Personal reflections on the origins and emergence of recombinant DNA technology

Gene Editing by Ferrying of CRISPR/Cas Ribonucleoprotein Complexes in Enveloped Virus-Derived Particles

The invention of next-generation CRISPR/Cas gene editing tools, like base and prime editing, for correction of gene variants causing disease, has created hope for in vivo use in patients leading to wider clinical translation. To realize this potential, delivery vehicles that can ferry gene editing tool kits safely and effectively into specific cell populations or tissues are in great demand. In this review, we describe the development of enveloped retrovirus-derived particles as carriers of "ready-to-work" ribonucleoprotein complexes consisting of Cas9-derived editor proteins and single guide RNAs. We present arguments for adapting viruses for cell-targeted protein delivery and describe the status after a decade-long development period, which has already shown effective editing in primary cells, including T cells and hematopoietic stem cells, and in tissues targeted in vivo, including mouse retina, liver, and brain. Emerging evidence has demonstrated that engineered virus-derived nanoparticles can accommodate both base and prime editors and seems to fertilize a sprouting hope that such particles can be further developed and produced in large scale for therapeutic applications.

A Critical Review on the Role of Probiotics in Lung Cancer Biology and Prognosis

Lung cancer remains the leading cause of cancer-related deaths worldwide. According to the American Cancer Society (ACS), it ranks as the second most prevalent type of cancer globally. Recent findings have highlighted bidirectional gut-lung interactions, known as the gut-lung axis, in the pathophysiology of lung cancer. Probiotics are live microorganisms that boost host immunity when consumed adequately. The immunoregulatory mechanisms of probiotics are thought to operate through the generation of various metabolites that impact both the gut and distant organs (e.g., the lungs) through blood. Several randomized controlled trials have highlighted the pivotal role of probiotics in gut health especially for the prevention and treatment of malignancies, with a specific emphasis on lung cancer. Current research indicates that probiotic supplementation positively affects patients, leading to a suppression in cancer symptoms and a shortened disease course. While clinical trials validate the therapeutic benefits of probiotics, their precise mechanism of action remains unclear. This narrative review aims to provide a comprehensive overview of the present landscape of probiotics in the management of lung cancer.

Evolution of Virology: Science History through Milestones and Technological Advancements

The history of virology, which is marked by transformative breakthroughs, spans microbiology, biochemistry, genetics, and molecular biology. From the development of Jenner's smallpox vaccine in 1796 to 20th-century innovations such as ultrafiltration and electron microscopy, the field of virology has undergone significant development. In 1898, Beijerinck laid the conceptual foundation for virology, marking a pivotal moment in the evolution of the discipline. Advancements in influenza A virus research in 1933 by Richard Shope furthered our understanding of respiratory pathogens. Additionally, in 1935, Stanley's determination of viruses as solid particles provided substantial progress in the field of virology. Key milestones include elucidation of reverse transcriptase by Baltimore and Temin in 1970, late 20th-century revelations linking viruses and cancer, and the discovery of HIV by Sinoussi, Montagnier, and Gallo in 1983, which has since shaped AIDS research. In the 21st century, breakthroughs such as gene technology, mRNA vaccines, and phage display tools were achieved in virology, demonstrating its potential for integration with molecular biology. The achievements of COVID-19 vaccines highlight the adaptability of virology to global health.

