Molecular Farming of Plants and Animals for Human and Veterinary Medicine

Molecular Farming of Plants and Animals for Human and Veterinary Medicine

Edited by

L. Erickson University of Guelph,

Department (~f Plant Agriculture, Geulph, Ontario, Canada

W.-J. Yu Syngenta Biotechnology Inc.,

Research Triangle Park, North Carolina, U.S.A.

J. Brandle Research Branch,

Agriculture and Agri-Food Canada, London, Ontario, Canada

and

R. Rymerson Research Branch,

Agriculture and Agri-Food Canada, London, Ontario, Canada

SPRINGER·SCIENCE+BUSINESS MEDIA, B.V.

A C.I.P. Catalogue record for this book is available from the Library of Congress.

ISBN 978-90-481-6110-2 ISBN 978-94-017-2317-6 (eBook) DOI 10.1007/978-94-017-2317-6

Printed on acid-free paper

All Rights Reserved © 2002 Springer Science+Business Media Dordrecht

Originally published by Kluwer Academic Publishers in 2002 Softcover reprint of the hardcover 1 st edition 2002

No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording

or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered

and executed on a computer system, for exclusive use by the purchaser of the work.

Contents

Preface XVll

1. TOBACCO, A PLATFORM FOR THE PRODUCTION OF RECOMBINANT PROTEINS 1 R. T. Rymerson, R. Menassa and J.E. Brandle 1. INTRODUCTION 1 2. AGRICULTURAL PRODUCTION OF BIOMASS 2 3. RECOMBINANT PROTEIN EXPRESSION IN

TOBACCO 4 3.1 Production in Seeds 4 3.2 Organelle Targeting 5 3.3 Chloroplast Transformation 6 3.4 Secretion to the Apoplast 7 3.5 Transient Expression 8

4. EXAMPLES 10 4.1 Antibodies 10 4.2 Biopharmaceuticals 12 4.3 Industrial Proteins 19 4.4 Vaccines 21

5. CONCLUSION 24

2. ALFALFA: AN EFFICIENT BIOREACTOR FOR CONTINUOUS RECOMBINANT PROTEIN PRODUCTION 33 M.-A. D'Aoust, U. Busse, M. Martel, L. Faye, D. Levesque and L.P. Vezina 1. INTRODUCTION 33 2. EXPRESSION CASSETTES 34 3. TRANSFORMATION METHODS 36

3.1 In vitro Culture 36 3.2 Transformation with Agrobacterium 37 3.3 Direct DNA Transfer 38 3.4 Other Methods 39

4. POPULATION RAMP-UP 40 5. EXTRACTION AND PURIFICATION 41

v

VI Contents

5.1 Extraction and Purification 41 6. N-GLYCOSYLATION OF ALFALFA PROTEINS 43 7. CASE STUDY 43

7.1 Characteristics of an Anti-human IgG Produced in Alfalfa 43

3. THE USE OF VIRAL VECTORS FOR THE PRODUCTION OF RECOMBINANT PROTEINS IN PLANTS 49 G.P. Lomonossoff 1. INTRODUCTION 49 2. CHOICE OF VIRUS FOR VECTOR DEVELOPMENT 50 3. TYPES OF EXPRESSION SYSTEMS 51 4. EXAMPLES OF THE EXPRESSION OF PEPTIDES

AND PROTEINS USING VIRAL VECTORS 52 4.1 Tobacco Mosaic Virus 52 4.2 Cowpea Mosaic Virus 57 4.3 Tomato Bushy Stunt Virus 60 4.4 Plum Pox Virus 62 4.5 Other Potyviruses 63 4.6 Potato virus X 63 4.7 Tobacco Rattle Virus 65 4.8 Subviral Systems 65

5. CONCLUSIONS 66

4. CONTROL OF THE N-GL YCOSYLATION OF THERAPEUTIC GL YCOPROTEINS PRODUCED IN TRANSGENIC PLANTS: A NEW CHALLENGE FOR GL YCOBIOLOGISTS 73 P. Lerouge, M. Bardor, S. Pagny, V. Gomord, A.-C. Fitchette andL. Faye 1. PLANT N-LINKED GL YCANS AND THEIR

DIFFERENCES WITH THEIR MAMMALIAN COUNTERPARTS 74 1.1 Structures of Plant N-linked Glycans 74 1.2 Processing of N-linked Glycans in Plants 77 1.3 N-glycosylation and Folding of Proteins 82 1.4 Complex N-glycans Are Ubiquitous among the Plant

