ABSTRACT
Dealing with an increasing population is challenging the global food system not only in productive terms, but also through the associated environmental pressures. A growing diagnostic effort is being made by global and national agencies. Innovative approaches are needed to support effective policy efforts. This study aims to illustrate the potentialities of the household metabolism approach in the diagnosis of the environmental pressures derived from household food consumption, using the Spanish regions and the effects of the 2008 crisis as case studies. The direct information concerning food consumption in physical terms provided by the Spanish household budget survey is used to estimate some relevant environmental pressures (food losses and waste along the food chain, as well as water and carbon footprint) for the Spanish food system at a sub-national level. These data are directly translated into differences in environmental pressures and compared with other dietary profiles. Furthermore, the physical information of environmental pressures is related to household socio-economic status, showing the potentialities of the association with household socio-economic information. Finally, our data illustrate with some examples how the economic crisis has acted as a driver of change in food consumption, promoting a better environmental performance at the cost of poorer diets.
ABSTRACT
BACKGROUND: Aberrant signaling by ErbB-2 (HER 2, Neu), a member of the human Epidermal Growth Factor (EGF) receptor family, is associated with an aggressive clinical behaviour of carcinomas, particularly breast tumors. Antibodies targeting the ErbB-2 pathway are a preferred therapeutic option for patients with advanced breast cancer, but a worldwide deficit in the manufacturing capacities of mammalian cell bioreactors is foreseen. METHODS: Herein, we describe a multi-platform approach for the production of recombinant Single chain Fragments of antibody variable regions (ScFvs) to ErbB-2 that involves their functional expression in (a) bacteria, (b) transient as well as stable transgenic tobacco plants, and (c) a newly developed cell-free transcription-translation system. RESULTS: An ScFv (ScFv800E6) was selected by cloning immunoglobulin sequences from murine hybridomas, and was expressed and fully functional in all the expression platforms, thereby representing the first ScFv to ErbB-2 produced in hosts other than bacteria and yeast. ScFv800E6 was optimized with respect to redox synthesis conditions. Different tags were introduced flanking the ScFv800E6 backbone, with and without spacer arms, including a novel Strep II tag that outperforms conventional streptavidin-based detection systems. ScFv800E6 was resistant to standard chemical radiolabeling procedures (i.e. Chloramine T), displayed a binding ability extremely similar to that of the parental monovalent Fab' fragment, as well as a flow cytometry performance and an equilibrium binding affinity (Ka approximately 2 x 10(8) M(-1)) only slightly lower than those of the parental bivalent antibody, suggesting that its binding site is conserved as compared to that of the parental antibody molecule. ScFv800E6 was found to be compatible with routine reagents for immunohistochemical staining. CONCLUSION: ScFv800E6 is a useful reagent for in vitro biochemical and immunodiagnostic applications in oncology, and a candidate for future in vivo studies.