The Antibiofilm Role of Biotics Family in Vaginal Fungal Infections

“Unity in strength” is a notion that can be exploited to characterize biofilms as they bestow microbes with protection to live freely, escalate their virulence, confer high resistance to therapeutic agents, and provide active grounds for the production of biofilms after dispersal. Naturally, fungal biofilms are inherently resistant to many conventional antifungals, possibly owing to virulence factors as their ammunitions that persistently express amid planktonic transition to matured biofilm state. These ammunitions include the ability to form polymicrobial biofilms, emergence of persister cells post-antifungal treatment and acquisition of resistance genes. One of the major disorders affecting vaginal health is vulvovaginal candidiasis (VVC) and its reoccurrence is termed recurrent VVC (RVVC). It is caused by the Candida species which include Candida albicans and Candida glabrata. The aforementioned Candida species, notably C. albicans is a biofilm producing pathogen and habitually forms part of the vaginal microbiota of healthy women. Latest research has implicated the role of fungal biofilms in VVC, particularly in the setting of treatment failure and RVVC. Consequently, a plethora of studies have advocated the utilization of probiotics in addressing these infections. Specifically, the excreted or released compounds of probiotics which are also known as postbiotics are being actively researched with vast potential to be used as therapeutic options for the treatment and prevention of VVC and RVVC. These potential sources of postbiotics are harnessed due to their proven antifungal and antibiofilm. Hence, this review discusses the role of Candida biofilm formation in VVC and RVVC. In addition, we discuss the application of pro-, pre-, post-, and synbiotics either individually or in combined regimen to counteract the abovementioned problems. A clear understanding of the role of biofilms in VVC and RVVC will provide proper footing for further research in devising novel remedies for prevention and treatment of vaginal fungal infections.

You can't keep a bad idea down: Dark history, death, and potential rebirth of eugenics

"Be careful what you wish for": This adage guides both how this project came to life, and how the topic covered in this review continues to unfold. What began as talks between two friends on shared interests in military history led to a 4-year discussion about how our science curriculum does little to introduce our students to societal and ethical impacts of the science they are taught. What emerged was a curricular idea centered on how "good intentions" of some were developed and twisted by others to result in disastrous consequences of state-sanctioned eugenics. In this article, we take the reader (as we did our students) through the long and soiled history of eugenic thought, from its genesis to the present. Though our focus is on European and American eugenics, we will show how the interfaces and interactions between science and society have evolved over time but have remained ever constant. Four critical 'case studies' will also be employed here for deep, thoughtful exploration on a particular eugenic issue. The goal of the review, as it is with our course, is not to paint humanity with a single evil brush. Instead, our ambition is to introduce our students/readers to the potential for harm through the misapplication and misappropriation of science and scientific technology, and to provide them with the tools to ask the appropriate questions of their scientists, physicians, and politicians.

Platforms for Production of Protein-Based Vaccines: From Classical to Next-Generation Strategies

To date, vaccination has become one of the most effective strategies to control and reduce infectious diseases, preventing millions of deaths worldwide. The earliest vaccines were developed as live-attenuated or inactivated pathogens, and, although they still represent the most extended human vaccine types, they also face some issues, such as the potential to revert to a pathogenic form of live-attenuated formulations or the weaker immune response associated with inactivated vaccines. Advances in genetic engineering have enabled improvements in vaccine design and strategies, such as recombinant subunit vaccines, have emerged, expanding the number of diseases that can be prevented. Moreover, antigen display systems such as VLPs or those designed by nanotechnology have improved the efficacy of subunit vaccines. Platforms for the production of recombinant vaccines have also evolved from the first hosts, Escherichia coli and Saccharomyces cerevisiae, to insect or mammalian cells. Traditional bacterial and yeast systems have been improved by engineering and new systems based on plants or insect larvae have emerged as alternative, low-cost platforms. Vaccine development is still time-consuming and costly, and alternative systems that can offer cost-effective and faster processes are demanding to address infectious diseases that still do not have a treatment and to face possible future pandemics.

Microbial Arsenal of Antiviral Defenses - Part I

Bacteriophages or phages are viruses that infect bacterial cells (for the scope of this review we will also consider viruses that infect Archaea). Constant threat of phage infection is a major force that shapes evolution of the microbial genomes. To withstand infection, bacteria had evolved numerous strategies to avoid recognition by phages or to directly interfere with phage propagation inside the cell. Classical molecular biology and genetic engineering have been deeply intertwined with the study of phages and host defenses. Nowadays, owing to the rise of phage therapy, broad application of CRISPR-Cas technologies, and development of bioinformatics approaches that facilitate discovery of new systems, phage biology experiences a revival. This review describes variety of strategies employed by microbes to counter phage infection, with a focus on novel systems discovered in recent years. First chapter covers defense associated with cell surface, role of small molecules, and innate immunity systems relying on DNA modification.

