Something a little different. What’s the worst that could happen...

Something a little different.

What’s the worst that could happen to MSB’s stem cells, when used as a Covid-19 therapeutic? 0ne possibility would be that the virus attacks the stem cells.

Some background. Viruses are unusual because they’re unable to reproduce themselves. In simple terms, a virus has to gain access to and infect a suitable host cell, take over that cells functioning and set it to work as a tiny virus making ‘factory’.

The host cell then either bursts, releasing virus to infect other cells, or remains intact and slowly releases or buds out virus (as in Covid-19), to do the same thing.

Viruses typically recognise and gain access to suitable host cells because the host expresses surface proteins complimentary to those of the virus. Generally, if a potential host lacks those proteins, it will not be attacked.

So if patients with Covid-19 have the virus attacking their cells, will the virus also attack the human donor bone marrow stem or stromal cell’s in Remestemcel-l, impacting their potency?

The astonishing spread of the pandemic has triggered massive worldwide study of SARS-CoV-2 virus structure and function, and provided some answers.

Researchers believe they now know the critical proteins expressed by suitable host cells. They are ACE2 and TMPRSS2. In fact expression of these is so important that one reason suggested for the low incidence and mortality of Covid-19 in Japan is due to relatively lower expression of ACE2 in the population.

Anyway the good news is this: Recently researchers have shown that a range of human MSC’s, including those sourced from bone marrow (as used in Mesoblasts Remestemcel-l), do not express the two critical proteins needed for SARS-CoV-2 infection.

There conclusion was: “We provide the first evidence that ACE2 and TMPRSS2 are not expressed by human mesenchymal stromal cells (hMSCs) derived from both adult and fetal human tissues, and, most importantly, that hMSCs are not permissive to SARS-CoV-2 infection. These results support the safety of MSCs as potential therapy for Covid-19."

So that’s another solid piece of evidence for MSB’s safety profile. Hope the FDA are paying attention this time.

https://stemcellsjournals.onlinelibrary.wiley.com/doi/10.1002/sctm.20-0385

Usual bias. Herro