[Frontiers in Bioscience, Landmark, 25, 912-929, Jan 1, 2020]

Alpha-fetoprotein is an autoantigen in hepatocellular carcinoma and juvenile Batten disease

Roberto Bei1, Gerald J. Mizejewski2

1Department of Clinical Sciences and Translational Medicine, University of Rome “Tor Vergata”, Rome 00133, Italy, 2Division of Translational Medicine, Molecular Diagnostics, Wadsworth Center, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, New York 12201-0509


1. Abstract
2. Introduction
3. Autoantigens and autoimmunity
4. Disordered self-proteins and autoimmunity
5. Is AFP a disordered protein?
6. Spontaneous immune response to AFP in hepatocellular cancer (HCC) patients
7. Batten disease and AFP autoantibodies
8. Conclusion
9. Acknowledgement
10. References


Failure of immune tolerance leads to production of autoantibodies to self-antigens. The repertoire of autoantibodies detected in cancer patients can indicate the presence of autoimmune disease. Alpha-fetoprotein (AFP) autoantibodies have been found in patients with hepatocellular carcinoma (HCC) and in juvenile Batten disease (BD), a neurodegenerative condition involving autoimmunity. Variant conformational forms of AFP together with exposed occult antigenic determinant sites on the AFP polypeptide resemble the features of a disordered protein which can impair central immune tolerance. These aberrant structural protein forms can lead to the persistence of autoantibody production by immune sensitized B-lymphocytes. Thus, it is not surprising that AFP, a self-antigen, can induce autoimmune responses in humans. Herein, we discuss the molecular and antigenic properties of AFP which make it a disordered protein, and its ability to induce autoantibody production to AFP cryptic epitopes in both HHC and BD patients. Such insights might aid in the future design of AFP-based vaccines and to discovery of novel pathogenic mechanisms of autoimmune diseases which demonstrate the presence of denatured intermediate forms of AFP.


1. K. Abbas, P. Lichtman, S. Pitlai: Cellular and molecular. Immunology, Ninth Edition Philadelphia, Elsevier, 97-107 (2018)

2. P. Parham: The Immune System, 3rd Edition, Garland Science, Taylor & Frances group, Philadelphia, 11 (2009)

3. N. R. Rose: The Autoimmune diseases, Chapter 2, Academic Press, New York (2013)

4. H. Wardemann, M.C. Nussenzweig: B-cell self-tolerance in humans. Adv Immunol, 95, 83-110 (2007)
DOI: 10.1016/S0065-2776(07)95003-8

5. B. Kyewski, L. Klein: A central role for central tolerance. Annu Rev Immunol 24, 571-606 (2006)
DOI: 10.1146/annurev.immunol.23.021704.115601

6. C.C. Goodnow, J. Sprent, B. Fazekas de St. Groth, C. G. Vinuesa: Cellular and genetic mechanisms of self tolerance and autoimmunity. Nature 435, 590-97 (2005)
DOI: 10.1038/nature03724

7. R. Bei, L. Masuelli, C. Palumbo, M. Modesti, A. Modesti: A common repertoire of autoantibodies is shared by cancer and autoimmune disease patients: Inflammation in their induction and impact on tumor growth. Cancer Lett 281, 8-23 (2009)
DOI: 10.1016/j.canlet.2008.11.009

8. M. Benvenuto, R, Mattera, L. Masuelli, I. Tresoldi, M.G. Giganti, G.V. Frajese, V. Manzari, A. Modesti, R. Bei: The crossroads between cancer immunity and autoimmunity: antibodies to self antigens. Front Biosci (Landmark Ed) 22, 1289-1329 (2017)
DOI: 10.2741/4545

9. R. Bei, G. J. Mizejewski: Alpha fetoprotein is more than a hepatocellular cancer biomarker: from spontaneous immune response in cancer patients to the development of an AFP-based cancer vaccine. Curr Mol Med 11, 564-81 (2011)
DOI: 10.2174/156652411800615162

10. J. A. Castaneda, D.A. Pearce: Identification of alpha-fetoprotein as an autoantigen in juvenile Batten disease. Neurobiology of Disease 29, 92-102 (2008)
DOI: 10.1016/j.nbd.2007.08.007

