Immuntherapie der Alzheimer-Krankheit

Zusammenfassung

In der Übersichtsarbeit wurden die Molekularbasis und der aktuelle Wissensstand über immuntherapeutische Strategien zur Vorbeugung und Behandlung der Alzheimer-Krankheit (AD) dargestellt. Die AD gehört unter den molekularen Gesichtspunkten zur Gruppe der konformationellen Erkrankungen. Nachdem die Studien in vitro demonstrierten, dass die Konformation der Aβ-Peptide durch die Bindung von Antikörpern moduliert werden kann, wurde dieser experimentelle Ansatz in Studien in vivo an transgenen Tieren geprüft, wobei zur Induzierung der Antikörper überwiegend das Aβ₄₂-Peptid als Immunogen eingesetzt wurde. Es stellte sich heraus, dass die Immunisation der jungen Tiere der Amyloidbildung und der begleitenden neuropathologischen Veränderungen vorbeugen könnte. Bei älteren Tieren reduzierte die Immunisation die präexistierenden neuropathologischen Läsionen. Anhand der tierpsychologischen Verfahren wurde festgestellt, dass die Immunisation den Leistungsdefiziten bei den jüngeren transgenen Mäusen vorbeugen kann. Bei den älteren Mäusen verbesserten sich nach Immunisation die Leistungen im Bereich des Gedächtnisses und Verhaltens. Die in den Studien verwendeten Immunogene induzierten eine T-Zellen-Immunantwort vom Typ T_H2. Die induzierten Antikörper gehörten überwiegend zu den Immunglobulin-Isotypen IgG1 und IgG2b. Die Stärke der Immunantwort hing vom Immunogentyp, Genotyp der transgenen Tiere, von der Dosis des Immunogens, von den Verabreichungsintervallen und Verabreichungswegen ab. Der Wirkmechanismus der Antikörper bei transgenen Tieren besteht in der Induzierung der Veränderungen in der Konformation und Löslichkeit der Aβ-Peptide sowie in deren Konzentrationssenkung in den peripheren Kompartimenten. Der Lymphozytenproliferationstest unter Anwendung von Aβ-Peptiden und Milzzellen immunisierter Tiere zeigte, dass das Vakzin die T-Zellen-Epitope stimulierte, die sich im Aβ-Peptid befinden. Bei einer umfangreichen quantitativen morphologisch-histochemischen und molekular-analytischen Untersuchung der Hirnschnitte von verschiedenen Genotypen der transgenen Tiere sowie von nicht-transgenen Tieren konnten keine Anhaltspunkte für eine Autoimmunreaktion, Komplementaktivierung oder Kreuzreaktion festgestellt werden. Histopathologische Untersuchung anderer Organe, einschließlich der Nieren, erbrachte keine pathologischen Befunde. Neuropathologische Untersuchung bei einer an AD erkrankten Patientin, die mit Vakzin behandelt wurde, wies ähnliche Impfeffekte wie im Tierexperiment auf. Bei 5 % der in eine klinische Studie eingeschlossenen Patienten, die das Vakzin mit dem Aβ₄₂-Peptid als Immunogen erhielten (AN1792), trat eine Meningoenzephalitis auf. Der kausale Zusammenhang mit der Vakzinverabreichung kann nicht ausgeschlossen werden, da bei transgenen Tieren eine vorübergehende Mikrogliaaktivierung gesehen wurde. Dennoch weist die niedrige Häufigkeit der unerwünschten Wirkung auf eine mögliche Mitbeteiligung der Risikofaktoren bei den behandelten Patienten hin, die z. Z. noch nicht definiert werden können. Im Hinblick auf die rasanten Fortschritte im Bereich der Biotechnologie, insbesondere der Vakzintechnologie, kann in absehbarer Zukunft die Entwicklung wirksamer und sicherer Immunogene sowie neuer Impftechniken für die Immuntherapie der AD erwartet werden.

