Semin Reprod Med 2016; 34(01): 017-026
DOI: 10.1055/s-0035-1570030
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Stem Cells and Pregnancy Disorders: From Pathological Mechanisms to Therapeutic Horizons

J. L. James
1   Department of Obstetrics and Gynaecology, University of Auckland, Grafton, Auckland, New Zealand
› Author Affiliations
Further Information

Publication History

Publication Date:
22 December 2015 (online)

Abstract

Blastocyst implantation, placental development, and fetal growth are all dependent on the interactions between the developing placenta and the decidualized endometrium. Adult stem cell populations resident in both the placenta and endometrium play key roles in directing cell fate and tissue organization throughout pregnancy. As we begin to understand how these stem cell populations contribute to successful pregnancies, we can begin to ask what roles they play in the pathogenesis of pregnancy disorders from implantation failure and miscarriage through fetal growth restriction and preeclampsia. Furthermore, as our understanding of the therapeutic applications of stem cells in other organs rapidly expands, can we make stem cell therapies a clinical reality in obstetric medicine? This review aims to summarize our current understanding of the role reproductive stem cells play in pregnancy success, and how they may help us better understand the underlying pathogenesis of pregnancy disorders to offer novel therapeutic solutions in the future.

 
  • References

  • 1 Villar J, Carroli G, Wojdyla D , et al; World Health Organization Antenatal Care Trial Research Group. Preeclampsia, gestational hypertension and intrauterine growth restriction, related or independent conditions?. Am J Obstet Gynecol 2006; 194 (4) 921-931
  • 2 Yu CK, Khouri O, Onwudiwe N, Spiliopoulos Y, Nicolaides KH ; Fetal Medicine Foundation Second-Trimester Screening Group. Prediction of pre-eclampsia by uterine artery Doppler imaging: relationship to gestational age at delivery and small-for-gestational age. Ultrasound Obstet Gynecol 2008; 31 (3) 310-313
  • 3 Barker DJ. The fetal origins of coronary heart disease. Eur Heart J 1997; 18 (6) 883-884
  • 4 James JL, Srinivasan S, Alexander M, Chamley LW. Can we fix it? Evaluating the potential of placental stem cells for the treatment of pregnancy disorders. Placenta 2014; 35 (2) 77-84
  • 5 James JL, Carter AM, Chamley LW. Human placentation from nidation to 5 weeks of gestation. Part I: What do we know about formative placental development following implantation?. Placenta 2012; 33 (5) 327-334
  • 6 Boyd J, Hamilton W. The Human Placenta. Cambridge: W. Heffer & Sons Ltd; 1970
  • 7 Cartwright JE, Fraser R, Leslie K, Wallace AE, James JL. Remodelling at the maternal-fetal interface: relevance to human pregnancy disorders. Reproduction 2010; 140 (6) 803-813
  • 8 Benirschke K, Kaufmann P. Pathology of the Human Placenta. 4th ed. New York: Springer-Verlag; 2000
  • 9 Salamonsen LA, Nie G, Hannan NJ, Dimitriadis E. Society for Reproductive Biology Founders' Lecture 2009. Preparing fertile soil: the importance of endometrial receptivity. Reprod Fertil Dev 2009; 21 (7) 923-934
  • 10 Koot YE, Teklenburg G, Salker MS, Brosens JJ, Macklon NS. Molecular aspects of implantation failure. Biochim Biophys Acta 2012; 1822 (12) 1943-1950
  • 11 Lathi RB, Gray Hazard FK, Heerema-McKenney A, Taylor J, Chueh JT. First trimester miscarriage evaluation. Semin Reprod Med 2011; 29 (6) 463-469
  • 12 Ford HB, Schust DJ. Recurrent pregnancy loss: etiology, diagnosis, and therapy. Rev Obstet Gynecol 2009; 2 (2) 76-83
  • 13 Tong M, Viall CA, Chamley LW. Antiphospholipid antibodies and the placenta: a systematic review of their in vitro effects and modulation by treatment. Hum Reprod Update 2015; 21 (1) 97-118
