidney and splenic lymphocytes possessed a subset of ASCs that were hydroxyurea resistant. Thus, in vitro production of plasma cells appears to be restricted to the latter two tissues, whereas peripheral blood is exclusively restricted to the production of plasmablasts. After immunization with trinitrophenyl-keyhole limpet hemocyanin, specific ASC could be isolated from all immune organs; however, the anterior kidney contained 98% of all ASC. Late in the response (>10 wk), anterior kidney ASC secreted specific Ab for at least 15 days in culture, indicating that they were long-lived plasma cells. Cells from spleen and peripheral blood lost all capacity to secrete specific Ab in the absence of Ag. Late in the Ab response, high serum titer levels are solely the result of Ig secretion from anterior kidney plasma cells.
Collapse
Affiliation(s)
- Erin S Bromage
- Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062, USA
| | | | | | | |
Collapse
|
17
|
Abstract
This review explores the evolutionary origins of lymphocyte development by focusing on the transcription factors that direct mammalian lymphocyte development today. Gene expression data suggest that the programs to make lymphocytes involve the same transcription factor ensembles in all animals with lymphocytes. Most of these factors, GATA, Runx, PU.1/Spi, EBF/Olf, Ikaros, and Pax-2/5/8 family members, are also encoded in the genomes of animals without lymphocytes. We consider the functions of these factors in animals without lymphocytes in terms of discrete program components, which could have been assembled in a new way to create the lymphocyte developmental program approximately 500 My ago.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
| | | |
Collapse
|
18
|
Abstract
Zebrafish have emerged as a useful vertebrate model system in which unbiased large-scale screens have revealed hundreds of mutations affecting vertebrate development. Many zebrafish mutants closely resemble known human disorders, thus providing intriguing prospects for uncovering the genetic basis of human diseases and for the development of pharmacologic agents that inhibit or correct the progression of developmental disorders. The rapid pace of advances in genomic sequencing and map construction, in addition to morpholino targeting and transgenic techniques, have facilitated the identification and analysis of genes associated with zebrafish mutants, thus promoting the development of zebrafish as a model for human disorders. This review aims to illustrate how the zebrafish has been used to identify unknown genes, to assign function to known genes, and to delineate genetic pathways, all contributing valuable leads toward understanding human pathophysiology.
Collapse
Affiliation(s)
- Trista E North
- Division of Hematology/Oncology, Department of Medicine, Children's Hospital of Boston, Enders Research Building, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
19
|
Boshra H, Li J, Peters R, Hansen J, Matlapudi A, Sunyer JO. Cloning, Expression, Cellular Distribution, and Role in Chemotaxis of a C5a Receptor in Rainbow Trout: The First Identification of a C5a Receptor in a Nonmammalian Species. THE JOURNAL OF IMMUNOLOGY 2004; 172:4381-90. [PMID: 15034053 DOI: 10.4049/jimmunol.172.7.4381] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
C3a, C4a, and C5a anaphylatoxins generated during complement activation play a key role in inflammation. C5a is the most potent of the three anaphylatoxins in eliciting biological responses. The effects of C5a are mediated by its binding to C5a receptor (C5aR, CD88). To date, C5aR has only been identified and cloned in mammalian species, and its evolutionary history remains ill-defined. To gain insights into the evolution, conserved structural domains, and functions of C5aR, we have cloned and characterized a C5aR in rainbow trout, a teleost fish. The isolated cDNA encoded a 350-aa protein that showed the highest sequence similarity to C5aR from other species. Genomic analysis revealed the presence of one continuous exon encoding the entire open reading frame. Northern blot analysis showed significant expression of the trout C5a receptor (TC5aR) message in PBLs and kidney. Flow cytometric analysis showed that two Abs generated against two different areas of the extracellular N-terminal region of TC5aR positively stained the same leukocyte populations from PBLs. B lymphocytes and granulocytes comprised the majority of cells recognized by the anti-TC5aR. More importantly, these Abs inhibited chemotaxis of PBLs toward a chemoattractant fraction purified from complement-activated trout serum. Our data suggest that the split between C5aR and C3aR from a common ancestral molecule occurred before the emergence of teleost fish. Moreover, we demonstrate that the overall structure of C5aR as well as its role in chemotaxis have remained conserved for >300 million years.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Blotting, Southern
- Cell Migration Inhibition
- Chemotaxis, Leukocyte/immunology
- Cloning, Molecular/methods
- DNA, Complementary/isolation & purification
- Gene Expression Regulation/immunology
- Humans
- Immune Sera/pharmacology
- Leukocytes/cytology
- Leukocytes/immunology
- Leukocytes/metabolism
- Molecular Sequence Data
- Oncorhynchus mykiss/genetics
- Oncorhynchus mykiss/immunology
- Protein Binding/immunology
