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

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).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Choi, Ji Sun

Contributors dc:contributor

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

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

Statement dc:rights

• Copyright 2014 Ji Sun Choi

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/50399