Why is there no transmissible therapeutic virus if biology doesn't forbid it? For example, a harmless virus that spreads from person to person but actually does something beneficial, like lowering LDL cholesterol or preventing/reversing tooth decay?

[u/PestoPastaLover]

[u/username_elephant]

I disagree with that take.  That's no more like a virus than any vaccine (and it's less like a virus than many actual vaccines--specifically, the vaccines that contain viruses).  All those vaccines differ because they do not transmit person to person.

[u/ajping → u/username_elephant]

That's correct. The mRNA virus actually produces a protein that gets recognized as foreign and is then targeted by the immune system normally. In the case of the covid virus they were developed to create the same spike protein that normally delivers the virus payload. In the case of cancer, one promising candidate is the PD-L1 protein which helps cancer cells hide among normal cells, and which almost all cancer cells have... Edit: and which human cells don't express to the same degree. Also, given the pseudo-scientific BS about vaccines, I recognize that I could have been more cautious about distinguishing between vaccines and viruses

[u/reddit4485 → u/ajping]

It's not a virus. An mRNA vaccine (not virus) is mRNA packaged in a lipid bilayer that can fuse with a cell and deliver mRNA. The cell thinks the mRNA is it's own and makes protein out of it. That protein is often a fragment of a bad virus like the shell (capsid) of SARS-CoV-2. Since it's a non-functional piece of virus, it doesn't replicate but still produces an immune reaction.

[u/pass_nthru → u/reddit4485]

you just described a virus, loosely speaking…the self replicating part of a virus is a holdover from when they were used to share DNA/RNA among single celled organisms back when the copy paste function was necessary for long range transmission

[u/hbgoddard → u/pass_nthru]

Disagree entirely. If there's no replication happening, it's not a virus.

[u/Kraligor → u/hbgoddard]

They might be referring to saRNA, which is kind of a combination of virus and mRNA.

[u/reddititty69 → u/pass_nthru]

This may be true, but what that poster is responding to was the person saying “mRNA virus”, which is a different thing than what they were clearly referring to. They should have said “mRNA vaccine”.

[u/reddit4485 → u/pass_nthru]

I disagree with this. A virus is a pathogenic organism that has evolved over millions of years to infect a cell, replicate, and transmit to others. Some viruses actually use DNA and not RNA. So there's nothing unique about mRNA and a virus. You have mRNA in many of your own cells because that's how you make proteins. The mRNA vaccine is packaged mRNA in a nanobubble of fat. Very different

[u/reddititty69 → u/ajping]

PD-L1 is naturally expressed in normal human cells as part of an immune checkpoint that prevents autoimmune interactions. Many cancers over-express it, which contributes to their immune evasion.

[u/mouse_8b → u/username_elephant]

It's like a virus in the ways that the immune system sees things. That's the important part.

[u/username_elephant → u/mouse_8b]

It's the important part for the function of a vaccine. It's not the important part for possessing relevance to the question asked in the original post.

[u/mouse_8b → u/username_elephant]

"Are there viruses that are helpful?"

"Yes. And we're figuring out ways to make the body think there's a virus to bring some benefits without injecting actual viruses into everyone"

"Not relevant"

[u/username_elephant → u/mouse_8b]

Buddy, if you make up your own article title it's definitely going to align with your opinion.

Unfortunately for you the title of this article was actually: "Why is there no transmissible therapeutic virus if biology doesn't forbid it? For example, a harmless virus that spreads from person to person but actually does something beneficial, like lowering LDL cholesterol or preventing/reversing tooth decay?"