11. J. Guo, X. Zhou: Regulatory T cells turn pathogenic. Cell Mol Immunol 12, 525-32 (2015)
DOI: 10.1038/cmi.2015.12

12. T. Tani, K. Tanaka, J. Idezuka, M. Nishizawa: Regulatory T cells in paraneoplastic neurological syndromes. J Neuroimmunol 196, 166-69 (2008)
DOI: 10.1016/j.jneuroim.2008.03.002

13. F. A. Cooles, J. D.Isaacs, A. E Anderson: Treg cells in rheumatoid arthritis: an update. Curr Rheumatol Rep 15, 352 (2013)
DOI: 10.1007/s11926-013-0352-0

14. A.B. Poletaev, L.P. Churilov, Y.L Stoev, M. Agapov: Immunophysiology and Immunopathology: natural autoimmunity in human health and disease. Pathophysiology, 19, 221-31 (2012)
DOI: 10.1016/j.pathophys.2012.07.003

15. J. Huang, W. Honda: CED: A conformational epitope database. BMC Immunology 7, 7-9 (2006)
DOI: 10.1186/1471-2172-7-7

16. C. Alberts: Molecular Biology of the Cell. Garland Science, New York, 1401-405 (2002)

17. P.H. Plotz: The autoantibody repertoire: searching for order, Nat Rev Immunol 3, 73-78 (2003)
DOI: 10.1038/nri976

18. P.L. Carl, B.R. Temple, P. L. Cohen: Most nuclear systemic autoantigens are extremely disordered proteins: implications for the etiology of systemic autoimmunity. Arthritis Res Ther 7, R1360-1374 (2005)
DOI: 10.1186/ar1832

19. A. Lanzavecchia: How can cryptic epitopes trigger autoimmunity. J Exp Med 181,1945-48 (1995)
DOI: 10.1084/jem.181.6.1945

20. G. J. Mizejewski: Alpha-fetoprotein as a biologic response modifier: relevance to domain and subdomain structure. Proc Soc Exp Biol Med 215, 333-62 (1997)
DOI: 10.3181/00379727-215-44143

21. A. J. Luft, F. L. Lorscheider: Structural analysis of human and bovine alpha-fetoprotein by electron microscopy, image processing, and circular dichroism. Biochemistry 22: 5978-81 (1983)
DOI: 10.1021/bi00294a043

22. G. Mizejewski, G. Smith, G. Butterstein: Review and proposed action of alpha-fetoprotein growth inhibitory peptides as estrogen and cytoskeleton-associated factors. Cell Biol Int 28, 913-33 (2004)
DOI: 10.1016/j.cellbi.2004.09.005

23. G. J. Mizejewski. The phylogeny of alpha-fetoprotein in vertebrates: survey of biochemical and physiological data. Crit Rev Eukaryot Gene Expr 5, 281-316 (1995)
DOI: 10.1615/CritRevEukarGeneExpr.v5.i3-4.40

24. S. Naidu, M. L. Peterson, B. T. Spear: Alpha-fetoprotein related gene (ARG): a new member of the albumin gene family that is no longer functional in primates. Gene 449, 95-102 (2010)
DOI: 10.1016/j.gene.2009.08.014

25. G. J. Mizejewski: Physiology of alpha-fetoprotein as a biomarker for perinatal distress: relevance to adverse pregnancy outcome. Exp Biol Med (Maywood) 232, 993-1004 (2007)
DOI: 10.3181/0612-MR-291

26. G. J. Mizejewski: New insights into AFP structure and function: potential biomedical applications. In: Mizejewski GJ. Porter IH, Eds. Alpha-Fetoprotein and Congenital Disorders. Orlando: Academic Press; 5-34 (1985)

27. H. F. Deutsch. Chemistry and biology of alpha-fetoprotein. Adv Cancer Res 56, 253-312 (1991)
DOI: 10.1016/S0065-230X(08)60483-2

28. K. Hirano, Y. Watanabe, T. Adachi, Y. Ito, M. Sugiura: Drug binding properties of human alpha-foetoprotein. Biochem J 231, 189-91 (1985)
DOI: 10.1042/bj2310189

