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Bellil H, Ghieh F, Hermel E, Mandon-Pepin B, Vialard F. Human testis-expressed (TEX) genes: a review focused on spermatogenesis and male fertility. Basic Clin Androl 2021; 31:9. [PMID: 33882832 PMCID: PMC8061069 DOI: 10.1186/s12610-021-00127-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/14/2021] [Indexed: 01/28/2023] Open
Abstract
Spermatogenesis is a complex process regulated by a multitude of genes. The identification and characterization of male-germ-cell-specific genes is crucial to understanding the mechanisms through which the cells develop. The term “TEX gene” was coined by Wang et al. (Nat Genet. 2001; 27: 422–6) after they used cDNA suppression subtractive hybridization (SSH) to identify new transcripts that were present only in purified mouse spermatogonia. TEX (Testis expressed) orthologues have been found in other vertebrates (mammals, birds, and reptiles), invertebrates, and yeasts. To date, 69 TEX genes have been described in different species and different tissues. To evaluate the expression of each TEX/tex gene, we compiled data from 7 different RNA-Seq mRNA databases in humans, and 4 in the mouse according to the expression atlas database. Various studies have highlighted a role for many of these genes in spermatogenesis. Here, we review current knowledge on the TEX genes and their roles in spermatogenesis and fertilization in humans and, comparatively, in other species (notably the mouse). As expected, TEX genes appear to have a major role in reproduction in general and in spermatogenesis in humans but also in all mammals such as the mouse. Most of them are expressed specifically or predominantly in the testis. As most of the TEX genes are highly conserved in mammals, defects in the male (gene mutations in humans and gene-null mice) lead to infertility. In the future, cumulative data on the human TEX genes’ physiological functions and pathophysiological dysfunctions should become available and is likely to confirm the essential role of this family in the reproductive process. Thirteen TEX genes are now referenced in the OMIM database, and 3 have been linked to a specific phenotype. TEX11 (on Xq13.1) is currently the gene most frequently reported as being associated with azoospermia.
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Affiliation(s)
- Hela Bellil
- Département de Génétique, CHI de Poissy St Germain en Laye, Poissy, France
| | - Farah Ghieh
- Université Paris-Saclay, UVSQ, INRAE, BREED, F-78350, Jouy-en-Josas, France.,Ecole Nationale Vétérinaire d'Alfort, BREED, F-94700, Maisons-Alfort, France
| | - Emeline Hermel
- Université Paris-Saclay, UVSQ, INRAE, BREED, F-78350, Jouy-en-Josas, France.,Ecole Nationale Vétérinaire d'Alfort, BREED, F-94700, Maisons-Alfort, France
| | - Béatrice Mandon-Pepin
- Université Paris-Saclay, UVSQ, INRAE, BREED, F-78350, Jouy-en-Josas, France.,Ecole Nationale Vétérinaire d'Alfort, BREED, F-94700, Maisons-Alfort, France
| | - François Vialard
- Département de Génétique, CHI de Poissy St Germain en Laye, Poissy, France. .,Université Paris-Saclay, UVSQ, INRAE, BREED, F-78350, Jouy-en-Josas, France. .,Ecole Nationale Vétérinaire d'Alfort, BREED, F-94700, Maisons-Alfort, France.
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Abstract
Most humans lack a functional CASP12 gene, with the nonfunctional variant (CASP12p1), found in 100% of the Caucasian and east Asian population, and in approximately 80% of people of African descent. However, 20% of Africans carry an intact allele of CASP12, which produces a full-length pro-enzyme and increases the risk of sepsis. We examined CASP12 allele distribution in persons from central and southern Asia and found that CASP12 was significantly present in members of the Dravidian language group, particularly in persons from the Indian state of Tamil Nadu.
