0000000000165831
AUTHOR
Antoine Bernard
Effect of high pressure on the antimicrobial activity and secondary structure of the bacteriocin nisin
International audience; Effect of high pressure (HP) treatment on the antimicrobial properties and the structure of nisin was evaluated. Nisin solutions at pH 2.8 or 6.1 were treated by HP at 500 MPa – 10 min – 20 °C and their antimicrobial potency was determined. It appeared that HP clearly impacted the antimicrobial activity of nisin, with respective activity loss of 22.5% and 49.9% at pH 2.8 and 6.1. Structural analysis of nisin by circular dichroism and Fourier transform-infrared spectroscopies revealed that the decrease of nisin antimicrobial activity was likely due to the unfolding of the protein induced by HP. A loss of nisin β-turns structure, particularly significant at neutral pH,…
Mise en évidence et étude d'une isoforme alternative du facteur de transcription IRF-1 dans la différenciation lymphocytaire Th1
It is now clearly established that immune system can affect cancer response to therapy. However, the influence of tumor microenvironment on immune cells is not completely understood. In this respect, alternative splicing is increasingly described to affect immune system biology.Here, we showed that tumor microenvironment, by increasing alternative splicing events, induced the expression of an alternative isoform of the IRF1 transcription factor in Th1 cells. Furthermore, we also showed, in both mice and humans, that IRF1 alternative isoform alters IRF1 full form transcriptional activity on Il12rb1 promotor, resulting in decreased IFN-γ secretion in Th1 cells.Thus, the expression of the IRF1…