29. P. Hanke, C. Rabe, M. Serwe, S. Böhm, C. Pagenstecher, T. Sauerbruch, W. H. Caselmann. Cirrhotic patients with or without hepatocellular carcinoma harbour AFP-specific T lymphocytes that can be activated in vitro by human alpha-fetoprotein. Scand J Gastroenterol 37, 949-55 (2002)
DOI: 10.1080/003655202760230928

30. C. M. Jr Vollmer, F. C. Eilber, L. H. Butterfield, A. Ribas, V. B. Dissette, A. Koh, L. D. Montejo, M. C. Lee, K. J. Andrews, W. H. McBride, J. A. Glaspy, J. S. Economou: Alpha-fetoprotein-specific genetic immunotherapy for hepatocellular carcinoma. Cancer Res 59, 3064-67 (1999)

31. G. J. Mizejewski. Biological role of alpha-fetoprotein in cancer: prospects for anticancer therapy. Expert Rev Anticancer Ther 2, 709-35 (2002)
DOI: 10.1586/14737140.2.6.709

32. G. J. Mizejewski: Alpha-fetoprotein structure and function: relevance to isoforms, epitopes, and conformational variants. Exp Biol Med (Maywood) 226, 377-408 (2001)
DOI: 10.1177/153537020122600503

33. Mizejewski GJ: Biological roles of alpha-fetoprotein during pregnancy and perinatal development. Exp Biol Med (Maywood) 229, 439-63 (2004)
DOI: 10.1177/153537020422900602

34. A. K. Yazova, A.I. Goussev, M. Christiansen, N.E. Kushlinsky, E. Stogova, B. Norgaard-Pedersen, G. I. Abelev: Human fetal and tumor alpha-fetoproteins differ in conformationally dependent epitope variants expression. Immunol Lett 85, 261-70 (2003)
DOI: 10.1016/S0165-2478(02)00207-9

35. S. S. Leong, A. P Middelberg: The refolding of different alpha-fetoprotein variants. Protein Sci 15, 2040-50 (2006)
DOI: 10.1110/ps.062262406

36. R. Bei, A. Budillon, M. G. Reale, G. Capuano, D. Pomponi, G. Budillon, L. Frati, R. Muraro: Cryptic epitopes on alpha-fetoprotein induce spontaneous immune responses in hepatocellular carcinoma, liver cirrhosis, and chronic hepatitis patients. Cancer Res 59, 5471-74 (1999)

37. B. Norgaard-Pedersen, N.H. Axelsen: Alpha-fetoprotein-like activity in sera from patients with malignant and non-malignant disease and healthy individuals. Clin Chem Acta 71, 343-47 (1976)
DOI: 10.1016/0009-8981(76)90551-9

38. L. Beneduce, F. Castaldi, M. Marino, N. Tono, A. Gatta, P. Pontisso, G. Faasina: Improvement of liver cancer detection with simultaneous assessment of circulating levels of free alpha-fetoprotein (AFP. and AFP-IgM complexes. Int J Biol Markers 19, 155-59 (2004)
DOI: 10.1177/172460080401900211

39. J. Jingting, W. Changping, X. Ning, Z. yibei, W. Jun, J. Mei, X. Bin, N.E. Peter, Z. Xueguan: Clinical evaluation of serum alpha-fetoprotein-IgM immune complexes on the diagnosis of primary hepatocellular carcinoma. J Clin Lab Anal 23, 213-18 (2009)
DOI: 10.1002/jcla.20321

40. S.L. Sheng, Q. Wang, G. Huang, B. Yu, W. X. Qin: Simultaneous determination of alpha-fetoprotein immune complexes and alpha-fetoprotein concentration in hepatocellular carcinoma using dual-label time-resolved immunofluorometric assays. J Clin Lab Anal 23, 179-85 (2009)
DOI: 10.1002/jcla.20316

41. J. Wu, H. Zou, J. T. Jiang, X. D. Li, X. M. Zhao, K. Jar, H. Wang, B. Xu, C. P. Wu: Clinical application of serum alpha-fetoprotein-IgM complexes on the diagnosis of primary hepatocellular carcinoma in Kazakh and Han populations. Tumori 99, 535-9 (2013)
DOI: 10.1177/030089161309900416