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Affiliation(s)
- M Yavari
- College of Osteopathic Medicine, Touro University-CA, Vallejo, CA, USA
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3
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Hermel E, Gafni J, Propp SS, Leavitt BR, Wellington CL, Young JE, Hackam AS, Logvinova AV, Peel AL, Chen SF, Hook V, Singaraja R, Krajewski S, Goldsmith PC, Ellerby HM, Hayden MR, Bredesen DE, Ellerby LM. Specific caspase interactions and amplification are involved in selective neuronal vulnerability in Huntington's disease. Cell Death Differ 2004; 11:424-38. [PMID: 14713958 DOI: 10.1038/sj.cdd.4401358] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder resulting in selective neuronal loss and dysfunction in the striatum and cortex. The molecular pathways leading to the selectivity of neuronal cell death in HD are poorly understood. Proteolytic processing of full-length mutant huntingtin (Htt) and subsequent events may play an important role in the selective neuronal cell death found in this disease. Despite the identification of Htt as a substrate for caspases, it is not known which caspase(s) cleaves Htt in vivo or whether regional expression of caspases contribute to selective neuronal cells loss. Here, we evaluate whether specific caspases are involved in cell death induced by mutant Htt and if this correlates with our recent finding that Htt is cleaved in vivo at the caspase consensus site 552. We find that caspase-2 cleaves Htt selectively at amino acid 552. Further, Htt recruits caspase-2 into an apoptosome-like complex. Binding of caspase-2 to Htt is polyglutamine repeat-length dependent, and therefore may serve as a critical initiation step in HD cell death. This hypothesis is supported by the requirement of caspase-2 for the death of mouse primary striatal cells derived from HD transgenic mice expressing full-length Htt (YAC72). Expression of catalytically inactive (dominant-negative) forms of caspase-2, caspase-7, and to some extent caspase-6, reduced the cell death of YAC72 primary striatal cells, while the catalytically inactive forms of caspase-3, -8, and -9 did not. Histological analysis of post-mortem human brain tissue and YAC72 mice revealed activation of caspases and enhanced caspase-2 immunoreactivity in medium spiny neurons of the striatum and the cortical projection neurons when compared to controls. Further, upregulation of caspase-2 correlates directly with decreased levels of brain-derived neurotrophic factor in the cortex and striatum of 3-month YAC72 transgenic mice and therefore suggests that these changes are early events in HD pathogenesis. These data support the involvement of caspase-2 in the selective neuronal cell death associated with HD in the striatum and cortex.
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Affiliation(s)
- E Hermel
- The Buck Institute for Age Research, Novato, CA, USA
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Rao RV, Hermel E, Castro-Obregon S, del Rio G, Ellerby LM, Ellerby HM, Bredesen DE. Coupling endoplasmic reticulum stress to the cell death program. Mechanism of caspase activation. J Biol Chem 2001; 276:33869-74. [PMID: 11448953 DOI: 10.1074/jbc.m102225200] [Citation(s) in RCA: 465] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The endoplasmic reticulum (ER) is the site of assembly of polypeptide chains destined for secretion or routing into various subcellular compartments. It also regulates cellular responses to stress and intracellular Ca(2+) levels. A variety of toxic insults can result in ER stress that ultimately leads to apoptosis. Apoptosis is initiated by the activation of members of the caspase family and serves as a central mechanism in the cell death process. The present study was carried out to determine the role of caspases in triggering ER stress-induced cell death. Treatment of cells with ER stress inducers such as brefeldin-A or thapsigargin induces the expression of caspase-12 protein and also leads to translocation of cytosolic caspase-7 to the ER surface. Caspase-12, like most other members of the caspase family, requires cleavage of the prodomain to activate its proapoptotic form. Caspase-7 associates with caspase-12 and cleaves the prodomain to generate active caspase-12, resulting in increased cell death. We propose that any cellular insult that causes prolonged ER stress may induce apoptosis through caspase-7-mediated caspase-12 activation. The data underscore the involvement of ER and caspases associated with it in the ER stress-induced apoptotic process.
