فصلنامه ایمنی زیستی
سال دهم شماره 3 (پاییز 1396)

DNA vaccination, or genetic immunization, is a novel vaccine technology that has great potential for reducing infectious disease and cancer- induced morbidity and mortality worldwide. This method has been used to stimulate protective immunity against many infectious pathogens, malignancies, and autoimmune disorders in animal models and extensively to develop vaccine safe, innovative and efficient in human and animals has been studied. DNA plasmids encoding foreign proteins may be used as immunogens by direct intramuscular injection alone, or with various adjuvants. The antibody, helper T lymphocyte, and cytotoxic T lymphocyte (CTL) responses have been induced in a laboratory and domesticated animals by these methods. In the inactive immunization method, the goal is only temporary protection and relief of the condition, but in active immunization, achieving a constant, long-term safety is the final goal. DNA vaccines are one of the novel candidates of genetic engineering in immunization fields. This article is aimed to introduce DNA vaccine and induced an immune response by it to achieve sustainable protection and further development of this technology at national research levels.

Chemical reactions that occur in plants known as metabolism and metabolites of important biochemical compounds, including carbohydrates, proteins and fats are. Other biochemical compounds that these three groups are known as secondary metabolites in a wide range of materials such as medicinal compounds, spices, pesticides and natural colors are included. One of the most important techniques of plant tissue culture in line with the industrial production of secondary metabolites because the production potential of these substances in normal conditions is very limited. The technique used in this area mainly include: cell culture, organ culture and hairy root cultures. Plant tissue culture is one of the most important techniques in line with the industrial production of secondary metabolites, but the use of cell culture plant for the production of compounds important drug for industrial use only becomes possible when the product greatly be produced, or more than one product from culture to be achieved. This selection of cell lines with conventional methods and other parameters related to growth or production is not possible. Therefore, we should be able to evaluate the metabolic pathways and the genes they regulate the process limiting production to overexpress (high expression) said. In general, it can be said that the use of these techniques in the production of certain drug can naturally bring great economic benefits.

Just as pathogens have evolved to colonize plants, so plants have developed means to prevent or tolerate their presence. During evolution, plants have developed mechanisms to cope with and adapt to different types of stress, including microbial infection. One of these mechanisms is to activate signaling pathways, leading to the induced expression of defense genes. Signaling transmit detection of pathogens into resistance. Such as defense mechanism, in effect activate signaling pathways can be the reinforcement of the cell wall by developing their defense structure, reactive oxygen species (ROS) production and create hypersensivity reaction (HR), programmed cell death (PCD), activation of defense genes and synthesis of secondary metabolites and defense hormones. In this article will be mentioned to review existing knowledge in conjunction with the induction of defense reaction in plants. The knowledge of these capabilities inherent in plants can be useful in the development of modern management of plant diseases.

β-Glucans are widely distributed among nature especially in fungus, yeasts, bacteria and cereals cell walls. β-Glucan comprises of D-glucose monomer units linked together via (1→3) β-glycosidic bonds and also they have connected to the side chains by either β (1→6) or β (1→4)-link within different distances. Because of their unique characteristics such as water solubility, viscosity, molecular weight and etc., they widely utilized in various food systems and in medicine also as the human health improvement. Among them, fungal β- glucans have a novel approach, due to anticancer, antitumor, anti-inflammatory and anti-aging properties, which are more considered as one of the most important bioactive compounds. Hence, considering the importance of fungal β-glucan sources in the food industry and medical, this study intends to via review and summarize the available, valid and recent literature, to introduce the structure, synthesis and biological activity of fungal β-glucan and their applications.

Given this fact that conventional crop technology, lonely, cannot feed the immense growing number of world’ population, the global scientific community agreed on a balanced and simultaneous consumption of both conventional and biotechnological (GM and non-GMtraits) crop. Although twenty years’ commercialization of biotech crops has confirmed no negative impacts of GM plant on environment and living organisms, still risk assessments are required. Since the traditional analysis is able to recognize solely the intended effects, omics approaches are applied to determine the unintended effects. These non-targeted approaches have become more comprehensive in characterizing the composition and performance of GM crops and detecting the unintended effects. Therefore, Omics studies would provide important information for understanding changes in different biological levels after genetic modification and are important for evaluating biological safety of GM crops.

