Single-cell approaches to assess hematopoietic stem cell response to matrix cues

Choi, Ji Sun

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https://hdl.handle.net/2142/50399 Copy

Description

Title

Single-cell approaches to assess hematopoietic stem cell response to matrix cues

Author(s)

Choi, Ji Sun

Issue Date

2014-09-16

Director of Research (if dissertation) or Advisor (if thesis)

Harley, Brendan A.

Doctoral Committee Chair(s)

Harley, Brendan A.

Committee Member(s)

• Cunningham, Brian T.
• Kraft, Mary L.
• Leckband, Deborah E.

Department of Study

Chemical & Biomolecular Engr

Discipline

Chemical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Hematopoietic stem cell
• Single cell approach
• Cell-matrix interactions

Abstract

Hematopoietic stem cells (HSC) are adult stem cells responsible for life-long hematopoiesis, the production of the full complement of blood and immune cells for hematological and immune systems. HSCs reside in the bone marrow within specialized microenvironments known as niches, comprised of various cellular and extracellular components including niche cells, extracellular matrix (ECM), and immobilized or soluble signaling molecules that provide extrinsic cues to regulate HSC fate decisions: quiescence, self-renewal, differentiation, mobilization, migration, retention, and apoptosis. Variations in structure and composition across the marrow niche microenvironments are believed to present combinations of signals that selectively regulate multiple stages of hematopoiesis. As predicted by such a hypothesis, HSCs exhibit dynamic behavior (e.g., mobilization, homing, migration) and localize non-uniformly within the marrow, with more primitive HSCs frequently localizing near the endosteum while less primitive, cycling progenitors associated with vascular sinusoids. The dynamic interplay between HSCs and a range of subregions within the bone marrow suggest that microenvironmental signals may be key regulators of HSC fate decisions. However, teasing apart the effect of niche-inspired biophysical cues on HSC fate decision processes have been challenging due to the rarity of HSCs within the marrow, our lack of technical ability to expand or differentiate HSCs freely in vitro, and a lack of available single cell metrics to continuously analyze the functional output of HSCs in situ. Our goal therefore is to build a multiplex in vitro culture platform that provides defined matrix cues while enabling label-free analysis of HSCs in situ. We first show that matrix cues do in fact directly impact HSC biophysical properties (Chapter 2) and fate decisions (Chapter 3) and identify a set of matrix cues that favor HSC self-renewal over lineage specification (Chapter 3). We then evaluate single cell analysis techniques (e.g., Raman Spectroscopy) as potential functional metrics for HSCs (Chapter 4). In particular, we assess the feasibility of using adhesive signatures of individual HSCs (e.g., Photonic crystal enhanced microscopy) as a new metric for monitoring their functional output (Chapter 5). Finally, we review our progress and discuss ongoing work and future opportunities (Conclusions).

Graduation Semester

2014-08

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http://hdl.handle.net/2142/50399

Copyright and License Information

Copyright 2014 Ji Sun Choi

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