Lösliches HLA‐G als Qualitätsparameter in der assistierten Reproduktion – ein Artefakt als Basis für eine (lebens-)wichtige Entscheidung?

 

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Zusammenfassung

Auf der Suche nach Qualitätsparametern als Ergänzung zur morphologischen Beurteilung des humanen Präimplantationsembryos, aber auch der Oozyten, wurde in den letzten Jahren zunehmend lösliches (solubles) HLA‐G (sHLA‐G) diskutiert. Während mancherorts die sHLA‐G-Bestimmung in Kulturmedien früher menschlicher Teilungsstadien schon im klinischen Bereich angeboten wurde und kommerzielle Testsysteme erhältlich sind, zeigt die vorhandene wissenschaftliche Literatur deutlich, dass der Einsatz von sHLA‐G für diese Zwecke bedenklich ist. Wir demonstrieren in unserer Übersichtsarbeit einerseits, dass sich bei genauerer Betrachtung technische Unzulänglichkeiten bei den derzeit publizierten Nachweismethoden offenbaren. Andererseits diskutieren wir deutliche Hinweise aus der Grundlagenforschung, wonach das Konzept vom „aktiv sezernierten solublen HLA‐G“ selbst im klaren Widerspruch zu etablierten molekularen Mechanismen zum Abbau schadhafter, potenziell toxischer Messenger-RNA-Moleküle steht. Aufgrund des „nonsense mediated RNA-decay“ (NMD) wäre gar nicht mit einer messbaren sHLA‐G-Menge im Kulturüberstand einzelner Eizellen oder Präimplantationsembryonen zu rechnen. Es ist nicht zuletzt im Sinne der Glaubwürdigkeit der biomedizinischen Forschung und zur Vermeidung von „Wissenschaftsblasen“ wichtig, dass vor einer Anwendung neuer Marker die nötigen wissenschaftlichen und technischen Grundlagen kritisch geprüft werden – insbesondere, wenn es um (lebens-)wichtige Entscheidungen wie die Auswahl menschlicher Embryonen für den Transfer in den Uterus geht.

Abstract

Soluble HLA‐G has been proposed as a useful parameter for embryo and probably oocyte viability in ART. But while some clinicians already offer sHLA‐G analysis of cultured human embryos to infertile patients using commercially available test systems, there is considerable doubt about the validity of this marker. We present a review of the available data in the literature, which reveals serious technical problems with the detection methods and a critical lack of standardisation and reproducibility. Moreover, the concept of “active secretion of HLA‐G” is clearly contradictory to well established concepts of RNA decay. Considering what is known of nonsense mediated RNA decay (NMD), measurable amounts of sHLA‐G should not be expected in supernatants of human oocytes and preimplantation embryos at all. To avoid creating “scientific bubbles”, the scientific and technical basis needs to be critically investigated before a “new marker” is introduced in clinics. In our opinion, the decision which oocytes to fertilise and cultivate or which embryos to transfer into the uterus are too important to be based on a probable artefact.

