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Brown AJ, White J, Shaw L, Gross J, Slabodkin A, Kushner E, Greiff V, Matsuda J, Gapin L, Scott-Browne J, Kappler J, Marrack P. MHC heterozygosity limits T cell receptor variability in CD4 T cells. Sci Immunol 2024; 9:eado5295. [PMID: 38996008 DOI: 10.1126/sciimmunol.ado5295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024]
Abstract
αβ T cell receptor (TCR) V(D)J genes code for billions of TCR combinations. However, only some appear on peripheral T cells in any individual because, to mature, thymocytes must react with low affinity but not high affinity with thymus expressed major histocompatibility (MHC)/peptides. MHC proteins are very polymorphic. Different alleles bind different peptides. Therefore, any individual might express many different MHC alleles to ensure that some peptides from an invader are bound to MHC and activate T cells. However, most individuals express limited numbers of MHC alleles. To explore this, we compared the TCR repertoires of naïve CD4 T cells in mice expressing one or two MHC alleles. Unexpectedly, the TCRs in heterozygotes were less diverse that those in the sum of their MHC homozygous relatives. Our results suggest that thymus negative selection cancels out the advantages of increased thymic positive selection in the MHC heterozygotes.
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MESH Headings
- Animals
- Mice
- CD4-Positive T-Lymphocytes/immunology
- Heterozygote
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/genetics
- Major Histocompatibility Complex/immunology
- Major Histocompatibility Complex/genetics
- Mice, Inbred C57BL
- Thymus Gland/immunology
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Mice, Transgenic
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Affiliation(s)
- Alexander J Brown
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - Janice White
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Laura Shaw
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Jimmy Gross
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Andrei Slabodkin
- Department of Immunology, University of Oslo and Oslo University Hospital, Postboks 4950 Nydalen OUS HF Rikshospitalet, 0424 Oslo, Norway
| | - Ella Kushner
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Victor Greiff
- Department of Immunology, University of Oslo and Oslo University Hospital, Postboks 4950 Nydalen OUS HF Rikshospitalet, 0424 Oslo, Norway
| | - Jennifer Matsuda
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Laurent Gapin
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - James Scott-Browne
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
| | - John Kappler
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, 1775 Aurora Ct, Aurora, CO 80045, USA
| | - Philippa Marrack
- Department of Immunology and Genomic Medicine, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA
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2
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Robert J. Experimental Platform Using the Amphibian Xenopus laevis for Research in Fundamental and Medical Immunology. Cold Spring Harb Protoc 2020; 2020:106625. [PMID: 32457040 DOI: 10.1101/pdb.top106625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The amphibian Xenopus constitutes a powerful, versatile, and cost-effective nonmammalian model with which to investigate important contemporary issues of immunity relevant to human health such as ontogeny of immunity, self-tolerance, wound healing, autoimmunity, cancer immunity, immunotoxicology, and adaptation of host immune defenses to emerging pathogens. This model system presents several attractive features: an external developmental environment free of maternal influence that allows for easy experimental access from early life stages; an immune system that is remarkably similar to that of mammals; the availability of large-scale genetic and genomic resources; invaluable major histocompatibility complex (MHC)-defined inbred strains of frogs; and useful tools such as lymphoid tumor cell lines, monoclonal antibodies, and MHC tetramers. Modern reverse genetic loss-of-function and genome-editing technologies applied to immune function further empower this model. Finally, the evolutionary distance between Xenopus and mammals permits distinguishing species-specific adaptation from more conserved features of the immune system. In this introduction, the advantages and features of Xenopus for immunological research are outlined, as are existing tools, resources, and methods for using this model system.
