Question: How are you going to make viruses which can take medicine to blood vessels?

Rachel Dakin answered on 12 Nov 2013:

Hi Iazamonsta great question : )
There are lots of steps involved – I’ll try and explain them one by one.
Firstly we have to choose the virus. In my lab we work with adenoviruses, these are naturally occuring viruses which can cause coughs and colds in children. The first thing to do is stop them making people ill. This is done by deleting certain genes of the virus. Without those genes the virus can still be made but won’t make people ill. We have adenoviruses like this in the lab. From years of research we know adenoviruses are a good choice because; they infect cells that are dividing and ones that aren’t, we can make large good quality batches of them and since they’ve had the bad genes deleted they are relatively safe to use in humans.
So I’m going to use adnoviruses, next step make sure they infect the cells I want – those in the the blood vessel wall. This is the bit I’m working on at the moment. Viruses attach to cells using receptors and ligands – these are a bit like a lock and key. The virus has the key (ligand) sticking out and it will attach to a cell with the matching lock (receptor). So now I have to find an adenovirus that has a ligand for blood vessels. Or I can alter an adenovirus to add a ligand that will bind to blood vessels.
I’ve been investigating how different types of adenovirus (there are 57!) infect cells from the wall of a human blood vessel (you can see pictures on my profile). I’ve also been changing the DNA sequence of an adenovirus to try and add or remove ligands (keys). Changing the sequence of DNA uses lots of molecular biology. We can cuts bits of DNA out, stick bits together and copy genes.
If/when I find a virus that is good at infecting the blood vessel walls and not other tissues there is still lots more to be done.
The ‘medicine’ that a virus will take to the blood vessel is most likely to be a gene. The virus would deliver it and then the blood vessel cell would read the instructions in the gene to make a protein. This gene will be specially selected so the protein it makes can stop a disease getting worse or prevent it from starting. We call these things biological medicines and a virus is a good way of delivering them because they will take the gene into the nucleus of a cell where it will be read to make the protein.
The virus and the gene will need to be extensively tested in preclinical tests and then eventually (hopefully) they would be tested on humans.

I hope that answers your question – if not let me know!