Kingdom 83 1.5 Structural Analysis of Plant N-glycans 84

2. N-GLYCOSYLATION OF THERAPEUTIC GL YCOPROTEINS PRODUCED IN TRANSGENIC

Contents Vll

PLANTS: CURRENT ASPECTS AND FUTURE TRENDS 89 2.1 N-glycan Patterns of Therapeutic Glycoproteins

Produced in Transgenic Plants 90 2.2 Immunogenicity and Allergenicity of Plant N-

glycans 91 2.3 Metabolic Engineering of the Glycosylation in Plants

to Obtain a Perfect Copy of Mammalian N-glycans 92 3. FUTURE PERSPECTNES 100

5. PRODUCTION AND COMMERCIALIZATION OF BIOPHARMACEUTICALS FROM MILK 111 M.G.A. Peters and M.F. Brink 1. INTRODUCTION 111 2. THE RISING COST OF PHARMACEUTICALS 112 3. ADVANCES IN BIOTECHNOLOGY 113 4. LIVESTOCK VERSUS BACTERIAL

FERMENTATION 115 5. TRANS GENESIS 116 6. TRANSGENIC MILK TECHNOLOGY 117 7. GENERATING TRANSGENIC ANIMALS THROUGH

MICRO- INJECTION 119 8. NEW DEVELOPMENTS: NUCLEAR TRANSFER

TECHNOLOGY 120 9. PHARMING'S TRANSGENIC CATTLE PLATFORM 122 10. EFFECTNENESS OF THE TRANSGENIC

PLATFORM 122 10.1 Human Lactoferrin 123 10.2 Human Fibrinogen 123

11. CONCLUSION 124

6. A SEED-DERNED ORAL SUBUNIT VACCINE FOR HUMAN CYTOMEGALOVIRUS 127 E.S. Tackaberry, K.E. Wright, A.K. Dudani, I. Altosaar and P.R. Ganz 1. PLANTS AS EXPRESSION SYSTEMS FOR

BIOTHERAPEUTICS 128 2. HUMAN CYTOMEGALOVIRUS 130 3. CONCERNS AND CHALLENGES 131 4. PREVIOUS WORK 132 5. TRANSFER OF THE HCMV Gb GENE TO TOBACCO 132

5.1 Vector Constructs and Transfer to Plants 132

V111 Contents

5.2 Molecular Analysis of Plants Containing the HCMV gBGene 134

6. Immunological Detection of gB and Quantification in Seed Protein Extracts 135 6.1 Extraction of Soluble Seed Proteins 135 6.2 gB-Specific ELISA 136

7. Antigenic Comparability of Seed-Derived gB vs. gB Produced in Infected Human Cells 137

8. Subcellular Localization of gB in Endosperm Tissue of Mature Transformed Seeds 140

9. GENERAL DISCUSSION 142 9.1 Cloning, Transfer and Expression of gB Protein 143 9.2 Sub-cellular Localization of gB in Seed Endosperm 144 9.3 Sorting of gB in Endosperm Cells 145

10. SUMMARY 146

7. USE OF PLANT VIRUS-BASED EXPRESSION SYSTEMS FOR THE PRODUCTION OF HIV VACCINES 155 G.G.Zhang 1. INTRODUCTION 156 2. CANDIDATE PEPTIDES AND PROTEINS FOR HIV

VACCINES 157 3. EXPRESSION OF HIV VACCINES USING RNA

PLANT VIRUS- BASED EXPRESSION VECTORS 160 3.1 Presentation of the Kennedy Epitope from HIV-l

gp41 on the Surface of Cowpea Mosaic Virus 160 3.2 Expression of V3 Loop from Hiv-l Gp120 Using

Tobacco Mosaic Virus 164 3.3 Expression of an Epitope from V3 Loop of Hiv-l

Gp120 and the Full-length P24 Using Tomato Bushy Stunt Virus 168

4. SUMMARY AND FUTURE PROSPECTS 171

8. SUPPRESSION OF AUTOIMMUNE DIABETES BY THE USE OF TRANSGENIC PLANTS EXPRESSING AUTOANTIGENS TO INDUCE ORAL TOLERANCE 179 S. Ma and A.M. Jevnikar 1. INTRODUCTION 179 2. ORAL TOLERANCE AND THE TREATMENT OF