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Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14620
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3
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Kaufman J. Unfinished Business: Evolution of the MHC and the Adaptive Immune System of Jawed Vertebrates. Annu Rev Immunol 2018; 36:383-409. [DOI: 10.1146/annurev-immunol-051116-052450] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jim Kaufman
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB2 0ES, United Kingdom
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4
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Petit J, David L, Dirks R, Wiegertjes GF. Genomic and transcriptomic approaches to study immunology in cyprinids: What is next? DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 75:48-62. [PMID: 28257855 DOI: 10.1016/j.dci.2017.02.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 02/24/2017] [Accepted: 02/26/2017] [Indexed: 06/06/2023]
Abstract
Accelerated by the introduction of Next-Generation Sequencing (NGS), a number of genomes of cyprinid fish species have been drafted, leading to a highly valuable collective resource of comparative genome information on cyprinids (Cyprinidae). In addition, NGS-based transcriptome analyses of different developmental stages, organs, or cell types, increasingly contribute to the understanding of complex physiological processes, including immune responses. Cyprinids are a highly interesting family because they comprise one of the most-diversified families of teleosts and because of their variation in ploidy level, with diploid, triploid, tetraploid, hexaploid and sometimes even octoploid species. The wealth of data obtained from NGS technologies provides both challenges and opportunities for immunological research, which will be discussed here. Correct interpretation of ploidy effects on immune responses requires knowledge of the degree of functional divergence between duplicated genes, which can differ even between closely-related cyprinid fish species. We summarize NGS-based progress in analysing immune responses and discuss the importance of respecting the presence of (multiple) duplicated gene sequences when performing transcriptome analyses for detailed understanding of complex physiological processes. Progressively, advances in NGS technology are providing workable methods to further elucidate the implications of gene duplication events and functional divergence of duplicates genes and proteins involved in immune responses in cyprinids. We conclude with discussing how future applications of NGS technologies and analysis methods could enhance immunological research and understanding.
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Affiliation(s)
- Jules Petit
- Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, PO Box 338, 6700 AH, Wageningen, The Netherlands
| | - Lior David
- Department of Animal Sciences, R. H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Ron Dirks
- ZF-screens B.V., J.H, Oortweg 19, 2333 CH, Leiden, The Netherlands
| | - Geert F Wiegertjes
- Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, PO Box 338, 6700 AH, Wageningen, The Netherlands.
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5
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Banach M, Edholm ES, Robert J. Exploring the functions of nonclassical MHC class Ib genes in Xenopus laevis by the CRISPR/Cas9 system. Dev Biol 2017; 426:261-269. [PMID: 27318386 PMCID: PMC5501940 DOI: 10.1016/j.ydbio.2016.05.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 05/12/2016] [Accepted: 05/20/2016] [Indexed: 12/31/2022]
Abstract
A large family of highly related and clustered Xenopus nonclassical MHC class Ib (XNC) genes influences Xenopus laevis immunity and potentially other physiological functions. Using RNA interference (RNAi) technology, we previously demonstrated that one of XNC genes, XNC10.1, is critical for the development and function of a specialized innate T (iT) cell population. However, RNAi limitation such as a variable and unstable degree of gene silencing in F0 and F1 generations is hampering a thorough functional analysis of XNC10.1 and other XNC genes. To overcome this obstacle, we adapted the CRISPR/Cas9-mediated gene editing technique for XNC genes. We efficiently and specifically generated single gene knockouts of XNC10.1, XNC11, and XNC1 as well as double gene knockouts of XNC10.1 and XNC11 in X. laevis. In single XNC10.1 knockout X. laevis tadpoles, the absence of XNC10.1 and Vα6-Jα1.43 invariant T cell receptor rearrangement transcripts indicated XNC10.1 loss-of-function and deficiency in Vα6-Jα1.43 iT cells. Notably, targeting XNC10.1 did not affect neighboring XNC genes exhibiting high sequence similarity. Furthermore, XNC1 gene disruption induced mortality during developmental stage 47, suggesting some non-immune but essential function of this gene. These data demonstrate that the CRISPR/Cas9 system can be successfully adapted for genetic analysis in F0 generation of X. laevis.
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Affiliation(s)
- Maureen Banach
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
| | - Eva-Stina Edholm
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA.