- Receptor, Anaphylatoxin C5a/genetics
- Receptor, Anaphylatoxin C5a/immunology
- Receptor, Anaphylatoxin C5a/metabolism
- Receptor, Anaphylatoxin C5a/physiology
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
Collapse
Affiliation(s)
- Hani Boshra
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | | | | | | |
Collapse
|
20
|
Cupit PM, Hansen JD, McCarty AS, White G, Chioda M, Spada F, Smale ST, Cunningham C. Ikaros family members from the agnathan Myxine glutinosa and the urochordate Oikopleura dioica: emergence of an essential transcription factor for adaptive immunity. THE JOURNAL OF IMMUNOLOGY 2004; 171:6006-13. [PMID: 14634112 DOI: 10.4049/jimmunol.171.11.6006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Ikaros multigene family encodes a number of zinc finger transcription factors that play key roles in vertebrate hemopoietic stem cell differentiation and the generation of B, T, and NK cell lineages. In this study, we describe the identification and characterization of an Ikaros family-like (IFL) protein from the agnathan hagfish Myxine glutinosa and the marine urochordate Oikopleura dioica, both of which lie on the evolutionary boundary between the vertebrates and invertebrates. The IFL molecules identified in these animals displayed high conservation in the zinc finger motifs critical for DNA binding and dimerization in comparison with those of jawed vertebrates. Expression of the IFL gene in hagfish was strongest in blood, intestine, and gills. In O. dioica, transcription from the IFL gene was initiated at or around the time of hatching and maintained throughout the life span of the animal. In situ hybridization localized O. dioica IFL expression to the Fol cells, which are responsible for generating the food filter of the house. Biochemical analysis of the DNA binding and dimerization domains from M. glutinosa and O. dioici IFLs showed that M. glutinosa behaves as a true Ikaros family member. Taken together, these results indicate that the properties associated with the Ikaros family preceded the emergence of the jawed vertebrates and thus adaptive immunity.
Collapse
Affiliation(s)
- Pauline M Cupit
- Sars International Centre for Marine Molecular Biology, High Technology Centre, Bergen, Norway
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Sun J, Matthias G, Mihatsch MJ, Georgopoulos K, Matthias P. Lack of the transcriptional coactivator OBF-1 prevents the development of systemic lupus erythematosus-like phenotypes in Aiolos mutant mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1699-706. [PMID: 12574333 DOI: 10.4049/jimmunol.170.4.1699] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Here we show that mice lacking the zinc finger transcription factor Aiolos develop the symptoms of human systemic lupus erythematosus (SLE), which is characterized by the production of anti-dsDNA Ab and immune complex-mediated glomerulonephritis. This finding indicates that normal Aiolos function is necessary to maintain immune homeostasis and suppress the development of systemic autoimmune disease and implicates Aiolos as a possible candidate gene for SLE. Interestingly, Aiolos-null mice can no longer mount autoimmune reactions and completely fail to develop SLE when they are deficient for the B cell-specific transcription coactivator OBF-1. The lack of OBF-1 reverses several Aiolos mutant mouse phenotypes, such as B cell hyperproliferation, high expression of activation marker on B cells, and spontaneous germinal center formation. Unexpectedly, B cell development at the immature B cell stage is severely impaired in the bone marrow of Aiolos/OBF-1 double-deficient mice, demonstrating the key role of these factors in the transition from pre-B to immature B cells. Our results indicate that B cells play a crucial role in the development of SLE in Aiolos mutant mice and might be useful for the strategy of SLE treatment.
Collapse
Affiliation(s)
- Jian Sun
- Friedrich Miescher Institute for Biomedical Research, Novartis Research Foundation, Basel, Switzerland
| | | | | | | | | |
Collapse
|
22
|
Boudarra N, Frippiat C, Dournon C, Frippiat JP. An alternative internal splicing site defines new Ikaros isoforms in Pleurodeles waltl. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2002; 26:659-673. [PMID: 12074930 DOI: 10.1016/s0145-305x(02)00014-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Ikaros gene encodes a family of transcription factors which plays a crucial role in hematopoiesis. To improve our knowledge about the immune system of Pleurodeles waltl, we sequenced the cDNA coding for the Ik-1 isoform of that salamander and analyzed its tissue expression by semi-quantitative RT-PCR. Ikaros transcripts are abundant in the thymus and the spleen, thereby confirming that these organs are, respectively, the primary and secondary lymphoid tissues of Pleurodeles. Analysis of the isoforms produced by this animal revealed two isoforms characteristic of amphibians in which an alternative internal splicing site deletes the 3' half of exon 3 which interestingly comprises the first Zn finger of Ikaros. Ikaros transcripts were found at the earliest stages of development of Pleurodeles indicating that Ikaros has a function at the very early lymphopoietic stages. Moreover, the presence of Ikaros transcripts in spermatozoa suggests that this protein could have another and yet unknown function.