42. L. H. Butterfield, A. Koh, W. Meng, C. M. Vollmer, A. Ribas, V. Dissette, E. Lee, J. A. Glaspy, W. H. McBride, J. S. Economou: Generation of human T-cell responses to an HLA-A2.1-restricted peptide epitope derived from alpha-fetoprotein. Cancer Res 59, 3134-42 (1999)

43. L. H. Butterfield, W. S. Meng, A. Koh, C. M. Vollmer, A. Ribas, V. B. Dissette, K. Faull, J. A. Glaspy, W. H. McBride, J. S. Economou: T cell responses to HLA-A*0201-restricted peptides derived from human alpha fetoprotein. J Immunol 166, 5300-8 (2001)
DOI: 10.4049/jimmunol.166.8.5300

44. Y. Liu, S. Daley, V. N. Evdokimova, D. D. Zdobinski, D. M. Potter, L. H. Butterfield: Hierarchy of alpha fetoprotein (AFP)-specific T cell responses in subjects with AFP-positive hepatocellular cancer. J Immunol 177, 712-21 (2006)
DOI: 10.4049/jimmunol.177.1.712

45. E. Mizukoshi, Y. Nakamoto, H. Tsuji, T. Yamashita, S. Kaneko: Identification of alpha-fetoprotein-derived peptides recognized by cytotoxic T lymphocytes in HLA-A24+ patients with hepatocellular carcinoma. Int J Cancer 118, 1194-204 (2006)
DOI: 10.1002/ijc.21468

46. V. Pichard, P. J. Royer, C. Richou, E. Cauchin, K. Goebes, A. Gaignerie, C. Masliah, J. Gournay, M. Gregoire, N. Ferry. Detection, isolation, and characterization of alpha-fetoprotein-specific T cell populations and clones using MHC class I multimer magnetic sorting. J Immunother 31, 246-53. (2008)
DOI: 10.1097/CJI.0b013e318169d55c

47. R. Thimme, M. Neagu, T. Boettler, C. Neumann-Haefelin, N. Kersting, M. Geissler, F. Makowiec, R. Obermaier, U. T. Hopt, H. E. Blum, H. C. Spangenberg: Comprehensive analysis of the alpha-fetoprotein-specific CD8+ T cell responses in patients with hepatocellular carcinoma. Hepatology 48, 1821-33 (2008)
DOI: 10.1002/hep.22535

48. A. Alisa, A. Ives, A. A. Pathan, C. V. Navarrete, R. Williams, A. Bertoletti, S. Behboudi: Analysis of CD4+ T-Cell responses to a novel alpha-fetoprotein-derived epitope in hepatocellular carcinoma patients. Clin Cancer Res 11, 6686-94 (2005)
DOI: 10.1158/1078-0432.CCR-05-0382

49. L. Ayaru, S. P. Pereira, A. Alisa, A. A. Pathan, R. Williams, B. Davidson, A. K. Burroughs, T. Meyer, S Behboudi: Unmasking of alpha-fetoprotein- specific CD4(+. T cell responses in hepatocellular carcinoma patients undergoing embolization. J Immunol 178, 1914-22 (2007)
DOI: 10.4049/jimmunol.178.3.1914

50. A. Alisa, S. Boswell, A. A. Pathan, L. Ayaru, R. Williams, S. Behboudi: Human CD4(+. T cells recognize an epitope within alpha-fetoprotein sequence and develop into TGFbeta-producing CD4(+). T cells. J Immunol 180, 5109-17 (2008)
DOI: 10.4049/jimmunol.180.7.5109

51. V. N. Evdokimova, Y. Liu, D. M. Potter, L. H. Butterfield: AFP specific CD4+ helper T-cell responses in healthy donors and HCC patients. J Immunother 30, 425-37 (2007)
DOI: 10.1097/CJI.0b013e31802fd8e2

52. S. Behboudi, S. Boswell, R. Williams: Cell-mediated immune responses to alpha-fetoprotein and other antigens in hepatocellular carcinoma. Liver Int 30, 521-6 (2010)
DOI: 10.1111/j.1478-3231.2009.02194.x