AUTOIMMUNE DISEASES 181 3. UNIQUE ADVANTAGES OF USING TRANSGENIC

PLANTS FOR ORAL TOLERANCE INDUCTION 183

Contents ix

4. TRANSGENIC PLANTS EXPRESSING GAD 185 5. ORAL IMMUNOGENICITY OF THE PLANT

DERIVED GAD PROTEIN 186 6. EXPRESSION OF CHOLERA TOXIN B SUBUNIT

(CTB)-INSULIN FUSION PROTEINS 189 7. EXPRESSION OF HUMAN GAD65 190 8. CONCLUSIONS AND FUTURE PROSPECTS 191

9. THE PRODUCTION AND DELIVERY OF THERAPEUTIC PEPTIDES IN PLANTS 197 L. Erickson, W.-J. Yu, J. Zhang, C.F.M. deLange, B .McBride and S. Du 1. PLANT SCIENCE IN THE CONTEXT OF

VETERINARY AND MEDICAL HEALTH 197 2. SIGNIFICANCE OF INTESTINAL DISEASE 198

2.1 Human 198 2.2 Animal 199

3. INTESTINAL DISEASE AND THE ROLE OF THE EPITHELIUM 199

4. GROWTH FACTORS AND THE EPITHELIUM 200 4.1 Epidermal Growth Factor 200 4.2 Glucagon-like Peptide-2 201

5. ANTIMICROBIAL PEPTIDES AND INTESTINAL HEALTH 202

6. PLANTS ENGINEERED TO CONTAIN NOVEL THERAPEUTIC PEPTIDES 203 6.1 Medicinal Plants 203 6.2 Expression of Xenoproteins in Plants: Problems and

Strategies 204 6.3 Expression of Mammalian Proteins in Plants 207

7. LEAF-BASED PRODUCTION SYSTEMS: ADVANTAGES AND DISADVANTAGES 212

8. DELIVERY OF THERAPEUTIC PEPTIDES TO THE INTESTINAL TRACT 214

9. REGULATORY CONSIDERATIONS 215

10. AN ORAL VACCINE IN MAIZE PROTECTS AGAINST TRANSMISSmLE GASTROENTERITIS VIRUS IN SWINE 223 J.Jilka 1. INTRODUCTION 223

x Contents

2. GENE CONSTRUCTS AND TRANSFORMATION OF MAIZE VIA AGROBACTERIUM 225

3. PROTOCOLS FOR FEEDING AND CLINICAL TRIALS 226 3.1 Transgenic Grain Production 226 3.2 Swine Feeding Trials 226 3.3 Vaccination of Feed Test Groups 226 3.4 Virus Challenge 227 3.5 Data and Sample Collection 227 3.6 Data Analysis 228 3.7 Swine Feeding Trial #1 (TGEV-1) 229 3.8 Swine Feeding Trial #2 (TGEV -2) 229

4. RESULTS FROM CLINICAL TRIALS 229 4.1 Observations of Clinical Symptoms for TGEV -1 229 4.2 Observations of Clinical Symptoms for TGEV -2 230

5. GENERAL DISCUSSION 232

11. PRODUCTION OF ANTIBODIES IN ALFALFA (MEDICAGO SATIVA) 237 U. Busse, V. Levee, S. Trepanier and L. Vezina 1. INTRODUCTION 238

1.1 Antibodies in Human and Veterinary Medicine 238 1.2 Antibody Production: from Fermentors to Molecular

Farming 239 2. MOLECULAR FARMING USING ALFALFA 241 3. PRODUCTION STRATEGIES IN ALFALFA 242

3.1 Genetic Programming 242 3.2 Gene Transfer 243 3.3 Production of Biomass 245 3.4 Recovery of Recombinant Molecules 247 3.5 Disposal of Biomass 248

4. CASE STUDY 249 5. FUTURE DEVELOPMENTS 251 6. CONCLUSION 253

12. THE PRODUCTION OF RECOMBINANT ANTIBODIES IN PLANTS AND PLANT CELLS 259 R. Fischer, N. Emans and S. Schillberg 1. INTRODUCTION 259 2. TRANSGENIC PLANTS AS BIOREACTORS FOR

RECOMBINANT PROTEIN PRODUCTION 262 2.1 Antibody Engineering 263

Contents xi

2.2 Antibody Production in Transgenic Plants 263 3. PROTEIN EXPRESSION IN PLANTS 267

3.1 Agroinfiltration 268 3.2 Viral Vectors 268 3.3 Expression in Stably Transformed Plants 270 3.4 The Ideal Crop for Production of Recombinant