Collapse
Affiliation(s)
- Najia Boudarra
- Laboratoire de Biologie Expérimentale et Immunologie, UPRES EA 2401, Université Henri Poincaré, Nancy 1, Boulevard des Aiguillettes, BP 239, F-54506 Vandoeuvre-lès-Nancy Cedex, France
| | | | | | | |
Collapse
|
23
|
Kakinuma S, Nishimura M, Sasanuma SI, Mita K, Suzuki G, Katsura Y, Sado T, Shimada Y. Spectrum of Znfn1a1 (Ikaros) inactivation and its association with loss of heterozygosity in radiogenic T-cell lymphomas in susceptible B6C3F1 mice. Radiat Res 2002; 157:331-40. [PMID: 11839096 DOI: 10.1667/0033-7587(2002)157[0331:soziia]2.0.co;2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ikaros (now known as Znfn1a1), a Krüppel-type zinc-finger transcription factor that plays a critical role in both lineage commitment and differentiation of lymphoid cells, has recently been shown to function as a tumor suppressor gene. We have previously reported a high frequency of LOH (approximately 50%) at the Znfn1a1 locus in radiation-induced T-cell lymphoma in susceptible B6C3F1 mice. The aim of the present study was to delineate the types of Znfn1a1 inactivation, with special reference to the LOH status, and to determine the relative contribution of each type of Znfn1a1 inactivation in radiation-induced T-cell lymphomas in B6C3F1 mice. We demonstrated that Znfn1a1 was frequently altered (in approximately 50% of T-cell lymphomas), and that its inactivation was caused by a variety of mechanisms, which came under one of the following four categories: (1) null expression (14%); (2) expression of unusual dominant-negative isoforms (11%); (3) amino acid substitutions in the N-terminal zinc-finger domain for DNA binding caused by point mutations (22%); (4) lack of the Znfn1a1 isoform 1 due to the creation of a stop codon by insertion of a dinucleotide in exon 3 (3%). The null expression, amino acid substitutions, and dinucleotide insertion inactivation types were well correlated with LOH at the Znfn1a1 allele (86%) and were consistent with Knudson's two-hit theory. On the other hand, T-cell lymphomas expressing dominant-negative Znfn1a1 isoforms retained both alleles. These results indicate that Znfn1a1 inactivation takes place by a variety of mechanisms in radiation-induced murine T-cell lymphomas and is frequently associated with LOH, this association depending on the type of inactivation.
Collapse
Affiliation(s)
- Shizuko Kakinuma
- Division of Low Dose Radiation and Experimental Carcinogenesis, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Willett CE, Kawasaki H, Amemiya CT, Lin S, Steiner LA. Ikaros expression as a marker for lymphoid progenitors during zebrafish development. Dev Dyn 2001; 222:694-8. [PMID: 11748838 DOI: 10.1002/dvdy.1223] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The Ikaros gene encodes a transcription factor that, in mice, has been shown to be essential for the correct differentiation of B and T lymphocytes and is expressed in all cells of the lymphoid lineage, including pluripotent hematopoietic stem cells. During development in zebrafish, Ikaros expression begins in lateral mesoderm, and continues in the intermediate cell mass (ICM), which is derived from lateral mesoderm and has been shown to generate primitive hematopoietic precursors. Cells expressing Ikaros were then seen on the ventral side of the dorsal aorta, known to be a location of definitive hematopoietic precursors in birds and mammals. Ikaros-expressing cells were also found in the pharyngeal region, near the forming thymus. Later, such cells were seen in the pronephros, the site of hematopoiesis in adult fish. The timing of appearance of Ikaros-expressing cells suggests that, similar to other vertebrates, lymphocytes in the thymus arise from hematopoietic tissue located near the dorsal aorta or in the ICM.
