Research Interests - Hélène Bierne

My research focuses on understanding how bacterial pathogens subvert host cell functions during infection to allow their survival, replication and resistance to immune responses. I specifically study how the pathogenic bacterium Listeria monocytogenes deregulates nuclear signaling pathways and exploits epigenetic mechanisms.

Our most recent work has identified the first bacterial factor targeting the host heterochromatin machinery (Lebreton et al., Science, 2011 Lebreton et al., Virulence, 2012). LntA secreted by intracellular Listeria counteracts repression by human BAHD1 to activate interferon responsive genes. We are also interested in other Listeria secreted proteins that may modulate nuclear processes (Personnic et al., Infect. Immun., 2011).


 

We have characterized the human protein BAHD1 as a novel chromatin regulator in vertebrates. BAHD1 acts as a silencer by tethering chromatin regulators (HP1, MBD1, KAP1) and chromatin-modifying enzymes (HMT and HDAC) to sequence-specific transcription factors, enabling local chromatin compaction at specific target genes. The set of genes repressed by the BAHD1 complex depends on the signal to which cells are submitted (Bierne et al. PNAS, 2009; Lebreton et al., Science, 2011).