Prospects for the genetic engineering of milk.

Milk and milk products comprise a substantial fraction of the protein intake of the industrialised West. The establishment of germline manipulation techniques in cows offers opportunities for directly manipulating milk composition to produce products with enhanced nutritional and processing properties. The major milk proteins are encoded by a small number of abundantly expressed single-copy genes and a number of possible manipulations are described. Milk proteins exhibit complex interactions with each other and with other constituents of milk. It will, therefore, be necessary to utilise model systems to evaluate the consequences of these proposed changes before embarking upon the costly and time-consuming process of manipulating the bovine genome.     

基因工程技术构建预防性HPV疫苗

宫颈癌的发生与高危型人乳头瘤病毒（human papillomavirus,HPV）感染高度相关已得到公认。利用基因重组技术开发HPV疫苗是目前预防宫颈癌唯一有效的方法。文章综述了近年来在基因工程HPV疫苗研制中广泛应用的载体表达系统及其特点、依据密码子偏爱原则优化病毒外壳蛋白基因序列显著提高外壳蛋白产量等方面的研究成果,以为进一步研制与优化HPV疫苗提供参考。     

Genetic engineering applied to the development of vaccines

The simplest application of the modern genetic manipulation methods to vaccine development is the expression in microbial cells of genes from pathogens that encode surface antigens capable of inducing neutralizing antibodies in the host of the pathogen involved. This procedure has been exploited successfully for development of a vaccine against hepatitis B virus (HBV) that is now widely used. Similar approaches have been directed towards formulations for immunization against several other animal and human diseases and some of these preparations are now presently in trials. Of no less importance is the impact of biotechnology in providing reagents for fundamental studies of topics such as the determination of virulence, antigenic variation, virus receptors and the immunological response to viral antigens. The core antigen of HBV is a good example of a product of genetic engineering that is a valuable diagnostic reagent, and that is finding important use in immunological studies of particular pertinence to vaccine development.     

Prospects of genetic engineering of plants for phytoremediation of toxic metals

Bioremediation is gaining a lot of importance in recent times as an alternate technology for removal of elemental pollutants in soil and water, which require effective methods of decontamination. Phytoremediation--the use of green plants to remove, contain or render harmless environmental pollutants--may offer an effective, environmentally nondestructive and cheap remediation method. The use of genetic engineering to modify plants for metal uptake, transport and sequestration may open up new avenues for enhancing efficiency of phytoremediation. Metal chelator, metal transporter, metallothionein (MT), and phytochelatin (PC) genes have been transferred to plants for improved metal uptake and sequestration. Transgenic plants, which detoxify/accumulate cadmium, lead, mercury, arsenic and selenium have been developed. A better understanding of the mechanisms of rhizosphere interaction, uptake, transport and sequestration of metals in hyperaccumulator plants will lead to designing novel transgenic plants with improved remediation traits. As more genes related to metal metabolism are discovered, facilitated by the genome sequencing projects, new vistas will be opened up for development of efficient transgenic plants for phytoremediation.     

Multivalent vaccines: Prospects and challenges

The advantages and disadvantages of combination vaccines are set out with a clear indication that, although there are many (described and discussed) influences on in the immunogenicity of a vaccine it would still be of considerable value to be able to deliver such materials with the minimum number of needle-stick injections. Such a situation may become facilitated in the future as vaccines based on plasmid DNA become available; a prospect which is examined in outline in the final section. Given at aFEMS International Symposium on Novel Methods and Standardization in Microbiology, at Košice (Slovakia), July 1–4, 1996.     

Pandemic influenza: overview of vaccines and antiviral drugs

Pandemic influenza has become a high priority item for all public health authorities. An influenza pandemic is believed to be imminent, and scientists agree that it will be a matter of when, where, and what will be the causative agent. Recently, most attention has been directed to human cases of avian influenza caused by a H5N1 avian influenza virus. An effective vaccine will be needed to substantially reduce the impact of an influenza pandemic. Current influenza vaccine manufacturing technology is not adequate to support vaccine production in the event of an avian influenza outbreak, and it has now become clear that new innovative production technology is required. Antiviral drugs, on the other hand, can play a very important role in slowing the disease spread but are in short supply and resistance has been a major issue. Here, we provide an update on the status of pandemic vaccine development and antiviral drugs. Finally, we conclude with some proposed areas of focus in pandemic vaccine preparedness.     

基因疫苗研究进展

随着免疫学,分子生物学的进展以及对发病机理的深入理解,大量疾病可能被接种疫苗所控制,大量新的方法被用于开发更为安全有效的疫苗,这些方法包括亚单位疫苗,基因修饰活疫苗以及最近的基因疫苗,本文重点介绍使用基因疫苗的新技术以及一些相关的例子。     

The development of and perspectives for genetic engineering of malaria parasites

The genetic manipulation of malaria parasites is a rapidly emerging technology that offers great promise for the investigation of many aspects of infection. Currently it is possible to transform avian, rodent, primate as well as human parasites, the latter three on a stable, drug selectable basis. This review focuses on the history of the development of the technology, current abilities and future perspectives.     

Cell engineering and genetic approaches to development of human embryonic stem cell models for genetic disorders

We introduced a novel approach for the establishment of genetically modified hESC lines, and have shown that mutant hESC may be derived from affected embryos after preimplantation genetic diagnosis (PGD) screening for a particular single gene disorder. Here we describe the procedure of embryo and cell manipulation, their diagnostic layout, and the analysis of the efficiency of embryo development and hESC establishment, as well as the developments for hESC derivation in animal-product-free conditions. Our study shows that a high efficiency of hESC derivation (50%) is especially crucial when working with rare and unique resources such as genetically screened embryos necessary for the derivation of hESC lines that represent specific genetic diseases.     