Collapse
Affiliation(s)
- C E Willett
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | | | | | |
Collapse
|
25
|
Wakahara M, Yamaguchi M. Erythropoiesis and Conversion of RBCs and Hemoglobins from Larval to Adult Type during Amphibian Development. Zoolog Sci 2001. [DOI: 10.2108/zsj.18.891] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
26
|
Cobb BS, Morales-Alcelay S, Kleiger G, Brown KE, Fisher AG, Smale ST. Targeting of Ikaros to pericentromeric heterochromatin by direct DNA binding. Genes Dev 2000; 14:2146-60. [PMID: 10970879 PMCID: PMC316893 DOI: 10.1101/gad.816400] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2000] [Accepted: 06/30/2000] [Indexed: 11/25/2022]
Abstract
Ikaros is a sequence-specific DNA-binding protein that is essential for lymphocyte development. Little is known about the molecular function of Ikaros, although recent results have led to the hypothesis that it recruits genes destined for heritable inactivation to foci containing pericentromeric heterochromatin. To gain further insight into the functions of Ikaros, we have examined the mechanism by which it is targeted to centromeric foci. Efficient targeting of Ikaros was observed upon ectopic expression in 3T3 fibroblasts, demonstrating that lymphocyte-specific proteins and a lymphoid nuclear architecture are not required. Pericentromeric targeting did not result from an interaction with the Mi-2 remodeling factor, as only a small percentage of Mi-2 localized to centromeric foci in 3T3 cells. Rather, targeting was dependent on the amino-terminal DNA-binding zinc finger domain and carboxy-terminal dimerization domain of Ikaros. The carboxy-terminal domain was required only for homodimerization, as targeting was restored when this domain was replaced with a leucine zipper. Surprisingly, a detailed substitution mutant analysis of the amino-terminal domain revealed a close correlation between DNA-binding and pericentromeric targeting. These results show that DNA binding is essential for the pericentromeric localization of Ikaros, perhaps consistent with the presence of Ikaros binding sites within centromeric DNA repeats. Models for the function of Ikaros that are consistent with this targeting mechanism are discussed.
Collapse
MESH Headings
- 3T3 Cells
- Adenosine Triphosphatases
- Amino Acid Sequence
- Animals
- Autoantigens/metabolism
- Base Sequence
- Binding Sites
- Blotting, Western
- Cell Line
- Centromere/metabolism
- DNA/metabolism
- DNA Helicases
- DNA, Complementary/metabolism
- DNA-Binding Proteins
- Heterochromatin/metabolism
- Humans
- Ikaros Transcription Factor
- Mi-2 Nucleosome Remodeling and Deacetylase Complex
- Mice
- Microscopy, Confocal
- Microscopy, Fluorescence
- Models, Biological
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Protein Binding
- Protein Isoforms
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Transcription Factors/biosynthesis
- Transcription Factors/chemistry
- Transcription Factors/genetics
- Transduction, Genetic
- Transfection
- Zinc Fingers
Collapse
Affiliation(s)
- B S Cobb
- Howard Hughes Medical Institute, Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095-1662, USA
| | | | | | | | | | | |
Collapse
|
27
|
Haire RN, Miracle AL, Rast JP, Litman GW. Members of the Ikaros gene family are present in early representative vertebrates. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:306-12. [PMID: 10861066 DOI: 10.4049/jimmunol.165.1.306] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Members of the Ikaros multigene family of zinc finger proteins are expressed in a tissue-specific manner and most are critical determinants in the development of both the B and T lymphocytes as well as NK and dendritic APC lineages. A PCR amplification strategy that is based on regions of shared sequence identity in Ikaros multigene family members found in mammals and several other vertebrates has led to the recovery of cDNAs that represent the orthologues of Ikaros, Aiolos, Helios, and Eos in Raja eglanteria (clearnose skate), a cartilaginous fish that is representative of an early divergence event in the phylogenetic diversification of the vertebrates. The tissue-specific patterns of expression for at least two of the four Ikaros family members in skate resemble the patterns observed in mammals, i.e., in hematopoietic tissues. Prominent expression of Ikaros in skate also is found in the lymphoid Leydig organ and epigonal tissues, which are unique to cartilaginous fish. An Ikaros-related gene has been identified in Petromyzon marinus (sea lamprey), a jawless vertebrate species, in which neither Ig nor TCRs have been identified. In addition to establishing a high degree of evolutionary conservation of the Ikaros multigene family from cartilaginous fish through mammals, these studies define a possible link between factors that regulate the differentiation of immune-type cells in the jawed vertebrates and related factors of unknown function in jawless vertebrates.