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6
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Affiliation(s)
- Hans Rudolf Kobel
- a Laboratoire de Génétique Animale et Végétale , Université de Genève
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Goyos A, Ohta Y, Guselnikov S, Robert J. Novel nonclassical MHC class Ib genes associated with CD8 T cell development and thymic tumors. Mol Immunol 2009; 46:1775-86. [PMID: 19237199 DOI: 10.1016/j.molimm.2009.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 01/25/2009] [Indexed: 11/30/2022]
Abstract
In jawed vertebrates, the heterogeneous nonclassical MHC class Ib (class Ib) gene family encodes molecules structurally similar to classical MHC class Ia (class Ia) but with more limited tissue distribution and lower polymorphism. In mammals, class Ib gene products are involved in stress responses, malignancy and differentiation of intrathymic CD8 T cells. The frog Xenopus laevis possesses at least 20 class Ib genes (XNCs), and 9 subfamilies have been defined so far. We have characterized two novel subfamilies, XNC10 and XNC11. XNC10 is phylogenetically and structurally distinct from both class Ia and other XNC genes. Besides thymic lymphoid tumors, XNC10 is preferentially expressed by circulating T cells and thymocytes of the CD8 lineage both in adult and in larvae from the onset of thymus organogenesis. XNC11 is expressed only by thymocytes and upregulated by several thymic lymphoid tumors. These data provide the first evidence of the expression of any class Ib genes in Xenopus larvae, and suggests evolutionary relationships between certain class Ib genes, malignancy and CD8 T cell ontogeny.
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Affiliation(s)
- Ana Goyos
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
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8
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Jackson JA, Tinsley RC. Parasite infectivity to hybridising host species: a link between hybrid resistance and allopolyploid speciation? Int J Parasitol 2003; 33:137-44. [PMID: 12633651 DOI: 10.1016/s0020-7519(02)00255-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Variation in host-specific infectivity was studied in monogenean polystome parasites (Protopolystoma spp.) of the interfertile, parapatric anurans Xenopus laevis laevis and Xenopus muelleri. Laboratory-raised host F1 hybrids were resistant to parasites respectively specific to each parent taxon in nature. This resistance occurred against parasite isolates from both inside and outside a host hybrid/sympatric zone (and no isolate was compatible with the foreign host species under experimental conditions). Geographical Protopolystoma xenopodis isolates showed variable infectivity to a single full-sib group of their usual host, X. l. laevis, and strains with high or low infectivity to these sibs co-occurred in spatially distant local areas (separated by 1,700 km). The host compatibility of P. xenopodis was also subject to host genotypexparasite genotype interactions. Refractoriness to some parasites or pathogens, as a consequence of hybridisation, may have conferred a selective advantage on the allopolyploid pathway by which most Xenopus spp. are believed to have evolved.
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Affiliation(s)
- J A Jackson
- School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, UK.
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9
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Flajnik MF, Kasahara M. Comparative genomics of the MHC: glimpses into the evolution of the adaptive immune system. Immunity 2001; 15:351-62. [PMID: 11567626 DOI: 10.1016/s1074-7613(01)00198-4] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
MHC gene organization (size, complexity, gene order) differs markedly among different species, and yet all nonmammalian vertebrates examined to date have a true "class I region" with tight linkage of genes encoding the class I presenting and processing molecules. Three paralogous regions of the human genome contain sets of linked genes homologous to various loci in the MHC class I, class II, and/or class III regions, providing insight into the organization of the "proto MHC" before the emergence of the adaptive immune system in the jawed vertebrates.
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Affiliation(s)
- M F Flajnik
- Department of Microbiology and Immunology, University of Maryland at Baltimore, Room 13-009, 655 West Baltimore Street, Baltimore, MD 21021, USA.
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10
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Host-specificity and distribution of cephalochlamydid cestodes: correlation with allopolyploid evolution of pipid anuran hosts. J Zool (1987) 2001. [DOI: 10.1017/s0952836901000905] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Courtet M, Flajnik M, Du Pasquier L. Major histocompatibility complex and immunoglobulin loci visualized by in situ hybridization on Xenopus chromosomes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2001; 25:149-157. [PMID: 11113284 DOI: 10.1016/s0145-305x(00)00045-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A technique for fluorescent in situ hybridization (FISH) on chromosomes of the amphibian Xenopus laevis is described. Positive results were obtained with cDNA probes of about 1kb when at least three adjacent copies of the gene are present. The immunoglobulin heavy chain locus is in the centre of the long arm of chromosome 1. Previously, family studies showed that bona fide MHC class Ib genes segregated independently. Now we show that MHC class II alpha and beta genes and class Ib genes are on the same acrocentric chromosome, with MHC in the middle of the long arm, the class Ib complex (XNC) at the tip or the same arm. Each locus or complex is found on only one pair of chromosomes confirming the diploidization of these genes in the pseudotetraploid X. laevis.
