The bacterial extract OM-85 reduces the binding of SARS-CoV-2 on human bronchial epithelial cells

A recently published in-vitro study in Biomedicines showed that the bacterial extract OM-85 (Broncho-Vaxom®) decreases the ability of the SARS-CoV-2, the COVID-19 virus, to infect lung epithelial cells. OM-85 is a bacterial lysate consisting mainly of cell membrane components obtained from eight different bacteria genera. It activates the innate immune system through different pathways and is registered for the prevention of recurrent respiratory tract infections. The research team of Prof. Michael Roth from the Pulmonary Cell Research Department of Biomedicines & Internal Medicine of the University Hospital of Basel in Switzerland investigated the effect of OM-85 on reducing the infection capability of SARS-CoV-2 on immortalized lung epithelial cells. The coronavirus is infecting epithelial cells by the interaction of the viral spike-protein (S-protein) with the human angiotensin converting enzyme 2 receptor (ACE2). The effect on other cell membrane components, which play a role by attaching the virus to the cell membrane, such as dipeptidyl peptidase-4 (DPP4), transmembrane protease serine subtype 2 (TMPRSS2), metalloprotease 17 (ADAM17), glycosaminoglycans (GAG), heparan sulfate (HS), and hyaluronic acid (HA), were also investigated in this study. The research team treated the human bronchial epithelial cells during 5 days with OM-85 and afterwards exposed the cells to a SARS-CoV-2 spike protein pseudo-typed lentivirus thus mimicking an exposure to the SARS-CoV-2. OM-85 significantly reduced the expression of ACE2 (p<0.001), DPP4 (p<0.005), TMPRSS2 (p<0.001) and cellular HS (p<0.01). These effects of OM-85 might contribute to the observation that the infection rate of the bronchial epithelial cells with the pseudo-typed lentivirus was reduced in comparison to non-OM-85-treated cells.

The release as fetched from its publisher. ompharma.com ↗