Nov. 14 at 10:58 AM
$SANA $IPSC Did a deep dive into
$IPSC immune evasion strategy. Conveniently,
$IPSC leaves out discussion of macrophage inhibition. No evidence in the literature that CD300a activation (what
$IPSC's synthetic CD300a-TASR protein is doing) completely eliminates macrophage phagocytosis.
$IPSC allo-evasion 5.0 cells may still get eliminated by macrophages, in other words it may not work in vivo or in humans.
$IPSC's synthetic CD300a-TASR protein is interesting and could do well at preventing NK cell mediated killing, but it is probably insufficient to achieve full immunoevasion. Their one and only paper on CD300a-TASR (here: https://ashpublications.org/bloodadvances/article/9/2/254/518079/Universal-protection-of-allogeneic-T-cell ) is very new and only used very limited in vitro experiments as a means of testing CD300a-TASR function. Macrophages weren't mentioned, let alone tested in the paper.
We have no in vivo data on CD300a-TASR. Even humanized mice data may be flawed. Basically,
$IPSC nowhere close to competing with
$SANA. Years away, plausible failure mode exists.
