Investigation of Neutrophil-Like HL-60 Cell Migration in a 3D Collagen Matrix

<p>It is known that cell migration in innate and adaptive immune system plays a fundamental role in human health. Among the immune cells, neutrophils are one of the most essential cells in protecting the body against invading pathogens. In the presence of chemoattractants, these cells are the first responders that start a directed migration toward the injured area. As neutrophils approach the site of infection, they transmigrate to the tissue and follow the chemoattractant concentration gradient to locate and eliminate the invading pathogens. Understanding the patterns and mechanism of neutrophil migration in the presence of chemoattractants could possibly play an important role in discovering new treatments for various immune dysfunction diseases such as sepsis or severe COVID-19. Here, to study cell migration patterns, we designed a 3D hydrogel model to create a concentration gradient inside a collagen gel that contained neutrophil-like (dHL-60) cells. Our experimental setup and computational analysis allowed us to study the cell migration indicators such as percentage and velocity of motile cells in a 3D environment. Evaluating these cell migration features showed 10 nM Formyl-Met-Leu-Phe (fMLP) was the most suitable initial concentration among 0, 10, and 100 nM fMLP to maximize the cell activity. In addition, as fMLP was invisible under the microscope, we performed experiments with a fluorescent dye that had a similar molecular weight as fMLP to estimate the chemoattractant concentration and its gradient with high spatiotemporal resolution at any location and time inside the collagen gel. Next, we analyzed the correlation between the cell migration patterns and the chemoattractant concentration and its gradient over time. The results showed that the highest levels of cell motility, measured by a variety of indicators, occurred at moderate fMLP concentrations (5 to 7 nM fMLP) and, counterintuitively,not at the highest concentrations. In summary, the combination of our novel experimental design and computational analysis allowed us to improve on previous studies by correlating the dHL-60 migration indicators to the local chemoattractant concentration at the cell location over time, painting a more complex picture of cell migratory behavior in a 3D environment.</p>

Name thesis:degree_name

Engineering and Industrial Applied Mathematics Joint PhD with California State University Long Beach, PhD

Level thesis:degree_level

Open Access Dissertation

Discipline thesis:degree_discipline

Institute of Mathematical Sciences

Year dc:date.available

2022

Author dc:creator

• Sedighian, Pouye

Contributors dc:contributor

• Ga-young Kelly Suh
• Claudia Rangel-Escareño
• Ali Nadim

• Cell Migration
• Cell Migration in a 3D Collagen Matrix
• Confocal Microscopy
• Flow Cytometry
• Neutrophil Cell Migration
• Neutrophil-Like HL-60 Cell Migration
• Computer Sciences
• Mathematics

Repository record dc:identifier

https://scholarship.claremont.edu/cgu_etd/467

OAI identifier oai:identifier

oai:scholarship.claremont.edu:cgu_etd-1498