Role of probiotics in prevention and treatment of enteric infections: a comprehensive review

Microorganisms that inhabits human digestive tract affect global health and enteric disorders. Previous studies have documented the effectiveness and mode of action of probiotics and classified as human-friendly biota and a competitor to enteric pathogens. Statistical studies reported more than 1.5 billion cases of gastrointestinal infections caused by enteric pathogens and their long-term exposure can lead to mental retardation, temporary or permanent physical weakness, and leaving the patient susceptible for opportunistic pathogens, which can cause fatality. We reviewed previous literature providing evidence about therapeutic approaches regarding probiotics to cure enteric infections efficiently by producing inhibitory substances, immune system modulation, improved barrier function. The therapeutic effects of probiotics have shown success against many foodborne pathogens and their therapeutic effectiveness has been exponentially increased using genetically engineered probiotics. The bioengineered probiotic strains are expected to provide a better and alternative approach than traditional antibiotic therapy against enteric pathogens, but the novelty of these strains also raise doubts about the possible untapped side effects, for which there is a need for further studies to eliminate the concerns relating to the use and safety of probiotics. Many such developments and optimization of the classical techniques will revolutionize the treatments for enteric infections.

Designing Biological Circuits: Synthetic Biology Within the Operon Model and Beyond

In 1961, Jacob and Monod proposed the operon model of gene regulation. At the model's core was the modular assembly of regulators, operators, and structural genes. To illustrate the composability of these elements, Jacob and Monod linked phenotypic diversity to the architectures of regulatory circuits. In this review, we examine how the circuit blueprints imagined by Jacob and Monod laid the foundation for the first synthetic gene networks that launched the field of synthetic biology in 2000. We discuss the influences of the operon model and its broader theoretical framework on the first generation of synthetic biological circuits, which were predominantly transcriptional and posttranscriptional circuits. We also describe how recent advances in molecular biology beyond the operon model-namely, programmable DNA- and RNA-binding molecules as well as models of epigenetic and posttranslational regulation-are expanding the synthetic biology toolkit and enabling the design of more complex biological circuits.

Current status and future trends of vaccine development against viral infection and disease

This paper focuses on the classification and representative studies of viral vaccines and future directions of vaccine design.

Cloning short DNA into plasmids by one-step PCR

Background

Plasmid construction of small fragments of interest (such as insertion of small fragment marker genes, expression of shRNA, siRNA, etc) is the basis of many biomolecular experiments. Here, we describe a method to clone short DNA into vectors by polymerase chain reaction (PCR), named one‐step PCR cloning. Our method uses PCR to amplify the entire circular plasmid. The PCR was performed by the primers containing the gene of short DNA with overlapping sequences between 10–15 bp. The PCR products were then transformed into E. coli and cyclized by homologous recombination in vivo.

Methods

The pEGFP‐N1‐HA plasmid was constructed by one‐step PCR and transformation. Cells were transfected with pEGFP‐N1‐HA and pEGFP‐N1 plasmid using TurboFect transfection reagent. Protein expression was detected by western blotting and the HA‐GFP fusion protein was detected by confocal microscopy.

Results

The pEGFP‐N1‐HA plasmid was successfully constructed and HA expression in cells.

Conclusions

Free from the limitations of restriction enzyme sites and omitting the ligation process, our method offers a flexible and economical option of plasmid construction.

Key points

Genomic research delivering on promises: From rejuvenation to vaccines and pharmacogenetics

What is known and Objective

There has been astounding progress made in the treatment of disease over recent years. This progress is particularly marked in cell therapy and in the personalization of therapy based on genetic insight, an approach known as genomic medicine. Our objective is to comment on the progress made in cell and genomic medicine against an historical backcloth of the search for rejuvenation.