Aluminium is the world’s second most-used metal after steel and the aluminium production industry is the largest, in volume of metal produced, in non-ferrous metal industry. In this study, results of the material flows (country and global scales) related to the production and use of aluminium and energy consumption in 1980 to 2012 were separately analysed. Also, overview of the current status of the aluminium industry, including the processes of bauxite mining, alumina refining and smelting, and the key economic and environmental issues were explained. Development in the aluminium producing industry, consumption and environmental implications, as well as identifying the alternative and future technologies that will impact the industry were discussed. Finally, some suggestions for the reduction of energy consumption in different stages were made. These analyses implied that world’s primary aluminium (made from bauxite) production has increased from 19.51 million tonnes metric in 1990 to 47.78 million tonnes metric in the year 2012. The production of world alumina also raised from 41.4 to 100.5 million tonnes metric at the same time, whereas secondary aluminium (made from fabrication and post-consumer scrap) produced another 16 million tonnes in 2012. Primary aluminium production is associated with serious environmental problems including high energy demand, substantial GHG emissions and solid waste generation. So that, it consumes about 1% of the globally produced electric energy and about 7% of the total energy consumed by industry worldwide and it is responsible for the 2.5% of the world’s CO2-equivalent emissions. The findings of the study revealed that due to the use of recent technologies, the average of electrical power consumption in the primary aluminium production declined per tonne from 16.9 MWh in 1990 to 14.6 MWh in 2012. The average of specific energy consumption for alumina refining was around 13.534 and 14.5 GJ per tonne in 2012 and 2000 respectively.

Foodborne illnesses associated with pathogens, toxins, and other contaminants pose serious threat to human health. Conventional detection methods for bacterial pathogens and toxins are time consuming and laborious, requiring certain sophisticated instruments and trained personnel. Nanomaterials including metal oxide and metal nanoparticles, carbon nanotubes, quantum dots, and other nano-based materials are gaining a prominent role in the design of sensors and biosensors for food analysis. In this review, various nanomaterial-based sensors reported in the literature for detection of several foodborne bacterial pathogens and toxins are summarized highlighting their principles, advantages, and limitations in terms of simplicity, sensitivity, and multiplex detection capability.

Many genome editing tools introduces and successfully used to modify the genome of various organisms up to now. Genetic modification using enzymes is a powerful tool in biological research. So far, two generations of enzyme genomic editing tools have been introduced, (SSRs: Genome editing mediated by Site- Specific recombinases) and (SSNs: Genome editing mediated by Site- Specific Nucleases). The need for an application to modify the genome for the effective administration of a variety of genes in eukaryotic and prokaryotic organisms, saving time and expenses, improving quality and increasing the quantity of agricultural products, Therapeutic applications, drug production, or secondary metabolites, understanding the function of genes and inter-gene relationships, all of this has made rapid evolution and progress of the genome editing tools. During the last decade, two types of genome-editing nucleases, TALEN and ZFN have been successfully used for editing and modifying plants. Recently, another new technique called CRISPR / cas9 has been discovered and is widely used for genomic editing in a wide range of species. Today, using the CRISPR / cas9 system and the programmable RNA, a huge revolution has been created in biological research and genetic engineering. In this article, we have introduced and discussed the genome editing based on engineered endonuclease.

Due to the increasing speed of approval and commercialization of GM crops around the world, matching tests for food, feed and seed samples according to relevant regulations will be very difficult and very expensive. Many of them have already adopted the so called “matrix approach” to rationalize the resources and efforts used to increase their efficiency within a limited budget. Most of the time, the “matrix approach” is implemented using limited information and some proprietary computational tool to efficiently use the available data. The tool makes use of a tabulated matrix of GM events and their genetic elements, of the laboratory analysis history and the available information about the sample at hand. The tool uses an optimization approach to suggest the most suited screening assays for the given sample. The practical GMOseek user interface allows the user to customize the search for a cost-efficient combination of screening assays to be employed on a given sample. It further guides the user to select appropriate analyses to determine the presence of individual GM events in the analyzed sample.

Selectable marker (SM) systems have been considered necessary to achieve acceptable rates in the generation of Genetic Modified (GM) plants. These systems allow the relatively straightforward identification and selection of plants that have stably incorporated not only the marker genes but also genes of interest. Since the creation of the first generation of GM, genes encoding resistance to specific antibiotics and herbicide have been largely used for selection and rapid identification of transformed cells. In most cases, once transgenic plants have been regenerated, permanence of SM genes in the plant genome is no longer necessary, and it becomes a matter of public concern, although no evidence of adverse biosafety effects has been found associated with marker genes. A valuable substitute to the SM genes are the reporter genes, which encode proteins whose activity can be easily identifiable, or make it possible to easily screen GM plant. In addition to replacement of marker genes with reporter, other methods such as co-transformation, site-specific recombination of FLP / FRT, Cre / lox, R / RS and loss-marker can be used to remove marker genes from transgenic plant. In the current paper, we present a list of SM that are widely used for the production of transgenic plants, their replacement, elimination strategies and biosafety are presented.