53. L. Sun, H. Guo, R. Jiang, L. Lu, T. Liu , Z. Zhang, X. He: Artificial antigen-presenting cells expressing AFP(158-166. peptide and interleukin-15 activate AFP-specific cytotoxic T lymphocytes. Oncotarget 7, 17579-90 (2016)
DOI: 10.18632/oncotarget.8198

54. J.A. James, J.B. Harley: B-cell epitope spreading in autoimmunity. Immunol Rev 164, 185-200 (1998)
DOI: 10.1111/j.1600-065X.1998.tb01220.x

55. J. Craft, S. Fatenejad: Self antigens and epitope spreading in systemic autoimmunity. Arthritis Rheum 40, 1374-82 (1997)
DOI: 10.1002/art.1780400803

56. U.S. Deshmukh, H. Bagavant, J. Lewis, F. Gaskin, S.M. Fu: Epitope spreading within lupus-associated ribonucleoprotein antigens. Clin. Immunol 117, 112-20 (2005)
DOI: 10.1016/j.clim.2005.07.002

57. F. Fernández-Madrid: Autoantibodies in breast cancer sera: candidate biomarkers and reporters of tumorigenesis. Cancer Lett 230, 187-198 (2005)
DOI: 10.1016/j.canlet.2004.12.017

58. R.M. Zinkernagel, H. Hengartner: Regulation of the immune response by antigen. Science 293, 251-53 (2001)
DOI: 10.1126/science.1063005

59. M.J. Shlomchik, J.E. Craft, M. J. Mamula: From T to B and back again: positive feedback in systemic autoimmune disease. Nat Rev Immunol 1, 147-53 (2001)
DOI: 10.1038/35100573

60. G. J. Mizejewski: Alpha-fetoprotein (AFP)-derived peptides as epitopes for hepatoma immunotherapy: a commentary. Cancer Immunol Immunother 58, 159-70 (2009)
DOI: 10.1007/s00262-008-0548-8

61. X.W. Wang, H. Xie: Alpha-fetoprotein enhances the proliferation of human hepatoma cells in vitro. Life Sci 64, 17-23 (1999)
DOI: 10.1016/S0024-3205(98)00529-3

62. M. Geissler, L. Mohr, R. Weth, G. Köhler, C. F. Grimm, T.U. Krohne, F. von Weizsäcker, H. E. Blum: Immunotherapy directed against alpha-fetoprotein results in autoimmune liver disease during liver regeneration in mice. Gastroenterology 121, 931-9 (2001)
DOI: 10.1053/gast.2001.28019

63. J.D Cooper: Moving towards therapies for juvenile Batten diseases? Exp. Neurol 21, 329-31 (2008).
DOI: 10.1016/j.expneurol.2008.02.016

64. J. Isosomppi: Lysosomal localization of the neuronal ceroid lipofuscinosis CLN5 protein Human Molecular Genetics 11, 885-89 (2002)
DOI: 10.1093/hmg/11.8.885

65. M. Haltia: The neuronal ceroid-lipofuscinoses: from past to present. Biochim Biophys Acta, 1762, 850-56 (2006)
DOI: 10.1016/j.bbadis.2006.06.010

66. C. A. Pardo, B. A. Rabin, D.N. Palmer, D. L. Price: Accumulation of the adenosine triphosphate synthase subunit C in the mnd mutant mouse. A model for neuronal ceroid lipofuscinosis. Am J Pathol 144, 829-35 (1994)

67. C. H. Chan, D. Ramirez-Montealegre, D. A. Pearce: Altered arginine metabolism in the central nervous system (CNS. of the Cln3-/- mouse model of juvenile Batten disease. Neuropathol Appl Neurobiol 35, 189-207 (2009)
DOI: 10.1111/j.1365-2990.2008.00984.x

68. S. Matsumota, J. Haberle, J. Kido, H. Mitsubuchi, F. Endo, K. Nakamura: Urea cycle disorders-update. J Hum Genet 64, 833-47 (2019)
DOI: 10.1038/s10038-019-0614-4

69. J. Collins, G.E. Holder, H. Herbert, G. G. W. Adams; Batten disease: features to facilitate early diagnosis. British Journal of Ophthalmology 90, 1119-24 (2006)
DOI: 10.1136/bjo.2006.091637