Collapse
Affiliation(s)
- R N Haire
- Department of Pediatrics and Institute for Biomolecular Sciences, University of South Florida College of Medicine, Children's Research Institute, St. Petersburg, FL 33701, USA
| | | | | | | |
Collapse
|
28
|
Anderson MK, Rothenberg EV. Transcription factor expression in lymphocyte development: clues to the evolutionary origins of lymphoid cell lineages? Curr Top Microbiol Immunol 2000; 248:137-55. [PMID: 10793477 DOI: 10.1007/978-3-642-59674-2_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- M K Anderson
- Department of Biology, California Institute of Technology, Pasadena 91125, USA
| | | |
Collapse
|
29
|
Peixoto BR, Mikawa Y, Brenner S. Characterization of the recombinase activating gene-1 and 2 locus in the Japanese pufferfish, Fugu rubripes. Gene 2000; 246:275-83. [PMID: 10767549 DOI: 10.1016/s0378-1119(00)00091-3] [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: 12/01/2022]
Abstract
The recombinase activating genes (RAG1 and RAG2) encode nuclear proteins that directly mediate the mechanism V(D)J recombination process that occurs in T- and B-lymphocytes. The expression of RAG1 and RAG2 is required for the proper development of maturing lymphocytes. To identify evolutionary conserved regulatory regions adjacent to both genes we isolated and sequenced a cosmid clone containing 43kb of genomic DNA of the Japanese pufferfish, Fugu rubripes. Fugu has a haploid genome of 400Mb and contains the same number of genes as the genome of higher vertebrates. With low abundance of repetitive DNA, the genome of the pufferfish has shown to be ideal for comparative genomics. We found three complete genes, RAG1, RAG2 and ACS (a possible homologue of the plant 1-aminocyclopropane-carboxylate synthase gene). There is also the 5' exon of a prohormone convertase gene, possibly PACE4. The genetic structure of both RAG1 and RAG2 is identical to that found in other fish, but the size of the intergenic region is smaller in Fugu. Expression analysis by RT-PCR shows the presence of RAG transcripts in kidney of adult Fugu. The human ACS was identified in a cosmid assigned to chromosome 11p11, which is close to the location of the RAGs (11p12). This indicates conservation of linkage between human and pufferfish.
Collapse
Affiliation(s)
- B R Peixoto
- The Molecular Sciences Institute, Berkeley, CA, USA.
| | | | | |
Collapse
|
30
|
Hansen JD, Strassburger P. Description of an ectothermic TCR coreceptor, CD8 alpha, in rainbow trout. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:3132-9. [PMID: 10706703 DOI: 10.4049/jimmunol.164.6.3132] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have cloned the first CD8 alpha gene from an ectothermic source using a degenerate primer for Ig superfamily V domains. Similar to homologues in higher vertebrates, the rainbow trout CD8 alpha gene encodes a 204-aa mature protein composed of two extracellular domains including an Ig superfamily V domain and hinge region. Differing from mammalian CD8 alpha V domains, lower vertebrate (trout and chicken) sequences do not contain the extra cysteine residue (C strand) involved in the abnormal intrachain disulfide bridging within the CD8 alpha V domain of mice and rats. The trout membrane proximal hinge region contains the two essential cysteine residues involved in CD8 dimerization (alpha alpha or alpha beta) and threonine, serine, and proline residues which may be involved in multiple O-linked glycosylation events. Although the transmembrane region is well conserved in all CD8 alpha sequences analyzed to date, the putative trout cytoplasmic region differs and, in fact, lacks the consensus p56lck motif common to other CD8 alpha sequences. We then determined that the trout CD8 alpha genomic structure is similar to that of humans (six exons) but differs from that of mice (five exons). Additionally, Northern blotting and RT-PCR demonstrate that trout CD8 alpha is expressed at high levels within the thymus and at weaker levels in the spleen, kidney, intestine, and peripheral blood leukocytes. Finally, we show that trout CD8 alpha can be expressed on the surface of cells via transfection. Together, our results demonstrate that the basic structure and expression of CD8 alpha has been maintained for more than 400 million years of evolution.