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Affiliation(s)
- M Courtet
- Basel Institute for Immunology, Grenzacherstrasse 487, 4005, Basel, Switzerland
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12
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Flajnik MF, Ohta Y, Greenberg AS, Salter-Cid L, Carrizosa A, Du Pasquier L, Kasahara M. Two Ancient Allelic Lineages at the Single Classical Class I Locus in the Xenopus MHC. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.7.3826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Unlike all other vertebrates examined to date, there is only one detectable class I locus in the Xenopus MHC. On the bases of a nearly ubiquitous and high tissue expression, extensive polymorphism, and MHC linkage, this gene is of the classical or class Ia type. Sequencing analysis of class Ia cDNAs encoded by eight defined MHC haplotypes reveals two very old allelic lineages that perhaps emerged when humans and mice diverged from a common ancestor up to 100 million years ago. The unprecedented age of these lineages suggests that different class Ia genes from ancestors of the laboratory model Xenopus laevis are now expressed as alleles in this species. The lineages are best defined by their cytoplasmic and α2 peptide-binding domains, and there are highly diverse alleles (defined by the α1 peptide-binding domain) in each lineage. Surprisingly, the α3 domains are homogenized in both lineages, suggesting that interallelic gene conversion/recombination maintains the high sequence similarity.
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Affiliation(s)
- Martin F. Flajnik
- *Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33136
- †Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201
| | - Yuko Ohta
- *Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33136
- †Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201
| | - Andrew S. Greenberg
- *Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33136
| | - Luisa Salter-Cid
- *Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33136
| | - Ana Carrizosa
- *Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33136
| | | | - Masanori Kasahara
- §Department of Biosystems Science, Graduate University for Advanced Studies, Hayama, Japan
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Flajnik MF, Ohta Y, Namikawa-Yamada C, Nonaka M. Insight into the primordial MHC from studies in ectothermic vertebrates. Immunol Rev 1999; 167:59-67. [PMID: 10319251 DOI: 10.1111/j.1600-065x.1999.tb01382.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
MHC classical class I and class II genes have been identified in representative species from all major jawed vertebrate taxa, the oldest group being the cartilaginous fish, whereas no class I/II genes of any type have been detected in animals from older taxa. Among ectothermic vertebrate classes, studies of MHC architecture have been done in cartilaginous fish (sharks), bony fish (several teleost species), and amphibians (the frog Xenopus). The Xenopus MHC contains class I, class II, and class III genes, demonstrating that all of these genes were linked in the ancestor of the tetrapods, but the gene order is not the same as that in mouse/man. Studies of polyploid Xenopus suggest that MHC genes can be differentially silenced when multiple copies are present; i.e. MHC 'subregions' can be silenced. Surprisingly, in all teleosts examined to date class I and class II genes are not linked. Likewise, class III genes like the complement genes factor B (Bf) and C4 are scattered throughout the genome of teleosts. However, the presumed classical class I genes are closely linked to the 'immune' proteasome genes, LMP2 and LMP7, and to the peptide-transporter genes (TAP), implying that a true 'class I region' exists in this group. A similar type of linkage group is found in chickens and perhaps Xenopus, and thus it may reveal the ancestral organization of class I-associated genes. In cartilaginous fish, classical and non-classical class I genes have been isolated from three shark species, and class II A and B chain genes from nurse sharks. Studies of MHC linkage in sharks are being carried out to provide further understanding of the putative primordial organization of MHC Segregation studies in one shark family point to linkage of classical class I and class II genes, suggesting that the non-linkage of these genes in teleosts is a derived characteristic.
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Affiliation(s)
- M F Flajnik
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore 21201, USA.
