Dec 1, 2020
One of the most exciting recent
discoveries in microbiology involves an immunological mechanism of
a single-celled organism.
CRISPR-Cas technology is a technique bacteria use for fighting
infection with phages. This podcast dives into the wild world of
CRISPR and bacteriophage interplay.
Listen and learn
Joseph Bondy-Denomy is an
associate professor of Microbiology and Immunology at UCSF. His lab
focuses on understanding how bacteria deal with their predators
like bacteriophages, which are bacteria-infecting viruses. While
they don't infect humans, they cover us and inhabit our bodies,
looking for prey.
CRISPR is one way bacteria protect themselves from phages, and scientists learned how to utilize the CRISPR for their own purposes, enabling foundational techniques for gene editing in the last decade. CRISPR-Cas9 and bacteriophage interaction in particular has made the news because of the usability of the Cas9 protein.
Dr. Bondy-Denomy offers
listeners effective analogies for understanding how this process
works, comparing this to taking a mugshot of a criminal, giving
that bacteria information to retain and work from when the same
type of phage tries to invade and infect again. He explains exactly
how the bacteria do so, storing the DNA snip in a region that lends
CRISPR its name, turns it into RNA, and then guides the CRISPR
proteins, like Cas9, to the same phage type if it returns,
He explains how understanding this mechanism led to two techniques: putting these systems into mammalian cells and showing how they could cut DNA and change a sequence intentionally and turning the mechanism into a programmable binding system. He discusses his own research as well, including continuing to understand how phages avoid CRISPR-Cas immunity and exploring new bacterial immune systems that have been discovered in the last few years.