Literatur

• 1 Rienzi L, Ubaldi F M, Iacobelli M et al. Significance of metaphase II human oocyte morphology on ICSI outcome.  Fertil Steril. 2008;  90 1692-1700
  CrossrefPubMedGoogle Scholar
• 2 Zollner U, Zollner K P, Hartl G et al. The use of a detailed zygote score after IVF/ICSI to obtain good quality blastocysts: the German experience.  Hum Reprod. 2002;  17 1327-1333
  CrossrefPubMedGoogle Scholar
• 3 Sakkas D, Gardner D K. Noninvasive methods to assess embryo quality.  Curr Opin Obstet Gynecol. 2005;  17 283-286
  CrossrefPubMedGoogle Scholar
• 4 Brison D R, Houghton F D, Falconer D et al. Identification of viable embryos in IVF by non-invasive measurement of amino acid turnover.  Hum Reprod. 2004;  19 2319-2324
  CrossrefPubMedGoogle Scholar
• 5 Gardner D K, Lane M, Stevens J et al. Noninvasive assessment of human embryo nutrient consumption as a measure of developmental potential.  Fertil Steril. 2001;  76 1175-1180
  CrossrefPubMedGoogle Scholar
• 6 Sakkas D, Lu C, Zulfikaroglu E et al. A soluble molecule secreted by human blastocysts modulates regulation of HOXA10 expression in an epithelial endometrial cell line.  Fertil Steril. 2003;  80 1169-1174
  CrossrefPubMedGoogle Scholar
• 7 Lopes A S, Greve T, Callesen H. Quantification of embryo quality by respirometry.  Theriogenology. 2007;  6 21-31
  PubMedGoogle Scholar
• 8 Vergouw C G, Botros L L, Roos P et al. Metabolomic profiling by near-infrared spectroscopy as a tool to assess embryo viability: a novel, non-invasive method for embryo selection.  Hum Reprod. 2008;  23 1499-1504
  CrossrefPubMedGoogle Scholar
• 9 O'Neill C, Gidley-Baird A A, Pike I L et al. Use of a bioassay for embryo-derived platelet-activating factor as a means of assessing quality and pregnancy potential of human embryos.  Fertil Steril. 1987;  47 969-975
  PubMedGoogle Scholar
• 10 Katz-Jaffe M G, Schoolcraft W B, Gardner D K. Analysis of protein expression (secretome) by human and mouse preimplantation embryos.  Fertil Steril. 2006;  86 678-685
  CrossrefPubMedGoogle Scholar
• 11 Jurisicova A, Casper R F, MacLusky N J et al. Embryonic human leukocyte antigen-G expression: possible implications for human preimplantation development.  Fertil Steril. 1996;  65 997-1002
  PubMedGoogle Scholar
• 12 Fuzzi B, Rizzo R, Criscuoli L et al. HLA-G expression in early embryos is a fundamental prerequisite for the obtainment of pregnancy.  Eur J Immunol. 2002;  32 311-315
  CrossrefPubMedGoogle Scholar
• 13 Sher G, Keskintepe L, Nouriani M et al. Expression of sHLA-G in supernatants of individually cultured 46-h embryos: a potentially valuable indicator of ‘embryo competency and IVF outcome.  Reprod Biomed Online. 2004;  9 74-78
  CrossrefPubMedGoogle Scholar
• 14 Noci I, Fuzzi B, Rizzo R et al. Embryonic soluble HLA-G as a marker of developmental potential in embryos.  Hum Reprod. 2005;  20 138-146
  PubMedGoogle Scholar
• 15 Sher G, Keskintepe L, Batzofin J et al. Influence of early ICSI-derived embryo sHLA-G expression on pregnancy and implantation rates: a prospective study.  Hum Reprod. 2005;  20 1359-1363
  CrossrefPubMedGoogle Scholar
• 16 Yie S M, Balakier H, Motamedi G et al. Secretion of human leukocyte antigen-G by human embryos is associated with a higher in vitro fertilization pregnancy rate.  Fertil Steril. 2005;  83 30-36
  CrossrefPubMedGoogle Scholar
• 17 Rebmann V, Switala M, Eue I et al. Rapid evaluation of soluble HLA-G levels in supernatants of in vitro fertilized embryos.  Hum Immunol. 2007;  68 251-258
  CrossrefPubMedGoogle Scholar
• 18 Rizzo R, Fuzzi B, Stignani M et al. Soluble HLA-G molecules in follicular fluid: a tool for oocyte selection in IVF?.  J Reprod Immunol. 2007;  74 133-142
  CrossrefPubMedGoogle Scholar