Comment

In 1741, close to seven decades after Antoine van Leeuwenhoek first saw his microscopic animalcules, Abraham Trembley, a tutor in Leiden, reported on an organism that could regenerate itself. The strange organism was thought to hold the secret of life. If it does, we have yet to prise the secret out. However, the ensuing study of cell programming and induced stem cells has shed considerable light on cellular development and provided new insights on the rejuvenative capacity of organisms. Inventive scientists have provided a deeper understanding of cell replication and, from this, developed new medicines for an increasing range of diseases. Targeted therapies, oligonucleotide therapy, therapeutic monoclonal antibodies and pharmacogenetics are all new therapeutic areas originating from the improved insights. More will surely follow.

What is new and conclusion

Immortality is for the gods, but man's search for its elusive secrets, perhaps as old as man himself, will continue. Huge leaps have been made, and effective medicines have been developed from our improved insights into the mechanism of life. However, only the foolish will predict how far this new knowledge will lead us, and more particularly, at what speed new therapies will follow.

The History of Transgenesis

A transgenic mouse carries within its genome an artificial DNA construct (transgene) that is deliberately introduced by an experimentalist. These animals are widely used to understand gene function and protein function. When addressing the history of transgenic mouse technology, it is apparent that a number of basic science research areas laid the groundwork for success. These include reproductive science, genetics and molecular biology, and micromanipulation and microscopy equipment. From reproductive physiology came applications on how to optimize mouse breeding, how to superovulate mice to produce zygotes for DNA microinjection or preimplantation embryos for combination with embryonic stem (ES) cells, and how to return zygotes and embryos to a pseudopregnant surrogate dam for gestation and birth. From developmental biology, it was learned how to micromanipulate embryos for morula aggregation and blastocyst microinjection and how to establish germline competent ES cells. From genetics came the foundational principles governing the inheritance of genes, the interactions of gene products, and an understanding of the phenotypic consequences of genetic mutations. From molecular biology came a panoply of tools and reagents that are used to clone DNA transgenes, to detect the presence of transgenes, to assess gene expression by measuring transcription, and to detect proteins in cells and tissues. Technical advances in light microscopes, micromanipulators, micropipette pullers, and ancillary equipment made it possible for experimentalists to insert thin glass needles into zygotes or embryos under controlled conditions to inject DNA solutions or ES cells. To fully discuss the breadth of contributions of these numerous scientific disciplines to a comprehensive history of transgenic science is beyond the scope of this work. Examples will be used to illustrate scientific developments central to the foundation of transgenic technology and that are in use today.

Proteomics and Penicillium chrysogenum: Unveiling the secrets behind penicillin production

Discovery, industrial production and clinical applications of penicillin, together with scientific findings on penicillin biosynthesis and its complex regulation, are model milestones of the historical evolution of the most recognized 'magic bullet' against microbial infections available in the worldwide market. Thousands of tons of penicillin produced nowadays are the result of a huge number of technical, industrial and scientific tackled and solved challenges. This combination of, sometimes unsuspected, findings has given Proteomics the chance to support the understanding of the physiology of the high-producing fungal strains and the development of enhanced mutants by means of inverse engineering. Thus, this review, which is part of the special issue entitled "A Tribute to J. Proteomics on its 10th Anniversary", describes how Proteomics has contributed to characterize different aspects related to penicillin production in Penicillium chrosogenum. It covers from global proteome characterizations (intracellular, extracellular and microbodies) to proteome-wide comparative analyses between different penicillin-producing mutant strains and conditions, paying special attention to the methodologies used, as well as to the most important outcomes. As a result, a guide of Proteomics approaches applied to the characterization of penicillin production by P. chrysogenum is detailed in the birthday of the Fleming's most relevant finding. SIGNIFICANCE: Although the discovery of penicillin is celebrating the 90th birthday and its clinical application is worldwide recognized, in fact, semisynthetic penicillins are still one of the most prescribed antibiotics, only the arrival of the post-genomic era during the first decade of the 21st century, and more precisely the Proteomics approaches, have contributed to unveil the industrial secrets behind penicillin production. This review provides relevant information, based on proteomics studies, about the molecular mechanisms responsible for increased penicillin titres, and therefore, may represent a clear model of inverse engineering in microorganisms.

