BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/Vienna
BEGIN:DAYLIGHT
DTSTART:20260329T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20261025T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:CET
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20260817T144453Z
UID:1788433200@ist.ac.at
DTSTART:20260903T130000
DTEND:20260903T140000
DESCRIPTION:Speaker: Nathalie Gruber\nhosted by Jérémie Palacci\nAbstract
 : Bacteria inhabit an extraordinary range of environments\, each shaped by
  its own selective pressures that can fluctuate within seconds to seasons.
  A persistent selective pressure across these environments is imposed by v
 iruses that infect bacteria\, called phages. This ongoing coevolution betw
 een bacteria and phages has led to multiple defense strategies on both sid
 es. Bacteria have defense strategies at multiple levels: at the cell surfa
 ce\, physical barriers such as capsules\, exopolysaccharides\, and recepto
 r modifications limit phage adsorption\, while intracellularly\, molecular
  defense systems degrade or restrict invading genomes. However\, how these
  spatially distinct layers are coordinated during infection remains largel
 y unexplored.To address this\, we investigated the genome-clustered anti-p
 hage defense island of Escherichia coli K-12\, which encodes four anti-pha
 ge systems. We found that a single system dominated intracellular defense 
 across diverse phages. Strikingly\, under sustained phage pressure\, a sec
 ond extracellular layer of defense emerges: phage-induced mucoidy. This is
  a regulator of capsule synthesis (Rcs)-dependent and quorum-sensing-indep
 endent response that generates protective extracellular matrix. This mucoi
 d matrix confers broad resistance\, protecting against 29 of the 31 phages
  tested. Critically\, the two layers are not independent\; the strength of
  the defense system-mediated restriction directly sets the phage dose thre
 shold at which mucoidy is induced. Therefore\, intracellular and extracell
 ular defenses do not operate in isolation but as a single\, quantitatively
  coupled immune response.By revealing a direct mechanistic link between in
 tracellular anti-phage systems and phenotypic switching to mucoidy\, this 
 work reframes bacterial immunity as an integrated\, multi-layered process\
 , with broad implications for phage–host coevolution and for the design 
 of phage therapies against mucoid variants\, which are associated with inc
 reased patient mortality.
LOCATION:Central Bldg / O1 / Ballroom (I01.O1.006) and Zoom\, ISTA
ORGANIZER:
SUMMARY:Nathalie Gruber: Thesis Defense: Genetic Strategies Enabling Bacter
 ial Adaptation to Selective Pressures
URL:https://talks-calendar.ista.ac.at/events/6591
END:VEVENT
END:VCALENDAR