Abstract

This review discusses the molecular basis and current status of immunotherapeutic strategies for prevention and treatment of Alzheimer's disease (AD). From the molecular view-point AD belongs to the group of conformational diseases. In-vitro studies demonstrated that monoclonal antibodies could modulate the conformation of Aβ peptides with subsequent inhibition of amyloid fibrils formation and aggregation. The efficacy of this approach was then successfully proved in the murine models of AD using predominantly Aβ₄₂ peptide as immunogen. Immunisation of the young animals essentially prevented the development of β-amyloid plaques formation and of concomittant neuropathology. Treatment of the older animals markedly reduced the pre-existing AD-like neuropathology. Immunisation was capable of preventing cognitive deficits in the young transgenic animals and improve the memory and behavioural disturbances in the older animals. Measurement of specific murine immunoglobulines in Aβ-vaccinated mice demonstrated a predominant IgG1 and IgG2b isotypes, suggesting a type 2 (T_H2) T-helper cell immune response, which drives humoral immunity. The intensity of the immune response depended on transgenic animals genotype, dose, frequency and route of immunogen administration. The mechanism of antibodies action in transgenic animals consists of inducing conformational and solubility changes in Aβ peptides as well as their peripheral sink. Lymphocyte proliferation assays using Aβ peptides and splenocytes from vaccinated mice demonstrated that vaccine specifically stimulated T-cell epitopes present within the Aβ-peptide. Extensive quantitative morphological, histochemical and molecular analysis of brain tissue from several species of Aβ-immunised transgenic and non-transgenic animals showed no evidence of autoimmune reaction, complement activation or cross-reaction. No pathological changes were found in all other organs, including the kidney. Neuropathologic examination in a patient treated with vaccine revealed similar vaccination effects as in experimental animals. An aseptic meningo-encephalitis was reported in 5 % of patients included in a clinical trial in which a vaccine containing Aβ₄₂ peptide (AN1792) was administered intramuscularly. The causal relationship to the vaccine administration cannot be excluded since in transgenic mice a transient microglia activation was seen. However, this relatively infrequent although severe adverse effect points to a possible participation of some actually unknown risk factors in the treated patients. With regard to the rapid progress in biotechnology, especially in the vaccines technology, the development of efficacious and safe immunogens as well as of new vaccination techniques for immuntherapy of AD can be expected in the next future.

Literatur

• 1 Citron M. Alzheimer's disease: treatments in discovery and development.  Nature Neuroscience suppl. 2002;  5 1055-1057
• 2 Haas Ch. New hope for Alzheimer's disease vaccine.  Nature Med. 2002;  8 1195-1196
• 3 Karkos J. Alzheimer-Krankheit: Perspektiven ihrer Therapie.  DAZ. 1998;  138 47-54
• 4 Karkos J. Recent approaches to the treatment of Alzheimer's disease.  Soc Clin Psychiat (Moscow). 2002;  12 86-89
• 5 Soto C. Plaque busters: strategies to inhibit amyloid formation in Alzheimer's disease.  Mol Med Today. 1999;  5 343-350
• 6 Selkoe D J. Alzheimer's disease results from the cerebral accumulation and cytotoxicity of amyloid-β-protein.  J Alzheimer's Dis. 2001;  3 75-81