Chloroplast-derived vaccines against human diseases: achievements, challenges and scopes

Infectious diseases represent a continuously growing menace that has severe impact on health of the people worldwide, particularly in the developing countries. Therefore, novel prevention and treatment strategies are urgently needed to reduce the rate of these diseases in humans. For this reason, different options can be considered for the production of affordable vaccines. Plants have been proved as an alternative expression system for various compounds of biological importance. Particularly, plastid genetic engineering can be potentially used as a tool for cost-effective vaccine production. Antigenic proteins from different viruses and bacteria have been expressed in plastids. Initial immunological studies of chloroplast-derived vaccines have yielded promising results in animal models. However, because of certain limitations, these vaccines face many challenges on production and application level. Adaptations to the novel approaches are needed, which comprise codon usage and choice of proven expression cassettes for the optimal yield of expressed proteins, use of inducible systems, marker gene removal, selection of specific antigens with high immunogenicity and development of tissue culture systems for edible crops to prove the concept of low-cost edible vaccines. As various aspects of plant-based vaccines have been discussed in recent reviews, here we will focus on certain aspects of chloroplast transformation related to vaccine production against human diseases.     

对遗传工程技术发展中道德伦理问题的认识

遗传工程已成为当今生物科学研究领域中最有生命力、最引人注目的前沿科学之一,它对农牧业、食品工业、能源开发、医药卫生等领域产生巨大效益,它在产生巨大作用的同时,也产生负面影响。本文探讨了遗传工程技术发展中的伦理问题,提出了避免遗传工程技术给社会带来负面影响和减少对人类道德伦理的冲击和破坏的看法。     

Design and engineering of a transmissible antiviral defense

Background

We propose, model, and implement a novel system of population-level intervention against a virus. One context is a treatment against a chronic infection such as HIV. The underlying principle is a form of virus ‘wars’ in which a benign, transmissible agent is engineered to protect against infection by and spread of a lethal virus. In our specific case, the protective agent consists of two entities, a benign virus and a gene therapy vector mobilized by the benign virus.

Results

Numerical analysis of a mathematical model identified parameter ranges in which adequate, population-wide protection is achieved. The protective system was implemented and tested using E. coli, bacteriophage M13 and a phagemid vector mobilized by M13 to block infection by the lethal phage T5. Engineering of M13 profoundly improved its dynamical properties for facilitating spread of the gene therapy vector. However, the gene therapy vector converts the host cell to resist T5 too slowly for protection on a time scale appropriate for T5.

Conclusions

Overall, there is a reasonable marriage between the mathematical model and the empirical system, suggesting that such models can be useful guides to the design of such systems even before the models incorporate most of the relevant biological details.

     

抗病毒免疫研究进展

抗病毒免疫的机制极其复杂,宿主的免疫系统需要经过抗原肽的加工提纯、淋巴细胞活化、抗体和细胞因子的产生等一系列步骤才能最终清除病毒的感染。从蛋白酶体在病毒肽抗原加工中的作用、免疫支配效应的意义、CTL杀伤病毒感染细胞的机制、细胞因子的作用和免疫逃逸机制等方面阐述了抗病毒免疫机制,对于病毒的防治将是十分重要的。     

Genetic engineering of radish: current achievements and future goals

Radish is a major root crop grown in the Far East and is especially important to some low-income countries where it is consumed on a daily basis. Developments in gene technology systems have helped to accelerate the production of useful germplasms, but progress has been slow, though achieved, via in planta methods and useful traits have been introduced. In the wake of the new Millennium, future goals in terms of improving transformation efficiency and selection of new traits for generating late-flowering radish are described. Furthermore, the techniques available for incorporating pharmaceutical proteins into radish to deliver edible proteins on-site are discussed. Finally, the concerns of releasing transgenic radish to the field in terms of pollen-mediated gene transfer are also reviewed. Such a report identifies key areas of research that is required to allow the crop satisfy the need of poor impoverished countries in the Far East.     

Journalists and genetic engineering

Mass media coverage of genetic engineering is considered as an essential cause of the public image which this technology has. Because most people have only few experiences with this technology, the influence of journalists, who report on genetic engineering, seems to be obviously high. Which attitudes do these journalists have? How do they inform themselves? These and other questions are to be answered by a standardized survey among German journalists. For the first time the results of this study reveal the methods of investigation and source selection of 'genetic engineering journalists' and afford an insight into the journalistic climate of opinion on genetic engineering and its applications. There is clear evidence of an altogether positive global judgement of journalists reporting on this technology, which finds support in their immediate professional social environment.     

Prospects in development of geobiophysics

The results of the discussion about the problems of biodiversity and geobiophysics are summarised. The conclusion about the necessity of developing a new scientific branch that unites Life Sciences and Earth Sciences is drawn.     

Strategies in cancer vaccines development

The recent definition of tumour-specific immunity in cancer patients and the identification of tumour-associated antigens have generated renewed enthusiasm for the application of immune-based therapies for the treatment of malignancies. Recent developments in cancer vaccines have also been based on an improved understanding of the cellular interactions required to induce a specific anti-tumour immune response. Consequently, a number of cancer vaccines have entered clinical trials. Targeting broad-spectrum tumour-associated antigens has emerged as a strategy to lower the risk of tumour escape due to the loss of specific nominal antigen. Amongst the most challenging of tumour-associated antigens to which to target in active specific immunotherapy applications are carbohydrate antigens. As carbohydrates are intrinsically T-cell-independent antigens, more novel approaches are perhaps needed to drive specific-T-cell-dependent immune responses to carbohydrate antigens. In this context peptide mimetics of core structures of tumour-associated carbohydrate antigens might be developed to augment immune responses to these broad-spectrum antigens.