  • 14 Bose P, Kadyrov M, Goldin R , et al. Aberrations of early trophoblast differentiation predispose to pregnancy failure: lessons from the anti-phospholipid syndrome. Placenta 2006; 27 (8) 869-875
  • 15 Pijnenborg R, Anthony J, Davey DA , et al. Placental bed spiral arteries in the hypertensive disorders of pregnancy. Br J Obstet Gynaecol 1991; 98 (7) 648-655
  • 16 James JL, Whitley GS, Cartwright JE. Pre-eclampsia: fitting together the placental, immune and cardiovascular pieces. J Pathol 2010; 221 (4) 363-378
  • 17 Clausson B, Gardosi J, Francis A, Cnattingius S. Perinatal outcome in SGA births defined by customised versus population-based birthweight standards. BJOG 2001; 108 (8) 830-834
  • 18 Eskenazi B, Fenster L, Sidney S, Elkin EP. Fetal growth retardation in infants of multiparous and nulliparous women with preeclampsia. Am J Obstet Gynecol 1993; 169 (5) 1112-1118
  • 19 Burton GJ, Woods AW, Jauniaux E, Kingdom JC. Rheological and physiological consequences of conversion of the maternal spiral arteries for uteroplacental blood flow during human pregnancy. Placenta 2009; 30 (6) 473-482
  • 20 Sibley CP. Understanding placental nutrient transfer—why bother? New biomarkers of fetal growth. J Physiol 2009; 587 (Pt 14): 3431-3440
  • 21 Langheinrich AC, Vorman S, Seidenstücker J , et al. Quantitative 3D micro-CT imaging of the human feto-placental vasculature in intrauterine growth restriction. Placenta 2008; 29 (11) 937-941
  • 22 Macara L, Kingdom JC, Kaufmann P , et al. Structural analysis of placental terminal villi from growth-restricted pregnancies with abnormal umbilical artery Doppler waveforms. Placenta 1996; 17 (1) 37-48
  • 23 Gargett CE, Masuda H. Adult stem cells in the endometrium. Mol Hum Reprod 2010; 16 (11) 818-834
  • 24 Tanaka S, Kunath T, Hadjantonakis AK, Nagy A, Rossant J. Promotion of trophoblast stem cell proliferation by FGF4. Science 1998; 282 (5396) 2072-2075
  • 25 Senner CE, Hemberger M. Regulation of early trophoblast differentiation - lessons from the mouse. Placenta 2010; 31 (11) 944-950
  • 26 James JL, Stone PR, Chamley LW. The isolation and characterization of a population of extravillous trophoblast progenitors from first trimester human placenta. Hum Reprod 2007; 22 (8) 2111-2119
  • 27 Telugu BP, Adachi K, Schlitt JM , et al. Comparison of extravillous trophoblast cells derived from human embryonic stem cells and from first trimester human placentas. Placenta 2013; 34 (7) 536-543
  • 28 Aboagye-Mathiesen G, Laugesen J, Zdravkovic M, Ebbesen P. Isolation and characterization of human placental trophoblast subpopulations from first-trimester chorionic villi. Clin Diagn Lab Immunol 1996; 3 (1) 14-22
  • 29 Blanpain C, Horsley V, Fuchs E. Epithelial stem cells: turning over new leaves. Cell 2007; 128 (3) 445-458
  • 30 Tiruthani K, Sarkar P, Rao B. Trophoblast differentiation of human embryonic stem cells. Biotechnol J 2013; 8 (4) 421-433
  • 31 Roberts RM, Loh KM, Amita M , et al. Differentiation of trophoblast cells from human embryonic stem cells: to be or not to be?. Reproduction 2014; 147 (5) D1-D12
  • 32 Hemberger M, Udayashankar R, Tesar P, Moore H, Burton GJ. ELF5-enforced transcriptional networks define an epigenetically regulated trophoblast stem cell compartment in the human placenta. Hum Mol Genet 2010; 19 (12) 2456-2467
  • 33 Genbacev O, Donne M, Kapidzic M , et al. Establishment of human trophoblast progenitor cell lines from the chorion. Stem Cells 2011; 29 (9) 1427-1436
  • 34 Spitalieri P, Cortese G, Pietropolli A , et al. Identification of multipotent cytotrophoblast cells from human first trimester chorionic villi. Cloning Stem Cells 2009; 11 (4) 535-556