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14
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Kasahara M, Flajnik MF, Ishibashi T, Natori T. Evolution of the major histocompatibility complex: a current overview. Transpl Immunol 1995; 3:1-20. [PMID: 7551974 DOI: 10.1016/0966-3274(95)80001-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- M Kasahara
- Department of Biochemistry, Hokkaido University School of Medicine, Sapporo, Japan
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15
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Affiliation(s)
- J D Graf
- Laboratoire d' Examens Biologiques Hôpital Cantonal Universitaire, Genève, Switzerland
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16
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Farag MA, el Ridi R. Functional markers of the major histocompatibility gene complex of snakes. Eur J Immunol 1990; 20:2029-33. [PMID: 2145172 DOI: 10.1002/eji.1830200922] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In optimal seasonal conditions, outbred adult snakes Psammophis sibilans displayed the major immunological functions related, in mammals, to the presence of the major histocompatibility gene complex (MHC). Thus, out of 30 snake random pairs that exchanged skin transplants 72.9% rejected their allograft in an acute or subacute manner. Strongly significant proliferative response was recorded in 67.3% of 168 separate one-way mixed leukocyte reaction (MLR) cultures. Lymphocytes from 6/11 snakes immunized by skin allografting displayed, after secondary stimulation in vitro, cell-mediated lympholysis (CML) in vitro of 51Cr-labeled lymphoblasts derived from the donor snake. Finally, cytotoxic alloantibodies were readily generated after snake priming with skin allograft and blood cells. Snakes did not only exhibit the major cell- and humoral-mediated immune functions, but these functions appeared to be linked with the degree of MLR disparity. Thus, animals with different MLR rejected skin allografts acutely and produced cytotoxic effector cells. In contrast, MLR-identical animals rejected the skin allograft of their partner chronically and failed to produce killer cells in CML. This significant positive correlation between MLR disparity, graft rejection and CML suggests that the responsible antigens are encoded, as in other vertebrates, by the same genetic system, the MHC.
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Affiliation(s)
- M A Farag
- Zoology Department, Faculty of Science, Cairo University, Giza, Egypt
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17
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Affiliation(s)
- M F Flajnik
- Department of Microbiology and Immunology, University of Miami, FL 33101
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18
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Kaastrup P, Stet RJ, Tigchelaar AJ, Egberts E, van Muiswinkel WB. A major histocompatibility locus in fish: serological identification and segregation of transplantation antigens in the common carp (Cyprinus carpio L.). Immunogenetics 1989; 30:284-90. [PMID: 2793208 DOI: 10.1007/bf02421332] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this study, experiments are described that were designed to investigate whether fish have an immune regulatory systems similar to the major histocompatibility complex (MHC) in higher vertebrate species. From combinations of gynogenetic carp showing either slow or fast rejection of skin transplants, the latter were chosen for alloantiserum production by hyperimmunization with peripheral blood leucocytes. The resulting alloantisera were analyzed for hemagglutinating reactivity with gynogenetic siblings and proved to be operationally monospecific in absorption experiments. The serologically determined carp erythrocyte specificities were shown to correspond to two codominantly expressed allelic products of a single locus and were designated K1 and K2, respectively. Flow cytometer analysis revealed that the same products are also present on leucocytes from peripheral blood, thymus, spleen, and pronephros. K1- and K2-homozygous second-generation gynogenetic siblings were used to study the histocompatibility nature of the K locus products. Skin transplants between K-allogeneic gynogenetic siblings were rejected significantly faster than within K-syngeneic combinations. Taken together, these data suggest that the K locus incorporates MHC class I-like characteristics.
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Affiliation(s)
- P Kaastrup
- Department of Experimental Animal Morphology and Cell Biology, Agricultural University, Wageningen, The Netherlands
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19
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Vidović D, Matzinger P. Unresponsiveness to a foreign antigen can be caused by self-tolerance. Nature 1988; 336:222-5. [PMID: 3143074 DOI: 10.1038/336222a0] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In mice, two sets of genes govern the immune response to the synthetic antigen GT. One maps to the major histocompatibility complex and behaves like a typical immune response gene. The second is a background gene encoding a cell surface structure found on B cells. Mice which express, and are therefore tolerant of, one form of this structure do not respond to GT. Thus, tolerance of self generates holes in the T-cell repertoire, partially crippling the immune system.