• 7 Younkin S G. The role of Aβ₄₂ in Alzheimer's disease.  J Physiology (Paris). 1998;  92 289-292
• 8 Findeis M A. Approaches to discovery and characterisation of inhibitors of amyloid β-peptide polymerisation.  Biochem Biophys Acta. 2000;  1502 76-84
• 9 Sigurdsson E M, Scholtzova H, Mehta P D, Frangione B, Wisniewski T. Immunization with a Nontoxic/Nonfibrillar Amyloid-β Homologous Peptide Reduces Alzheimer's Disease-Associated Pathology in Transgenic Mice.  Am J Pathol. 2001;  159 439-447
• 10 Solomon B, Koppel R, Hannan E, Katzaw T. Monoclonal antibodies inhibit in vitro fibrillar aggregation of the Alzheimer's β-amyloid peptide.  Proc Natl Acad Sci USA. 1996;  93 452-455
• 11 Solomon B. Immunotherapeutic Strategies for Prevention and Treatment of Alzheimer's Disease.  DNA Cell Biol. 2001;  20 697-703
• 12 Schenk D, Barbour R, Dunn W, Gordon G, Grajeda H, Guido T, Hu K, Huang J, Johnson-Wood K, Khan K, Kholodenko D, Lee M, Zhenmei L, Lieberburg I, Motter R, Mutter L, Soriano F, Shopp G, Vasquez N, Vandevert C, Walker S, Wogulis M, Yednock T, Games D, Seubert P. Immunization with amyloid-β attenuates Alzheimer's disease-like pathology in the PDAPP mouse.  Nature. 1999;  400 173-177
• 13 Bard F, Cannon C, Barbour R, Burke R-L, Games D, Grajeda H, Guido T, Hu K, Huang J, Johnson-Wood K, Khan K, Kholodenko D, Lee M, Lieberburg I, Motter R, Nguyen M, Soriano F, Vasquez N, Weiss K, Welch B, Seubert P, Schenk D, Yednock T. Peripherally administered antibodies against amyloid beta peptide enter the central nervous system and reduce pathology in a mouse model of Alzheimer's disease.  Nature Med. 2000;  6 916-920
• 14 Morgan D, Diamond D M, Gottschall P E, Ugen K E, Dickey C, Hardy J, Duff K, Jantzen P, DiCarlo G, Wilcock D, Connor K, Hatcher J, Hope C, Gordon M, Arendash G W. Aβ-peptide vaccination prevent memory loss in an animal model of Alzheimer's disease.  Nature. 2000;  408 982-985
• 15 Janus C, Pearson J, McLaurin J, Mathews P M, Jiang Y, Schmidt S D, Azhar Chisti M, Horne P, Heslin D, French J, Mount H TJ, Nixon R A, Mercken M, Bergeron C, Fraser P E, St George-Hyslop P, Westaway D. Aβ-peptide immunisation reduces behavioural impairment and plaques in a model of Alzheimer's disease.  Nature. 2000;  408 979-982
• 16 Hock Ch, Konietzko U, Papassotiropoulos A, Wollmer A, Streffer J, von Rotz R C, Davey G, Moritz E, Nitsch R M. Generation of antibodies specific for β-amyloid by vaccination of patients with Alzheimer disease.  Nature Med. 2002;  8 1270-1275
• 17 Steinberg D. Companies halt first Alzheimer vaccine trial.  The Scientist. 2002;  16 24-26
• 18 Faria A MC, Weiner H L. Oral tolerance: mechanisms and therapeutic applications.  Adv Immunol. 1999;  73 153-264
• 19 Bitar D M, Whitacre C C. Suppression of experimental autoimmune encephalomyelitis by the oral administration of myelin basic protein.  Cell Immunol. 1988;  112 364-370
• 20 Higgins P, Weiner H L. Suppression of experimental autoimmune encephalomyelitis by oral administration of myelin basic protein and its fragments.  J Immunol. 1988;  140 440-445
• 21 Metzler B, Wraith D C. Inhibition of experimental autoimmune encephalomyelitis by inhalation but not oral administration of the encephalitogenic peptide: Influence of MHC binding affinity.  Int Immunol. 1993;  5 1159-1165
• 22 Okumura S, McIntosh K, Drachman D B. Oral administration of acetylcholine receptor: effects on experimental myasthenia gravis.  Ann Neurol. 1994;  36 704-713
• 23 Daniel D, Wegmann D R. Protection of nonobese diabetic mice from diabetes by intranasal or subcutaneous administration of insulin peptide B-(9 - 23).  Proc Natl Acad Sci USA. 1996;  93 956-960
