Red blood cells as an antigen-delivery system.

The use of adjuvants is usually required to induce strong immunological responses to protein antigens. However, in many cases these adjuvants cannot be extensively applied in human and veterinary vaccinations because of associated inflammatory reactions or granuloma formation. We show here that protein antigens (bovine serum albumin, hog liver uricase, and yeast hexokinase), coupled to autologous red blood cells by way of a biotin-avidin-biotin bridge, elicit an immunological response in mice similar to or higher than that obtained by the use of Freund's adjuvant. Quantities as low as 0.5 micrograms/mouse are high enough to generate these immunological responses. Furthermore, splenocytes of mice immunized by red blood cell-coupled antigens can be used to generate hybridomas secreting monoclonal antibodies. Thus, the delivery of antigens by autologous red blood cells is an effective way to avoid the use of adjuvants for producing anti-peptide antibodies and possibly to generate peptide vaccines.     

Exploited for pets: the harvest and trade of amphibians and reptiles from Indonesian New Guinea

Over-exploitation of wildlife is a significant threat to global biodiversity, but addressing the sustainability of harvests can be difficult when trade is conducted illegally. The wildlife trade is driven chiefly by consumer demand, largely in developed nations (but increasingly in Asia), and more species are traded to meet international demand for pets than for any other purpose. We surveyed traders of amphibians and reptiles in the Indonesian provinces of Maluku, West Papua and Papua between September 2010 and April 2011. We recorded 5,370 individuals representing 52 species collected solely for the pet trade. At least 44?% were either fully protected or had not been allocated a harvest quota, making their harvest and trade illegal. Approximately half were listed within the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Trade operates via a complex chain, with hunters receiving little income compared to middlemen and exporters. Examination of Indonesian harvest quotas for amphibians and reptiles suggests limited knowledge of species distributions, with quotas often set for species in provinces where they do not occur. Illegal trade is due, partly, to an inadequate understanding of the species being traded and is facilitated by poor monitoring and enforcement at key trade hubs. As a first step to combatting illegal trade, and to better understand the effects of harvest on wild populations, we recommend the need for increased monitoring and enforcement, improving the knowledge base of species traded and educating consumers about the effects their demand for pets has on these species.     

Molecular basis of biodegradation of chloroaromatic compounds

Chlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacterial attack and often necessitate evolution of novel pathways. An understanding of such evolutionary processes is essential for developing genetically improved strains capable of mineralizing highly chlorinated compounds. This article provides an overview of the genetic aspects of dissimilation of chloroaromatic compounds and discusses the potential of gene manipulation to promote enhanced evolution of the degradative pathways.     

Effect of cadmium on photosynthetic pigments in synchronously growing Chlorella cells

Cadmium ions introduced at concentration of 30 ppm to the cultivation medium of synchronously growing Chlorella vulgaris decreased concentration of chlorophylls a and b, carotenes alpha and beta and lutein at various stages of the cell cycle, while at concentration of 1 ppm synthesis of the photosynthetic pigments was stimulated. The pigment content in the cadmium treated cells was related to the morphometrically determined changes in the size and shape of the cells.     

Highlights in Biocatalysis – Historical Landmarks and Current Trends

Biocatalysis has ancient roots, yet it is developing into a key tool for synthesis in a wide range of applications. Important events in the history of enzyme technology from the 19^th century onwards are highlighted. Considering the most relevant progress steps, the production of penicillanic acid and the impact of genetic engineering are traced in more detail. Applied biocatalysis has been defined as the application of a biocatalyst to achieve a desired conversion selectively, under controlled, mild conditions in a bioreactor. Biocatalysts are currently used to produce a wide range of products in the fields of food manufacture (such as bread, cheese, beer), fine chemicals (e.g., amino acids, vitamins), and pharmaceuticals (e.g., derivatives of antibiotics). They not only provide access to innovative products and processes, but also meet criteria of sustainability. In organic synthesis, recombinant technologies and biocatalysts have greatly widened the scope of application. Examples of current applications and processes are given. Recent developments and trends are presented as a survey, covering new methods for accessing biodiversity with new enzymes, directed evolution for improving enzymes, designed cells, and integrated downstream processing.     

Establishment of a temperature-inducible cell line for human plasminogen activator (tissue-type) by transfection of monkey cells with expression constructs

An expression construct for human tissue-type plasminogen activator (t-pA) cDNA [containing a simian virus 40 (SV40) origin of replication] was introduced into CV1, COS-7 and COSts2 cells; in the latter cell line the amount of functionally active large T antigen of SV40 is regulated by the temperature. In a transient system, the expression in COSts2 cells at the permissive temperature for large T antigen was improved sixfold compared to COS-7 cells. By cotransfection with a plasmid conferring resistance to G418 into COSts2 cells, a cell line (COSts2Glob t-pA) could be isolated with barely detectable expression of t-pA at the semi-permissive and non-permissive temperature and inducible secretion of t-pA at the permissive temperature. The kinetics of induction, inducibility after continued propagation at the semi-permissive temperature and the influence of the temperature during previous propagation on inducibility were investigated. The biological activity of the secreted material was demonstrated by a functional assay. Inducibility of t-pA by temperature was accompanied by a dramatic increase of the copy number of episomal plasmids (up to 2000 copies per cell).