Improving Immunotherapy Through Glycodesign

Immunotherapy is revolutionizing health care, with the majority of high impact "drugs" approved in the past decade falling into this category of therapy. Despite considerable success, glycosylation-a key design parameter that ensures safety, optimizes biological response, and influences the pharmacokinetic properties of an immunotherapeutic-has slowed the development of this class of drugs in the past and remains challenging at present. This article describes how optimizing glycosylation through a variety of glycoengineering strategies provides enticing opportunities to not only avoid past pitfalls, but also to substantially improve immunotherapies including antibodies and recombinant proteins, and cell-based therapies. We cover design principles important for early stage pre-clinical development and also discuss how various glycoengineering strategies can augment the biomanufacturing process to ensure the overall effectiveness of immunotherapeutics.

Shock wave-induced permeabilization of mammalian cells

Controlled permeabilization of mammalian cell membranes is fundamental to develop gene and cell therapies based on macromolecular cargo delivery, a process that emerged against an increasing number of health afflictions, including genetic disorders, cancer and infections. Viral vectors have been successfully used for macromolecular delivery; however, they may have unpredictable side effects and have been limited to life-threatening cases. Thus, several chemical and physical methods have been explored to introduce drugs, vaccines, and nucleic acids into cells. One of the most appealing physical methods to deliver genes into cells is shock wave-induced poration. High-speed microjets of fluid, emitted due to the collapse of microbubbles after shock wave passage, represent the most significant mechanism that contributes to cell membrane poration by this technique. Herein, progress in shock wave-induced permeabilization of mammalian cells is presented. After covering the main concepts related to molecular strategies whose applications depend on safer drug delivery methods, the physics behind shock wave phenomena is described. Insights into the use of shock waves for cell membrane permeation are discussed, along with an overview of the two major biomedical applications thereof-i.e., genetic modification and anti-cancer shock wave-assisted chemotherapy. The aim of this review is to summarize 30 years of data showing underwater shock waves as a safe, noninvasive method for macromolecular delivery into mammalian cells, encouraging the development of further research, which is still required before the introduction of this promising tool into clinical practice.

Receptor visualization and the atomic bomb. A historical account of the development of the chemical neuroanatomy of receptors for neurotransmitters and drugs during the Cold War

This is a historical account of how receptors for neurotransmitters and drugs got to be seen at the regional, cellular, and subcellular levels in brain, in the years going from the end of the World War II until the collapse of the Soviet Union, the Cold War (1945-1991). The realization in the US of the problem of mental health care, as a consequence of the results of medical evaluation for military service during the war, let the US Government to act creating among other things the National Institute for Mental Health (NIMH). Coincident with that, new drug treatments for these disorders were introduced. War science also created an important number of tools and instruments, such as the radioisotopes, that played a significant role in the development of our story. The scientific context was marked by the development of Biochemistry, Molecular Biology and the introduction in the early 80's of the DNA recombinant technologies. The concepts of chemical neurotransmission in the brain and of receptors for drugs and transmitters, although proposed before the war, where not generally accepted. Neurotransmitters were identified and the mechanisms of biosynthesis, storage, release and termination of action by mechanisms such as reuptake, elucidated. Furthermore, the synapse was seen with the electron microscope and more important for our account, neurons and their processes visualized in the brain first by fluorescence histochemistry, then using radioisotopes and autoradiography, and later by immunohistochemistry (IHC), originating the Chemical Neuroanatomy. The concept of chemical neurotransmission evolved from the amines, expanded to excitatory and inhibitory amino acids, then to neuropeptides and finally to gases and other "atypical" neurotransmitters. In addition, coexpression of more than one transmitter in a neuron, changed the initial ideas of neurotransmission. The concept of receptors for these and other messengers underwent a significant evolution from an abstract chemical concept to their physical reality as gene products. Important steps were the introduction in the 70's of radioligand binding techniques and the cloning of receptor genes in the 80's. Receptors were first visualized using radioligands and autoradiography, and analyzed with the newly developed computer-assisted image analysis systems. Using Positron Emission Tomography transmitters and receptors were visualized in living human brain. The cloning of receptor genes allowed the use of in situ hybridization histochemistry and immunohistochemistry to visualize with the light and electron microscopes the receptor mRNAs and proteins. The results showed the wide heterogeneity of receptors and the diversity of mode of signal transmission, synaptic and extra-synaptic, again radically modifying the early views of neurotransmission. During the entire period the interplay between basic science and Psychopharmacology and Psychiatry generated different transmitter or receptor-based theories of brain drug action. These concepts and technologies also changed the way new drugs were discovered and developed. At the end of the period, a number of declines in these theories, the use of certain tools and the ability to generate new diagnostics and treatments, the end of an era and the beginning of a new one in the research of how the brain functions.

