Virus processing (filtration) of blood - How to? - (Dec/27/2014 )

I am invited to join a team who want to remove virus contamination from human blood. They are medical doctors and don't know much about molecular virology. Since I am a virus man they want me to help them to filtrate blood plasma and later do QC on their samples using some viruses known as "model viruses". This topic is new to me and I can't find any info on internet about such viruses. Maybe they just translated the term from English to my language, and that's the closest they came up with. 

Does anybody have info about this process?

Hi Curtis,

I suspect that "model viruses" is just a term used to group the viruses they are interested in looking at, so it could include almost any species that infects the model organism (mouse? human? etc?). I would suspect common viruses such as influenza (perhaps MERS strain?) and similar high burden diseases, but it could be that they are looking for low level viruses that aren't causing disease. It's going to be a big ask to filter blood and use that as a model, as far as I know, most viruses tend to stick to the cells, but I could easily be wrong on that.

I found a WHO guideline for that. Some viruses are mentioned as model viruses e.g. HIV !! Here's the link:

http://www.who.int/bloodproducts/publications/WHO_TRS_924_A4.pdf

There is also an FDA approval procedure that we need to take into consideration. I'll post later if I find it.

It's an exciting project. I'm starting it tomorrow. Wish me luck.

As far as the protocols show, I don't think the QC protocols are able to determine viral contamination in blood if the virus load is really low. Even qPCR fails sometimes. This has happened to me a lot in the past. So the virions could still be there in the final steps of filtration and removal. The questions is, if the virus load is low, can innate immunity degrade it? Or for example, can one active particle of HIV cause the disease? Or the virus load needs to be high to make someone ill? I am not very strong in immunology, I don't know this.

Sounds like an interesting project.

Infectious dose for HIV must have been worked out by now, but I don't know it off hand.  I suspect that a only a few viral particles will be required. Low dose HIV is something like 50 viral particles per ml of blood (i.e. the current detection limit), and this is a level that can be maintained by HAART, and I don't think there is any evidence that the immune system can cope with it, but I'm no immunologist either.

I worked on an avian paramyxovirus for more than 8 years but I still don't know how many particles can cause sickness in birds. It's difficult to say. But there are companies like Baxter and CSL who have been doing virus processing for years and have patents for that. I am being sent to one of these companies for training early next year, but one thing I learned is that first they purify the blood factors, and later remove viruses when the product is completely separated from plasma. This makes sense considering you might need to use chemicals or heat that degrade other factors.