A Microphysiological System to Study Leukocyte-Endothelial Cell Interaction during Inflammation
December 9th, 2021
3.3K views
In this protocol, a biomimetic microfluid assay, which can reproduce a physiologically relevant microvascular environment and reproduce the entire leukocyte adhesion/migration cascade, is employed to study leukocyte-endothelial cell interactions in inflammatory disease.
Overview
This protocol describes a biomimetic microfluidic assay (bMFA) designed to replicate a physiologically relevant microvascular environment. It enables the study of leukocyte-endothelial cell interactions, particularly in the context of inflammatory diseases.
Key Study Components
Area of Science
- Neuroscience
- Cell Biology
- Inflammatory Disease Research
Background
- Leukocyte-endothelial interactions are crucial in the pathophysiology of inflammatory diseases.
- Dysregulation of inflammation can lead to organ damage due to altered endothelial barrier function.
- The bMFA mimics in-vivo conditions, allowing for real-time observation of leukocyte behavior.
- Utilizing primary human cells enhances the clinical relevance of the findings.
Purpose of Study
- To investigate the adhesion and migration of leukocytes in a controlled environment.
- To provide insights into the mechanisms of inflammatory responses.
- To facilitate the screening of potential therapeutic interventions.
Methods Used
- Development of a biomimetic microfluidic assay.
- Real-time assessment of neutrophil behavior.
- Use of primary human cells and patient samples.
- Insertion of tubes into microfluidic ports for assay setup.
Main Results
- The bMFA successfully replicates the microvascular environment.
- Real-time monitoring reveals detailed leukocyte adhesion and migration patterns.
- Findings support the potential for clinical translation of the assay.
- Demonstrated procedures enhance reproducibility and reliability of results.
Conclusions
- The biomimetic microfluidic assay is a valuable tool for studying inflammatory processes.
- It allows for the exploration of leukocyte dynamics in a physiologically relevant context.
- This approach may lead to improved therapeutic strategies for inflammatory diseases.
Frequently Asked Questions
What is the biomimetic microfluidic assay?
The bMFA is a system that mimics the conditions of microvascular networks to study leukocyte behavior.
How does the bMFA contribute to understanding inflammatory diseases?
It allows researchers to observe leukocyte-endothelial interactions in real-time, providing insights into inflammation mechanisms.
What types of cells can be used in the bMFA?
Primary human cells and clinically relevant patient samples can be utilized in the assay.
Who demonstrated the procedures for the bMFA?
Mr. Qingliang Yang, a graduate research assistant, demonstrated the procedures in the study.
What are the potential applications of the bMFA?
The bMFA can be used for screening potential therapeutics and understanding the dynamics of inflammatory responses.
How does the bMFA enhance clinical translation?
By using primary human cells, the findings from the bMFA are more relevant to clinical settings.
Executive Industry Relevance
The biomimetic microfluidic assay (bMFA) enables physiologically relevant modeling of leukocyte-endothelial interactions under controlled shear stress and vascular topology, addressing a critical gap in inflammatory disease target validation. By recapitulating the leukocyte rolling/adhesion/migration cascade using human primary cells, the system enhances predictive confidence in preclinical screening of anti-inflammatory therapeutics. This supports early de-risking of therapeutic candidates by linking mechanistic insights to translatable organ-level pathophysiology.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses by quantifying neutrophil adhesion and migration in response to inflammatory stimuli such as TNF-alpha.
- Scientific Value: Supports functional target validation through modulation of adhesion molecule expression and endothelial permeability under physiologically relevant flow conditions.
- Scientific Value: Facilitates pathway clarification by correlating spatial adhesion patterns with low shear rate regions and vascular bifurcations identified via CFD modeling.
Screening & Assay Development
- Operational Value: Provides a standardized, reproducible platform for real-time quantification of leukocyte rolling velocity, adhesion frequency, and migration into tissue compartments.
- Operational Value: Enables rapid screening of potential therapeutics using human lung microvascular endothelial cells and primary neutrophils, increasing clinical translatability.
- Operational Value: Supports assay scalability through microfluidic network design derived from in vivo rodent microvascular topology and PDMS microfabrication.
Translational & Preclinical Research
- Translational Value: Uses human-related samples to bridge discovery findings with clinical relevance in inflammatory diseases such as sepsis.
- Translational Value: Measures endothelial integrity via permeability and trans-endothelial electrical resistance (TEER), enabling assessment of barrier function during inflammation.