• 24 Staines N A, Harper N, Ward F J, Malmström V, Holmdahl R, Bansal S. Mucosal tolerance and suppression of collagen-induced arthritis (CIA) induced by nasal inhalation of synthetic peptide 184 - 198 of bovine type II collagen (CII) expressing a dominant T cell epitope.  Clin Exp Immunol. 1996;  103 368-375
• 25 Hyman B T, Smith C, Buldyrev I, Whelan C, Brown H, Tang M-X, Mayeux R. Autoantibodies to amyloid-β in Alzheimer's disease.  Ann Neurol. 2001;  49 808-810
• 26 Pawelec G, Adibzadeh M, Pohla H, Schaut K. Immunosenescence: ageing of the immune system.  Immunol Today. 1995;  16 420-422
• 27 Thomas P J, Qu B-H, Pedersen P L. Defective protein folding as a basis of human disease.  Trends Biochem Sci. 1995;  20 456-459
• 28 Anfinsen Ch B. Principles that Govern the Folding of Protein Chains.  Science. 1973;  181 223-230
• 29 Carrell R W, Lomas D A. Conformational disease.  Lancet. 1997;  350 134-138
• 30 Barrow C J, Zagorski M G. Solution structures of β-peptide and its constituent fragments.  Science. 1991;  253 179-182
• 31 Hollosi M, Otvos L, Kaijtar J, Percell A, Lee V MY. Is amyloid deposition in Alzheimer's disease preceded by an environment induced double conformational transition?.  Peptide Res. 1989;  2 109-113
• 32 Sticht H, Bayer P, Willbold D, Dames S, Hilbich C, Beyreuther K, Frank R W, Rösch P. Structure of amyloid A4-(1 - 40)-peptide of Alzheimer's disease.  Eur J Biochem. 1995;  233 293-298
• 33 Barrow C J, Yasuda A, Kenny P T, Zagorski M G. Solution conformations and aggregational properties of synthetic amyloid beta-peptides of Alzheimer's disease.  J Mol Biol. 1992;  225 1075-1093
• 34 Soto C, Castaño E M. The conformation of Alzheimer's β-peptide determines the rate of amyloid formation.  Biochem J. 1996;  314 701-707
• 35 Maggio J E, Stimson E R, Ghilardi J R, Allen C J, Dahl C E, Whitcomb D C, Vigna S R, Vinters H V, Labensky M E, Mantyh P W. Reversible in vitro growth of Alzheimer disease β-amyloid plaques by deposition of labeled amyloid peptide.  Proc Natl Acad Sci USA. 1992;  89 5462-5466
• 36 Jarret J T, Lansbury Jr P T. Seeding „one-dimensional crystallization” of amyloid: A pathogenic mechanism in Alzheimer's disease and scrapie?.  Cell. 1993;  73 1055-1058
• 37 Soto C, Sigurdsson E M, Morelli L, Kumar R A, Castaño E M, Frangione B. β-sheet breaker peptides inhibit fibrillogenesis in a rat brain model of amyloidosis.  Nature Med. 1998;  4 822-826
• 38 Maggio J E, Mantyh P W. Brain amyloid - A physicochemical perspective.  Brain Pathol. 1996;  6 147-162
• 39 Mucke L, Masliah E, Yu G-Q, Mallory M, Rockstein E M, Tatsuno G, Hu K, Kholodenko D, Johnson-Wood K, McConlogue L. High Level Neuronal Expression of Abeta1 - 42 in Wild-Type Human Amyloid Precursor Protein Transgenic Mice: Synaptotoxicity without Plaque Formation.  J Neurosci. 2000;  20 4050-4058
• 40 Van Gool W A, Kuiper M A, Walstra G JM, Wolters E CH, Bolhuis P A. Concentrations of amyloid β-protein in cerebrospinal fluid of patients with Alzheimer's disease.  Ann Neurol. 1994;  37 277-279
• 41 Esler W P, Stimson E R, Jennings J M, Ghilardi J R, Mantyh P W, Maggio J E. Zinc-induced aggregation of human and rat β-amyloid peptides in vitro.  J Neurochem. 1996;  66 723-732
• 42 Mantyh P W, Ghilardi J R, Rogers S, DeMaster E, Allen C J, Stimson E R, Maggio J E. Aluminium, iron and zinc ions promote aggregation of physiological concentrations of β-amyloid peptide.  J Neurochem. 1993;  61 1171-1174