Institutional Oversight of Occupational Health and Safety for Research Programs Involving Biohazards

Research with hazardous biologic materials (biohazards) is essential to the progress of medicine and science. The field of microbiology has rapidly advanced over the years, partially due to the development of new scientific methods such as recombinant DNA technology, synthetic biology, viral vectors, and the use of genetically modified animals. This research poses a potential risk to personnel as well as the public and the environment. Institutions must have appropriate oversight and take appropriate steps to mitigate the risks of working with these biologic hazards. This article will review responsibilities for institutional oversight of occupational health and safety for research involving biologic hazards.

Technological Microbiology: Development and Applications

Over thousands of years, modernization could be predicted for the use of microorganisms in the production of foods and beverages. However, the current accelerated pace of new food production is due to the rapid incorporation of biotechnological techniques that allow the rapid identification of new molecules and microorganisms or even the genetic improvement of known species. At no other time in history have microorganisms been so present in areas such as agriculture and medicine, except as recognized villains. Currently, however, beneficial microorganisms such as plant growth promoters and phytopathogen controllers are required by various agricultural crops, and many species are being used as biofactories of important pharmacological molecules. The use of biofactories does not end there: microorganisms have been explored for the synthesis of diverse chemicals, fuel molecules, and industrial polymers, and strains environmentally important due to their biodecomposing or biosorption capacity have gained interest in research laboratories and in industrial activities. We call this new microbiology Technological Microbiology, and we believe that complex techniques, such as heterologous expression and metabolic engineering, can be increasingly incorporated into this applied science, allowing the generation of new and improved products and services.

Probiotic engineering: towards development of robust probiotic strains with enhanced functional properties and for targeted control of enteric pathogens

There is a growing concern about the increase in human morbidity and mortality caused by foodborne pathogens. Antibiotics were and still are used as the first line of defense against these pathogens, but an increase in the development of bacterial antibiotic resistance has led to a need for alternative effective interventions. Probiotics are used as dietary supplements to promote gut health and for prevention or alleviation of enteric infections. They are currently used as generics, thus making them non-specific for different pathogens. A good understanding of the infection cycle of the foodborne pathogens as well as the virulence factors involved in causing an infection can offer an alternative treatment with specificity. This specificity is attained through the bioengineering of probiotics, a process by which the specific gene of a pathogen is incorporated into the probiotic. Such a process will subsequently result in the inhibition of the pathogen and hence its infection. Recombinant probiotics offer an alternative novel therapeutic approach in the treatment of foodborne infections. This review article focuses on various strategies of bioengineered probiotics, their successes, failures and potential future prospects for their applications.

Livestock in biomedical research: history, current status and future prospective

Livestock models have contributed significantly to biomedical and surgical advances. Their contribution is particularly prominent in the areas of physiology and assisted reproductive technologies, including understanding developmental processes and disorders, from ancient to modern times. Over the past 25 years, biomedical research that traditionally embraced a diverse species approach shifted to a small number of model species (e.g. mice and rats). The initial reasons for focusing the main efforts on the mouse were the availability of murine embryonic stem cells (ESCs) and genome sequence data. This powerful combination allowed for precise manipulation of the mouse genome (knockouts, knockins, transcriptional switches etc.) leading to ground-breaking discoveries on gene functions and regulation, and their role in health and disease. Despite the enormous contribution to biomedical research, mouse models have some major limitations. Their substantial differences compared with humans in body and organ size, lifespan and inbreeding result in pronounced metabolic, physiological and behavioural differences. Comparative studies of strategically chosen domestic species can complement mouse research and yield more rigorous findings. Because genome sequence and gene manipulation tools are now available for farm animals (cattle, pigs, sheep and goats), a larger number of livestock genetically engineered (GE) models will be accessible for biomedical research. This paper discusses the use of cattle, goats, sheep and pigs in biomedical research, provides an overview of transgenic technology in farm animals and highlights some of the beneficial characteristics of large animal models of human disease compared with the mouse. In addition, status and origin of current regulation of GE biomedical models is also reviewed.