  • 35 James J, Chamley L. Isolation of trophoblast Hoechst side populations from human first trimester villi. Placenta 2012; 33 (9) A54
  • 36 Gamage T, Chamley L, James J. Side-population trophoblasts can be isolated from human placentae throughout gestation. Reprod Sci 2015; 22 (Suppl. 01) 300A
  • 37 Dominici M, Le Blanc K, Mueller I , et al. Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for Cellular Therapy position statement. Cytotherapy 2006; 8 (4) 315-317
  • 38 Yen BL, Huang HI, Chien CC , et al. Isolation of multipotent cells from human term placenta. Stem Cells 2005; 23 (1) 3-9
  • 39 Igura K, Zhang X, Takahashi K, Mitsuru A, Yamaguchi S, Takashi TA. Isolation and characterization of mesenchymal progenitor cells from chorionic villi of human placenta. Cytotherapy 2004; 6 (6) 543-553
  • 40 Asahara T, Masuda H, Takahashi T , et al. Bone marrow origin of endothelial progenitor cells responsible for postnatal vasculogenesis in physiological and pathological neovascularization. Circ Res 1999; 85 (3) 221-228
  • 41 Gang EJ, Jeong JA, Han S, Yan Q, Jeon CJ, Kim H. In vitro endothelial potential of human UC blood-derived mesenchymal stem cells. Cytotherapy 2006; 8 (3) 215-227
  • 42 Castrechini NM, Murthi P, Gude NM , et al. Mesenchymal stem cells in human placental chorionic villi reside in a vascular Niche. Placenta 2010; 31 (3) 203-212
  • 43 Kong P, Xie X, Li F, Liu Y, Lu Y. Placenta mesenchymal stem cell accelerates wound healing by enhancing angiogenesis in diabetic Goto-Kakizaki (GK) rats. Biochem Biophys Res Commun 2013; 438 (2) 410-419
  • 44 Meraviglia V, Vecellio M, Grasselli A , et al. Human chorionic villus mesenchymal stromal cells reveal strong endothelial conversion properties. Differentiation 2012; 83 (5) 260-270
  • 45 Pittenger MF, Mackay AM, Beck SC , et al. Multilineage potential of adult human mesenchymal stem cells. Science 1999; 284 (5411) 143-147
  • 46 Caplan AI, Dennis JE. Mesenchymal stem cells as trophic mediators. J Cell Biochem 2006; 98 (5) 1076-1084
  • 47 Shohara R, Yamamoto A, Takikawa S , et al. Mesenchymal stromal cells of human umbilical cord Wharton's jelly accelerate wound healing by paracrine mechanisms. Cytotherapy 2012; 14 (10) 1171-1181
  • 48 Gnecchi M, Zhang Z, Ni A, Dzau VJ. Paracrine mechanisms in adult stem cell signaling and therapy. Circ Res 2008; 103 (11) 1204-1219
  • 49 Mirotsou M, Zhang Z, Deb A , et al. Secreted frizzled related protein 2 (Sfrp2) is the key Akt-mesenchymal stem cell-released paracrine factor mediating myocardial survival and repair. Proc Natl Acad Sci U S A 2007; 104 (5) 1643-1648
  • 50 Cervelló I, Gil-Sanchis C, Mas A , et al. Human endometrial side population cells exhibit genotypic, phenotypic and functional features of somatic stem cells. PLoS ONE 2010; 5 (6) e10964
  • 51 Masuda H, Matsuzaki Y, Hiratsu E , et al. Stem cell-like properties of the endometrial side population: implication in endometrial regeneration. PLoS ONE 2010; 5 (4) e10387
  • 52 Miyazaki K, Maruyama T, Masuda H , et al. Stem cell-like differentiation potentials of endometrial side population cells as revealed by a newly developed in vivo endometrial stem cell assay. PLoS ONE 2012; 7 (12) e50749
  • 53 Masuda H, Anwar SS, Bühring HJ, Rao JR, Gargett CE. A novel marker of human endometrial mesenchymal stem-like cells. Cell Transplant 2012; 21 (10) 2201-2214
  • 54 Schwab KE, Gargett CE. Co-expression of two perivascular cell markers isolates mesenchymal stem-like cells from human endometrium. Hum Reprod 2007; 22 (11) 2903-2911
  • 55 Cervelló I, Mas A, Gil-Sanchis C , et al. Reconstruction of endometrium from human endometrial side population cell lines. PLoS ONE 2011; 6 (6) e21221
