Demonstrated Results
MICA development has been intimately linked with a major Sandia study of the innate immune system. Understanding how each component of the immune cell responds to invasion—and how these individual events are interconnected—is key to improving diagnostics and therapeutics.
To fully explore these events, Sandia needed a tool with highly advanced capabilities. Researchers therefore pooled deep core competencies in numerous areas—biology, computational modeling, microfluidics, imaging, and systems engineering—to develop the MICA prototype.
This effort has yielded notable accomplishments in two primary areas: the development of the MICA tool set and the use of MICA to gain new information about cellular pathways.
MICA Development
- Prototyped the MICA integrated microfluidic platform and and proved MICA’s ability to image and measure host-pathogen interactions with single-cell resolution.
- Executed entire experiments on a single chip, from sample preparation to flow cytometry.
- Demonstrated time resolution of ~seconds and analysis of both adherent and suspended cells.
- Demonstrated radical improvements in speed, multiplexing, single-cell resolution, and sensitivity in conventional assays adapted to MICA.
- Performed measurements not previously possible, such as measuring kinase activity and translocation, in the same population of cells.
- Enabled the on-demand imaging of selected cells by integrating cell sorting (flow cytometry) with optical tweezing.
Knowledge Creation
- Synthesized 26 antibodies and 18 fusion constructs (representing 9 different proteins with different promoters and fluorescent tags) and demonstrated their use in the microfluidic platform, as well as in Westerns, flow cytometry, and imaging, for comprehensive coverage of the TLR4 pathways.
- Observed previously unseen oscillations in NF-κB localization (nucleus vs. cytoplasm) and modeled these oscillations in a macrophage for the first time.
- Quantified the TLR-4 cytokine response in macrophages as a function of the LPS chemotype. Observed that TLR4-mediated responses vary in degree, but not in type or nature, depending upon the LPS chemotype.
- Validated model predictions by observing that the cellular heterogeneity of NF-κB oscillations results from a mixture of four distinct dynamic responses.
- Constructed a discrete model for macrophage gene transcription upon LPS simulation and a continuous model of FF-B dynamics.