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Affiliation(s)
- D Vidović
- Basel Institute for Immunology, Switzerland
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21
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Wolff J, Kobel HR. Creatine kinase isozymes in pipid frogs: Their genetic bases, gene expressional differences, and evolutionary implications. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jez.1402340314] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Bürki E. The expression of creatine kinase isozymes in Xenopus tropicalis, Xenopus laevis laevis, and their viable hybrid. Biochem Genet 1985; 23:73-88. [PMID: 3994660 DOI: 10.1007/bf00499114] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Starch gel electrophoresis of creatine kinase (CK) isozymes of Xenopus tropicalis shows that at least two different genes code for CK in this diploid (2n = 20) species. These genes seen to be orthologous to the CK-A and CK-C genes of extant crossopterygian fish. Additional isozymes may be interpreted either as products of duplicate genes or, more probably, as epigenetically modified forms of the homodimers AtAt and CtCt, respectively. The originally tetraploid species X. laevis laevis (2n = 36), which may have arisen by hybridization of diploid ancestors some 30-40 million years ago, has retained expression of all duplicate CK-A and CK-C genes. Differential expression during ontogenesis (CK-A genes) and in different adult tissues (CK-C genes) indicates that divergence occurred not only with respect to the primary sequence of these duplicate genes, but also with respect to the regulation of their expression. In the interspecific hybrid X. l. laevis x X. tropicalis, all parental CK genes appear to be expressed simultaneously in the heart. However, several subunit combinations cannot be detected on the zymograms.
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Saad AH, El Ridi R. Mixed leukocyte reaction, graft-versus-host reaction, and skin allograft rejection in the lizard, Chalcides ocellatus. Immunobiology 1984; 166:484-93. [PMID: 6237047 DOI: 10.1016/s0171-2985(84)80025-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In optimal seasonal conditions, splenocytes derived from adult lizards, Chalcides ocellatus, responded to vigorous proliferation in two- and one-way mixed leukocyte reaction cultures (MLRC). Data based on a large number of reciprocal MLRC provided evidence for the presence of strong and diverse lymphocyte activating determinants. These findings were fully confirmed in studies of systemic graft-versus-host reaction as intraperitoneal injection of splenocytes into newborn allogeneic recipients consistently induced splenomegaly, retarded growth and mortality. In favourable ambient conditions, adult lizards were also able to reject skin allografts in a subacute manner (mean survival time +/- S.E. = 28.8 +/- 0.88). The results clearly indicate that the lizard, Chalcides ocellatus, is endowed with an advanced type of cell-mediated immunity, and possesses strong and polymorphic histocompatibility antigens. Cellular alloreactivity in MLRC and towards skin grafts was, however, abrogated in winter and significantly diminished during spring through mid-summer as compared to mid-summer till autumn. The present study, thus, suggests that immunological defects attributed to reptiles might be more apparent than real, and essentially ascribable to the fact that the immune capacity of these ectothermic vertebrates is profoundly modulated by environmental conditions.
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Abstract
H-2 restriction is an established characteristic of T-cell behaviour and, in effect, it means that mouse T cells are activated against foreign antigens only if those antigens are presented in a membrane association with molecules of the mouse major histocompatibility complex, H-2. Whether T-cell inactivation or tolerance is also H-2-restricted is a question which has been tested directly and indirectly several times in the past. In each case the answer was 'No' but in each case the answer was inconclusive. Doubts arose because of the observation that activation of T cells, in vivo, is an H-2-restricted event which appears unrestricted because of antigen processing by the host. If antigen processing is involved in the induction of tolerance, then tolerance might also be an H-2-restricted process disguised to appear unrestricted. We report here a study designed to minimize antigen processing in which we find that T-cell tolerance induction to 'self' minor histocompatibility (H) antigens is indeed H-2-restricted.
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Vonwyl E. Lactate dehydrogenase isozymes in the genus Xenopus: analyses of complex isozyme patterns. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1983; 74:725-733. [PMID: 6861472 DOI: 10.1016/0305-0491(83)90134-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
1. Previous work showed that seven out of 13 Xenopus species and subspecies possess a simple pattern of 5 LDH isozymes as it is common to most vertebrates. 2. The remaining six species with more complicated patterns are further analyzed in the present paper. 3. X. l. laevis, X. vestitus and X. wittei are characterized by the appearance of an anodal "sixth band". Two explanations are given. 4. A comparison of organs in X. borealis reveals the bands additional to the five banded pattern as secondary isozymes. 5. The five bands in the A4 region in X. ruwenzoriensis, combinations of A subunits in nature as demonstrated by treatment with antibodies against the purified A4 homopolymer, must be considered as being the result of a duplicated A. locus. 6. The same is possibly true for the closely spaced cathodal bands in X. fraseri. 7. The occurrence of only few expressed duplicated loci among the genus Xenpus indicates progressed diploidization within this genus.