Antibodies 270 4. PROTEIN PRODUCTION IN PLANT SUSPENSION

CULTURED CELLS 271 4.1 Suspension Cell Transformation 273

5. DOWNSTREAM PROCESSING OF RECOMBINANT ANTmODIES FROM TRANSGENIC PLANT CELLS 274

6. APPLICATIONS OF RECOMBINANT ANTmODIES EXPRESSED IN PLANTS 275 6.1 The Safety of Plant Produced Recombinant

Antibodies 275 6.2 USING RECOMBINANT PLANT-DERIVED

ANTmODIES IN HUMAN HEALTH CARE 276 7. PERSPECTIVES 277

13. IMMUNOTHERAPEUTIC POTENTIAL OF ANTmODIES PRODUCED IN CHICKEN EGGS 287 Y. Mine and J. Kovacs-Nolan 1. INTRODUCTION 288 2. PHYSIOLOGY OF CHICKEN EGG FORMATION 289 3. CHICKEN EGGS AS AN ALTERNATIVE SOURCE

OF ANTmODIES 291 3.1 STRUCTURAL CHARACTERISTICS OF

CHICKENIGY 293 3.2 Production and Isolation of Chicken IgY 295

4. IMMUNOTHERAPEUTIC POTENTIAL OF CHICKEN IGY297 4.1 Application of IgY for the Prevention of Human

Rotavirus Infection 297 4.2 Application of Ig Y for the Prevention of Yersinia

ruckeri in Rainbow Trout 301 4.3 Application of Ig Y for the Prevention of

Enterotoxigenic Escherichia coli Infection 302 4.4 Application of IgY for the Prevention of

Salmonellosis 306 4.5 Other Applications of IgY 308

5. CONCLUSION AND FUTURE STUDIES 309

Xll Contents

14. THE PRODUCTION OF RECOMBINANT CYTOKINES IN PLANTS 319 R. Menassa, A. Jevnikar and J. Brandle 1. INTRODUCTION 319 2. EXPERIMENTAL RESULTS FROM PLANTS 321

2.1 Human Erythropoietin 322 2.2 Human Interferons 323 2.3 Human Granulocyte-Macrophage Colony

Stimulating Factor (GM- CSF) 326 2.4 Human Interleukin-2 327 2.5 Human Interleukin-4 328

3. PRODUCTION PLATFORM CONSIDERATIONS 331 4. QUALITY CONTROL AND STANDARDIZATION

ISSUES 332 5. CONCLUSION 333

15. EDIBLE VACCINES IN PLANTS FOR LIVESTOCK PATHOGENS 339 L. Erickson, W.-J. Yu, T. Tuboly, E. Nagy, A. Bailey, J. Zhang, D. Yoo and S. Du 1. INTRODUCTION 339 2. ADVANTAGES OF EDIBLE PLANT-BASED

VACCINES TO INDUSTRY AND THE CONSUMER 340 3. OBSTACLES TO THE DEVELOPMENT OF EDIBLE

PLANT- BASED VACCINES 341 3.1 Expression Levels of Antigens in Plants 341 3.2 Degradation of Antigens in the Gut 343 3.3 Immunogenicity of Antigens Produced in Plants and

Delivered Orally 344 4. STRATEGIES FOR PRODUCTION AND DELNERY

OF EDIBLE VACCINES IN PLANTS 346 4.1 Expression of Antigens Using Native Gene

Constructs 346 4.2 Synthetic Genes 351 4.3 Fusion Proteins 355 4.4 Inducible Systems 357 4.5 Reducing Degradation and Enhancing

Immunogenicity 359 5. EDIBLE DNA VACCINES IN PLANTS 362

Index 369

Contents xiii

List of Tables

Table 1. Pharmaceutical proteins expressed in tobacco .............. 17 Table 2. Industrial proteins expressed in tobacco . . . . . . .. . . . . . . . . . .. 20 Table 3. Methods and conditions for increasing the population of alfalfa plants

to production scales of recombinant protein .................... 40 Table 4. Candidate HIV / AIDS vaccines in development and clinical trials

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 159 Table 5. Genetic engineering of plants with non-plant AMPs. . . . . . . .. 211 Table 6. Summary of study design (TGEV -1) . . . . . . . . . . . . . . . . . . . .. 229 Table 7. Summary of study design (TGEV-2) .................... 230 Table 8. Summary of clinical data for TGEV -1 ................... 231 Table 9. Summary of clinical data for TGEV -2 ................... 231 Table 10. Genetic transformation of Medicago sativa using direct DNA

transformation methods. ............................... .•.. 245 Table 11. Propagation methods and field settings for alfalfa at different

production scales of recombinant protein. . . . . . . . . . . . . . . . . . . . .. 246 Table 12. Comparison of mammalian IgG and chicken IgY ......... 296 Table 13. Anti-human rotavirus VP8 IgY neutralization titres . . . . . . .. 301 Table 14. Effects on rainbow trout by passive immunization with anti- Y.