• 43 Evans K C, Berger E P, Cho C-G, Weisgraber K H, Lansbury Jr P T. Apolipoprotein E is kinetic but not a thermodynamic inhibitor of amyloid formation: Implications for the pathogenesis and treatment of Alzheimer disease.  Proc Natl Acad Sci USA. 1995;  92 763-767
• 44 Ma J, Yee A, Brewer Jr H B, Das S, Potter H. Amyloid-associated protein a₁-antichymotrypsin and apolipoprotein E promote assembly of Alzheimer β-protein into filaments.  Nature. 1994;  372 92-94
• 45 Halverson K, Fraser P E, Kirschner D A, Lansbury Jr P T. Molecular determinants of amyloid deposition in Alzheimer's disease: Conformational studies of synthetic β-protein fragments.  Biochemistry. 1990;  29 2639-2644
• 46 Jarret J T, Costa P R, Griffin R G, Lansbury Jr P T. Models of the β-protein C-terminus: Differences in amyloid structure may lead to segregation of „long” and „short” fibrils.  J Am Chem Soc. 1993;  116 9741-9742
• 47 Lue L-F, Kuo Y-M, Roher A E. Soluble amyloid β-peptide concentration as a predictor of synaptic change in Alzheimer's disease.  Am J Pathol. 1999;  155 853-862
• 48 McLean C A, Cherny R A, Fraser F W, Fuller S J, Smith M J, Beyreuther K, Bush A I, Masters C L. Soluble pool of Aβ-amyloid as a determinant of severity of neurodegeneration in Alzheimer's disease.  Ann Neurol. 1999;  46 860-866
• 49 Näslund J, Haroutunian V, Mohs R, Davis P, Greengard P, Buxbaum J D. Correlation Between Elevated Levels of Amyloid β-Peptide in the Brain and Cognitive Decline.  JAMA. 2000;  283 1571-1577
• 50 Wang J, Dickson D W, Trojanowski J Q, Lee V M-Y. The Levels of Soluble versus Insoluble Brain Aβ Distinguish Alzheimer's Disease from Normal and Pathologic Aging.  Exp Neurol. 1999;  158 328-337
• 51 Karplus M, Petsko G A. Molecular dynamics simulations in biology.  Nature. 1990;  347 631-639
• 52 Katzav-Gozansky T, Hanan E, Solomon B. Effect of monoclonal antibodies in preventing carboxypeptidase A aggregation.  Biotechnol Appl Biochem. 1996;  23 227-230
• 53 Carlson J D, Yarmush M L. Antibody assisted protein refolding.  Biotechnology. 1992;  10 86-91
• 54 Kelly J W. Alternative conformations of amyloidogenic proteins govern their behavior.  Curr Opin Struct Biol. 1996;  6 11-17
• 55 Solomon B, Schwartz F. Chaperone-like effect of monoclonal antibodies on refolding of heat-denaturated carboxypeptidase A.  J Mol Recog. 1995;  8 72-76
• 56 Frenkel D, Solomon B, Benhar I. Modulation of Alzheimer's beta-amyloid neurotoxicity by site-directed single-chain antibody.  J Neuroimmunol. 2000;  106 23-31
• 57 Solomon B, Koppel R, Frenkel D, Hanan-Aharon E. Disaggregation of Alzheimer β-amyloid by site-directed mAb.  Proc Natl Acad Sci USA. 1997;  94 4109-4112
• 58 Hoogenboom H R, De Bruine A P, Hufton S E, Hoet R M, Arends J W, Roovers R C. Antibody phage display technology and its applications.  Immunotechnology. 1998;  4 1-20
• 59 Frenkel D, Balass M, Kachalsky-Katzir E, Solomon B. High affinity binding of monoclonal antibodies to the sequential epitope EFRH of β-amyloid peptide is essential for modulation in fibrillar aggregation.  J Neuroimmunol. 1999;  95 136-142
• 60 Frenkel D, Kariv N, Solomon B. Generation of auto-antibodies towards Alzheimer's disease vaccination.  Vaccine. 2001;  19 2615-2619
• 61 Frenkel D, Balass M, Solomon B. N-Terminal EFRH sequence of Alzheimer's β-amyloid peptide represents the epitope of its anti-aggregating antibodies.  J Neuroimmunol. 1998;  88 85-90
• 62 Frenkel D, Katz O, Solomon B. Immunization against Alzheimer's β-amyloid plaques via EFRH phage administration.  Proc Natl Acad Sci USA. 2000;  97 11 455-11 459
