Programmable DNA Circuit-Facilitated Determination of Circulating Extracellular Vesicle PD-L1 for Lung Cancer Diagnosis and Immunotherapy Response Prediction

Abstract

Circulating extracellular vesicle (EV) PD-L1 is correlated with the occurrence and progression of lung cancer and has great potential as a valuable diagnostic and immunotherapy predictive biomarker. In this work, we propose a fluorescent biosensing method for the sensitive and accurate determination of circulating EV PD-L1. Specifically, after the phosphatidylserinetargeting peptide-assisted magnetic enrichment, a programmable DNA circuit is designed to translate the presence of PD-L1 to the appearance of numerous duplex DNA probes on the circulating EV surface. Upon fructose treatment, these newly formed duplex DNA probes are released from the EV surface to activate the transcleavage activity of CRISPR/Cas12a system, which finally produces a significant fluorescence signal. Experimental results reveal that the method not only enables sensitive determination of EV PD-L1 with a detection limit of 67 particles/mL but also demonstrates the potential use in the diagnosis and immunotherapy response prediction of lung cancer in a principle-of-proof study. Therefore, the method may provide a useful tool for EV PD-L1 determination, which may provide valuable information for the precise diagnosis and personalized treatment of lung cancer patients.

Engineered biological nanoparticles as nanotherapeutics for tumor immunomodulation

“…20B). 265 Such a platform is helpful as a diagnostic cum immunotherapy platform. However, the system is not yet tested in vivo , and it is a critical factor as PD-L1 positive cells are also present in healthy cell populations.…”

“…Ex vivo applications can also be explored as the team performed a preliminary investigation using blood samples from 15 patients with lung cancer and 5 healthy controls, demonstrating the platform's potential for clinical diagnostic utility. 265 In another example, Zhang et al identified correlations between circulating extracellular vesicles and responses to immune checkpoint inhibitors (ICIs) in gastric cancer patients, indicating a use of the exosomes as treatment prognostic markers. 218 Moreover, in non-small-cell lung cancer patients, high levels of TGF-β in exosomes were associated with poor responses to ICIs, indicating their potential as predictive indicators for treatment outcomes.…”

“…The treatment also exhibited antiangiogenic effects via CD47 blockade with significant tumor growth inhibition. The use of plasma and red blood cell-derived exosomes are demonstrated by Bo et al and Zhang et al 265,266 Plasma-derived exosomes have been investigated as a potential biomarker for predicting and monitoring immunotherapeutic outcomes in various cancers. A proof-of-concept study by Bo et al exemplifies the innovative use of EVs and CRISPR/Cas9 system to generate a fluorescence signal in the presence of PD-L1 positive lung tumors (Fig.…”