Maternal acceptance of genetically disparate tissue during semiallogeneic pregnancy is believed to require strict regulation of HLA class I gene expression in trophoblast cells at the maternal-fetal interface. Because inappropriate expression might lead to pregnancy failure, it is of the utmost importance to elucidate expression, to establish the mechanisms regulating expression, and to identify pregnancy-associated functions of antigens derived from this multigene family. Significant progress toward these long-range goals has been made in the current funding period, where molecular approaches established differential expression of the HLA class I genes in subpopulations of trophoblast cells, showed that a novel member of the HLA class I gene family, HLA-G, is expressed in placentas, and identified a placenta-targeting 5' regulatory sequence in the HLA-G gene. Further studies suggest that availability of light chains, peptide transporters (TAP-1, TAP-2), proteasome components (LMP2, LMP7), cytokines and cytokine receptors may uniquely govern HLA class I expression in trophoblast cells. Experiments done on HLA-G transgenic mouse placentas have established the usefulness of this model for further studies on HLA class I gene expression and regulation, and other advances that include the technology for generating mouse trophoblast cell lines have been made. Molecular, biochemical, immunological and cell culture techniques will be used to achieve the four Specific Aims of the proposed research. The goal of Specific Aim 1 is to determine whether or not class Ia (HLA-A, -B, -C) and class Ib (HLA-G) genes are co-expressed in human placental cells and whether the proportions of Ia:Ib or their cellular locations change during the course of gestation.
In Specific Aim 2, transgenic mice are used for fine analysis of developmental regulation and cellular localization of HLA class Ia (represented by HLA-B27 transgenic mice) and Ib (HLA-G transgenic) through the course of pregnancy.
Specific Aim 3 addresses the hypothesis that limited availability of intracellular and/or extracellular promoters of HLA class I expression on cell membranes (light chains, TAP- 1, TAP-2, LMP2, LMP7, cytokines and cytokine receptors) controls expression in some trophoblast cell subpopulations.
In Specific Aim 4, trophoblast cell lines generated from the placentas of outbred mice, founder strain mice and mice transgenic for class Ia and Ib genes will be used to establish the role of cytokines in determining class Ia:Ib ratios, steady state levels of class I mRNA and the subcellular location(s) of HLA class I antigens. We expect the results of this research to shed considerable light on crucial issues of HLA-related fertility and reproduction.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD026429-08
Application #
2888993
Study Section
Special Emphasis Panel (ZRG2-BCE (01))
Program Officer
Yoshinaga, Koji
Project Start
1990-01-01
Project End
2001-03-31
Budget Start
1999-04-01
Budget End
2001-03-31
Support Year
8
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Kansas
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
016060860
City
Kansas City
State
KS
Country
United States
Zip Code
66160
Pace, Judith L; Morales, Pedro J; Phillips, Teresa A et al. (2006) Analysis of the soluble isoforms of HLA-G mRNAs and proteins. Methods Mol Med 122:181-203
Hunt, Joan S; Petroff, Margaret G; McIntire, Ramsey H et al. (2005) HLA-G and immune tolerance in pregnancy. FASEB J 19:681-93
McIntire, Ramsey H; Morales, Pedro J; Petroff, Margaret G et al. (2004) Recombinant HLA-G5 and -G6 drive U937 myelomonocytic cell production of TGF-beta1. J Leukoc Biol 76:1220-8
Petroff, Margaret G; Chen, Lieping; Phillips, Teresa A et al. (2003) B7 family molecules are favorably positioned at the human maternal-fetal interface. Biol Reprod 68:1496-504
Morales, Pedro J; Pace, Judith L; Platt, Jeralyn Sue et al. (2003) Placental cell expression of HLA-G2 isoforms is limited to the invasive trophoblast phenotype. J Immunol 171:6215-24
Hunt, J S; Pace, J L; Morales, P J et al. (2003) Immunogenicity of the soluble isoforms of HLA-G. Mol Hum Reprod 9:729-35
Langat, Daudi K; Morales, Pedro J; Fazleabas, Asgerally T et al. (2002) Baboon placentas express soluble and membrane-bound Paan-AG proteins encoded by alternatively spliced transcripts of the class Ib major histocompatibility complex gene, Paan-AG. Immunogenetics 54:164-73
Petroff, Margaret G; Sedlmayr, Peter; Azzola, Dagmar et al. (2002) Decidual macrophages are potentially susceptible to inhibition by class Ia and class Ib HLA molecules. J Reprod Immunol 56:3-17
Audus, Kenneth L; Soares, Michael J; Hunt, Joan S (2002) Characteristics of the fetal/maternal interface with potential usefulness in the development of future immunological and pharmacological strategies. J Pharmacol Exp Ther 301:402-9
Petroff, M G; Chen, L; Phillips, T A et al. (2002) B7 family molecules: novel immunomodulators at the maternal-fetal interface. Placenta 23 Suppl A:S95-101

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