Selection of Tissue Factor-Deficient Cell Transplants as a Novel Strategy for Improving Hemocompatibility of Human Bone Marrow Stromal Cells

Abstract

Intravascular transplantation of tissue factor (TF)-bearing cells elicits an instant blood-mediated inflammatory reaction (IBMIR) resulting in thrombotic complications and reduced engraftment. Here we studied the hemocompatibility of commonly used human white adipose tissue (WAT), umbilical cord (UC) and bone marrow stromal cells (BMSC) and devised a possible strategy for safe and efficient stromal cell transplantation.Methods: Stromal cell identity, purity, and TF expression was tested by RTQ-PCR, flow cytometry and immunohistochemistry. Pro-coagulant activity and fibrin clot formation/stabilization was measured In Vitro by viscoelastic rotational plasma-thromboelastometry and in vivo by injecting sorted human stromal cells intravenously into rats. The impact of TF was verified in factor VII-deficient plasma and by sort-depleting TF/CD142+ BMSC.Results: We found significantly less TF expression by a subpopulation of BMSC corresponding to reduced pro-coagulant activity. UC and WAT stroma showed broad TF expression and durable clotting. Higher cell numbers significantly increased clot formation partially dependent on coagulation factor VII. Depleting the TF/CD142+ subpopulation significantly ameliorated BMSC's hemocompatibility without affecting immunomodulation. TF-deficient BMSC did not produce thromboembolism in vivo, comparing favorably to massive intravascular thrombosis induction by TF-expressing stromal cells.Conclusion: We demonstrate that plasma-based thromboelastometry provides a reliable tool to detect pro-coagulant activity of therapeutic cells. Selecting TF-deficient BMSC is a novel strategy for improving cell therapy applicability by reducing cell dose-dependent IBMIR risk. The particularly strong pro-coagulant activity of UC and WAT preparations sounds an additional note of caution regarding uncritical systemic application of stromal cells, particularly from non-hematopoietic extravascular sources.

A functional corona around extracellular vesicles enhances angiogenesis during skin regeneration and signals in immune cells

“…S7). In particular for systemic applications, selection of products with sufficient hemocompatibility due to low/absent tissue factor expression or lack of complement activation may be beneficial as described for cell transplants [39]. Results obtained in these studies might have an impact on future protocols for EV manufacturing [40].…”

“…Thromboelastometry was determined in the absence or presence of one million PLX cells or one billion crude or purified PLX-EVs as recently described [39].…”

Stem/Stromal Cells for Treatment of Kidney Injuries With Focus on Preclinical Models

“…Some recent studies addressed MSC effects on hemocompatibility/thrombosis/instant blood mediated reaction and indicate that MSCs expressing tissue factor can induce thrombosis and instant blood mediated reactions. Oeller et al suggest that selecting tissue-factor deficient or low expressing cells may improve therapeutic outcomes ( 99 ). With respect to this, clinical trial protocols have already been modified to add anti-thrombotics such as heparin or hirudin ( 100 – 103 ).…”

Mesenchymale Stromazellen auf dem Weg zur klinischen Anwendung: Update 2018

“…MSC exprimieren Tissue Faktor und können so die Gerinnungskaskade anstoßen [42,43]. Eigene Daten zeigen auch, dass MSC mit Thrombozyten interagieren und überschießende Thrombozytenaktivierung drosseln (Netsch et al, Stem Cell Research & Therapy, accepted).…”