Genomics and future biological weapons: the need for preventive ...

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© 2001 Nature Publishing Group http://genetics.nature.com

Genomics and future biological weapons: the need for preventive action by the biomedical community © 2001 Nature Publishing Group http://genetics.nature.com

Claire M. Fraser1 & Malcolm R. Dando2 Published online: 22 October 2001, DOI: 10.1038/ng763 There is an increasing concern within both the scientific and security communities that the ongoing revolution in biology has great potential to be misused in offensive biological weapons programs. In light of the 11 September tragedy, we can no longer afford to be complacent about the possibility of biological terrorism. Here we review the major relevant trends in genomics research and development, and discuss how these capabilities might be misused in the design of new bioweapons. We also discuss how the breakthroughs that have come from the genomics revolution may be used to enhance detection, protection and treatment so that biological warfare agents are never used.

Biological warfare attacks have often been dismissed as science fiction or as so immoral as to be beyond imagination. The tragic events in the United States on 11 September 2001 show that they are neither, and will force a reconsideration of international security. It can no longer be assumed that the deliberate causing of mass civilian fatalities is impossible in the developed world; it will thus be necessary to look again at the problems caused by the proliferation of nuclear, chemical and biological weapons of mass destruction. Of these, biological weapons pose by far the greatest threat, because they can be as lethal as nuclear weapons and are easier to obtain. In fact, a crude attack with biological weapons would probably be easier to plan and execute than was the attack on the World Trade Center. In addition, biological weapons are constrained by a weak international arms control regime. US President George W. Bush called attention to this earlier in the year, when speaking in Iowa just before his visit to Europe in June 2001; he stated that the United States and its allies “...ought to develop the capacity to address the true threats of the 21st century. The true threats are biological and information warfare1.” This statement seems to reflect an increasing tide of concern, among both the scientific and security communities2, that the revolution in biology could be misused in offensive biological weapons programs directed against human beings and their staple crops or livestock. Any such misuse of biology is prohibited by the 1975 Biological and Toxin Weapons Convention (BTWC). Article I of the Convention states: “Each State Party to this Convention undertakes never in any circumstances to develop, produce, stockpile or otherwise acquire or retain: 1. Microbial or other biological agents, or toxins whatever their origin or method of production, of types or in quantities that have no justification for prophylactic, protective or other peaceful purposes.” The italicized section above forms what has become known as the ‘General Purpose Criterion’. The prohibition clearly did not

apply just to the possible misuse of science and technology at the time that the Convention came into force. It refers not to any particular activity, but to the intent of any activity. This prohibition, now accepted by over 140 States Party to the Convention, applied yesterday, applies today and will apply in the future. The problem with the BTWC is not in the scope of its prohibition—it lies in the fact that States Party could not agree to effective verification procedures, to ensure that they live up to their obligations, in the Cold War era of the 1970s when it was negotiated3. The BTWC did, however, include a mechanism by which it could be subjected to review at five-year intervals. This mechanism has allowed the States Party to extend their common understanding of how the new dual-use (civil and military) technology might potentially be misused, and of what is thus prohibited. There can be little doubt that States Party are aware that advances in modern biology might be misused. In light of the current scientific and technological revolution, it is incumbent upon us all to consider the societal implications of our work. This paper is intended as a step in that direction, reviewing, prior to the Fifth Review Conference of the BTWC in November and December of this year, some of the problems and benefits relevant to the prevention of biological warfare that could arise from the genomics revolution. The historical context Although it is not widely appreciated by the biomedical community, the historical record clearly shows a series of offensive biological weapons programs carried out by major states such as Germany, France, Japan, the UK, the USA, the USSR and Iraq during the 20th century. These programs may be reasonably divided into three generations4: (i) the relatively unscientific programs created during the First World War and between the world wars (ii) the science-based, effective programs created during and after the Second World War and (iii) the programs carried out toward the end of the Cold War,

1The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, Maryland 20850, USA. 2Department of Peace Studies, University of Bradford,

UK. Correspondence should be addressed to C.M.F. (e-mail: [email protected]).