• 19 Menicucci A, Noci I, Fuzzi B et al. Nonclassic sHLA class I in human oocyte culture medium.  Hum Immunol. 1999;  60 1054-1057
  CrossrefPubMedGoogle Scholar
• 20 Jurisicova A, Casper R F, MacLusky N J et al. HLA-G expression during preimplantation human embryo development.  Proc Natl Acad Sci USA. 1996;  93 161-165
  CrossrefPubMedGoogle Scholar
• 21 Geraghty D E, Koller B H, Orr H A T. A human major histocompatibility complex class I gene that encodes a protein with a shortened cytoplasmic segment.  Proc Natl Acad Sci USA. 1987;  84 9145-9149
  CrossrefPubMedGoogle Scholar
• 22 Kuhlmann D, Dohr G, Pusch H H et al. Absence of HLA class I and class II antigens as well as beta 2-microglobulin from normal and pathological human spermatozoa.  Tissue Antigens. 1986;  27 179-184
  CrossrefPubMedGoogle Scholar
• 23 Dohr G A, Motter W, Leitinger S et al. Lack of expression of HLA [corrected] class I and class II molecules on the human oocyte.  J Immunol. 1987;  138 3766-3770
  PubMedGoogle Scholar
• 24 Kovats S, Main E K, Librach C et al. A class I antigen, HLA-G, expressed in human trophoblasts.  Science. 1990;  248 220-223
  CrossrefPubMedGoogle Scholar
• 25 Hutter H, Hammer A, Blaschitz A et al. Expression of HLA class I molecules in human first trimester and term placenta trophoblast.  Cell Tissue Res. 1996;  286 439-447
  CrossrefPubMedGoogle Scholar
• 26 Ober C. HLA and pregnancy: the paradox of the fetal allograft.  Am J Hum Genet. 1998;  62 1-5
  CrossrefPubMedGoogle Scholar
• 27 Moffett A, Loke C. Immunology of placentation in eutherian mammals.  Nat Rev Immunol. 2006;  6 584-594
  CrossrefPubMedGoogle Scholar
• 28 Bainbridge D, Ellis S, Le Bouteiller P et al. HLA-G remains a mystery.  Trends Immunol. 2001;  22 548-552
  CrossrefPubMedGoogle Scholar
• 29 Apps R, Gardner L, Moffett A. A critical look at HLA-G.  Trends Immunol. 2008;  29 313-321
  CrossrefPubMedGoogle Scholar
• 30 Fujii T, Ishitani A, Geraghty D E. A soluble form of the HLA-G antigen is encoded by a messenger ribonucleic acid containing intron 4.  J Immunol. 1994;  153 5516-5524
  PubMedGoogle Scholar
• 31 Hiby S E, King A, Sharkey A et al. Molecular studies of trophoblast HLA-G: polymorphism, isoforms, imprinting and expression in preimplantation embryo.  Tissue Antigens. 1999;  53 1-13
  CrossrefPubMedGoogle Scholar
• 32 Ulbrecht M, Maier S, Hofmeister V et al. Truncated HLA-G isoforms are retained in the endoplasmic reticulum and insufficiently provide HLA-E ligands.  Hum Immunol. 2004;  65 200-208
  CrossrefPubMedGoogle Scholar
• 33 Bainbridge D R, Ellis S A, Sargent I L. The short forms of HLA-G are unlikely to play a role in pregnancy because they are not expressed at the cell surface.  J Reprod Immunol. 2000;  47 1-16
  CrossrefPubMedGoogle Scholar
• 34 Paul P, Cabestre F A, Ibrahim E C et al. Identification of HLA-G7 as a new splice variant of the HLA-G mRNA and expression of soluble HLA-G5, -G6, and -G7 transcripts in human transfected cells.  Hum Immunol. 2000;  61 1138-1149
  CrossrefPubMedGoogle Scholar
• 35 [No authors listed]. Proceedings from the 4th International Conference on HLA-G. July 2006, Paris, France.  Hum Immunol. 2007;  68 219-306
  CrossrefPubMedGoogle Scholar
• 36 Davies B, Hiby S, Gardner L et al. HLA-G expression by tumors.  Am J Reprod Immunol. 2001;  45 103-107
  CrossrefPubMedGoogle Scholar
• 37 Blaschitz A, Juch H, Volz A et al. The soluble pool of HLA-G produced by human trophoblasts does not include detectable levels of the intron 4-containing HLA-G5 and HLA-G6 isoforms.  Mol Hum Reprod. 2005;  11 699-710
  CrossrefPubMedGoogle Scholar
• 38 Rehwinkel J, Jeroen R, Izauralde E. Nonsense mediated mRNA-decay: target genes and functional diversification of effectors.  Trends Biochem Sci. 2006;  31 639-646
