Multiplexing Phenotype and Function for More Biologically Relevant Insights - 29

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This work revealed that the loss of Glis3 from human embryonic stem cells impaired
their differentiation into pancreatic progenitor and β-like cells and increased the
death of these cell types. As part of a high-content chemical screen that looked for
candidates that could rescue this increased cell death, investigators in Dr. Chen's lab
identified a TGF-β inhibitor that is currently in Phase II trials.
The TGF-β inhibitor, galunisertib, specifically rescued the cell death caused by the
Glis3 deletion in vitro and in vivo, without affecting wild-type cells. The high-content
approach used to identify galunisertib as a drug candidate could be applied more
generally. "High-content screening," Dr. Chen predicts, "will be more and more
broadly used in drug screening."
The protocol developed by Dr. Chen and colleagues for differentiating individual
pancreatic cell types and modeling human disease has several advantages. "When
we perform screenings, we can combine insulin, which is a β-cell marker, and
glucagon, which is an α-cell marker, and we can obtain information about small
molecules that promote differentiation to either of these cell lineages," explains Dr.
Chen.
Another advantage is the ability to evaluate cell death and cell proliferation at the
same time. Interrogating cell death and cell proliferation markers together could
lead to the identification of certain small molecules that cause cell death, and others
that block cell proliferation, as opposed to causing cell death. "In that scenario,"
asserts Dr. Chen, "we already have some mechanistic clues from the primary
screening of the cells."
Flow Cytometry in Antibody Discovery
"We developed an approach that relies on high-throughput flow cytometry (HTFC)
to identify antibody binders," says Yana Wang, Ph.D., scientist, lead discovery,
Oncology Discovery Unit, Takeda Pharmaceuticals. To support antibody discovery
programs, Dr. Wang and colleagues at Takeda developed a HTFC approach that
combines the iQue Screener with a modular robotic system. The approach amounts
to a HTFC workflow.
By incorporating sample miniaturization, acquisition speed, and plate-based data
management, HTFC provides a flexible and modular solution for integrated applications, and it allows multiple parameters to be concomitantly measured robustly and
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| January, 2019

accurately. HTFC enabled Dr. Wang and colleagues to multiplex cytokine beads and
several cell types.
Essentially, the scientists used HTFC to demonstrate how multiple cytokine levels
and cell activation parameters could be monitored simultaneously, providing
high-content information. The scientists also showed how their new platform
could be more efficient than older platforms, which use 96-well plates and require
manual sample preparation. The new platform allowed sixteen 384-well plates to be
processed within 8 hours.
In previous years, Takeda scientists established powerful programs for the HTS of
small-molecule therapeutics. "We are trying to use this already established highthroughput screening infrastructure to develop platforms that support the needs of
Takeda's growing biologicals programs," says Dr. Wang.
While some of the challenges are shared between the two types of therapeutics,
biologicals present an additional set of unique limitations. As indicated by Dr. Wang,
"Normalizing all the purified antibodies to the same starting concentration, developing the best storage conditions, and optimizing buffers-these are some of the
challenges that we are specifically addressing for biologicals." n

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Multiplexing Phenotype and Function for More Biologically Relevant Insights

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