5 ms·
> If it senses another (somewhat famous) protein, PD-L1, the immune cell self destructs So why don't pathogens evolve to display PD-L1 on their surfaces, to ma
by cabalamat 3y ago
> If it senses another (somewhat famous) protein, PD-L1, the immune cell self destructs
So why don't pathogens evolve to display PD-L1 on their surfaces, to make immune cells harmless against them? Or do they?
- imdsm 3y agoWhat a horrifying thought
- tux3 3y agoA glance at Wikipedia confirms that some pathogens are aware of PD-L1 and like to mess with proteins that regulate the immune system. Epstein-Barr Virus (EBV), the most common human virus, the herpes that 90% of people have had and a common cause of cancer, apparently has a protein that induces expression of PD-L1. Some other viruses in mice have been observed to do it. What a mess. I love immunology.
- refurb 3y agoPD-L1 already exists in human cells, for cancers leverage it, they just need to overexpress it, which can be a minor genetic change. Pathogens, like bacteria, don't have PD-L1 and it's a very large transmembrane protein. Rather than a small genetic change to over express it, pathogens would need to generate the entire protein by scratch. Possible, but highly unlikely.
- Teever 3y agocouldn't a retrovirus accidentally copy it during replication?
- refurb 3y agoRetroviruses don't have cellular membranes. They could over-express PD-L1 in a cell it infects, but they don't need the cell to live, they want it to lyse and release more viruses (though I guess you could argue it wants it to survive immune attack long enough to do so). Bacteria could potentially do it, but also bacteria cell walls are very different than human. I'm not sure an expressed transmembrane protein could actually be embedded in a bacterial cell wall and still remain functional.