  • 56 Gargett CE, Ye L. Endometrial reconstruction from stem cells. Fertil Steril 2012; 98 (1) 11-20
  • 57 James JL, Carter AM, Chamley LW. Human placentation from nidation to 5 weeks of gestation. Part II: Tools to model the crucial first days. Placenta 2012; 33 (5) 335-342
  • 58 Salker M, Teklenburg G, Molokhia M , et al. Natural selection of human embryos: impaired decidualization of endometrium disables embryo-maternal interactions and causes recurrent pregnancy loss. PLoS ONE 2010; 5 (4) e10287
  • 59 Teklenburg G, Salker M, Heijnen C, Macklon NS, Brosens JJ. The molecular basis of recurrent pregnancy loss: impaired natural embryo selection. Mol Hum Reprod 2010; 16 (12) 886-895
  • 60 Murakami K, Lee YH, Lucas ES , et al. Decidualization induces a secretome switch in perivascular niche cells of the human endometrium. Endocrinology 2014; 155 (11) 4542-4553
  • 61 Karaer A, Cigremis Y, Celik E, Urhan Gonullu R. Prokineticin 1 and leukemia inhibitory factor mRNA expression in the endometrium of women with idiopathic recurrent pregnancy loss. Fertil Steril 2014; 102 (4) 1091-1095.e1
  • 62 Salker MS, Nautiyal J, Steel JH , et al. Disordered IL-33/ST2 activation in decidualizing stromal cells prolongs uterine receptivity in women with recurrent pregnancy loss. PLoS ONE 2012; 7 (12) e52252
  • 63 Murakami K, Bhandari H, Lucas ES , et al. Deficiency in clonogenic endometrial mesenchymal stem cells in obese women with reproductive failure—a pilot study. PLoS ONE 2013; 8 (12) e82582
  • 64 Reus AD, Stephenson MD, van Dunné FM , et al. Chorionic villous vascularization related to phenotype and genotype in first trimester miscarriages in a recurrent pregnancy loss cohort. Hum Reprod 2013; 28 (4) 916-923
  • 65 Sipos PI, Bourque SL, Hubel CA , et al. Endothelial colony-forming cells derived from pregnancies complicated by intrauterine growth restriction are fewer and have reduced vasculogenic capacity. J Clin Endocrinol Metab 2013; 98 (12) 4953-4960
  • 66 Ligi I, Simoncini S, Tellier E , et al. A switch toward angiostatic gene expression impairs the angiogenic properties of endothelial progenitor cells in low birth weight preterm infants. Blood 2011; 118 (6) 1699-1709
  • 67 Rolfo A, Giuffrida D, Nuzzo AM , et al. Pro-inflammatory profile of preeclamptic placental mesenchymal stromal cells: new insights into the etiopathogenesis of preeclampsia. PLoS ONE 2013; 8 (3) e59403
  • 68 Meekins JW, Luckas MJ, Pijnenborg R, McFadyen IR. Histological study of decidual spiral arteries and the presence of maternal erythrocytes in the intervillous space during the first trimester of normal human pregnancy. Placenta 1997; 18 (5–6) 459-464
  • 69 Zhao G, Zhou X, Chen S , et al. Differential expression of microRNAs in decidua-derived mesenchymal stem cells from patients with pre-eclampsia. J Biomed Sci 2014; 21: 81
  • 70 Hwang JH, Lee MJ, Seok OS , et al. Cytokine expression in placenta-derived mesenchymal stem cells in patients with pre-eclampsia and normal pregnancies. Cytokine 2010; 49 (1) 95-101
  • 71 Bills VL, Hamdollah-Zadeh M, Soothill PW, Harper SJ, Bates DO. The role of VEGF-A165b in trophoblast survival. BMC Pregnancy Childbirth 2014; 14: 278
  • 72 Segerer SE, Rieger L, Kapp M , et al. MIC-1 (a multifunctional modulator of dendritic cell phenotype and function) is produced by decidual stromal cells and trophoblasts. Hum Reprod 2012; 27 (1) 200-209
  • 73 Zhu XY, Lerman A, Lerman LO. Concise review: mesenchymal stem cell treatment for ischemic kidney disease. Stem Cells 2013; 31 (9) 1731-1736
  • 74 Devine SM, Cobbs C, Jennings M, Bartholomew A, Hoffman R. Mesenchymal stem cells distribute to a wide range of tissues following systemic infusion into nonhuman primates. Blood 2003; 101 (8) 2999-3001