• 63 Games D, Adams D, Alessandrini R, Barbour R, Berthelette R, Blackwell C, Carr T, Clemens J, Donaldson T, Gillespie R, Guido T, Hagopian S, Johnson-Wood K, Khan K, Lee M, Leibowitz P, Lieberburg I, Little S, Masliah E, McConlogue L, Montoyazavalla M, Mucke L, Paganini L, Peniman E, Power M, Schenk D, Seubert P, Snyder B, Soriano R, Tan H, Vitale J, Wadsworth S, Wolozin B, Zhao O. Alzheimer-type neuropathology in transgenic mice overexpressing V717F β-amyloid precursor protein.  Nature. 1995;  373 523-527
• 64 Vehmas A K, Borchelt D R, Price D L, McCarthy D, Wills-Karp M, Peper M J, Rudow G, Luyinbazi J, Siew L T, Troncoso J C. β-Amyloid Peptide Vaccination Results in Marked Changes in Serum and Brain Aβ Levels in APPswe/PS1 ΔE9 Mice, as Detected by SELDI-TOF-Based ProteinChip®-Technology.  DNA Cell Biol. 2001;  20 713-721
• 65 Weiner H L, Lemere C A, Maron R, Spooner E T, Grenfell T J, Mori C, Issazadeh S, Hancock W W, Selkoe D J. Nasal administration of amyloid-β peptide decreases cerebral amyloid burden in a mouse model of Alzheimer's disease.  Ann Neurol. 2000;  48 567-579
• 66 George-Hyslop P St, Westway A. Antibody clears senile plaques.  Nature. 1999;  400 116-117
• 67 Dickey C A, Morgan D G, Kudchodkar S, Weiner D B, Bai Y, Cao C, Gordon M N, Ugen K E. Duration and Specificity of Humoral Immune Responses in Mice Vaccinated with the Alzheimer's Disease-Associated β-Amyloid 1 - 42 Peptide.  DNA Cell Biol. 2001;  20 723-729
• 68 Wilcock D M, Gordon M N, Ugen K E, Gottschall P E, Dicarlo G, Dickey C, Boyett K W, Jantzten P T, Connor K E, Melachrino J, Hardy J, Morgan D. Number of Aβ Inoculation in APP+PS1 Transgenic Mice Influences Antibody Titers, Microglial Activation, and Congophilic Plaque Levels.  DNA Cell Biol. 2001;  20 731-736
• 69 Johnstone E M, Chaney M O, Norris F H, Pascual R, Little S P. Conservation of the sequence of the Alzheimer's disease amyloid peptide in dog, polar bear and five other mammals by cross-species polymerase chain reaction analysis.  Mol Brain Res. 1991;  10 299-305
• 70 Kawarabayashi T, Younkin L H, Saido T C, Shoji M, Ashe K H, Younkin S G. Age-dependent changes in brain, CSF, and plasma amyloid-β-protein in the Tg2576 transgenic mouse model of Alzheimer's disease.  J Neurosci. 2001;  21 372-381
• 71 Lee V M-Y. Aβ-immunisation: Moving Aβ-peptide from brain to blood.  Proc Natl Acad Sci USA. 2001;  98 8931-8932
• 72 Matsuoka Y, Saito M, LaFrancois J, Saito M, Gaynor K, Olm V, Wang L, Casey E, Lu Y, Shiratori C, Lemere C, Duff K. Novel Therapeutic Approach for the Treatment of Alzheimer's disease by Peripheral Administration of Agents with an Affinity to β-Amyloid.  J Neurosci. 2003;  23 29-33
• 73 Lemere C A, Maron R, Selkoe D J, Weiner H L. Nasal Vaccination with β-Amyloid Peptide for the Treatment of Alzheimer's Disease.  DNA Cell Biol. 2001;  20 705-711
• 74 Siegrist C-A, Lambert P-H. Antigen-Presentation Systems, Immunomodulators, and Immune Responses to Vaccines. In: Perlmann P, Wigzell H (Hrsg). Handbook of Experimental Pharmacology. Berlin-Heildelberg: Springer 1999: 57-92
• 75 McLaurin J, Cecal R, Kierstead M E, Tian X, Phinney A L, Manea M, French J E, Lamberon M HL, Darabie A A, Brown M E, Janus C, Chishti M A, Horne P, Westaway D, Frase P E, Mount H TJ, Przybylski M, St George-Hyslop P. Therapeutically effective antibodies against amyloid-β peptide target amyloid-β residues 4 - 10 and inhibit cytotoxicity and fibrillogenesis.  Nature Med. 2002;  8 1263-1269
• 76 DeMattos R B, Bales K R, Cummins D J, Dodart J-C, Paul S M, Holtzman D M. Peripheral anti-Aβ antibody alters CNS and plasma Aβ clearance and decreases brain Aβ burden in a mouse model of Alzheimer's disease.  Proc Natl Acad Sci. 2001;  98 8850-8855