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Wolff J, Kobel HR. Lactate dehydrogenase of Xenopus laevis laevis and Xenopus borealis depends on a multiple gene system. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1982; 223:203-10. [PMID: 7175448 DOI: 10.1002/jez.1402230302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Lactate dehydrogenase isozymes have been reinvestigated in Xenopus laevis laevis and Xenopus borealis. High resolution zymograms of various organs demonstrate that in both species the LDH isozymes are governed basically by a three-gene system: Ldh-a coding for positively charged polypeptide, and Ldh-b and Ldh-c for negatively charged polypeptides (at pH 8.9). These three LDH subunits when assembled in tetramers show differential sensitivity to heat inactivation; the C4 homotetramer is the most labile isozyme. Xenopus is thus similar to Osteichthyes, birds, and mammals that also have a three-gene system for LDH. With respect to tissue specific isozyme expression, Xenopus resembles the more primitive families of bony fish. Superimposed on this three-gene system is a probable gene duplication for both LDH-a and Ldh-b. Heterotetrameric isozymes are formed between the various subunits leading to multibanded zymograms with a total of at least 21 distinct zones of LDH activity. The expression of genes is tissue specific not only for the basic genes, but also for their presumed duplicates. Since both species of Xenopus are ancient tetraploids, duplication of Ldh genes is not surprising.
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Du Pasquier L, Blomberg B. The expression of antibody diversity in natural and laboratory-made polyploid individuals of the clawed toad Xenopus. Immunogenetics 1982; 15:251-60. [PMID: 6802750 DOI: 10.1007/bf00364333] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Antibody diversity, as measured by isoelectric focusing of dinitrophenol-specific antibodies, was compared in different polyploid species of the clawed toad Xenopus. Antibody heterogeneity increased with chromosome number and DNA content from Xenopus tropicalis (2n = 20 chromosome) to Xenopus ruwenzoriensis (2n = 108 chromosomes). Laboratory allopolyploids made by hybridization between two species showing different antibody diversities and different chromosome numbers gave antibody patterns intermediate between the two parents. On the other hand, autopolyploid individuals showed no increase in antibody diversity, showing that increased polyploidy alone cannot be responsible for increased heterogeneity. In contrast to the increase in antibody diversity following polyploidization, the number of expressed major histocompatibility complex alleles, as measured by a mixed lymphocyte reaction, did not increase. This locus appeared to be diploid or in the process of rediploidization in all the Xenopus species studied. Selection has thus operated differentially on the polyploid immunoglobulin and major histocompatibility loci. It apparently preserved the additional heterogeneity acquired for immunoglobulins favoring the expression of an expanded antibody repertoire in polyploid species.
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Blomberg B, Bernard CC, Du Pasquier L. In vitro evidence for T-B lymphocyte collaboration in the clawed toad, Xenopus. Eur J Immunol 1980; 10:869-76. [PMID: 6161828 DOI: 10.1002/eji.1830101112] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Requirements for an in vitro secondary antibody response to the soluble antigens dinitrophenylated keyhole limpet hemocyanin and dinitrophenylated flow gamma-globulin are described for the clawed toad, Xenopus. Priming of both hapten and carrier-specific cells is required in order to obtain good responses to the hapten. The carrier-reactive ("helper") cells do not adhere to nylon wool, are X ray-resistant and surface Ig-negative. The cell adherence and X ray sensitivity characteristics of these Xenopus "T" cells and their ability to generate a mixed lymphocyte response, allogeneic cytotoxic and helper activities, are identical to those of thymus-derived (T) cells in higher vertebrates. The hapten-reactive, antibody-secreting cell precursors are nylon-adherent, X ray-sensitive and surface Ig-positive. In the absence of other distinguishing serological markers for T cells in frogs, and considering the thymus dependency of the helper activity described here, the evidence presented is interpreted as demonstrating the requirement for antigen-specific T-B cell cooperation in response to soluble protein antigens in vitro for Xenopus.
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Vonwyl E, Fischberg M. Lactate dehydrogenase isozymes in the genusXenopus: Species-specific patterns. ACTA ACUST UNITED AC 1980. [DOI: 10.1002/jez.1402110305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Cohen N. Salamanders and the evolution of the major histocompatibility complex. CONTEMPORARY TOPICS IN IMMUNOBIOLOGY 1980; 9:109-39. [PMID: 6444859 DOI: 10.1007/978-1-4615-9131-3_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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