nature genetics • advance online publication

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More recently, a group of scientists considering “New Scientific and Technological Developments of Relevance to the Biological and Toxin Weapons Convention” at a NATO Advanced Studies Workshop10 noted a number of other future concerns. These include the consequences of advances in the technology of plant inoculants and in biocontrol in agriculture, the possible misuse of large-scale databases containing information on the genetics of specific populaNew forms of biological warfare Microbiologists who have looked carefully at the possible appli- tions, the impact of genomics on our understanding of receptors cations of currently available technology to offensive biological for bioregulators and similar signaling molecules11 and the increasweapons programs suggest that it might now be possible to, ing potential for manipulation of the immune system. among other things, enhance the antibiotic The latter concern was clearly enhanced by resistance of biological agents, modify their antithe inadvertent creation of a lethal mousepox “…‘tailoring’ of genic properties or transfer pathogenic propervirus in Australia in the course of perfectly legal classical biological ties between them5. Such ‘tailoring’ of classical research12,13. Another, rather more general surbiological warfare agents could make them warfare agents could prise has been the realization that there could be harder to detect, diagnose and treat. It could, in make them harder to a common (RNAi) mechanism available to short, make them more militarily useful6 and detect, diagnose and switch off any gene in an organism, and that this mechanism will soon be elucidated—again for thus increase the temptation to pursue offensive treat. It could, in quite proper reasons14. programs. Should such development of the third short, make them generation of offensive biological weapons proThese examples delineate a multifaceted risk grams be allowed to occur, what might happen that could become a real threat in the not-too-dismore militarily in fourth-generation programs—say, in a tant future; but how realistic is this assessment? useful…” decade or two—after the genomics revolution What are the major relevant trends in genomics has consolidated and spread around the world? research and development, and could any of the In a 1997 version of a publication entitled Proliferation: Threat new techniques in development be easily misused in new and Response, the United States Department of Defense identi- bioweapons? By contrast, could the genomics revolution also be fied a number of trends that could be significant in relation to used to develop enhanced means of detection, protection and treatthe development of future biological weapons7. These include ment to ensure that biological warfare agents are never used? the increasing use of genetically engineered vectors and the growing understanding of both infectious disease mechanisms Major relevant trends in the genomics revolution and the immune defense system. Other scientists have con- In a 1995 editorial in Nature, following publication of the second ducted open analyses of the possibilities and suggest a variety of complete microbial genome sequence, Barry Bloom, now the specific concerns. dean of the Harvard School of Public Health, stated15: R.A. Zilinskas, in summarizing a set of well-informed essays8, “The power and cost effectiveness of modern genome has suggested that it could take about five years for scientists sequencing technology mean that complete genome working for “proliferant governments or subnational groups” to sequences of 25 of the major bacterial and parasitic effectively employ the new biotechnologies. He envisaged, after pathogens could be available within 5 years. For about that time, major advances in improving microbial agents for use, $100 million we could buy the sequence of every viruand perhaps in better targeting them against particular groups. lence determinant, every protein antigen, and every drug He also concluded that there would be little chance of detecting target. It would represent for each pathogen a one-time and identifying pathogens in real time before these developments investment from which the information derived would took place, or in the foreseeable future. be available to all scientists for all time. We could then Steven Block of the Princeton University molecular biology think about a new post-genomic era of microbe biology.” department has reported a study of “Biological Threats Enabled by Molecular Biology” carried out by a JASON Group of scienWe have in fact surpassed this goal, and genomics efforts in labotists in the later 1990s9. The group concluded that “...progress in biomedical science inevitably has a dark side, and potentiates the ratories around the world will deliver the complete sequence of development of an entirely new class of weapons of mass destruc- more than 70 major bacterial, fungal and parasitic pathogens of tion (WMD): genetically engineered pathogens....” They also human, animals and plants in the next year or two (see the TIGR concluded that a real danger exists that such weapons will be web site at http://www.tigr.org/tdb/mdb/mdbcomplete.html). developed, and that the weapons would pose “extraordinary This deluge of DNA sequence data, representing approximately 250,000 predicted coding sequences, has been a tremendous boon challenges for detection, mitigation, and remediation.” The group reviewed a range of illustrative examples of what to the fields of infectious disease research and comparative might become possible, rather than producing an all-inclusive genomics. It has already begun to provide many novel insights into typology; some of their examples may best be regarded as pre- the biology of disease-causing agents and is being used in the sent, third-generation possibilities. Others, however, are design of new diagnostics, anti-microbial compounds and vacindicative of substantial future concerns that could arise in cines. This is good news indeed, because infectious and parasitic fourth-generation programs. Notably, they considered the pos- diseases remain the second-leading cause of death worldwide. The sibility of ‘stealth’ viruses that could be introduced covertly continual emergence of antibiotic-resistant clones in the more into the genomes of a given population and then triggered later common human pathogens suggests that someday our arsenal of by a signal, and also of ‘designer’ diseases, such as one that pro- available anti-microbial compounds may no longer be effective. At the same time, the ready availability of DNA and protein duces apoptosis by multiple pathways. The ability to tag the genome of a given population and attack it at will, or to pro- sequence data from natural pathogens, together with advances duce an entirely new pathogen, clearly represents an order-of- in transgenic and transformation technologies, might facilitate the development of bioengineered weapons by those with more magnitude change in capabilities.