Collapse
Affiliation(s)
- J D Hansen
- Basel Institute for Immunology, Basel, Switzerland.
| | | |
Collapse
|
31
|
Abstract
The molecular and cellular requirements for the development of different populations of human dendritic cells (DC) were studied. Conditions were defined that support DC production from lymphoid progenitors but that fail to induce DC formation from peripheral monocytes. The production of these lymphoid-related DC was severely blocked when hematopoietic progenitors overexpressed Ik7, a mutant dominant-negative Ikaros protein. In contrast, Ik7 did not block the formation of DC in conditions supporting the development of monocyte-derived DC. Furthermore, Ik7 did not block the formation of monocyte/macrophages and enhanced granulopoiesis. One of the molecular mechanisms mediated by Ik7 appears to be down-regulation of the flt3-receptor mRNA. Thus, distinct signals control the formation of DC demonstrating that some aspects of DC diversity are determined in part by distinct molecular cues at the hematopoietic level. (Blood. 2000;95:128-137)
Collapse
|
32
|
Abstract
Abstract
The molecular and cellular requirements for the development of different populations of human dendritic cells (DC) were studied. Conditions were defined that support DC production from lymphoid progenitors but that fail to induce DC formation from peripheral monocytes. The production of these lymphoid-related DC was severely blocked when hematopoietic progenitors overexpressed Ik7, a mutant dominant-negative Ikaros protein. In contrast, Ik7 did not block the formation of DC in conditions supporting the development of monocyte-derived DC. Furthermore, Ik7 did not block the formation of monocyte/macrophages and enhanced granulopoiesis. One of the molecular mechanisms mediated by Ik7 appears to be down-regulation of the flt3-receptor mRNA. Thus, distinct signals control the formation of DC demonstrating that some aspects of DC diversity are determined in part by distinct molecular cues at the hematopoietic level. (Blood. 2000;95:128-137)
Collapse
|
33
|
Sun L, Goodman PA, Wood CM, Crotty ML, Sensel M, Sather H, Navara C, Nachman J, Steinherz PG, Gaynon PS, Seibel N, Vassilev A, Juran BD, Reaman GH, Uckun FM. Expression of aberrantly spliced oncogenic ikaros isoforms in childhood acute lymphoblastic leukemia. J Clin Oncol 1999; 17:3753-66. [PMID: 10577847 DOI: 10.1200/jco.1999.17.12.3753] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE We sought to determine if molecular abnormalities involving the Ikaros gene could contribute to the development of acute lymphoblastic leukemia (ALL) in children. PATIENTS AND METHODS We studied Ikaros gene expression in normal human bone marrow, normal thymocytes, normal fetal liver-derived immature lymphocyte precursor cell lines, eight different ALL cell lines, and leukemic cells from 69 children with ALL (T-lineage ALL, n = 18; B-lineage ALL, n = 51). Expression of Ikaros protein and its subcellular localization were examined by immunoblotting and confocal laser-scanning microscopy, respectively. Polymerase chain reaction (PCR) and nucleotide sequencing were used to identify the specific Ikaros isoforms expressed in these cells. Genomic sequencing of splice junction regions of the Ikaros gene was performed in search for mutations. RESULTS In each of the ALL cases, we found high-level expression of a non-DNA-binding or aberrant DNA-binding isoform of Ikaros with abnormal subcellular compartmentalization patterns. In contrast, only wild-type Ik-1 and Ik-2 isoforms with normal subcellular localization were found in normal bone marrow cells and thymus-derived or fetal liver-derived normal lymphocyte precursors. In leukemic cells expressing the aberrant Ikaros coding sequences with the 30-base-pair deletion, genomic sequence analysis of the intron-exon junctions between exons 6 and 7 yielded the wild-type sequence. We identified a single nucleotide polymorphism (SNP) affecting the third base of the triplet codon for a proline (CCC or CCA) in the highly conserved bipartite activation region (viz, A or C at position 1002 numbering from the translation start site of Ik-1) within our Ikaros clones. Bi-allelic expression of truncated and/or non-DNA-binding isoforms along with wild-type isoforms was observed in leukemic cells, which implicates trans-acting factor(s) affecting splice site recognition. CONCLUSION Our findings link specific molecular defects involving the Ikaros gene to childhood ALL. Posttranscriptional regulation of alternative splicing of Ikaros RNA seems to be defective in leukemic lymphocyte precursors from most children with ALL. Consequently, leukemic cells from ALL patients, in contrast to normal lymphocyte precursors, express high levels of non-DNA-binding Ikaros isoforms that are reminiscent of the non-DNA-binding Ikaros isoforms that lead to lymphoblastic leukemia in mice.