  CrossrefPubMedGoogle Scholar
• 39 Mendell J T, Sharifi N A, Meyers J L et al. Nonsense surveillance regulates expression of diverse classes of mammalian transcripts and mutes genomic noise.  Nat Genet. 2004;  36 1073-1078
  CrossrefPubMedGoogle Scholar
• 40 Park G M, Lee S, Park B et al. Soluble HLA-G generated by proteolytic shedding inhibits NK-mediated cell lysis.  Biochem Biophys Res Commun. 2004;  313 606-611
  CrossrefPubMedGoogle Scholar
• 41 Juch H, Blaschitz A, Daxböck C et al. A novel sandwich ELISA for alpha1 domain based detection of soluble HLA-G heavy chains.  J Immunol Methods. 2005;  307 96-106
  CrossrefPubMedGoogle Scholar
• 42 Sageshima N, Shobu T, Awai K et al. Soluble HLA-G is absent from human embryo cultures: a reassessment of sHLA-G detection methods.  J Reprod Immunol. 2007;  75 11-22
  CrossrefPubMedGoogle Scholar
• 43 Van Lierop M J, Wijnands F, Loke Y W et al. Detection of HLA-G by a specific sandwich ELISA using monoclonal antibodies G233 and 56B.  Mol Hum Reprod. 2002;  8 776-784
  CrossrefPubMedGoogle Scholar
• 44 Juch H, Daxboeck C, Blaschitz A et al. Human preimplantation embryos do not produce detectable amounts of any soluble isoform of HLA-G.  Placenta. 2008;  29 A51
  CrossrefPubMedGoogle Scholar
• 45 Fuzzi B, Rizzo R, Criscuoli L et al. HLA-G expression in early embryos is a fundamental prerequisite for the obtainment of pregnancy.  Eur J Immunol. 2002;  32 311-315
  CrossrefPubMedGoogle Scholar
• 46 Sher G, Keskintepe L, Nouriani M et al. Expression of sHLA-G in supernatants of individually cultured 46-h embryos: a potentially valuable indicator of ‘embryo competency and IVF outcome.  Reprod Biomed Online. 2004;  9 74-78
  CrossrefPubMedGoogle Scholar
• 47 Noci I, Fuzzi B, Rizzo R et al. Embryonic soluble HLA-G as a marker of developmental potential in embryos.  Hum Reprod. 2005;  20 138-146
  PubMedGoogle Scholar
• 48 Yie S M, Balakier H, Motamedi G et al. Secretion of human leukocyte antigen-G by human embryos is associated with a higher in vitro fertilization pregnancy rate.  Fertil Steril. 2005;  83 30-36
  CrossrefPubMedGoogle Scholar
• 49 Sher G, Keskintepe L, Batzofin J et al. Influence of early ICSI-derived embryo sHLA-G expression on pregnancy and implantation rates: a prospective study.  Hum Reprod. 2005;  20 1359-1363
  CrossrefPubMedGoogle Scholar
• 50 Yao Y Q, Barlow D H, Sargent I L. Differential expression of alternatively spliced transcripts of HLA-G in human preimplantation embryos and inner cell masses.  J Immunol. 2005;  175 8379-8385
  PubMedGoogle Scholar
• 51 Ménézo Y, Elder K, Viville S. Soluble HLA-G release by the human embryo: an interesting artefact?.  Reprod Biomed Online. 2006;  13 763-764
  CrossrefPubMedGoogle Scholar
• 52 Sargent I, Swales A, Ledee N et al. sHLA-G production by human IVF embryos: can it be measured reliably?.  J Reprod Immunol. 2007;  75 128-132
  CrossrefPubMedGoogle Scholar
• 53 Warner C M, Comiskey M, Clisham P R et al. Soluble HLA-G (sHLA-G) a predictor of IVF outcome?.  J Assist Reprod Genet. 2004;  21 315-316
  CrossrefPubMedGoogle Scholar
• 54 Vercammen M J, Verloes A, Van de Velde H et al. Accuracy of soluble human leukocyte antigen-G for predicting pregnancy among women undergoing infertility treatment: meta-analysis.  Hum Reprod Update. 2008;  14 209-218
  CrossrefPubMedGoogle Scholar
• 55 Rebmann V, Switala M, Eue I et al. Rapid evaluation of soluble HLA-G levels in supernatants of in vitro fertilized embryos.  Hum Immunol. 2007;  68 251-258
  CrossrefPubMedGoogle Scholar

Dr. med. Herbert Juch

Institut für Zellbiologie, Histologie und Embryologie
Medizinische Universität Graz

Harrachgasse 21/7

8010 Graz

Österreich

Email: herbert.juch@medunigraz.at