70. K. Luiro, O. Kopra, T. Blom, M. Gentile, H. M. Mitchison, I. Hovatta, K. Tornquist, A. Jalanko: Batten disease (JNCL. is linked to disturbances in mitochondrial, cytoskeletal, and synaptic compartments. Journal of Neuroscience Research 84, 1124-38 (2006)
DOI: 10.1002/jnr.21015

71. S. B. Narayan, D. Rakheja, L. Tan, J.V. Pastor, M. J. Bennett: CLN3P, the Batten's disease protein, is a novel palmitoyl-protein Delta-9 desaturase. Annals of Neurology 60, 570-77 (2006)
DOI: 10.1002/ana.20975

72. A.R. Leman, D. A. Pearce, P. G. Rothberg: Gene symbol: CLN3. Disease: Juvenile neuronal ceroid lipofuscinosis (Batten disease). Human Genetics 116: 544 (2005)

73. S.N. Phillips, J. W. Benedict, J. M Weimer, D. A. Pearce: Center for aging and developmental biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA. CLN3, the protein associated with batten disease: structure, function and localization. Journal of Neuroscience Research 79, 573-83 (2005)
DOI: 10.1002/jnr.20367

74. S. E. Mole, R. E. Williams, H. H. Goebel: Correlations between genotype, ultrastructural morphology and clinical phenotype in the neuronal ceroid lipofuscinoses. Neurogenetics 6: 107-26 (2005)
DOI: 10.1007/s10048-005-0218-3

75. J. M Weimer, A. W. Custer, J. W. Benedict, N. A. Alexander, E. Kingsley, H. J. Federoff, J D. Cooper, D. A. Pearce: Visual deficits in a mouse model of Batten disease are the result of optic nerve degeneration and loss of dorsal lateral geniculate thalamic neurons. Neurobiology of Disease 22, 284-93 (2006)
DOI: 10.1016/j.nbd.2005.11.008

76. C. C. Pontikis, S. L. Cotman, M. E. MacDonald, J. D. Cooper: Thalamocortical neuron loss and localized astrocytosis in the Cln3 Deltaex 7/8 knock-in mouse model of Batten disease. Neurobiology of Disease 20, 823-36 (2005)
DOI: 10.1016/j.nbd.2005.05.018

77. M. L. Katz, H. Shibuya, B.C. Liu, S. Kaur: A mouse gene knockout model for juvenile ceroid lipofusinosis (Batten's disease). J. Neurosci Res 57, 551-56 (1999)
DOI: 10.1002/(SICI)1097-4547(19990815)57:4<551::AID-JNR15>3.0.CO;2-R

78. S. Chattopadhyay, M. Ito, J. D. Cooper, A. L. Brooks, T. M. Curran, J. M. Powers, D. A. Pearce: An autoantibody inhibitory to glutamic acid decarboxylase in the neurodegenerative disorder Batten disease. Hum Mol Genet 11, 1421-31 (2002)
DOI: 10.1093/hmg/11.12.1421

79. S. L. Cotman, V. Vrbanac, L. A. Lebel, R. L. Lee, K. A. Johnson, L. R. Donahue, A.M. Teed: Cln3(Deltaex7/8. knock-in mice with the common JNCL mutatio8n exhibit progressive neurologic disease that begins before birth. Hum Mol Genet 11, 2709-21 (2002)
DOI: 10.1093/hmg/11.22.2709

80. D. A. Persaud-Sawin, R-M. N. Boustany: Cell death pathways in juvenile Batten disease. Apoptosis 10, 973-85 (2005)
DOI: 10.1007/s10495-005-0733-6

81. D. Rajheja, S. B. Narayan, M. J. Bennett: Juvenile neuronal ceroid-lipofuscinosis (Batten disease): a brief review and update. Curr Mol Med 6, 603-8 (2007)
DOI: 10.2174/156652407781695729

82. D. Ramirez-Montealegre, S. Chattopadhyay, T. M. Curran, C. Wasserfal, L. Pritchard, D. Schatz, J. Petitto, D. Hopkins, J. X. She, P. G. Rothberg, M. Atkinson, D. A. Pearce: Autoimmunity to glutamic and acid decarboxylase (gad. in the neurodegenerative disorder Batten disease. Neurology 64, 743-45 (2005)
DOI: 10.1212/01.WNL.0000151973.08426.7E