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Affiliation(s)
- R V Rao
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, California 94945, USA
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5
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Chun T, Hermel E, Gaskins HR, Aldrich CJ. Cytotoxic T lymphocyte and cDNA sequence analyses of the MHC class Ib molecule Qa1 in nonobese diabetic mice. Immunogenetics 2001; 53:506-10. [PMID: 11685462 DOI: 10.1007/s002510100357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2001] [Indexed: 11/30/2022]
Affiliation(s)
- T Chun
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Hermel E, Smith C, Aldrich CJ. Allogeneic responses to the class Ib antigen Qa1: limited T-cell receptor Valpha but not Vbeta chain usage. Immunogenetics 2000; 51:600-5. [PMID: 10912511 DOI: 10.1007/s002510000190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E Hermel
- Indiana University School of Medicine, Evansville Center, 47712, USA
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Affiliation(s)
- E Hermel
- Department of Microbiology and Immunology, Indiana University School of Medicine, Evansville Center, Evansville, IN 47712, USA
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Abstract
Proper peptide presentation by major histocompatibility complex (MHC)-encoded class II antigens is dependent on the products of the MHC DM loci. We identified the rabbit orthologues (RLA-DMA and -DMB) of human HLA-DMA and -DMB and found that they have 76.9% and 78.8% identity with HLA-DMA and -DMB, respectively. Like classical class II MHC genes, RLA-DM genes are more closely related to human HLA-DM genes than to mouse H2-DM. Among the DM family, there is a high degree of variability at the amino terminus of the DMa chains, and length variability in the cytoplasmic tails of both DMalpha and DMbeta. The rabbit DM genes are coexpressed with class II genes in lymphoid tissues, as are the DM genes of other mammals. The RLA-DM locus maps to the class II region of the rabbit MHC, and is flanked by the DP and DOB loci. Despite having some similarities to class II genes of bony fishes, the DM family represents a separate branch of the MHC class II family.
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Affiliation(s)
- E Hermel
- Department of Molecular Genetics, University of Cincinnati, Cincinnati, OH 45267-0524, USA.
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Affiliation(s)
- T Chun
- University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801, USA
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Abstract
Class I histocompatibility antigen display is defective in the RMA-S mutant cell line due to a mutation in the Tap-2 gene, which encodes a peptide transporter. Incubation of RMA-S cells with oligomycin, an inhibitor of mitochondrial ATPase, strongly increased lysis by cytotoxic T lymphocytes (CTL) specific for the class Ib antigen H2-M3, and lysis by Qa-1b-specific CTL was restored. Oligomycin did not affect normal class I display on RMA cells. Treatment of RMA-S cells with other inhibitors of mitochondrial function failed to increase lysis by anti-H2-M3 or Qa-1b CTL. Lysis by allogenic CTL specific for H-2b antigens was either not enhanced or only weakly increased, depending upon the H-2 haplotype of the alloreactive effector cells used.
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Affiliation(s)
- E Hermel
- Indiana University School of Medicine, Evansville Center, Indiana 47112, USA
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Kasai M, Hirokawa K, Kajino K, Ogasawara K, Tatsumi M, Hermel E, Monaco JJ, Mizuochi T. Difference in antigen presentation pathways between cortical and medullary thymic epithelial cells. Eur J Immunol 1996; 26:2101-7. [PMID: 8814253 DOI: 10.1002/eji.1830260921] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Antigen presentation by thymic epithelial cells (TEC) to T cells that undergo maturation is one of the major events in the selection of the T cell repertoire. We have already reported that medullary TEC lines (mTEC) established from newborn C57BL/6 (H-2b) mice are able to present a soluble antigen, ovalbumin (OVA), to OVA-specific, I-Ab restricted helper T cell lines but cortical TEC (cTEC) lines are not (Mizuochi, T. et al., J. Exp. Med. 1992. 175: 1601). In this report, to clarify the cause of this difference, we analyzed the biochemical nature as well as the distribution of both major histocompatibility complex (MHC) class II molecules and invariant chains (Ii) in both TEC by immunoprecipitation and laser confocal scanning microscopic analysis, as well as the expression of mRNA encoding H-2Ma or H-2Mb. Our results demonstrate that cTEC and mTEC are both able to present peptide antigens to peptide-specific, I-Ab-restricted helper T cell hybridoma and are able to present class II MHC alloantigens to an I-Ab-specific T cell line, that mRNA for H-2Ma and H-2Mb are expressed in both TEC, that cTEC and mTEC apparently incorporate tetramethylrhodamine isothiocyanate-labeled OVA in the same manner, and that the SDS-stable MHC class II molecules, onto which peptides were loaded, are formed in both cTEC and mTEC. However, these molecules were more rapidly degraded in mTEC than in cTEC. In addition, two Ii-derived polypeptides of approximately 21 kDa and 10 kDa were precipitated by the anti-class II monoclonal antibody Y3P; 10-kDa polypeptides were detected in the both TEC, while 21-kDa polypeptides were detected only in cTEC. Finally, beta chains of MHC class II with less sialylated oligosaccharides were precipitated from the cell surface of cTEC. Taken together, these results suggest that there are substantial differences in the antigen-presenting pathways of cTEC and mTEC, and these difference might be responsible for T cell selection events in the thymus.