Collapse
Affiliation(s)
- L Sun
- Parker Hughes Cancer Center and Children's Cancer Group ALL Biology Reference Laboratory, Hughes Institute, St Paul, MN 55113, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Hansen JD, Strassburger P, Thorgaard GH, Young WP, Du Pasquier L. Expression, Linkage, and Polymorphism of MHC-Related Genes in Rainbow Trout, Oncorhynchus mykiss. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.2.774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The architecture of the MHC in teleost fish, which display a lack of linkage between class I and II genes, differs from all other vertebrates. Because rainbow trout have been examined for a variety of immunologically relevant genes, they present a good teleost model for examining both the expression and organization of MHC-related genes. Full-length cDNA and partial gDNA clones for proteasome δ, low molecular mass polypeptide (LMP) 2, TAP1, TAP2A, TAP2B, class Ia, and class IIB were isolated for this study. Aside from the expected polymorphisms associated with class I genes, LMP2 and TAP2 are polygenic. More specifically, we found a unique lineage of LMP2 (LMP2/δ) that shares identity to both LMP2 and δ but is expressed like the standard LMP2. Additionally, two very different TAP2 loci were found, one of which encodes polymorphic alleles. In general, the class I pathway genes are expressed in most tissues, with highest levels in lymphoid tissue. We then analyzed the basic genomic organization of the trout MHC in an isogenic backcross. The main class Ia region does not cosegregate with the class IIB locus, but LMP2, LMP2/δ, TAP1A, and TAP2B are linked to the class Ia locus. Interestingly, TAP2A (second TAP2 locus) is a unique lineage in sequence composition that appears not to be linked to this cluster or to class IIB. These results support and extend the recent findings of nonlinkage between class I and II in a different teleost order (cyprinids), suggesting that this unique arrangement is common to all teleosts.
Collapse
Affiliation(s)
- John D. Hansen
- *Basel Institute for Immunology, Basel, Switzerland; and Departments of
| | | | - Gary H. Thorgaard
- †Zoology,
- ‡Genetics, and Cell Biology, Washington State University, Pulman, WA
| | | | - Louis Du Pasquier
- *Basel Institute for Immunology, Basel, Switzerland; and Departments of
| |
Collapse
|
35
|
Abstract
This review addresses issues related to the evolution of the complex multigene families of antigen binding receptors that function in adaptive immunity. Advances in molecular genetic technology now permit the study of immunoglobulin (Ig) and T cell receptor (TCR) genes in many species that are not commonly studied yet represent critical branch points in vertebrate phylogeny. Both Ig and TCR genes have been defined in most of the major lineages of jawed vertebrates, including the cartilaginous fishes, which represent the most phylogenetically divergent jawed vertebrate group relative to the mammals. Ig genes in cartilaginous fish are encoded by multiple individual loci that each contain rearranging segmental elements and constant regions. In some loci, segmental elements are joined in the germline, i.e. they do not undergo genetic rearrangement. Other major differences in Ig gene organization and the mechanisms of somatic diversification have occurred throughout vertebrate evolution. However, relating these changes to adaptive immune function in lower vertebrates is challenging. TCR genes exhibit greater sequence diversity in individual segmental elements than is found in Ig genes but have undergone fewer changes in gene organization, isotype diversity, and mechanisms of diversification. As of yet, homologous forms of antigen binding receptors have not been identified in jawless vertebrates; however, acquisition of large amounts of structural data for the antigen binding receptors that are found in a variety of jawed vertebrates has defined shared characteristics that provide unique insight into the distant origins of the rearranging gene systems and their relationships to both adaptive and innate recognition processes.
Collapse
Affiliation(s)
- G W Litman
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA.
| | | | | |
Collapse
|
36
|
Abstract
Recently, molecular markers such as recombination activating genes (RAG), terminal deoxynucleotidyl transferase (TdT), stem cell leukemia hematopoietic transcription factor (SCL), Ikaros and gata-binding protein (Gata)-family members have been isolated and characterized from key lower vertebrates, adding to our growing knowledge of lymphopoiesis in ectotherms. In all gnathostomes there appear to be two main embryonic locations derived from the early mesoderm, both intra- and extraembryonic, which contribute to primitive and definitive hematopoiesis based upon their differential expression of SCL, Gata-1, Gata-2 and myeloblastosis oncogene (c-myb). In teleosts, a unique intraembryonic location for hematopoietic stem cells termed the intermediate cell mass (ICM) of Oellacher appears to be responsible for primitive or definitive hematopoiesis depending upon the species being investigated. In Xenopus, elegant grafting studies in combination with specific molecular markers has led to a better definition of the roles that ventral blood islands and dorsal lateral plate play in amphibian hematopoiesis, that of primitive and definitive lymphopoiesis. After the early embryonic contribution to hematopoiesis, specialized tissues must assume the role of providing the proper microenvironment for T and B-lymphocyte development from progenitor stem cells. In all gnathostomes, the thymus is the major site for T-cell maturation as evidenced by strong expression of developmental markers such as Ikaros, Rag and TdT plus expression of T-cell specific markers such as T-cell receptor beta and lck. In this respect, several zebrafish mutants have provided new insights on the development of the thymopoietic environment. On the other hand, the sites for B-cell lymphopoiesis are less clear among the lower vertebrates. In elasmobranchs, the spleen, Leydig's organ and the spiral valve may all contribute to B-cell development, although pre-B cells have yet to be fully addressed in fish. In teleosts, the kidney is undeniably the major source of B-cell development based upon functional, cellular and molecular indices. Amphibians appear to use several different sites (spleen, bone marrow and/or kidney) depending upon the species in question.
