Price JM, Hisada Y, Hazeldine J, Bae-Jump V, Luther T, Mackman N, Harrison P. Detection of tissue factor-positive extracellular vesicles using the ExoView R100 system.
Res Pract Thromb Haemost 2023;
7:100177. [PMID:
37333992 PMCID:
PMC10276261 DOI:
10.1016/j.rpth.2023.100177]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/19/2023] [Accepted: 04/30/2023] [Indexed: 06/20/2023] Open
Abstract
Background
Tissue factor (TF) is essential for hemostasis. TF-expressing extracellular vesicles (TF+ EVs) are released in pathological conditions, such as trauma and cancer, and are linked to thrombosis. Detection of TF+ EV antigenically in plasma is challenging due to their low concentration but may be of clinical utility.
Objectives
We hypthesised that ExoView can allow for direct measurement of TF+ EV in plasma, antigenically.
Methods
We utilized the anti-TF monoclonal antibody 5G9 to capture TF EV onto specialized ExoView chips. This was combined with fluorescent TF+ EV detection using anti-TF monoclonal antibody IIID8-AF647. We measured tumor cell-derived (BxPC-3) TF+ EV and TF+ EVs from plasma derived from whole blood with or without lipopolysaccharide (LPS) stimulation. We used this system to analyze TF+ EVs in 2 relevant clinical cohorts: trauma and ovarian cancer. We compared ExoView results with an EV TF activity assay.
Results
BxPC-3-derived TF+ EVs were identified with ExoView using 5G9 capture with IIID8-AF647 detection. 5G9 capture with IIID8-AF647 detection was significantly higher in LPS+ samples than in LPS samples and correlated with EV TF activity (R2 = 0.28). Trauma patient samples had higher levels of EV TF activity than healthy controls, but activity did not correlate with TF measurements made by ExoView (R2 = 0.15). Samples from patients with ovarian cancer have higher levels of EV TF activity than those from healthy controls, but activity did not correlate with TF measurement by ExoView (R2 = 0.0063).
Conclusion
TF+ EV measurement is possible in plasma, but the threshold and potential clinical applicability of ExoView R100, in this context, remain to be established.
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