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Affiliation(s)
- M Kasai
- Department of Bacterial and Blood Products, National Institute of Health, Tokyo, Japan
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12
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Affiliation(s)
- E Hermel
- Department of Molecular Genetics and the Howard Hughes Medical Institute, University of Cincinnati, Cincinnati, Ohio 45267-0524 USA
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13
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Abstract
The products of the class II-like H2-M genes of the major histocompatibility complex are required for class II antigen processing. We sequenced H2-Ma and Mb from several mouse strains to determine whether these genes are polymorphic like the classical H2-A and E genes, or are oligomorphic, like H2-O. Both Mb loci appear to be transcribed and are distinct from each other. Mb1 and Mb2 differ by about 11% at the nucleotide level and are most dissimilar in their second exons (corresponding to the beta 1 domain). Relative to the published Mb1d haplotype sequence, the products of the b, g7, f, and k2 alleles of Mb1 from Mus musculus domesticus and the separate mouse species Mus spretus differ by only one to four amino acids. The majority of the changes occurred in the second exon of Mb1, in contrast to HLA-DMB, the human orthologue. Little polymorphism was seen for Mb2, and Ma was invariant in all strains tested. The similarity of the g7 allele to those from other haplotypes makes it unlikely that the M class II genes play a role in the autoimmune diabetes of NOD strain mice. The M genes are regulated in a manner similar to classical class II genes, in that they are upregulated by IFN-gamma in macrophages, and to a lesser extent by IL4 in B cells. When modeled on the crystal structure of the HLA-DR1 class II molecule, nearly all of the differences between M beta 1 and M beta 2 affect residues facing away from the putative peptide binding groove.
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Affiliation(s)
- E Hermel
- Department of Molecular Genetics, University of Cincinnati, OH 45267-0524, USA
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Hermel E, Robinson PJ, She JX, Lindahl KF. Sequence divergence of B2m alleles of wild Mus musculus and Mus spretus implies positive selection. Immunogenetics 1993; 38:106-16. [PMID: 8482575 DOI: 10.1007/bf00190898] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mouse beta 2-microglobulin (beta 2m) is polymorphic. Sequences of five allelic wild mouse B2m genes have been determined from the large exons of genomic DNA using the polymerase chain reaction. Relative to the standard B2m(a) allele, the products of four alleles of Mus musculus origin (w2, w3, w4, and w5), differ by only one or two amino acids. w5 has a single nucleotide change, Asp85-->Val, and is identical to the c allele. w3 has two changes, Val(-13)-->Ile and Lys44-->Glu. w2 differs at Arg81-->Thr and w4 at His34-->Gln, and they share the Asp85-->Val change with B2mc and B2mw5. w5 and c cells are lysed by S19.8, a monoclonal antibody specific for beta 2mb (Ala85), in a complement-mediated cytotoxicity assay, whereas w4 cells are not. Thus, distant changes appear to introduce subtle conformational effects on beta 2m structure. Five independent isolates of Mus spretus (w1) differ the most from B2m(a), with 12 amino acid changes and only one silent substitution. Replacements predicted from the nucleotide sequence occur in loops of the molecule facing away from the class I heavy chain and not in regions where beta 2m associates with class I alpha 3 domains. Concordantly, the w1-5 allelic forms of beta 2m associate well with H-2 heavy chains. The many amino acid changes in the spretus sequence and the paucity of silent substitutions suggest that B2m has been subject to positive selection.