Collapse
Affiliation(s)
- J D Hansen
- Basel Institute for Immunology, Switzerland.
| | | |
Collapse
|
37
|
Sunyer JO, Zarkadis I, Sarrias MR, Hansen JD, Lambris JD. Cloning, Structure, and Function of Two Rainbow Trout Bf Molecules. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.8.4106] [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 factor B (Bf) and C2 complement genes are closely linked within the MHC class III region and are thought to have arisen by gene duplication from a single gene encoding an ancestral molecule; the animal phyla in which this duplication event took place is unknown. Two teleost fish, (zebrafish and medaka fish) have each been shown to possess only a single molecule that shows an equivalent degree of similarity to mammalian Bf and C2. In contrast, here we present the characterization of two factor B molecules (Bf-1 and Bf-2) in another teleost fish (the rainbow trout) that are about 9% more similar to mammalian factor B than C2, yet play a role in both alternative and classical pathways of complement activation. The full lengths of Bf-1 and Bf-2 cDNAs are 2509 and 2560 bp, respectively, and their deduced amino acid sequences are 75% identical. Both trout Bf genes are mainly expressed in liver and appear to be single-copy genes. The isolated Bf-1 and Bf-2 proteins are able to form the alternative pathway C3 convertase and are cleaved (in the presence of purified trout C3, trout factor D, and Mg2+EGTA) into Ba- and Bb-like fragments in a manner similar to that seen for mammalian factor B. The most remarkable feature of trout Bf-2 is its ability to restore the hemolytic activity of trout Bf-depleted serum through both the alternative and classical pathways; whether Bf-1 possess similar activity is unclear at present.
Collapse
Affiliation(s)
- J. Oriol Sunyer
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ioannis Zarkadis
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
- †Department of Biology, University of Patras, Patras, Greece; and
| | - Maria Rosa Sarrias
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | - John D. Lambris
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| |
Collapse
|
38
|
Kelley CM, Ikeda T, Koipally J, Avitahl N, Wu L, Georgopoulos K, Morgan BA. Helios, a novel dimerization partner of Ikaros expressed in the earliest hematopoietic progenitors. Curr Biol 1998; 8:508-15. [PMID: 9560339 DOI: 10.1016/s0960-9822(98)70202-7] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Normal hematopoietic development depends on the activity of the Ikaros transcription factor, which contains distinct zinc-finger domains that mediate DNA binding and protein dimerization. Mice homozygous for a transgene encoding a dominant-negative version of Ikaros that lacks the DNA-binding domain but not the dimerization domain have a more severe phenotype than Ikaros null mice. This observation suggests the presence of factor(s) that can dimerize with Ikaros and partially complement its function. One previously identified factor, Aiolos, probably serves this role in the lymphoid system; a related factor involved in hematopoietic progenitors remains unknown, however. RESULTS Here, we describe the cloning of an Ikaros-related gene, Helios. Analysis of the primary sequences of Helios, Ikaros and Aiolos revealed that the DNA-binding, transcriptional activation and dimerization domains are functionally conserved. Helios activated transcription from Ikaros DNA-binding sites and could dimerize with itself, Ikaros or Aiolos. Expression of Helios was detected in the earliest hematopoietic sites of the embryo, in hematopoietic stem cells in the adult and was subsequently restricted to a subset of cells in the T cell lineage. Helios co-localized with Ikaros and Aiolos proteins in macromolecular nuclear structures and formed stable complexes in vivo with the dominant-negative version of Ikaros. CONCLUSIONS Distinct but overlapping expression patterns of members of the Ikaros gene family during hematopoiesis might result in the formation of different multimeric complexes that have specific roles in lineage progression. The preferential expression of Helios in the earliest stages of hematopoiesis suggests that this gene functions predominantly in early progenitors.
Collapse
Affiliation(s)
- C M Kelley
- Laboratory of Molecular Immunology Cutaneous Biology Research Center Massachusetts General Hospital Harvard Medical School Charlestown, Massachusetts, 02129, USA
| | | | | | | | | | | | | |
Collapse
|