Virologists, a question.

I was wondering, to what effect could a virus potentially alter a person?

I’ve been discussing the possibilities in another forum, but I really don’t know much about virus’s, so it’s basically pure speculation.

Can (or could a man made virus) change a person’s skeletal structure/musculature/etc?

Can a virus ever be beneficial to the host?

The first thing that comes to mind is the fact that many viruses go a long way to disguise the fact that their host cell is infected.

IIRC, Herpes Simplex Virus has a neat trick. Normal cells have many surface proteins that are lost upon viral infection. Certain immune cells will attack and kill cells that lack this protein, thus destroying the virus’ base of operations. HSV encodes proteins that mimic these normal proteins, so the immune system doesn’t catch on that the host cell is infected.

So major changes to cell structure could actually help the immune system locate and destroy infected cells.

That’s not to say it’s impossible. Viruses respond very quickly to natural selection. If there’s a balance between major structural change and flying under the immune system’s radar (or just shutting down the immune system entirely), viruses can find it.

Viruses do have the ability to isert foreign DNA into a host - that’s one way gene therapy works. However, to do something this radical, the DNA would have to be altered quite early on during development - the more radical the change, the earlier. Also, you’d probably be talking about simulatneously changing dozens or more genes in different areas of the genome, wich is more sophisticated than we can do now.

If you’re talking about rearranging stuff in a fully developed adult, that would be much more difficult. You’d have to target some cells to die, and target other cells to begin development in new directions. I’d say that would require much more information and direction than could fit in anything we could call a “virus”, by an stretch of the meaning.

Theoretically, perhaps. Again, that’s how gene therapy works. Engineered viruses deliver needed DNA segments to cells. There are plenty of known natural viruses that have no noticeable affect on their hosts. But I’m not aware of any natural viruses that are actually beneficial.

Check out Greg Bear’s book, Darwin’s Radio. Granted it’s sci-fi, but it’s all about this, and Greg Bear is generally pretty good about doing “hard” sci-fi.

It sounds like what I’m getting here is that while it’s not possible now it might be possible (at least hypothetically) in the future?

If you accept that certain virus’s cause Cancer then the answer is definitely "Yes a natural virus can cause changes to musculature, internal organs and the skeletal system.

Pagets Disease (skeleton), Human papilloma (skin), & Ebola (internal structure) are all viruses causing bodily change.

I think the spirit of the OP is asking changes in a sci-fi “cool” way tho & I don’t know about that – but if naturual viruses can why can’t a man made virus?

Here is a cite for ** Smeghead **’s correct assertion about use of virus’ now in Gene therapy as a way to deliver new genes

You might be able to insert a gene for growth hormone releasing hormone into a suitable virus, and induce acromegaly. With active forms of the hormone weighing in at ~45 amino acids, it wouldn’t be terribly disruptive to viral structure, even if you slapped on a sequence to ensure that the hormone was exported from infected cells.