Do all bactriophages cross the blood brain barrier?

[Ahmedbadr132]

TL;DR Summary

Do all bactriophages cross the blood brain barrier?

Hi
Bactriophages can cross the blood brain barrier but do all of them cross?
They are very diverse.

 

[berkeman]

TL;DR Summary: Do all bactriophages cross the blood brain barrier?

Hi
Bactriophages can cross the blood brain barrier but do all of them cross?
They are very diverse.

A Google search of your thread title turns up lots of good hits, including this one:

https://ami-journals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.2004.02422.x

These observations indicate that bacteriophages are able to cross the blood–brain barrier.

Paging @jim mcnamara and @Laroxe for more information...

 

[jim mcnamara]

...back from a 13 hour power outage.
doi: 10.3389/fimmu.2021.729336
PMCID: PMC8462735
PMID: 34566987
"Filamentous Bacteriophage—A Powerful Carrier for Glioma Therapy"

The blood brain barrier (BBB) does not admit all medication or virus particles or bacteriophages to cross, but filamentous bacteriophages are an exception. The paper suggests the use of filamentous bacteriophages as a possible method of getting medication into the brain, past the BBB.

So the answer is no - not all phages can pass the BBB. In general terms: "all" in the context of a biological processes at the cellular level is very likely to run into an exception.

 

[TonyStewart]

Penetration depends on many factors. My wife had an ear infection drained 3mos before Staph. Bacterial meningitis, which all Dr.'s said ear infection was not related, yet all MRI show skull air sacs still filled with fluid only on the same side as ear infection, even MRI 2 years after recovery with >2 mos of antibiotic treatment. She also had same ear 30 dB on/off hearing loss and on/off taste/smell loss with random cycling for the next few years. We also never have had CV-19 but did have 3 Vax, if that is relevant. https://ami-journals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.2004.02422.x

 

[Laroxe]

A bacteriophage is a virus that preys on specific bacteria, this implies that there will be at least as many types as there are types of bacteria, they tend to be fairly species specific. The answer to this question really depends on what is meant by penetration and the issue we are trying to address. Viral particles or virions are everywhere, but are essentially dead, our immune system will still remove them but other than that they can have no impact. So for a phage to pass through the blood brain barrier and have an impact it would need to be carried inside a cell and be capable of reproduction. Pathogenic bacteria often cause inflammatory changes in the blood brain barrier which increases its permeability so during an infection phages could cross the BB barrier and multiply.

Unfortunately, the way in which viruses reproduce which usually involves a massive release of virions that then need to passively find a receptor on a suitable cell, makes them particularly vulnerable to our own defences. The majority simply can't infect human cells and our own defence's that have effectively prevented the systematic use of phage therapies. There has in fact been a great deal of research in the potential use of phages in therapy but the problems remain. The article linked by Berkemen was a bit confusing as it suggests that penetration into the organism determines the therapy potential, I beg to differ, the little buggers get everywhere but that doesn't mean they can do anything.:) The article does explain some of the potential actions being based on the re-engineering of the virus to give it the ability to enter human cells, without an adequate rational as to why anyone would, we already have a number of human viruses that show oncolytic activity.
Phages have been used effectively to treat some superficial infections where our immune system can't get to them.

Vincent Rachaniello, in the first of his series of virology lectures, tells is that there are more than 10 to the power of 30 bacteriophage particles in the world's waters. Interestingly, the length of such a number, measured head to tail would stretch 100 million light years. Simply the number of potential viruses, the majority of which we know very little about would seem to suggest the question can't be answered but the same issue of the vast numbers involved, must mean that it's highly unlikely.