in which the USSR began making use of new genetic engineering techniques while the USA de-emphasized bioweapons. This history suggests that if the process is not halted, we will see a fourth generation of programs in the new century that will increasingly use knowledge gained from the genomics revolution.

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agent in a single assay will greatly reduce the delays inherent in current detection methods. This future scenario could serve as a possible deterrent to the deployment of biowarfare agents if the verification of an attack and the identification of an infectious agent can be accomplished quickly, allowing for a rapid and highly effective response. Development of new vaccines is a second area that has already “The Conference, conscious of apprehensions arising begun to benefit from the availability of pathogen genome sequence from relevant scientific and technological developments, information. In a study published in Science in 2000, the use of inter alia, in the fields of microbiology, biotechnology, molegenome sequence information from serotype B Neisseria meningicular biology, genetic engineering and any applications tidis (MenB) in the identification of new vaccine candidates that resulting from genome studies, and the possibilities of their confer protective immunity to this pathogen was first described22. use for purposes inconsistent with the objectives and the provision of the Convention, reaffirms that the undertakThe strategy of targeting the major carbohydrate antigen of the caping given by the States Party in Article I applies to all such sular polysaccharide in designing a vaccine, used with other developments.” (emphasis added) serotypes of N. meningitidis, was not feasible with MenB because the predominant antigen on these cells is sialic acid, which is also a For a proliferator, there are several main advantages of biologi- major cell-surface carbohydrate in humans. In the time required to cal weapons: (i) they are easy to manufacture (ii) the starting complete the MenB genome sequencing project (approximately a materials, such as bacterial and viral strains and plasmids, can be year), bioinformatics efforts to identify all potential cell-surface easily obtained by requesting them from the scientists working antigens, together with large-scale screening methods, were used to with them or from culture repositories and (iii) the ever-expand- select 7 of a total of 570 possible vaccine candidates. In a more ing microbial genome databases now provide a parts-list of all recent study from MedImmune, a similar strategy was used to mine potential genes involved in pathogenicity and the genome data of S. pneumoniae to identify six virulence, adhesion and colonization of host new vaccine targets23. Genome-enabled efforts are “Fortunately, the cells, immune response evasion and antibiotic also underway in laboratories around the world in resistance from which to pick and choose the the search for new T-cell epitopes for those same advances in most lethal combinations. microbial genomics pathogens against which cell-mediated immunity Ongoing efforts in functional genomics using that could be used to is most effective. As yet this approach has not been DNA arrays and proteomic analysis have begun as successful as the development of vaccines that to reveal the subsets of genes in the genome of produce bioweapons stimulate humoral immunity, but having all can also be used to potential antigens available as a result of genome each pathogen that are required for infection and that are involved in virulence and antibiotic sequencing efforts has been enormously valuable. set up resistance17,18. One might argue that this could A third area in which advances in microbial countermeasures genomics hold great promise is the design of further accelerate the potential misuse of against them.” new anti-microbial compounds. Current antibigenomic data through the identification of the otics target three