  • 75 Barbash IM, Chouraqui P, Baron J , et al. Systemic delivery of bone marrow-derived mesenchymal stem cells to the infarcted myocardium: feasibility, cell migration, and body distribution. Circulation 2003; 108 (7) 863-868
  • 76 von Bahr L, Batsis I, Moll G , et al. Analysis of tissues following mesenchymal stromal cell therapy in humans indicates limited long-term engraftment and no ectopic tissue formation. Stem Cells 2012; 30 (7) 1575-1578
  • 77 Pellegrini G, Rama P, Mavilio F, De Luca M. Epithelial stem cells in corneal regeneration and epidermal gene therapy. J Pathol 2009; 217 (2) 217-228
  • 78 Proulx S, Fradette J, Gauvin R, Larouche D, Germain L. Stem cells of the skin and cornea: their clinical applications in regenerative medicine. Curr Opin Organ Transplant 2011; 16 (1) 83-89
  • 79 Jones H, Klanke C, Ayres N , et al. Nanoparticle-mediated trophoblast-specific gene transfer in an in vitro model of human trophoblast. Reprod Sci 2013; 20 (3) 303A
  • 80 Harris LK, Kotamraju VR, Teesalu T, Ruoslahti E. Identification of novel placental homing peptides. Placenta 2012; 33 (9) A44
  • 81 Birchmeier C, Birchmeier W. Molecular aspects of mesenchymal-epithelial interactions. Annu Rev Cell Biol 1993; 9: 511-540
  • 82 Nagori CB, Panchal SY, Patel H. Endometrial regeneration using autologous adult stem cells followed by conception by in vitro fertilization in a patient of severe Asherman's syndrome. J Hum Reprod Sci 2011; 4 (1) 43-48
  • 83 Hayashi T, Kitaya K, Tada Y, Taguchi S, Funabiki M, Nakamura Y. Single curettage endometrial biopsy injury in the proliferative phase improves reproductive outcome of subsequent in vitro fertilization-embryo transfer cycle in infertile patients with repeated embryo implantation failure. Clin Exp Obstet Gynecol 2013; 40 (3) 323-326
  • 84 Potdar N, Gelbaya T, Nardo LG. Endometrial injury to overcome recurrent embryo implantation failure: a systematic review and meta-analysis. Reprod Biomed Online 2012; 25 (6) 561-571
  • 85 Introna M, Rambaldi A. Mesenchymal stromal cells for prevention and treatment of graft-versus-host disease: successes and hurdles. Curr Opin Organ Transplant 2015; 20 (1) 72-78
  • 86 Jaslow CR, Carney JL, Kutteh WH. Diagnostic factors identified in 1020 women with two versus three or more recurrent pregnancy losses. Fertil Steril 2010; 93 (4) 1234-1243
  • 87 Tse WT, Pendleton JD, Beyer WM, Egalka MC, Guinan EC. Suppression of allogeneic T-cell proliferation by human marrow stromal cells: implications in transplantation. Transplantation 2003; 75 (3) 389-397
  • 88 Augello A, Tasso R, Negrini SM, Cancedda R, Pennesi G. Cell therapy using allogeneic bone marrow mesenchymal stem cells prevents tissue damage in collagen-induced arthritis. Arthritis Rheum 2007; 56 (4) 1175-1186
  • 89 Aggarwal S, Pittenger MF. Human mesenchymal stem cells modulate allogeneic immune cell responses. Blood 2005; 105 (4) 1815-1822
  • 90 Melief SM, Schrama E, Brugman MH , et al. Multipotent stromal cells induce human regulatory T cells through a novel pathway involving skewing of monocytes toward anti-inflammatory macrophages. Stem Cells 2013; 31 (9) 1980-1991
  • 91 Smith SD, Dunk CE, Aplin JD, Harris LK, Jones RL. Evidence for immune cell involvement in decidual spiral arteriole remodeling in early human pregnancy. Am J Pathol 2009; 174 (5) 1959-1971
  • 92 Robertson SA, Moldenhauer LM. Immunological determinants of implantation success. Int J Dev Biol 2014; 58 (2–4) 205-217
  • 93 Jin LP, Chen QY, Zhang T, Guo PF, Li DJ. The CD4+CD25 bright regulatory T cells and CTLA-4 expression in peripheral and decidual lymphocytes are down-regulated in human miscarriage. Clin Immunol 2009; 133 (3) 402-410
