The poultry industry has been using antibiotics to enhance bird performance through the control of microbial agents in the gastrointestinal tract; however antibiotic alternatives must be investigated. The effect of yeast-derived products such as brewer’s yeast (Y), yeast cell wall polysaccharide-rich product (YCW), wheat/corn distiller dried grains with solubles (DDGS), nucleotide-rich product (N), processed yeast/nucleotide-rich product (PY+N) and D+mannose (M) was assessed using chicken B cells (DT40 cell line) and a LPS challenge model. Relative gene expression of toll-like receptors (TLR) and cytokines was then characterized.. These results show that yeast and yeast-derived products stimulate LPS-challenged B cells to produce Th2-associated cytokines which may lead to in vivo antibody production and gram-negative bacteria clearance. Furthermore, the up-regulation of IL-10 caused by the presence of Y, DDGS, N and PY+N is an important finding as it illustrates the regulatory activity stimulated by these treatments in the presence of Escherichia coli-derived LPS.

The poultry industry has been using antibiotics to enhance bird performance through the control of microbial agents in the gastrointestinal tract; however antibiotic alternatives must be investigated. The effect of yeast-derived products such as brewer’s yeast (Y), yeast cell wall polysaccharide-rich product (YCW), wheat/corn distiller dried grains with solubles (DDGS), nucleotide-rich product (N), processed yeast/nucleotide-rich product (PY+N) and D+mannose (M) was assessed using chicken B cells (DT40 cell line) and a LPS challenge model. Relative gene expression of toll-like receptors (TLR) and cytokines was then characterized.. These results show that yeast and yeast-derived products stimulate LPS-challenged B cells to produce Th2-associated cytokines which may lead to in vivo antibody production and gram-negative bacteria clearance. Furthermore, the up-regulation of IL-10 caused by the presence of Y, DDGS, N and PY+N is an important finding as it illustrates the regulatory activity stimulated by these treatments in the presence of Escherichia coli-derived LPS.

IL-6 spielt eine wichtige Rolle bei der Immunantwort, Entzündung und Hämatopoese. Das Glykoprotein 130 (gp130) wird ubiquitär exprimiert und bildet als Dimer die signaltransduzierende Rezeptoreinheit für das IL-6 Signal. Die biologische Wirkung des IL-6 ist abhängig von der Dauer und Stärke des induzierten Signals. Die gp130 Rezeptorexpression stellt einen bedeutenden Faktor zur Beeinflussung des IL-6 Signals dar. Die im Rahmen dieser Arbeit untersuchte gp130LLAA Maus weist eine Punktmutation im gp130 Rezeptor auf, bei der das Dileucin-Motiv (L874, L785) im zytoplasmatischen Bereich von gp130 zu Dialanin verändert wurde. Für die Endozytose ist das intrazelluläre Dileucin-Motiv erforderlich, da das Adapterprotein AP-2 an dieses Motiv bindet und dadurch den Transport mittels Clathrin-umhüllter Vesikel begünstigt. Die beschriebene Punktmutation hat zur Folge, dass die veränderte Form von gp130 resistent gegenüber der Liganden- und crosstalk-vermittelten Endozytose ist. Da IL-6 generell eine wichtige Rolle bei der Differenzierung hämatopoetischer Zellen spielt, so auch bei T- und B-Zellen, wurde der Einfluss der gp130LLAA Mutation auf die Homöostase dieser lymphoiden Zellen untersucht. Für die Versuche wurden sowohl B- und T-Zellen und jeweilige Subpopulationen aus der Milz von WT Mäusen und gp130LLAA Mäusen untersucht. / IL-6 plays an important role in immune response, inflammation and hematopoiesis. Glycoprotein 130 (gp130) is ubiquitously expressed and forms the signal transducing receptor moiety for IL-6 signaling as a dimer. The biological effect of IL-6 is dependent on the duration and strength of the induced signal. The gp130 receptor expression represents a significant factor influencing the IL-6 signal. The gp130LLAA mouse studied in this work has a point mutation in the gp130 receptor in which the dileucine motif (L874, L785) in the cytoplasmic region of gp130 has been changed to dialanine. The intracellular dileucine motif is required for endocytosis because the adaptor protein AP-2 binds to this motif, thereby promoting transport by clathrin-coated vesicles. The described point mutation results in the altered form of gp130 being resistant to ligand- and crosstalk-mediated endocytosis. Because IL-6 generally plays an important role in the differentiation of hematopoietic cells, including T and B cells, the effect of the gp130LLAA mutation on the homeostasis of these lymphoid cells was investigated. For the experiments, both B and T cells and respective subpopulations from the spleens of WT mice and gp130LLAA mice were examined.