cellular processes in the bactermost relevant genes in the pathogen collection. In addition, several companies, such as Maxygen in Redwood ial cell: DNA synthesis, protein synthesis and cell-wall synthesis. City, California, are developing technologies to carry out The reason that these three pathways make excellent targets for ‘directed molecular evolution’, in which genes are broken down anti-microbial compounds is that they represent essential cellular into smaller pieces and then shuffled during their reassembly to functions. By extension, any other protein essential for cell viabilcreate ‘daughter genes’ with new properties19. It has been esti- ity is a possible target for new classes of antibiotics. Methods such mated that this process could accelerate what can be accom- as transposon mutagenesis and in vivo expression technology plished by more classical recombination techniques by at least (IVET), for example, have permitted large-scale screening for 20-fold. Although Maxygen has been using this method to essential proteins in vitro and in vivo, even in cases where the bioenhance the properties of proteins of interest to the biotechnol- logical function of a protein is not known. New targets identified through such screening programs can be used in high-throughogy industry, it also has serious implications for biowarfare. Fortunately, the same advances in microbial genomics that put screening assays with combinatorial chemistry libraries to could be used to produce bioweapons can also be used to set up identify potential small-molecule inhibitors of protein function. countermeasures against them. One of the most important con- This kind of approach makes full use of the information in tributions may come from the development of more rapid meth- genome databases by allowing the assay system to drive the idenods for detecting biological agents, regardless of whether or not tification of new targets24. It is not limited by a priori knowledge they have been engineered. Comparative genome hybridization of the function of a specific protein. Although one can argue the using DNA arrays has already proven useful in the identification pros and cons of developing new broad-spectrum antibiotics verof strain-specific differences related to virulence and antigenicity sus those that are highly specific for a particular infectious agent, in Helicobacter pylori and Streptococcus pneumoniae20,21. It is not it is possible to achieve success on both fronts by putting genomic at all unreasonable to contemplate the fabrication of a DNA chip information to use in the drug discovery process. The completion of the human genome sequence also provides containing all of the predicted coding sequences from multiple isolates of the most important human, animal and plant a new starting point for better understanding of the infectious pathogens as a first step in the development of new detection disease process, and this has tremendous potential against technologies. The readout from such a detector could provide biowarfare. Using DNA-array and proteomics approaches, it information on the full genetic complement of any biological should become possible to analyze the cascade of events that warfare agent, even if it contained genes or plasmids from other occur in a human cell following infection with a pathogen (or the species, had unusual virulence or antibiotic-resistance properties uptake of a toxin molecule or immune modulator), as well as the or was a synthetic organism built from component genes. The events that occur in the pathogen25,26. Given that the functions of ability to quickly identify and characterize a potential biowarfare approximately one-half of all genes in both pathogens and


sinister intentions. In 1996, at the Fourth Review Conference of the States Party to the Convention of the Prohibition of the Development, Production, and Stockpiling of Biological and Toxin Weapons and on their Destruction, the final declaration was drafted to state that16:


