Murine bone marrow-derived mesenchymal stem cells exert anti-viral and barrier-protective properties in influenza virus infection

Introduction. Influenza virus (IV) infects the upper respiratory tract and occasionally spreads to the alveolar compartment causing primary IV pneumonia. This frequently progresses to acute respiratory distress syndrome (ARDS). Antiviral therapies are only effective in the very beginning of infection and specific treatment strategies for IV-induced ARDS are lacking. Recently, mesenchymal stem cells (MSC) were attributed a beneficial role in acute and chronic lung injury. Methods: MSC were isolated by flow-cytometry (FACS) from mice bone morrow and cultured in vitro. Murine bone marrow (mBM) MSC experession markers and stem cell properties were characterized by FACS and microscopy. IV-infected primary alveolar epithelia cells (AECs) were co-cultured with mBN-MSC and subsequently cells were submitted for genome array and FACS analysis. mBM-MSC were injected intratracheally to IV-infected C57B16 and IFNAR mice. The effect of mBM-MSC treatment was evaluated in mice survival experiments and the impact of these cells on alveolar damage was quantified by microscopy and FACS measurements. [...].