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Comment by jhickner | Hacker News Reader

If you thought of organisms as computers with IP addresses, each functional group of cells in the organism would be listening to the environment through its own active port. So, as port 25 maps specifically to SMTP services on a computer, port H1 maps specifically to the windpipe region on a human. Interestingly, the same port H1 maps to the intestinal tract on a bird.

Could anyone expand a bit on this subject? I found this completely fascinating, but I'm having trouble finding further reading on the underlying mechanics of "ports", as the article calls them.

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As i understand it, your body is made of various different types of cells. Now, a virus has to be able to mate with these cells to break through and then change the RNA of the cell so it can replicate- remember, viruses are sub-cell agents and need to cause mutations of good cells to replicate.

So given your body is made of different types of cells, viruses only have the keys to certain cells - where there's enough in common in their RNA to mate. This is kind of what's meant by the ports the author describes- H1N1 has enough similar encoding to the cells in your throat, nose and sinuses to mate and cause mutations.

I don't believe this is correct. First a virus does not cause a cell to mutate. It's more akin to handing the cell a new set of work orders, but it doesn't mutate the cell's DNA.

Second, I think the "port" is not that the RNA is similar, but rather the virus has a protein key on it's surface that physically allows it to enter the cell.

In the micro world things move by atomic forces. In this case the virus has a protein on it's surface that is the same shape as a protein on the surface of the cell. The same shape means the electrical charges line up, and the virus is drawn toward the cell by electrostatic forces.

If the charge pattern does not match up, the virus will not be drawn toward the cell. Remember the virus has no ability to move.

Not all viruses cause mutations, but some do: http://en.wikipedia.org/wiki/Retrovirus

Different species have a different type from the protein family Hemagglutinin(HA)(they all look similar to each other) these proteins are similar to services offered on a port. Viruses like Influenza target HA but only of certain types. In the case of Influenza HA doesn't actually act as a port, its not designed to allow things to go into the cell, the virus however uses HA as a recognition marker for where it will attack.

As a side note H1N1 means HA type 1, and Neuraminidase (NA) type 1. NA is a necessary protein for Influenza to leave the cell after replication.

Not entirely correct. Hemagglutinin is the protein on the virus coat. It binds to sialic acid on the surface of the cells. Sialic acids can have different glycosidic linkages. In humans, the predominant linkage type is alpha-1,6. In birds the predominant linkage is alpha-1,4. Pigs have a fairly even mix of both alpha-1,4 and alpha-1,6 which explains why they make good hosts for recombination.

I am under the impression that once a virus binds to a site, it attempts to push itself into the cell.

Would it be possible or practical to make a filter media, or throat spray using sialic acid to catch H1N1 viruses and fool them into 'thinking' they have reached a target location? The goal being to selectively trap or destroy as the virus attempts to enter a fake target cell. Could something like this help prevent infection or help to quell severe infections?

Would this be the computer analogous metaphor for a 'honey pot'.

Something in between a honey pot and a tarpit; which hopefully helps you develop your idea further because it sounds fascinating--from the perspective of me, with my no knowledge whatsoever of virology.

http://en.wikipedia.org/wiki/Tarpit_(networking)

Unfortunately, chemistry would thwart your efforts. The binding of proteins to other molecules (like sialic acid) is a reversible process. In other words, it's not as if each Hemaglutinin binds to a single sialic acid molecule and that's it. Each Hemaglutinin is constantly binding and unbinding, so adding extra sialic acid might slow down the process of fusing with the host cell, but it wouldn't prevent it.

Actually, the way that the current antivirals work is sort of the opposite. When the new viral particles are emerging from their host cell they end up stuck on the sialic acid molecules on the surface. That's where the Neuraminidase (the "N" of H1N1) comes in. It's job is to cut the new virus particles free of the host cell that produced them. If you block that, you can effectively stall the infection before it gets started.

There is something - mucus.

It doesn't fool them like you suggested, but rather it catches and tangles the viruses and physically prevents them from infecting a cell.

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