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Affiliation(s)
- E Hermel
- Howard Hughes Medical Institute, Graduate Immunology Program, Dallas, TX
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15
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Aldrich CJ, Waltrip R, Hermel E, Attaya M, Lindahl KF, Monaco JJ, Forman J. T cell recognition of QA-1b antigens on cells lacking a functional Tap-2 transporter. J Immunol 1992; 149:3773-7. [PMID: 1460275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
MHC class Ia H chains and beta 2-microglobulin assemble with appropriate peptides to form stable cell surface molecules that serve as targets for Ag-specific CTL. The structural similarities of class Ia and the less polymorphic Q/T/M (class Ib) molecules suggest that class Ib molecules also play a role in antigen presentation, although the origin of the peptides they present remains mostly unclear. The cell line RMA-S has a defect in class I Ag presentation, presumably due to a mutation in a peptide transporter gene. This defect can be overcome by transfection of RMA-S cells with the Tap-2 gene (formerly Ham-2) that encodes an ATP-binding transporter protein. We now show that a substantial portion of alloreactive CTL specific for Qa-1 class Ib molecules recognize Qa-1b on RMA-S cells and thus differ from most class Ia specific CTL. Those anti-Qa-1b CTL that do not recognize untransfected RMA-S do lyse RMA-S transfected with Tap-2. We also examine the effects of Qdm, a gene that maps to the D region and alters recognition of Qa-1. Qdm(k) strains lack an epitope(s) recognized by some (Qdm dependent) anti-Qa-1 CTL whereas Qdm+ strains express this epitope. Thus, Qdm-dependent CTL do not recognize Qa-1 on Qdm(k) targets whereas Qdm-independent CTL recognize Qa-1 epitopes in all strains. Although Qdm-independent CTL varied as to whether they recognized RMA-S vs RMA, all nine Qdm-dependent clones only recognized Qa-1b on RMA and not RMA-S. This result is consistent with Qdm encoding a peptide dependent upon the TAP transporter for cell membrane expression.
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Affiliation(s)
- C J Aldrich
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
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16
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Aldrich CJ, Waltrip R, Hermel E, Attaya M, Lindahl KF, Monaco JJ, Forman J. T cell recognition of QA-1b antigens on cells lacking a functional Tap-2 transporter. The Journal of Immunology 1992. [DOI: 10.4049/jimmunol.149.12.3773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
MHC class Ia H chains and beta 2-microglobulin assemble with appropriate peptides to form stable cell surface molecules that serve as targets for Ag-specific CTL. The structural similarities of class Ia and the less polymorphic Q/T/M (class Ib) molecules suggest that class Ib molecules also play a role in antigen presentation, although the origin of the peptides they present remains mostly unclear. The cell line RMA-S has a defect in class I Ag presentation, presumably due to a mutation in a peptide transporter gene. This defect can be overcome by transfection of RMA-S cells with the Tap-2 gene (formerly Ham-2) that encodes an ATP-binding transporter protein. We now show that a substantial portion of alloreactive CTL specific for Qa-1 class Ib molecules recognize Qa-1b on RMA-S cells and thus differ from most class Ia specific CTL. Those anti-Qa-1b CTL that do not recognize untransfected RMA-S do lyse RMA-S transfected with Tap-2. We also examine the effects of Qdm, a gene that maps to the D region and alters recognition of Qa-1. Qdm(k) strains lack an epitope(s) recognized by some (Qdm dependent) anti-Qa-1 CTL whereas Qdm+ strains express this epitope. Thus, Qdm-dependent CTL do not recognize Qa-1 on Qdm(k) targets whereas Qdm-independent CTL recognize Qa-1 epitopes in all strains. Although Qdm-independent CTL varied as to whether they recognized RMA-S vs RMA, all nine Qdm-dependent clones only recognized Qa-1b on RMA and not RMA-S. This result is consistent with Qdm encoding a peptide dependent upon the TAP transporter for cell membrane expression.