ruckeri IgY following immersion challenge ................... 303 Table 15. Rates of isolation of ETEC K88+, K99+' and 987P+strains from

newborn piglets after challenge and treatment with antibody powder at various titres ........................................... 305

Table 16. Effect of egg yolk antibody on in vitro adhesion of S. enteriditis and S. typhimurium to HeLa cells. .............................. 307

Table 17. Human cytokines expressed in plants . . . . . . . . . . . . . . . . . .. 321 Table 18. Expression of antigen genes from livestock pathogens in plants

...................................................... 342

xiv Contents

List of Figures

Figure 1. Inducibility of GUS expression with Med-I302Texpression cassette in tobacco leaves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35

Figure 2. Comparison of Med-2IOI and 35S promoters for leaf GUS expression capacity in transgenic tobacco. ..................... 36

Figure 3. Steps of alfalfa processing toward the purification of Rubisco. 42 Figure 4. Major N-glycans found on alfalfa proteins ................ 44 Figure 5. Epitope presentation using tobacco mosaic virus (TMV). .... 53 Figure 6. Genome organization of viruses in which the CP sg promoter is used

to drive expression of the heterologous protein. ................. 56 Figure 7. Epitope presentation using cowpea mosaic virus (CPMV). ... 58 Figure 8. Genome organization of viruses in which protein processing is used

to obtain expression of the heterologous protein (hatched). ........ 61 Figure 9. Structures of a) high-mannose-type N-glycans that are common to

plants and animals, b) plant complex-type N-glycans, c) plant paucimannosidic-type N-glycans, d) plant hybrid-type N-glycans and e) mammalian sialylated bi-antennary N-glycan. .................. 75

Figure 10. Processing of plant N-linked glycans. . . . . . . . . . . . . . . . . . .. 78 Figure 11. Distribution ofN-glycan structures in the plant cell. ....... 82 Figure 12. Structure of the most abundant matured - linked glycans

isolated from plant glycoproteins. .......................... 84 Figure 13. Encircled glycan sequences correspond to epitopes recognized by

antibodies used for immunoblotting analysis of plant glycoproteins.. 86 Figure 14. Structure (a), HPAEC-PAD profile (b), FACE analysis (c) and

MALDI-TOF mass spectrum (d) ofglycans N-linked to PHA-L. ... 88 Figure 15. Immuno- and affinodetection of the gastric lipase expressed in

transgenic tobacco plants. .................................. 91 Figure 16. Strategies to metabolically engineer the N-glycosylation in plants .

....................................................... 94 Figure 17. Processing of the N-linked glycans in wild-type A. thaliana, and in

the cgl and the murl mutant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 96 Figure 18. Humanization of plant N-glycans by expression of the humanp(1,

4 )-galactosyItransferase in tobacco BY2 cells (1) and tobacco plants (2) . ... ......... .... ..... ........... ....................... 99

Figure 19. Structure of glycans N-linked to Mgr48 expressed in hybridoma cells, tobacco plants and tobacco plants expressing the human P(1, 4)­galactosyItransferase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 100

Figure 20. Biotechnology medicines in development. .............. 115 Figure 21. Transgenic rabbit system. ........................... 118 Figure 22. Nuclear transfer system. ............................ 121

Contents xv

Figure 23. Engineering of pRD400/pPH2/gBINOS-T, an expression vector designed to target synthesis ofthe heterologous viral glycoprotein gB to the seeds of tobacco plants. .................................. 133

Figure 24. Southern blot analysis of genomic DNA. ............... 135 Figure 25. Detection and quantification of gB protein in soluble extracts of

tobacco seeds.. ......................................... 137 Figure 26. Comparability of gB derived from seeds and gB, in HCMV -infected

cells, by inhibition of immunofluorescence.. .................. 139 Figure 27. Immunogold labelling of endosperm from freshly harvested mature

seeds. ................................................ 141 Figure 28. Immunogold labeling of endosperm from stored mature seeds. 142 Figure 29. HIV-l genome organization ......................... 158 Figure 30. Presentation of foreign peptides on the surface of the CPMV

particle.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 162 Figure 31. Presentation of vaccine epitopes on the surface ofTMV. . .. 166 Figure 32. Expression ofV3 loop from HIV -1 gp 120 using TMV with an AMV

coat protein amplicon.. ................................... 167 Figure 33. Expression ofpep13 and p24 using TBSV. . . . . . . . . . . . . .. 169 Figure 34. Oral administration of plant material expressing mouse GAD67

prevents development of diabetes in NOD mice. ............... 188 Figure 35. T-DNA region of the binary vector containing synthetic porcine