- Translational Value: Models cell/cell communication critical to organ function, supporting preclinical continuity from target engagement to tissue-level response.
Pipeline & Workflow Integration
The bMFA integrates into the discovery continuum by enabling hypothesis-driven interrogation of leukocyte-endothelial interactions, supporting assay readiness for compound screening, and generating quantitative, imaging-based outputs for data-driven decision-making in lead optimization.
- Discovery Biology: Supports mechanistic de-risking by visualizing spatiotemporal dynamics of neutrophil adhesion and migration under controlled inflammatory stimulation.
- Screening: Delivers quantitative, multiplexed readouts including adhesion maps, migration maps, and endothelial activation states for compound efficacy ranking.
- Analytics: Generates shear rate-correlated adhesion profiles and time-lapse migration data enabling statistical comparison across treatment conditions.
- Translational Research: Connects endothelial activation and neutrophil trafficking to organ-level pathophysiology through permeability and TEER measurements.
- Enterprise Reuse: Establishes a reusable microfluidic platform adaptable to multiple disease models and cell types beyond neutrophil-endothelial interactions.
Operational & Enterprise Impact
- Scientific Value: Reduces mechanistic ambiguity in leukocyte trafficking by decoupling shear stress, vascular geometry, and biochemical stimulation in a controlled environment.
- Operational Value: Ensures reproducibility through standardized fabrication, cell seeding under flow, and defined stimulation protocols using TNF-alpha and fMLP.
- Strategic Value: Improves go/no-go decisions by providing early efficacy signals for novel inhibitors such as PKC delta inhibitor in neutrophil migration assays.
- Portfolio Impact: Enables risk-adjusted prioritization of anti-inflammatory candidates based on quantitative inhibition of adhesion and migration in human-relevant systems.
Implementation Considerations
- Requires expertise in microfluidic device fabrication, primary cell culture, and confocal microscopy for image acquisition and analysis.
- Depends on access to syringe pumps, pneumatic priming systems, and CFD simulation tools for shear rate mapping.
- Necessitates standardization across teams for consistent channel coating, cell seeding density, and stimulation timing to ensure data comparability.
- Involves adaptation considerations when extending the model to other vascular beds or cell types due to organ-specific shear profiles and endothelial heterogeneity.
- Limited by the need for meticulous degassing and bubble-free fluid handling to maintain laminar flow and accurate shear stress delivery.
Biopharma FAQs
Why does shear rate mapping matter for target validation in leukocyte-endothelial assays?
Shear rate mapping via CFD modeling identifies regions of low shear stress and vascular bifurcations where neutrophil adhesion preferentially occurs, enabling mechanistic interpretation of adhesion patterns under inflammatory stimulation.
How does isolating TNF-alpha as an independent variable improve discovery pipeline efficiency?
Isolating TNF-alpha stimulation allows researchers to quantify its specific effect on endothelial activation and neutrophil adhesion/migration, enabling clear attribution of observed changes to inflammatory pathway activation rather than confounding variables.
What quantitative dependent variable measurements enable lead compound screening in bMFA?
The assay enables quantification of neutrophil rolling velocity, number of adhered leukocytes, number of migrated leukocytes, endothelial permeability, and adhesion molecule expression, providing multiplexed, objective readouts for compound efficacy assessment.
Why do replication requirements matter for cross-functional collaboration in microfluidic assay development?
Replication across multiple bMFA devices ensures data reliability and reproducibility, which is essential for aligning discovery biology, assay development, and preclinical teams around consistent, interpretable results.
What statistical analysis capabilities are required before implementing bMFA in therapeutic screening?
Implementation requires the ability to perform time-lapse image analysis, quantify fluorescence intensity in defined regions of interest, and compare adhesion and migration metrics across treatment groups using appropriate statistical tests to determine significant differences.
Chapters in this video
0:04
Introduction
1:13
Priming and Coating the Device with Human Fibronectin
3:01
Seeding Biomimetic Microfluid Assay (bMFA) with HLMVEC
4:37
Cell Culture Under Flow for 48 Hours
5:26
Cytokine and/or Therapeutic Treatment
6:19
Neutrophil Adhesion and Migration Experiment with bMFA
8:33
Acquire Image
9:59
Results: Biomimetic Microfluid Assay to Study Leukocyte-Endothelial Cell Interactions
12:06
Conclusion