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Affiliation(s)
- C J Aldrich
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - R Waltrip
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - E Hermel
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - M Attaya
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - K F Lindahl
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - J J Monaco
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
| | - J Forman
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
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17
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Attaya M, Jameson S, Martinez CK, Hermel E, Aldrich C, Forman J, Lindahl KF, Bevan MJ, Monaco JJ. Ham-2 corrects the class I antigen-processing defect in RMA-S cells. Nature 1992; 355:647-9. [PMID: 1538753 DOI: 10.1038/355647a0] [Citation(s) in RCA: 244] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The murine major histocompatibility complex (MHC) contains two genes (Ham-1 and Ham-2) that encode members of a super-family of ATP-dependent transport proteins. These genes are believed to mediate the transport of peptide antigen from the cytoplasm into the lumen of the endoplasmic reticulum for binding by MHC class I molecules. Evidence for such a function has come from the rescue of class I surface expression by a cloned copy of the human homologue of Ham-1, PSF-1, in a human cell line that is defective in antigen processing. A mutant murine cell line, RMA-S, has an identical antigen-processing-defective phenotype. Here we show that expression of a cloned copy of the Ham-2 gene in RMA-S cells results in recovery of the ability to process and present class I-restricted antigens to cytotoxic T lymphocytes, and in partial recovery of class I surface expression. Processing defects for classical (H-2 K and D) and non-classical (Qa1 and HMT) class I molecules are corrected by Ham-2. These data indicate that both MHC-linked transporter genes are probably required for class I antigen processing, and that the functional transporter in this pathway may consist of a Ham-1/Ham-2 heterodimer.
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Affiliation(s)
- M Attaya
- Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0678
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18
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Abstract
Molecular identification proved Mta, the maternally transmitted antigen of mice, to be a model minor histocompatibility (H) antigen. It consists of a peptide, MTF, that is presented on the cell surface by an H-2 class-I molecule, HMT. MTF is derived from ND1, a mitochondrially encoded protein, and the amino-terminal N-formyl-methionine is essential for binding to HMT; conservative substitutions at the sixth residue causes MTF to be a minor H antigen. HMT is encoded by the M3 gene at the telomeric end of the H-2 complex. The peptide-binding site of HMT is hydrophobic, and allelic forms of the mature protein differ by only three amino acids. Homologues and analogues of the mouse Mta system have recently been identified in rats.
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Affiliation(s)
- K Fischer Lindahl
- Howard Hughes Medical Institute, Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9050
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19
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Davies JD, Wilson DH, Hermel E, Lindahl KF, Butcher GW, Wilson DB. Generation of T cells with lytic specificity for atypical antigens. I. A mitochondrial antigen in the rat. J Exp Med 1991; 173:823-32. [PMID: 1672544 PMCID: PMC2190809 DOI: 10.1084/jem.173.4.823] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
F1 rats primed with normal parental strain lymphocyte populations and restimulated in culture with parental lymphoblasts generate potent cytotoxic T cell responses to unusual antigen systems. Here we describe in the Lewis (L)/DA anti-DA combination an antigen system most likely of mitochondrial origin with the following properties: it is transmitted maternally from DA strain females, inherited in an extra-chromosomal manner, restricted by class I RT1Aa major histocompatibility complex gene products, extinguished on target cells treated with chloramphenicol, and its pattern of expression in different rat strains correlates with restriction fragment-length polymorphisms of mitochondrial DNA. Sequence analysis of the rat ND1 gene indicates that the maternally transferred factor in the rat is not a homologue of the maternally transmitted factor responsible for the mitochondrial antigen in mice. In keeping with its inheritance from DA females, this antigen is present on target cells from (DA female x L male)F1 donors and all other F1 combinations derived from DA female parents, but absent from target cells from some F1 combinations (L/DA and Wistar-Furth [WF]/DA) derived from DA strain males. The presence of this antigen in other F1 combinations (Brown Norway [BN]/DA, August 2880 [AUG]/DA, and PVG/DA) indicates that this mitochondrial antigen system is shared by the DA, BN, and PVG strains, but not by the L and WF strains.