• 77 DeMattos R B, Bales K R, Cummins D J, Paul S M, Holtzman D M. Brain to plasma amyloid-β efflux: A measure of brain amyloid burden in a mouse model of Alzheimer's disease.  Science. 2002;  295 2264-2267
• 78 Thomson E J, Keir G. Laboratory investigation of cerebral fluid proteins.  Ann Clin Biochem. 1990;  27 425-435
• 79 Steinberg D. Testing Potential Alzheimer Vaccines.  The Scientist. 2002;  16 23-24
• 80 Nicoll J AR, Wilkinson D, Holmes C, Steart Phil, Markham H, Weller R O. Neuropathology of human Alzheimer disease after immunization with amyloid-β-peptide: a case report.  Nature Med. 2003;  9 448-452
• 81 Okamoto I, Kawano Y, Murakami D, Sasayama T, Araki N, Miki T, Wong A J, Saya H. Proteolytic release of CD44 intracellular domain and its role in the CD44 signaling pathway.  J Cell Biol. 2001;  155 755-762
• 82 Wyss-Coray T, Lin C, Yan F, Yu G-Q, Rohde M, McConlogue L, Masliah E, Mucke L. TGF-β1 promotes microglial amyloid-β clearance and reduces plaque burden in transgenic mice.  Nature Med. 2001;  7 612-618
• 83 Weggen S, Eriksen J L, Das P, Sagi S A, Wang R, Pietrzik C U, Finflay K A, Smith T E, Murphy M P, Bulter T, Kang D E, Marquez-Sterling N, Golob T E, Koo E H. A subset of NSAIDs lower amyloidogenic A_β42 independently of cyclooxygenase activity.  Nature. 2001;  414 212-216
• 84 Kensil C R. Saponins as vaccine adjuvans.  Crit Rev Ther Drug Carrier Syst. 1996;  13 1-55
• 85 Wu J Y, Gardner B H, Murphy C I, Seals J R, Kensil C R, Recchia J, Beltz G A, Newman G W, Newman M J. Saponin adjuvant enhancement of antigen-specific immune responses to an experimental HIV-1 vaccine.  J Immunol. 1992;  148 1519-1525
• 86 Birmingham K, Frantz S. Set back to Alzheimer vaccine studies.  Nature Med. 2002;  8 199-200
• 87 Bush A I. Therapeutic targets in the biology of Alzheimer's disease.  Cur Opin Psychiat. 2001;  14 341-348
• 88 Check E. Nerve inflammation halts trial for Alzheimer's drug.  Nature. 2002;  415 462
• 89 Eastwood R, Förstl H. The Vanishing Plaque. AN-1792: A Frank Revolution?.  International Psychogeriatrics. 2001;  13 3-4
• 90 Golde T E. Inflammation takes on Alzheimer disease.  Nature Med. 2002;  8 936-938
• 91 Levey A I. Immunization for Alzheimer's disease: A Shot in the Arm or a Whiff?.  Ann Neurol. 2000;  48 553-555
• 92 Münch G, Robinson S R. Alzheimer's vaccine: a cure as dangerous as the disease?.  J Neural Transm. 2002;  109 537-539
• 93 Smith M A, Joseph J A, Atwood C S, Perry G. Dangers of the amyloid-β vaccination.  Acta Neuropathol. 2002;  104 110
• 94 Smith M A, Atwood C S, Joseph J A, Perry G. Predicting the failure of amyloid-β vaccine.  The Lancet. 2002;  359 1864-1865
• 95 Poland G A, Murray D, Bonilla-Guerrero R. New vaccine development.  BMJ. 2002;  324 1315-1319
• 96 Schild G, Corbel M, Corran P, Minor P. Vaccines: Past, Present und Future. In: Perlmann P, Wigzell H (Hrsg). Handbook of Experimental Pharmacology. Berlin-Heildelberg: Springer 1999: 1-19
• 97 Hudson P J, Souriau C. Engineered antibodies.  Nature Med. 2003;  9 129-134
• 98 Bergmann J, Kienzl E, Janetzky B, Preddie E, Jellinger K A. Alternatives to the suspended Alzheimer's disease vaccine.  Acta Neuropathol. 2002;  104 111-112
• 99 Felician O, Sandson T A. The Neurobiology and Pharmacotherapy of Alzheimer's Disease.  J Neuropsychiatry Clin Neurosci. 1999;  11 19-31
• 100 Irizarry M C, Hyman B T. Alzheimer Disease Therapeutics.  J Neuropathol Exp Neurol. 2001;  60 923-928