Vaccine technologies: From whole organisms to rationally designed protein assemblies

Vaccines have been the single most significant advancement in public health, preventing morbidity and mortality in millions of people annually. Vaccine development has traditionally focused on whole organism vaccines, either live attenuated or inactivated vaccines. While successful for many different infectious diseases whole organisms are expensive to produce, require culture of the infectious agent, and have the potential to cause vaccine associated disease in hosts. With advancing technology and a desire to develop safe, cost effective vaccine candidates, the field began to focus on the development of recombinantly expressed antigens known as subunit vaccines. While more tolerable, subunit vaccines tend to be less immunogenic. Attempts have been made to increase immunogenicity with the addition of adjuvants, either immunostimulatory molecules or an antigen delivery system that increases immune responses to vaccines. An area of extreme interest has been the application of nanotechnology to vaccine development, which allows for antigens to be expressed on a particulate delivery system. One of the most exciting examples of nanovaccines are rationally designed protein nanoparticles. These nanoparticles use some of the basic tenants of structural biology, biophysical chemistry, and vaccinology to develop protective, safe, and easily manufactured vaccines. Rationally developed nanoparticle vaccines are one of the most promising candidates for the future of vaccine development.

Julian Davies and the discovery of kanamycin resistance transposon Tn5

This paper recounts some of my fond memories of a collaboration between Julian Davies and myself that started in 1974 in Geneva and that led to our serendipitous discovery of the bacterial kanamycin resistance transposon Tn5, and aspects of the lasting positive impact of our interaction and discovery on me and the community. Tn5 was one of the first antibiotic resistance transposons to be found. Its analysis over the ensuing decades provided valuable insights into mechanisms and control of transposition, and led to its use as a much-valued tool in diverse areas of molecular genetics, as also will be discussed here.

Asilomar moments: formative framings in recombinant DNA and solar climate engineering research

We examine the claim that in governance for solar climate engineering research, and especially field tests, there is no need for external governance beyond existing mechanisms such as peer review and environmental impact assessments that aim to assess technically defined risks to the physical environment. By drawing on the historical debate on recombinant DNA research, we show that defining risks is not a technical question but a complex process of narrative formation. Governance emerges from within, and as a response to, narratives of what is at stake in a debate. In applying this finding to the case of climate engineering, we find that the emerging narrative differs starkly from the narrative that gave meaning to rDNA technology during its formative period, with important implications for governance. While the narrative of rDNA technology was closed down to narrowly focus on technical risks, that of climate engineering continues to open up and includes social, political and ethical issues. This suggests that, in order to be legitimate, governance must take into account this broad perception of what constitutes the relevant issues and risks of climate engineering, requiring governance that goes beyond existing mechanisms that focus on technical risks. Even small-scale field tests with negligible impacts on the physical environment warrant additional governance as they raise broader concerns that go beyond the immediate impacts of individual experiments.

