A microfluidic live cell assay to study anthrax toxin induced cell lethality assisted by conditioned medium

Area of Science:

• Cellular biology
• Toxicology
• Biotechnology

Background:

• Investigating secreted protein function in real-time is challenging.
• Anthrax toxin internalization, mediated by Dickkopf-1 (DKK1) and its receptor, leads to cell death.

Purpose of the Study:

• To develop a method for monitoring the dynamic interaction of anthrax toxin components in live cells.
• To quantify the role of DKK1 in anthrax toxin internalization and cell viability.

Main Methods:

• Utilized an integrated microfluidic device for real-time, controlled cell culture.
• Performed parallel cell viability assays with continuous perfusion of conditioned medium containing secreted proteins.
• Exposed DKK1-knocked-down cells to anthrax toxin and assessed rescue effects.

Main Results:

• Exogenous DKK1 rescued DKK1-knocked-down cells from anthrax toxin-induced sensitivity.
• The microfluidic assay precisely quantified the dynamic interactions between toxin and DKK1.
• Provided independent evidence for DKK1's function in anthrax toxin internalization.

Conclusions:

• The developed microfluidic system enables high-throughput analysis of secreted protein function in real-time.
• DKK1 plays a crucial protective role against anthrax toxin by modulating its internalization.
• This work offers new insights into the mechanisms of anthrax toxicity and potential therapeutic strategies.