Current Status of Cell-Based Therapies for Respiratory Virus Infections: Applicability to COVID-19

Khoury, Maroun; Cuenca, Jimena; Cruz, Fernanda F.; Figueroa, Fernando E.; Rocco, Patricia R. M.; Weiss, Daniel J.

Severe respiratory consequences of the COVID-19 pandemic have prompted urgent need for novel therapies. Cell-based approaches, primarily using mesenchymal stem (stromal) cells (MSCs), have demonstrated safety and possible efficacy in patients with the acute respiratory distress syndrome (ARDS), although not as yet well studied in respiratory virus-induced ARDS. Limited pre-clinical data suggest that systemic MSC administration can significantly reduce respiratory virus (Influenza strains H5N1 and H9N2)-induced lung injury, however, there are no available data in models of coronavirus respiratory infection. There are a rapidly increasing number of clinical investigations of cell-based therapy approaches for COVID-19. These utilise a range of different cell sources, doses, dosing strategies, and targeted patient populations. To provide a rationale strategy to maximise potential therapeutic use, it is critically important to understand the relevant pre-clinical studies and postulated mechanisms of MSC actions in respiratory virus-induced lung injuries. These are presented along with consideration of current clinical investigations.