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humans are currently unknown, data derived from functional Received 5 September; accepted 24 September 2001. genomics studies over the next few years should reveal entirely 1. The White House. Remarks by the President in Tax Celebration Event, Barrett new proteins and pathways involved in such processes. These Farm, Dallas Center, Iowa, 8 June 2001. J. (ed.) Biological Weapons: Limiting the Threat. (MIT Press, data will complement ongoing work in the design of novel vac- 2. Lederberg, Cambridge,1999). cines and anti-microbial compounds in ways that we perhaps 3. British Medical Association. Biotechnology, Weapons and Humanity. (Harwood Academic, London, 1999). cannot even imagine at this stage. 4. Dando, M. R. Defense Analysis, 15, 43–62 (1999). It has been argued by some that the availability of the human 5. Nixdorff, K., Brauburger, J. & Hahlbohm, D. The biotechnology revolution: the science and applications. in Verification of the Biological And Toxin Weapons genome sequence will facilitate the development of biowarfare Convention NATO ASI Series, I. Disarmament Technologies Vol. 32 (eds Dando, agents targeted to specific ethnic groups or individuals. Although M.R., Pearson, G.S. & Tóth, T.). 77–124 (Kluwer Academic, Dordrecht, 2000). 6. Zilinskas, R.A. (ed.) Biological Warfare: Modern Offense and Defense. (Lynne this may not be impossible, for a number of reasons it seems Rienner, Boulder, 2000). extremely unlikely. Though genetic susceptibility to infectious 7. Cohen, W. Proliferation: Threat and Response. (Department of Defense, Washington, D.C., 1997). disease has been described27,28, the reductionist view that the 8. Zilinskas, R.A. in Biological Warfare: Modern Offense and Defense (ed. Zilinskas, human genetic code is the sole determinant of disease susceptiR.A.) 247–254 (Lynne Rienner, Boulder, 2000). bility is unsubstantiated. Analysis of the human genome 9. Block, S.M. Living nightmares: biological threats enabled by molecular biology. in The New Terror: Facing the Threat of Biological and Chemical Weapons (eds Drell, sequence to date has failed to reveal any polymorphisms that can S.D., Sofaer, A.D. & Wilson, G.D.) 39–75 (Hoover Institution, Stanford, 1999). 29 10. Pearson, G.S. New Scientific and Technological Developments of Relevance to the be used to absolutely define racial groups . In fact, genetic diverFifth Review Conference. Review Conference Paper No. 3, Department of Peace sity in human populations is low relative to other species, supStudies, University of Bradford (2001). porting the notion of the recent origin and small size of the 11. Dando, M.R. The New Biological Weapons: Threat, Proliferation and Control (Lynne Boulder, 2001). ancestral human population30. A number of recent studies of 12. Nowak,Rienner, R. Disaster in the making: an engineered mouse virus leaves us one step away from the ultimate bioweapon. New Scientist 19 January, 4–5 (2001). polymorphisms in mitochondrial, Y-chromosome and autosoJackson, R.J. et al. Expression of mouse interleukin-4 by a recombinant ectromelia mal DNA have shown that most human genetic diversity exists 13. virus suppresses cytolytic lymphocyte response and overcomes genetic resistance to mousepox. J. Virol. 75, 1205–1210 (2001). within, rather than between, populations31. A greater current Kuwabara, P.E. & Coulson, A. RNAi—prospects for a general technique for concern must be the limited genomic variation in our staple 14. determining gene function. Parasitology Today 16, 347–349 (2000). crops and animals that makes agriculture such a vulnerable target 15. Bloom, B.R. Genome sequences. A microbial minimalist. Nature 378, 236 (1995). 16. United Nations. Final Declaration. Fourth Review Conference of the Parties to the for biological attack32. Convention on the Prohibition of the Development, Production and Stockpiling Conclusion The genomics revolution holds great promise for the advancement of basic biology, medicine and agriculture. Unfortunately, the threat of biological warfare and terrorism, though limited today, is real, and the genomics revolution has the potential to have major impacts on this most chilling threat during the 21st century. To ensure that the benign potential of genomics is realized, biologists will have to overcome their reluctance to discuss the implications of their work in the context of biowarfare and terrorist activities. With the probable failure of the last ten years of efforts to strengthen the Biological and Toxin Weapons Convention with a verification protocol33, an even greater responsibility falls on the biomedical community worldwide. To avoid another three decades (or more) of neglect34 of this pivotal, norm-setting element in the prevention of biological warfare and terrorism, we must come to see the Convention as something for which we have a special duty of care. Moreover, we need to develop and fund specific research programs aimed at addressing the threat of biological weapons, rather than hoping that relevant progress will be made as a consequence of research activities in more benign areas. The difficulties of detection, protection and treatment should not be underestimated, but that does not mean this aspect of the overall policy response cannot be improved. In short, the biomedical community must play its proper part in the generation of a true web of deterrence35,36 that will render biological warfare or terrorism an obviously futile as well as a morally unacceptable act. To do anything less is to accept that the events of 11 September could be repeated on an even larger scale through the misuse of the science and technology we generate for peaceful purposes.

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