EGF gene. ............................................. 208 Figure 36. Production of recombinant proteins in alfalfa.. ........... 243 Figure 37. Inducibility of B-glucuronidase (GUS) expression in alfalfa and

tobacco leaves using Medicago's Med-1302T expression cassette .. 244 Figure 38. Production schedule for a monoclonal antibody in transformed

alfalfa plants. ........................................... 247 Figure 39. Protein blot analysis of C5-1 light and heavy chain assembly in

alfalfa. ................................................ 249 Figure 40. Stability of C5-1 in alfalfa. .......................... 250 Figure 41. Degradation rate of alfalfa derived and hybridoma derived C5-1 in

the blood stream of mice. ................................. 251 Figure 42. Forms of recombinant antibodies produced in plants. ..... 264 Figure 43. Maximum scFvT84.66 antibody production levels in wheat and rice

leaves and seeds, pea seeds and tobacco leaves. ............... 271 Figure 44. The reproductive system of the hen, ovary and oviduct.). . .. 291 Figure 45. Structure ofIgG and IgY

294 Figure 46. Antibody response in the egg yolks of a hen injected with

recombinant VP8.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 300 Figure 47. Constructs containing the native eDNA for the S gene. .... 347

XVI Contents

Figure 48. Analysis oftransgenic plants containing the S gene by Southern (A), Northern (B) and Western (C) blots. . . . . . . . . . . . . . . . . . . . . . . . .. 348

Figure 49. Potential mRNA processing signals in the native S gene. . .. 349 Figure 50. Synthesis of the redesigned 1856 bp S gene by overlap extension

peR and construction of the expression vector pSS 1. ........... 352 Figure 51. Binary vectors containing a swine viral epitope fused to plant

protein genes.. .......................................... 356

Preface

Molecular farming has been hailed as the "third wave" of genetically-modified organisms produced through biotechnology for the bio-based economy of the future. Unlike products of the first wave, such as herbicide resistant crop plants, which were perceived to benefit only the farmers who used them and the agrochemical companies who developed them, products of molecular farming are designed specifically for the benefit of the consumer. Such products could be purified from food or non-food organisms for a range of applications in industry, as well as animal and human health. Alternatively, the products of this technology could be consumed more directly in some edible format, such as milk, eggs, fruits or vegetables.

There is a rapidly-growing interest Qn the part of the public as well as in the medical community in the role food plays in health, especially in the immunophysiological impact of food over and above the role of basic nutrition. As a result, there is an expanding opportunity and need for those working in plant and animal biology to conduct research in a broader scientific and social context than in the past. Such research requires a multidisciplinary approach and, despite the potential for discovery and wider relevance of such research, there are not many examples of plant or animal scientists straying far beyond the boundaries of their disciplines to collaborate with colleagues, for example, in the medical community. Yet, the significance of food and feed products far exceeds that of providing the biochemical building blocks for humans and their animals. Many constituents of food have both a beneficial and harmful impact on health through effects on the immune, endocrine, nervous, circulatory and digestive systems. The rapidly expanding bodies of knowledge in the various branches of biological science now enable us to combine and utilize this knowledge in new ways to solve problems old and new in human and animal health.

The mUltidisciplinary approach required for development of the products of molecular farming is amply illustrated in the chapters ofthis book.

xvii

XVlll Preface

The problems addressed by the authors range from HIV-Aids in humans to diseases in swine. The approaches to these problems range from oral vaccines produced in plants to antibodies produced in eggs. The array of platforms and strategies being developed for the products of molecular farming demonstrates not only the creativity of the scientists involved and the flexibility of biological systems as biosynthetic factories, but also the potential complexities for the regulation and commercialization of these products.

L. Erickson, Principal Editor

Preface XlX

Acknowledgements

The editors are indebted to the infinitely patient and superbly competent assistance of Jennifer Kingswell and Angela Hill in the Department of Plant Agriculture, University of Guelph, for the completion of this work.