Type II restriction endonucleases--a historical perspective and more

This article continues the series of Surveys and Summaries on restriction endonucleases (REases) begun this year in Nucleic Acids Research. Here we discuss 'Type II' REases, the kind used for DNA analysis and cloning. We focus on their biochemistry: what they are, what they do, and how they do it. Type II REases are produced by prokaryotes to combat bacteriophages. With extreme accuracy, each recognizes a particular sequence in double-stranded DNA and cleaves at a fixed position within or nearby. The discoveries of these enzymes in the 1970s, and of the uses to which they could be put, have since impacted every corner of the life sciences. They became the enabling tools of molecular biology, genetics and biotechnology, and made analysis at the most fundamental levels routine. Hundreds of different REases have been discovered and are available commercially. Their genes have been cloned, sequenced and overexpressed. Most have been characterized to some extent, but few have been studied in depth. Here, we describe the original discoveries in this field, and the properties of the first Type II REases investigated. We discuss the mechanisms of sequence recognition and catalysis, and the varied oligomeric modes in which Type II REases act. We describe the surprising heterogeneity revealed by comparisons of their sequences and structures.

DNA cloning: a personal view after 40 years

In November 1973, my colleagues A. C. Y. Chang, H. W. Boyer, R. B. Helling, and I reported in PNAS that individual genes can be cloned and isolated by enzymatically cleaving DNA molecules into fragments, linking the fragments to an autonomously replicating plasmid, and introducing the resulting recombinant DNA molecules into bacteria. A few months later, Chang and I reported that genes from unrelated bacterial species can be combined and propagated using the same approach and that interspecies recombinant DNA molecules can produce a biologically functional protein in a foreign host. Soon afterward, Boyer's laboratory and mine published our collaborative discovery that even genes from animal cells can be cloned in bacteria. These three PNAS papers quickly led to the use of DNA cloning methods in multiple areas of the biological and chemical sciences. They also resulted in a highly public controversy about the potential hazards of laboratory manipulation of genetic material, a decision by Stanford University and the University of California to seek patents on the technology that Boyer and I had invented, and the application of DNA cloning methods for commercial purposes. In the 40 years that have passed since publication of our findings, use of DNA cloning has produced insights about the workings of genes and cells in health and disease and has altered the nature of the biotechnology and biopharmaceutical industries. Here, I provide a personal perspective of the events that led to, and followed, our report of DNA cloning.

The roots--a short history of industrial microbiology and biotechnology

Early biotechnology (BT) had its roots in fascinating discoveries, such as yeast as living matter being responsible for the fermentation of beer and wine. Serious controversies arose between vitalists and chemists, resulting in the reversal of theories and paradigms, but prompting continuing research and progress. Pasteur's work led to the establishment of the science of microbiology by developing pure monoculture in sterile medium, and together with the work of Robert Koch to the recognition that a single pathogenic organism is the causative agent for a particular disease. Pasteur also achieved innovations for industrial processes of high economic relevance, including beer, wine and alcohol. Several decades later Buchner, disproved the hypothesis that processes in living cells required a metaphysical 'vis vitalis' in addition to pure chemical laws. Enzymes were shown to be the chemical basis of bioconversions. Studies on the formation of products in microbial fermentations, resulted in the manufacture of citric acid, and chemical components required for explosives particularly in war time, acetone and butanol, and further products through fermentation. The requirements for penicillin during the Second World War lead to the industrial manufacture of penicillin, and to the era of antibiotics with further antibiotics, like streptomycin, becoming available. This was followed by a new class of high value-added products, mainly secondary metabolites, e.g. steroids obtained by biotransformation. By the mid-twentieth century, biotechnology was becoming an accepted specialty with courses being established in the life sciences departments of several universities. Starting in the 1970s and 1980s, BT gained the attention of governmental agencies in Germany, the UK, Japan, the USA, and others as a field of innovative potential and economic growth, leading to expansion of the field. Basic research in Biochemistry and Molecular Biology dramatically widened the field of life sciences and at the same time unified them considerably by the study of genes and their relatedness throughout the evolutionary process. The scope of accessible products and services expanded significantly. Economic input accelerated research and development, by encouraging and financing the development of new methods, tools, machines and the foundation of new companies. The discipline of 'New Biotechnology' became one of the lead sciences. Although biotechnology has historical roots, it continues to influence diverse industrial fields of activity, including food, feed and other commodities, for example polymer manufacture, biofuels and energy production, providing services such as environmental protection, and the development and production of many of the most effective drugs. The understanding of biology down to the molecular level opens the way to create novel products and efficient environmentally acceptable methods for their production.