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Affiliation(s)
- J D Davies
- Medical Biology Institute, La Jolla, California 92037
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Abstract
The RMA-S mutant T cell line is defective in H-2b restricted antigen presentation and has markedly reduced surface expression of Kb and Db. We examined RMA-S for the expression of the medial class I histocompatibility antigens Qa1b and Mta. While RMA-S targets varied in their susceptibility to lysis by cytotoxic T lymphocytes (CTL) specific for Qa1b, Mta levels were detectable but consistently low compared to the parent RMA cell line. Addition of synthetic ND1 alpha 1-26 or ND1 alpha 1-17 peptides that mimic MTF alpha (the ligand of Mta) increased killing of RMA-S by anti-Mta alpha CTL to levels comparable to or better than RMA, with 300 nM peptide being fully effective. None of the MTF peptides increased the killing of RMA-S by anti-H-2b or anti-Qa1b CTL, even at the highest (1 microM) peptide concentrations. RMA-S cells treated with 100 microM of either the ND1 alpha 4-26 or ND1 alpha 1-26 peptides showed a small increase in the fluorescent staining for beta 2-microglobulin but not for H-2Kb or H-2Db. These results show that Mta and Qa1b, although affected, are not obliterated by the defect in RMA-S cells; that the association of MTF peptides with HMT is exclusive; and that MTF enters the endoplasmic reticulum in the same fashion as other endogenous peptides.
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Affiliation(s)
- E Hermel
- Howard Hughes Medical Institute, Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9050
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21
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Davies JD, Wilson DH, Hermel E, Lindahl KF, Butcher GW, Wilson DB. A maternally transmitted antigen system in the rat. Transplant Proc 1990; 22:2547-8. [PMID: 2264144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- J D Davies
- Medical Biology Institute, La Jolla, California
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22
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Loveland B, Wang CR, Yonekawa H, Hermel E, Lindahl KF. Maternally transmitted histocompatibility antigen of mice: a hydrophobic peptide of a mitochondrially encoded protein. Cell 1990; 60:971-80. [PMID: 2317868 DOI: 10.1016/0092-8674(90)90345-f] [Citation(s) in RCA: 276] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
MTF, a murine minor histocompatibility antigen, is maternally inherited and thought to be encoded by a mitochondrial gene. We sequenced the entire mitochondrial genomes from three strains that differ in MTF Mtf beta, Mtf gamma, and Mtf delta) and compared the sequences with the known, Mtf alpha, mitochondrial DNA sequence. We found only one site where all four genomes differed, affecting amino acid residue 6 of ND1, a subunit of NADH dehydrogenase. Incubation of non-Mtf alpha target cells with synthetic peptide ND1 alpha 1-17 (the first 17 amino acid of the ND1 protein of Mtf alpha mice) rendered them susceptible to lysis by MTF alpha-specific cytotoxic T cells (CTLs). Similarly, non-Mtf beta target cells were lysed by MTF beta-specific CTLs after incubation with the allelic form ND1 beta 1-17. Thus, Mtf is attributable to allelic variation at a single residue of the ND1 protein. Cells can therefore display peptides derived from mitochondrially encoded proteins, and such peptides can be histocompatibility antigens.
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Affiliation(s)
- B Loveland
- Howard Hughes Medical Institute, Department of Microbiology, Dallas, Texas
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23
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Fischer Lindahl K, Hermel E, Loveland BE, Richards S, Wang CR, Yonekawa H. Molecular definition of a mitochondrially encoded mouse minor histocompatibility antigen. Cold Spring Harb Symp Quant Biol 1989; 54 Pt 1:563-9. [PMID: 2700946 DOI: 10.1101/sqb.1989.054.01.067] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- K Fischer Lindahl
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas 75235-9050
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