Integrated non-invasive system for quantifying secreted human therapeutic hIL2

Area of Science:

• Biotechnology
• Cell Biology
• Biomedical Engineering

Background:

• Cell encapsulation enables in vivo therapeutic protein secretion for chronic conditions like diabetes and ALS.
• Current protein detection methods are invasive, requiring blood sampling or device extraction.

Purpose of the Study:

• To develop a non-invasive method for measuring secreted protein concentration using a co-expressed red fluorescent protein marker.
• To establish a bicistronic expression system for simultaneous intracellular marker production and therapeutic protein secretion.

Main Methods:

• Constructed a bicistronic expression vector for intracellular DsExDR (red fluorescent protein) and secreted human interleukin-2 (hIL2).
• Transfected the vector into C2C12, HEK293, and Jurkat cell lines.
• Analyzed the correlation between intracellular marker expression and secreted therapeutic protein concentration.

Main Results:

• Demonstrated linear correlations between DsExDR (intracellular) and hIL2 (secreted) with transfection DNA concentration across all tested cell lines.
• Confirmed a direct linear relationship between secreted hIL2 and accumulated intracellular DsExDR.
• HEK293 and C2C12 cells showed higher hIL2 expression and secretion than Jurkat cells, while maintaining linearity.

Conclusions:

• The developed bicistronic expression strategy enables non-invasive monitoring of therapeutic protein secretion.
• DsExDR serves as an effective intracellular marker for secreted hIL2.
• This reporting strategy shows significant potential for advancing cell encapsulation therapies.