Academic Background
Caterina
Strambio De Castillia grew up in Italy and received her Laurea in
Biologia (equivalent to B.S./M.S.) from the University of Pavia in 1988. She
obtained her Ph.D. (1992-1998) working with Gunter Blobel at The
Rockefeller University, where she investigated the manner in which the
nuclear pore complex interfaces with the cellular genome in yeast. She
continued this work at the same institution in the laboratory of Mike Rout,
initially as a postdoctoral fellow (1998-2002) and then as a Research
Associate (2002-2006). She then moved to the IRB-Bellinzona and to the University of Geneva, Switzerland, where she was a
staff Research Scientist (2006-2012) developing imaging and proteomics
methods to study the mechanism by which HIV-1 interacts with the host
defense mechanisms to gain access to the cell nucleus. Her work has been
supported by the American Cancer Society, the European Union and
the Swiss National Science Foundation. In 2012, Dr. Strambio De
Castillia joined the Program in Molecular Medicine at the University of
Massachusetts Medical School.
Dissecting the interplay between HIV-1 and human cells during viral entry
After
HIV-1 fuses with a target cell membrane, the virion core is delivered
into the cytosol of the infected cell. A DNA copy (cDNA) of the HIV-1
RNA genome is produced by the HIV-1 reverse transcriptase (RT) and the
cDNA is ligated to host cell chromosomal DNA by HIV-1 integrase. Despite
30 years of research, detailed understanding of these essential early
steps in HIV-1 replication remains elusive. Some of the open questions
ask:
Does the virion core need to undergo an “uncoating” process to enable reverse transcription?
Is RT active in the cytoplasm or the nucleus?
Does the intracellular path followed by the virion core influence its ability to give rise to a productive infection?
How does HIV-1 reach the nucleus?
Up
to this point, progress has been impeded by the fragile nature of HIV-1
replication intermediates and the low infectivity-to-particle ratio of
virions, which makes it difficult if not impossible to meaningfully
dissect different steps in the pathway by bulk biochemical means alone.
Tracking HIV-1 as it traverses living cells in real-time
The
goal of the Strambio De Castillia laboratory is to remedy this lack
of understanding by developing methods to label and track infectious
HIV-1 as it traverses living cells in real-time. The aim is to identify those
rare particles that have successfully integrated into chromosomal DNA, retrace their intracellular path as they travel to reach the cellular genome and
identify their intracellular interaction partners, in a time and space
resolved manner. Such information will be invaluable for furthering our
understanding of the initial steps in the HIV-1 life cycle and for the
rational design of anti-HIV-1 drugs that target them.
Quantitative analysis of viral trajectories gives insight about viral-host interactions
Using
dynamic imaging followed by rigorous computational analysis of viral
particle trajectories, the complex interplay between HIV-1 and cellular
components can be solved. A major hurdle, has been the difficulty of
keeping track of multiple moving viral particles with sufficient
temporal and spatial resolution while at the same time probing multiple
experimental contexts.
A three-pronged multidisciplinary approach
In
order to meet this challenge, the Strambio De Castillia group is
engaged in a multidisciplinary, collaborative effort aimed at developing
integrated workflows that will provide the analysis, data management
and visualization capabilities required to drive a more complete
understanding of viral-host interactions in the context of living human
tissues. The project articulates on three fronts:
Real-time recording of HIV-1 viral core movement in infected human cells.
Viral particle tracking and motion analysis.
Building
a novel bio-image informatics framework to support the comprehensive
examination of particle movement across multiple experimental models and
conditions.