83. M. J. Lim, J. Beake, E. Bible, T. M. Curran, D. Ramirez-Montealegre, D. A. Pearce, J. D. Cooper: Distinct patterns of serum immunoreactivity as evidence for multiple brain-directed autoantibodies in juvenile neuronal ceroid lipofuscinosis. Neuropathology & Applied Neurobiology 32, 469-82 (2006)
DOI: 10.1111/j.1365-2990.2006.00738.x

84. C.D. Toran-Allerand: Regional differences in intraneuronal localization of alpha-fetoprotein in developing mouse brain. Brain Res 281, 213-17 (1982)
DOI: 10.1016/0165-3806(82)90161-4

85. M. J. Villacampa, F. Lampreave, M. Calvo, J Naval, A. Pineiro, J. Uriel: Incorporation of radiolabelled alpha fetoprotein in the brain and other tissues of the developing rat. Brain Res 314, 77-82 (1984)
DOI: 10.1016/0165-3806(84)90177-9

86. H. M. Mitchison, D. J. Bernard: Targeted disruption of the Cln3 gene provides a mouse model for Batten disease. Neurobiol Diseases 6, 321-34 (1999)
DOI: 10.1006/nbdi.1999.0267

87. R. W, Benno, T. H. Williams: Evidence for intracellular intracellular localization of alpha-fetoprotein in the developing rat brain. Brain Res 142, 182-86 (1978)
DOI: 10.1016/0006-8993(78)90189-0

88. J. Bakker, C. DeMees; Alpha-fetoprotein protects the developing female mouse brain from masculinization and defeminization by estrogens. Nature Neurosci, 9, 230-36 (2006)
DOI: 10.1038/nn1624

89. C. DeMees, J. F. Laes: Alpha-fetoprotein controls female fertility and prenatal development of the gonadotropin-releasing hormone pathway through an antiestrogenic action. Mol Cell Biol, 26, 2012-18 (2006)
DOI: 10.1128/MCB.26.5.2012-2018.2006

90. B. S. Schachter, C. D. Toran-Allerand: Intraneural alpha-fetoprotein and albumin are not synthesized in the developing brain. Brain Res 281, 93-98 (1982)
DOI: 10.1016/0165-3806(82)90116-X

91. G. J. Mizejewski: Levels of alpha-fetoprotein during pregnancy and early infancy in normal and disease states. Obstet Gynecol Surv 58, 804-26 (2003)
DOI: 10.1097/01.OGX.0000099770.97668.18

92. G. J. Mizejewski: Autoimmune disorders during pregnancy: effect of biomarkers on maternal serum screening and course of disease. Curr. Women's Health Reviews 12, 95-104 (2016)
DOI: 10.2174/1573404812666160727122345

93. E. Ruoslahti, H. Pihko, M. Becker, and O. Makela: Rabbit a-fetoprotein: normal levels and breakage tolerance with haptenated homologous a-fetoprotein. Eur J Immunol 5, 7-10 (1975)
DOI: 10.1002/eji.1830050103

94. H. Taga: The effect of active immunization of rats with heterologous a-fetoprotein upon hepatocarcinogenesis induced by 39-methyl-4-dimethylaminoazobenzene. Gann 74, 248-57 (1983)

95. K. J. Lafferty, and L. S. Gazda: Tolerance: a case of self/not self discrimination maintained by clonal deletion? Hum. Immunol 52, 119-26 (1997)
DOI: 10.1016/S0198-8859(96)00294-7

Key Words: Alpha-fetoprotein, Autoimmunity, Antigens, Epitopes, Disordered Protein, Autoimmune Disorders, Batten Disease, Review

Send correspondence to: Roberto Bei, Dept. of Clinical Sciences and Translational Medicine, Faculty of Medicine, University of Rome “Tor Vergata”, Via Montpellier 1, 00133, Rome, Italy, Tel: 39 06-72596522, Fax: 39 06-72596506, E-mail: bei@med.uniroma2.it