Genetics vectors- endosomes/lysozymes

[bioquest]

okay so I was talking to my friend, and they used the wrong term for a while, or said that they used the wrong term, so now I'm not 100% sure whether it's endosomes or lysozymes, but I was wondering, what are the dangers to a person who is doing gene therapy on an animal using endosomes/lysozymes- if that is safe for a person to use an animal (Aside from the things that might happen to the animal) What are other vectors for gene/protein delivery that are safe/possibly safe for a person to use? Sorry if that sounded like a stupid question

 

[Ygggdrasil]

I believe the correct term you are looking for is liposomes. These are small vesicles that contain are composed of a lipid bilayer. For gene delivery, they are composed of a special mixture of cationic lipids that promote fusion with plasma membrane of cells. I don't know if they are used for gene delivery into live animals.

Endosomes are vesicles that are, by definition, inside cells. Lysosomes are organelles that are involved in the degradation of cellular components.

 

[bioquest]

are you sure they don't just inject endosomes for gene delivery and have the cells take up/in the endosomes?

What are the methods of delivering genes? Which ones are safe for the humans using it on the animal (not for the animal but for the human using on the animal) to use, and which ones aren't? Why/why not?
thanks

 

[Mike H]

As Ygggdrasil said, it's a matter of semantics - if it's inside a cell, a vesicle is called an endosome. If it's outside a cell, it's a liposome.

If you're referring to gene therapy, you have a variety of methods for gene delivery. You can work with viral vectors, naked DNA, liposomes, various polymer/DNA complexes, and antisense methods. Each method has its pros and cons, although given that it's still a very active topic of research, I'm not sure exactly how much consensus is out there on each method.

 

[bioquest]

oh cool okay, thanks for verifying that a bit

So if you use liposomes to transfer genes into an animal- what risk is there to you in doing that? (the genetic changes in the animal inside) I mean, when using the liposomes would there be a risk if you accidentally injecting yourself and being genetically altered or anything? There's obviously risks to using viruses on an animal right because you could inhale them or or something? (To the person using the viruses)

 

[Mike H]

My understanding of liposomes as vectors is that they are less efficient than viruses and their robustness is lower than viral vectors. One needs to make sure that the plasmid (or plasmids) gets out of the liposome and into the target cell without getting digested along the way. Viruses, as we know, are quite good at getting DNA (or RNA) into living cells. I'm sure people are working on ways to extend their lifetime in the body, but I recall hearing that liposomes get scavenged by the body pretty quickly. Liposomal methods mostly been used for direct injection into a target area, as a result, which thus far limits their applicability. They may not be anywhere near as much of a direct physical health risk as viruses, but trying to get them to work as well as viruses in certain regards may take a toll on a researcher's mental health. Heh. Naked DNA shouldn't be much of a problem (we have nucleases on our skin), and the others would probably vary depending on the details.

One still, of course, has the standard issues of concerns with gene therapy regardless of delivery method (making sure that it incorporates into the genome in a beneficial manner, that it doesn't spark an immunological response against the gene therapy-treated cell, and so on).

 

[bioquest]

When you say "nowhere near as much of a direct physical health risk as viruses"- could you elaborate on the health risks that a person using liposomes to deliver genes on an animal might be taking by doing so? (Aside from the genetic changes to an animal)

 

[Mike H]

I can't really elaborate on it beyond the observation that liposomes appear to be less efficient (at least at the current time) as vectors than viruses. If you make a mistake as a researcher with something that works 90% of the time (just an arbitrary number to make a point) at delivering foreign genes to a cell such as a virus, you stand a better chance in having something unpleasant happen to you than if you make a mistake when handling something that works 15% of the time (another arbitrary number to make a point) such as a liposomal vector.

That's all.