  • 94 Kuon RJ, Strowitzki T, Sohn C, Daniel V, Toth B. Immune profiling in patients with recurrent miscarriage. J Reprod Immunol 2015; 108: 136-141
  • 95 Spaggiari GM, Capobianco A, Abdelrazik H, Becchetti F, Mingari MC, Moretta L. Mesenchymal stem cells inhibit natural killer-cell proliferation, cytotoxicity, and cytokine production: role of indoleamine 2,3-dioxygenase and prostaglandin E2. Blood 2008; 111 (3) 1327-1333
  • 96 Abumaree MH, Al Jumah MA, Kalionis B , et al. Human placental mesenchymal stem cells (pMSCs) play a role as immune suppressive cells by shifting macrophage differentiation from inflammatory M1 to anti-inflammatory M2 macrophages. Stem Cell Rev 2013; 9 (5) 620-641
  • 97 Hida N, Nishiyama N, Miyoshi S , et al. Novel cardiac precursor-like cells from human menstrual blood-derived mesenchymal cells. Stem Cells 2008; 26 (7) 1695-1704
  • 98 Patel AN, Park E, Kuzman M, Benetti F, Silva FJ, Allickson JG. Multipotent menstrual blood stromal stem cells: isolation, characterization, and differentiation. Cell Transplant 2008; 17 (3) 303-311
  • 99 Salgado SS, Pathmeswaran A. Effects of placental infarctions on the fetal outcome in pregnancies complicated by hypertension. J Coll Physicians Surg Pak 2008; 18 (4) 213-216
  • 100 McDermott M, Gillan JE. Chronic reduction in fetal blood flow is associated with placental infarction. Placenta 1995; 16 (2) 165-170
  • 101 Tran TC, Kimura K, Nagano M , et al. Identification of human placenta-derived mesenchymal stem cells involved in re-endothelialization. J Cell Physiol 2011; 226 (1) 224-235
  • 102 Redline RW. Villitis of unknown etiology: noninfectious chronic villitis in the placenta. Hum Pathol 2007; 38 (10) 1439-1446
  • 103 Salafia CM, Vintzileos AM, Silberman L, Bantham KF, Vogel CA. Placental pathology of idiopathic intrauterine growth retardation at term. Am J Perinatol 1992; 9 (3) 179-184
  • 104 Le Maitre CL, Baird P, Freemont AJ, Hoyland JA. An in vitro study investigating the survival and phenotype of mesenchymal stem cells following injection into nucleus pulposus tissue. Arthritis Res Ther 2009; 11 (1) R20
  • 105 Hare JM, Difede D, Heldman AW. Use of stem cells for ischemic cardiomyopathy—reply. JAMA 2013; 309 (14) 1458-1459
  • 106 Abumaree M, Al Jumah M, Pace RA, Kalionis B. Immunosuppressive properties of mesenchymal stem cells. Stem Cell Rev 2012; 8 (2) 375-392
  • 107 Abumaree MH, Al Jumah MA, Kalionis B , et al. Phenotypic and functional characterization of mesenchymal stem cells from chorionic villi of human term placenta. Stem Cell Rev 2013; 9 (1) 16-31
  • 108 Freyman T, Polin G, Osman H , et al. A quantitative, randomized study evaluating three methods of mesenchymal stem cell delivery following myocardial infarction. Eur Heart J 2006; 27 (9) 1114-1122
  • 109 Srinivasan S, Chamley L, James J. Exploring the potential of mesenchymal stem cell transplantation into human placentae in vitro. Reprod Sci 2015; 22 (Suppl 1): 301A
  • 110 Schumacher B, Moise Jr KJ. Fetal transfusion for red blood cell alloimmunization in pregnancy. Obstet Gynecol 1996; 88 (1) 137-150
  • 111 Mold JE, Michaëlsson J, Burt TD , et al. Maternal alloantigens promote the development of tolerogenic fetal regulatory T cells in utero. Science 2008; 322 (5907) 1562-1565
  • 112 Khosrotehrani K, Johnson KL, Cha DH, Salomon RN, Bianchi DW. Transfer of fetal cells with multilineage potential to maternal tissue. JAMA 2004; 292 (1) 75-80
  • 113 Campagnoli C, Roberts IA, Kumar S, Bennett PR, Bellantuono I, Fisk NM. Identification of mesenchymal stem/progenitor cells in human first-trimester fetal blood, liver, and bone marrow. Blood 2001; 98 (8) 2396-2402