Umbilical cord-derived CD362+ mesenchymal stromal cells for E. coli pneumonia: impact of dose regimen, passage, cryopreservation, and antibiotic therapy

Shahd Horie,Steve Elliman,Daniel O’Toole,Paul Loftus,John G Laffey,Claire Masterson,Emma Horan,Jack Brady,Timothy O’Brien,Frank Barry,Lisa O’Flynn

doi:10.1186/s13287-020-01624-8

Abstract

BackgroundMesenchymal stromal cells (MSCs) demonstrate considerable promise for acute respiratory distress syndrome (ARDS) and sepsis. However, standard approaches to MSC isolation generate highly heterogeneous cell populations, while bone marrow (BM) constitutes a limited and difficult to access MSC source. Furthermore, a range of cell manufacturing considerations and clinical setting practicalities remain to be explored.MethodsAdult male rats were subject to E. coli-induced pneumonia and administered CD362+ umbilical cord (UC)-hMSCs using a variety of cell production and clinical relevance considerations. In series 1, animals were instilled with E. coli and randomized to receive heterogeneous BM or UC-hMSCs or CD362+ UC-hMSCs. Subsequent series examined the impact of concomitant antibiotic therapy, MSC therapeutic cryopreservation (cryopreserved vs fresh CD362+ UC-hMSCs), impact of cell passage on efficacy (passages 3 vs 5 vs 7 vs 10), and delay of administration of cell therapy (0 h vs 6 h post-injury vs 6 h + 12 h) following E. coli installation.ResultsCD362+ UC-hMSCs were as effective as heterogonous MSCs in reducing E. coli-induced acute lung injury, improving oxygenation, decreasing bacterial load, reducing histologic injury, and ameliorating inflammatory marker levels. Cryopreserved CD362+ UC-hMSCs recapitulated this efficacy, attenuating E. coli-induced injury, but therapeutic relevance did not extend beyond passage 3 for all indices. CD362+ UC-hMSCs maintained efficacy in the presence of antibiotic therapy and rescued the animal from E. coli injury when delivered at 6 h + 12 h, following E. coli instillation.ConclusionsThese translational studies demonstrated the efficacy of CD362+ UC-hMSCs, where they decreased the severity of E. coli-induced pneumonia, maintained efficacy following cryopreservation, were more effective at early passage, were effective in the presence of antibiotic therapy, and could continue to provide benefit at later time points following E. coli injury.

Highlights

Human mesenchymal stem/stromal cells are a promising therapeutic strategy for the treatment of acute respiratory distress syndrome (ARDS) [1], demonstrating beneficial effects in a number of pre-clinical models including pulmonary [2,3,4] and abdominal sepsis [5,6,7], ventilator-induced lung injury (VILI) [8], bleomycininduced acute lung injury [9] and fibrosis [10]
Horie et al Stem Cell Research & Therapy (2020) 11:116 (Continued from previous page). These translational studies demonstrated the efficacy of CD362+ umbilical cord (UC)-Human mesenchymal stem/stromal cells (hMSCs), where they decreased the severity of E. coli-induced pneumonia, maintained efficacy following cryopreservation, were more effective at early passage, were effective in the presence of antibiotic therapy, and could continue to provide benefit at later time points following E. coli injury
Heterogeneous bone marrow (BM)-derived, heterogeneous UC-derived, and CD362+ UC-hMSC therapy attenuated the decrease in arterial oxygenation that was seen in the vehicle animal controls (Fig. 1a). hMSCs attenuated the increase in lung microvascular permeability with the wet to dry ratio significantly reduced in the BM and CD362+ UC-hMSC groups (Fig. 1b)

Summary

Introduction

Human mesenchymal stem/stromal cells (hMSCs) are a promising therapeutic strategy for the treatment of acute respiratory distress syndrome (ARDS) [1], demonstrating beneficial effects in a number of pre-clinical models including pulmonary [2,3,4] and abdominal sepsis [5,6,7], ventilator-induced lung injury (VILI) [8], bleomycininduced acute lung injury [9] and fibrosis [10]. Current approaches to isolating MSCs rely largely on the separation of the “plastic adherent” component of the BM mononuclear cell (MNC) population, followed by elucidation of their cell surface marker profile and differentiation assays [15]. This generates a heterogeneous hMSC population that may increase batch-to-batch variability and may be insufficiently pure to meet emerging regulatory requirements for advanced therapeutic medicinal products (ATMPs). A range of cell manufacturing considerations and clinical setting practicalities remain to be explored

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