Evidence from Studies with Heat-Stressed Caco-2 Cells, C. elegans and Growing Broilers

Climatic changes and heat stress have become a great challenge in the livestock industry, negatively affecting, in particular, poultry feed intake and intestinal barrier malfunction. Recently, phytogenic feed additives were applied to reduce heat stress effects on animal farming. Here, we investigated the effects of ginseng extract using various in vitro and in vivo experiments. Quantitative real-time PCR, transepithelial electrical resistance measurements and survival assays under heat stress conditions were carried out in various model systems, including Caco-2 cells, Caenorhabditis elegans and jejunum samples of broilers. Under heat stress conditions, ginseng treatment lowered the expression of HSPA1A (Caco-2) and the heat shock protein genes hsp-1 and hsp-16.2 (both in C. elegans), while all three of the tested genes encoding tight junction proteins, CLDN3, OCLN and CLDN1 (Caco-2), were upregulated. In addition, we observed prolonged survival under heat stress in Caenorhabditis elegans, and a better performance of growing ginseng-fed broilers by the increased gene expression of selected heat shock and tight junction proteins. The presence of ginseng extract resulted in a reduced decrease in transepithelial resistance under heat shock conditions. Finally, LC-MS analysis was performed to quantitate the most prominent ginsenosides in the extract used for this study, being Re, Rg1, Rc, Rb2 and Rd. In conclusion, ginseng extract was found to be a suitable feed additive in animal nutrition to reduce the negative physiological effects caused by heat stress. View Full-Tex

Division of the major birch pollen allergen, Bet v 1, into two non-anaphylactic fragments

We have expressed in Escherichia coli two halves of the major birch pollen allergen, Bet v 1. Both fragments representing the complete 17-kD allergen were purified to homogeneity. In contrast to the complete recombinant, Bet v 1, the fragments had almost completely lost their IgE-binding capacity and exhibited a random coil structure as analyzed by circular dichroism. The ability of the recombinant fragments to trigger histamine release from allergic patients' basophils as well as their capacity to elicit skin reactions were also largely abolished. Both non-anaphylactic Bet v 1 fragments carried the majority of T cell epitopes and may therefore be considered as safe tools for immunotherapy of tree pollen and associated food allergy

Conversion of the major birch pollen allergen, Bet v 1, into two nonanaphylactic T cell epitope-containing fragments: candidates for a novel form of specific immunotherapy.

A novel approach to reduce the anaphylactic activity of allergens is suggested. The strategy makes use of the presence of conformational immunoglobulin E (IgE) epitopes on one of the most common allergens. The three dimensional structure of the major birch pollen allergen, Bet v 1, was disrupted by expressing two parts of the Bet v 1 cDNA representing amino acids 1-74 and 75-160 in Escherichia coli. In contrast to the complete recombinant Bet v 1, the fragments showed almost no allergenicity and exhibited random coil conformation as analyzed by circular dichroism. Both nonanaphylactic fragments induced proliferation of human Bet v 1-specific T cell clones, indicating that they harbored all dominant T cell epitopes and therefore may be considered as a basis for the development of a safe and specific T cell immunotherapy

Division of the major birch pollen allergen, Bet v 1, into two non-anaphylactic fragments

We have expressed in Escherichia coli two halves of the major birch pollen allergen, Bet v 1. Both fragments representing the complete 17-kD allergen were purified to homogeneity. In contrast to the complete recombinant, Bet v 1, the fragments had almost completely lost their IgE-binding capacity and exhibited a random coil structure as analyzed by circular dichroism. The ability of the recombinant fragments to trigger histamine release from allergic patients' basophils as well as their capacity to elicit skin reactions were also largely abolished. Both non-anaphylactic Bet v 1 fragments carried the majority of T cell epitopes and may therefore be considered as safe tools for immunotherapy of tree pollen and associated food allergy

Conversion of the major birch pollen allergen, Bet v 1, into two nonanaphylactic T cell epitope-containing fragments - Candidates for a novel form of specific immunotherapy

A novel approach to reduce the anaphylactic activity of allergens is suggested. The strategy makes use of the presence of conformational immunoglobulin E (IgE) epitopes on one of the most common allergens. The three dimensional structure of the major birch pollen allergen, Bet v 1, was disrupted by expressing two parts of the Bet v 1 cDNA representing amino acids 1-74 and 75-160 in Escherichia coli. In contrast to the complete recombinant Bet v 1, the fragments showed almost no allergenicity and exhibited random coil conformation as analyzed by circular dichroism. Both nonanaphylactic fragments induced proliferation of human Bet v 1-specific T cell clones, indicating that they harbored all dominant T cell epitopes and therefore may be considered as a basis for the development of a safe and specific T cell immunotherapy

Genetic engineering of recombinant hypoallergenic oligomers of the major birch pollen allergen, Bet v 1: Candidates for specific immunotherapy

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