Is there any good viruses for human beings?

[Jin S Zhang]

As we all know, some bacteria are good and beneficial to human beings. How about viruses? Is there any good viruses that can be used for human beings?

[socrunningman]

If one remembers the story by HG Wells, "War of the Worlds" Viruses are our defenders in case of an alien attack(let us hope that they don't bring small pox blankets)

here is another story of viruses doing good, and helping us make discoveries along the way. In 1796 Edward Jenner noticed that milk maids who caught the Cowpox did not ever get the deadly smallpox virus. He developed a a method to infect people with the more benign virus so as to not catch the smallox. We call this Vaccination today, and millions of lives have been saved by "weak" viruses, preventing other similar viruses(or those of a different strain)

A contentious "good" is biological warfare.

Lastly, viruses play a minor role in spreading genes around, and may have been part of the earlier stages of the development of life(quick note, I can not source this at all at the moment, but i do remember hearing it in a discussion a few years ago. so take this with a grain of salt) on earth, especially RNA viruses.

~socrunningman

[Smachine]

Actually there are really many applications of viruses, like gene therapy or using bacteriophage to treat some bacterial infections is another potential use. Also the RNA virus enzyme - reverse transcriptase is used a lot in molecular biology to get DNA version of RNA.

[JonMoulton]

Sheep need them and cannot reproduce without them. I don't know about humans.

Dunlap KA, Palmarini M, Varela M, Burghardt RC, Hayashi K, Farmer JL, Spencer TE. Endogenous retroviruses regulate periimplantation placental growth and differentiation. Proc Natl Acad Sci U S A. 2006 Sep 26;103(39):14390-5. Epub 2006 Sep 15.
http://www.ncbi.nlm.nih.gov/pubmed/16980413

[nuby]

I've wondered about this myself..

Going by evolution logic, wouldn't it make more sense if a virus actually was beneficial to the body it lives in? That way the virus could be easily spread to other hosts over a longer period (since it would make the host live longer on average)...

Example: a virus that attacks harmful bacteria, then "idles" in the body.

[farful]

These are all lower bound estimations.

Us humans are composed of about 10 trillion 'human' cells. There's more than 100 trillion bacteria in us as well. Bacteriologists love to see us in this manner. Furthermore, virologists love to see us as having over 1000 trillion viruses in our bodies.

Fact of the matter is, we are our own ecosystem. We need the bacteria to survive. Furthermore, we need the virus to survive as well. They play an extremely crucial role in maintaining the enviornment (human body or otherwise).

[mgb_phys]

Going by evolution logic, wouldn't it make more sense if a virus actually was beneficial to the body it lives in? That way the virus could be easily spread to other hosts over a longer period (since it would make the host live longer on average)...


The energy in every cell in your body is generated by mitochondria. These are virus like bodies with their own DNA (actually RNA) that were originally viruses that infected the first cells. We (and all other animals) can't live without them and they do pretty well living off us.

[Biophreak]

mgb_phys- your statement about mitochondria being virus-like entities is only partly true, insomuch as they are slightly parasitic. Other than that, comparisons show that mitochondria are descendent from bacteria- namely, the alpha-proteobacteria (also the predecessors of chloroplasts in photosynthetic organisms).

As many have said, yes, viruses do play important roles in the human body, though not in the same manner as symbiotic bacteria ( e.g. e. coli producing vitamin k). It's is supposed by many evolutionary anthropologists that viruses, specifically retrovirus, which employ the enzyme RNA dependent DNA polymerase (reverse transcriptase), have been responsible for many of the translocations found in mammilian evolution. furthermore, several virus species are responsible for healthy bacterial growth, which, in turn, benefit the human host.

[Moonbear]

Sheep need them and cannot reproduce without them. I don't know about humans.

Dunlap KA, Palmarini M, Varela M, Burghardt RC, Hayashi K, Farmer JL, Spencer TE. Endogenous retroviruses regulate periimplantation placental growth and differentiation. Proc Natl Acad Sci U S A. 2006 Sep 26;103(39):14390-5. Epub 2006 Sep 15.
http://www.ncbi.nlm.nih.gov/pubmed/16980413


Wow! I actually know one of the authors of that study. I'll have to ask him about it. Though, be careful of stating that they can NOT reproduce without it. It might be that it helps, but is not required.

[nuby]

The energy in every cell in your body is generated by mitochondria. These are virus like bodies with their own DNA (actually RNA) that were originally viruses that infected the first cells. We (and all other animals) can't live without them and they do pretty well living off us.

Cool. I wonder if any other components to the human body evolved from a virus or bacteria? White blood cells maybe?

[Ygggdrasil]

It is possible that telomerase, the enzyme involved in extending the lifetime of cells and maintaining stem cells, evolved from viral enzymes since it's closest relatives are retroviral reverse transcriptase enzymes.

[Biophreak]

Cool. I wonder if any other components to the human body evolved from a virus or bacteria? White blood cells maybe?

It is supposed by many that eukaryotes in general are a conglomeration of several prokaryotic species. The general theory goes that, through endocytosis, various elements such as mitichondria (from proteobacteria), flagella [found on sperm] (from spirochetes), etc all hail from a meshing of many organisms. This theory allows the eukaryotic branch in the tree of life to form most easily. as you can imagine, it would be quite an extraordinary jump to go from prokaryotic- lacking organelles etc, to an organism with membrane bound organelles through simple mutation alone.

an example of this happening in real life is in the paramecium bursarii, which houses the algae chlorella so that the algae can provide oxygen for it. in turn, the paramecium protects the algae from predators and viruses. So in essence, this paramecium has a new "organ" per se that produces food for it, similar to the way our stomach takes nutrients from what we eat, and then breaks it down into useable glucose, salts, etc- this algae takes some of the inorganic Carbon (co2) and converts it to useable O2