Viral infection may trigger Crohn's disease in susceptible individuals

[Waverunner]

If you ever asked yourself, if a viral infection is able to cause a chronic and seemingly unrelated disease in susceptible individuals, here could be the answer.

http://www.ncbi.nlm.nih.gov/pubmed/20602997

Abstract
It is unclear why disease occurs in only a small proportion of persons carrying common risk alleles of disease susceptibility genes. Here we demonstrate that an interaction between a specific virus infection and a mutation in the Crohn's disease susceptibility gene Atg16L1 induces intestinal pathologies in mice. This virus-plus-susceptibility gene interaction generated abnormalities in granule packaging and unique patterns of gene expression in Paneth cells. Further, the response to injury induced by the toxic substance dextran sodium sulfate was fundamentally altered to include pathologies resembling aspects of Crohn's disease. These pathologies triggered by virus-plus-susceptibility gene interaction were dependent on TNFalpha and IFNgamma and were prevented by treatment with broad spectrum antibiotics. Thus, we provide a specific example of how a virus-plus-susceptibility gene interaction can, in combination with additional environmental factors and commensal bacteria, determine the phenotype of hosts carrying common risk alleles for inflammatory disease.

 

[Legendrew]

I'm not shocked by this as viruses have been long implicated as triggering events for many autoimmune diseases, it's nice to see the reason for this is being explored through studies such as this - I am however a little wary of the animal model being used as things tend to look really promising yet don't transfer smoothly into human biology.

 

[Waverunner]

I'm not shocked by this as viruses have been long implicated as triggering events for many autoimmune diseases, it's nice to see the reason for this is being explored through studies such as this - I am however a little wary of the animal model being used as things tend to look really promising yet don't transfer smoothly into human biology.

True. Still we have to wonder why we lack antivirals and why most doctors don't seem to care about most viruses, despite their possible implication in so many diseases.

 

[heapsreal]

It would be interesting to see the state their immune function is like nk and t cell function as well as compare this to other auto immune conditions as well as cfsme.

I think the simple explanation of autoimmune conditions is the body attacks itself. This just doesn't really make sense to me. I wonder if auto immune illnesses are just viruses intergrated into our dna much like ihhv6. So it may appear the immune system is attacking our bodies but in reality the immune system is trying to kill the infected dna/cells??

 

[Tammy]

It would be interesting to see the state their immune function is like nk and t cell function as well as compare this to other auto immune conditions as well as cfsme.

I think the simple explanation of autoimmune conditions is the body attacks itself. This just doesn't really make sense to me. I wonder if auto immune illnesses are just viruses intergrated into our dna much like ihhv6. So it may appear the immune system is attacking our bodies but in reality the immune system is trying to kill the infected dna/cells??

I agree 100%. Autoimmune has never made sense to me either. The body doesn't attack itself..............it attacks an invader.

 

[RogerBlack]

True. Still we have to wonder why we lack antivirals and why most doctors don't seem to care about most viruses, despite their possible implication in so many diseases.

We have wide spectrum antibacterials as there are many bacterial structures common to all bacteria.
(a separate and serious issue is antibiotic resistance).

Viruses have problems.
They do not (in general) have any common structure over large numbers of types of viruses, and they evolve _very_ fast.
This means that antiviral compounds discovered by chance will almost always rapidly become useless unless they are given in cocktails of multiple compounds.

And, because you need (mostly) separate research processes to work on each virus, that means that you need of the order of a hundred times the effort to get decent antivirals, compared to antibiotics.

This is why we have antivirals that work well for a handful of viruses.

This also is why doctors 'don't care' - as for most diseases (with the notable exception of hep C and HIV), antivirals either don't exist, or they shorten the disease by an almost un-noticable fraction.

There is also the question of 'trigger' - trigger may not mean the virus remains, and if it does not, antivirals will be about as much use as putting on a helmet after you've broken your nose falling off a bike.

 

[RogerBlack]

I agree 100%. Autoimmune has never made sense to me either. The body doesn't attack itself..............it attacks an invader.

The body very much does attack itself.
The immune system is an extraordinarily complex and finely tuned interacting system, which normally works.

The immune system identifies things that look 'wierd' to it, and then makes antibodies to attack them.
Sometimes the things presented to it to make antibodies to are 'self' - and there is an effectivec censorship mechanism that stops antibodies that will attack the body being produced - but this isn't perfect.

There are 20000 or so proteins in the human body, and probably several ways an antibody might interact with them. The censorship mechanism is an attempt to stop antibody candidates that would interact with any one of this perhaps 100000 parts of the self. It doesn't always work.

 

[Tammy]

The body very much does attack itself.
The immune system is an extraordinarily complex and finely tuned interacting system, which normally works.

The immune system identifies things that look 'wierd' to it, and then makes antibodies to attack them.
Sometimes the things presented to it to make antibodies to are 'self' - and there is an effectivec censorship mechanism that stops antibodies that will attack the body being produced - but this isn't perfect.

There are 20000 or so proteins in the human body, and probably several ways an antibody might interact with them. The censorship mechanism is an attempt to stop antibody candidates that would interact with any one of this perhaps 100000 parts of the self. It doesn't always work.

You're certainly entitled to your opinion......................I still don't buy into it.

 

[lansbergen]

We have wide spectrum antibacterials as there are many bacterial structures common to all viruses.

???? Do you mean common to all bacteria?

 

[RogerBlack]

???? Do you mean common to all bacteria?

Indeed I did. Edited.