new XMRV research (talks about prostate cancer but mentions EBV promoting XMRV

[taniaaust1]

"NF-{kappa}B Activation Stimulates Transcription and Replication of Xenotropic Murine Leukemia Virus-Related Virus in Human B-lineage and Prostate Carcinoma Cells.
Sakakibara S, Sakakibara K, Tosato G.

Laboratory of Cellular Oncology, and Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA."

Seems the NCI and NIH is doing some good research http://www.ncbi.nlm.nih.gov/pubmed/21270144

We identify two NF-κB binding sites (designated κB-1 and κB-2) in the long terminal repeat (LTR) U3 region of XMRV, and demonstrate that both sites bind to the NF-κB component p65/RelA. Mutation of the κB-1 site, but not the κB-2 site, impaired responsiveness to TNFα and LMP1 in reporter assays. A mutant XMRV at the κB-1 site replicated significantly less efficiently than the wild-type XMRV in the prostate carcinoma LNCaP, DU145 and PC3 cell lines, HEK293 cells, the EBV-immortalized cell line IB4 and the Burkitt's lymphoma cell line BJAB. These results demonstrate that TNFα and EBV LMP1 enhance XMRV replication in prostate carcinoma and B-lineage cells through the κB-1 site in the XMRV LTR, suggesting that inflammation, EBV infection and other conditions leading to NF-κB activation may promote XMRV spread in man.

Very confuses to a non scientific person such as myself but i still got something out of it and having had mono, found it interesting.

**now im going to look up what NF-kB is.....as im interested what else activates that and what its to do with seeing it promotes XMRV**

 

[taniaaust1]

for anyone wondering too, from the normal wikipedia on NF-kB

"NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) is a protein complex that controls the transcription of DNA. NF-κB is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, ultraviolet irradiation, oxidized LDL, and bacterial or viral antigens.[1][2][3][4][5] NF-κB plays a key role in regulating the immune response to infection (kappa light chains are critical components of immunoglobulins). On the converse, incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development. NF-κB has also been implicated in processes of synaptic plasticity and memory.[6]
"

 

[Mark]

TNF-alpha:

http://en.wikipedia.org/wiki/Tumor_necrosis_factor-alpha

Tumor necrosis factor (TNF, cachexin or cachectin and formerly known as tumor necrosis factor-alpha) is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction.
The primary role of TNF is in the regulation of immune cells. TNF is able to induce apoptotic cell death, to induce inflammation, and to inhibit tumorigenesis and viral replication. Dysregulation of TNF production has been implicated in a variety of human diseases, including major depression[1], Alzheimer's disease[2] and cancer.[3]

 

[Mark]

More about NF-kB:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1140602/

The NF-κB transcription factor is a vital regulator of cellular processes involved in immune response, cellular proliferation, differentiation, and apoptosis (6, 38, 47, 53).

Constitutive activation of NF-κB is also thought to contribute to multiple pathophysiological conditions such as rheumatoid arthritis (55), inflammatory bowel disease (60), and AIDS (22) and, with ever increasing evidence, cancer (1, 5, 33, 48).
In mammals, the NF-κB family consists of RelA (from here on referred to as p65), c-Rel, and RelB, as well as p105 and p100 and their processed forms, p50 and p52, respectively (31). Each subunit contains a Rel homology domain (RHD) specifying DNA binding, protein dimerization, and nuclear localization. In addition, p65, c-Rel, and RelB contain transactivation domains (TAD) located at the carboxy terminus. Although in vitro most NF-κB subunits possess the ability to homo- or heterodimerize, in vivo, NF-κB primarily exists as a p50/p65 heterodimer.

 

[Mark]

Long Terminal Repeats: The Retroviral Promoter - Stanford Tutorial:
http://www.stanford.edu/group/nolan/tutorials/retcl_3_ltrs.html

[FONT=Verdana, Arial, Helvetica, sans-serif]The long terminal repeat (LTR) is the control center for gene expression.[/FONT]..[FONT=Verdana, Arial, Helvetica, sans-serif]all of the requisite signals for gene expression are found in the LTRs: Enhancer, promoter, transcription initiation (capping), transcription terminator and polyadenylation signal.[/FONT]

For retroviruses like MuLV, embryonal tissues and cells do not host viral gene expression whereas differentiated or adult tissues and cells express viral RNA to high levels.

These differences, which are due to enhancer "activators" and "repressors" have been studied in cell lines that can be differentiated in cell cultures.

Changes in the structures of the binding sites in the LTRs can be correlated with tissue-specific expression patterns of mutant MLV and their induction of tumor formation in those tissues.

The above appears to describe what the NCI have now shown is also true of the XMRV Long Terminal Repeat.

The enhancer and other transcription regulatory signals are contained in the U3 region of the 5' LTR,

 

[Cort]

That would mean inflammation would spark XMRV replication - a good finding for CFS and particularly good that NF-kB is involved because NF-kB has been implicated in quite a few different areas in CFS before.

Azithromycins effectiveness in some patients may be due to its NF-kb altering capabilities

Azithromycin (Zithromax) Is an antibiotic with immunomodulatory factors used to treat mild to moderate bacterial infections such as bronchitis, pneumonia, sexually transmitted diseases and others (chlamydiae pneumoniae, mycoplasma pneumoniae, streptococcus pneumoniae,etc). It's ability to suppress the NF-kB transcription factor responsible for the production of pro-inflammatory cytokines indicates it has immuno-modulating properties as well.

http://www.aboutmecfs.org/Trt/TrtAzithromycin.aspx

Its also been suggested to play a major role in the upregulation of the IFN isoform (100 kDA) that appears to lead to the RNase L problems in CFS and the PKR enzyme, which is often upregulated in CFS - turns NF-kB on.. This suggests that NF-kB activation could play a role in the RNase L problems in CFS as well.

II. Activation of the 100-kDa 2-5OAS gene -Unlike p69, however, the promoter region of p100 contains an NF-kB motif. This suggests that the p100 enzyme is, in contrast to p69, involved not just in the IFN mediated immune response but in the NF-kB mediated immune response as well. It suggests that the RNA that turns on the p100 isoform maybe a product of inflammatory activities.

(Perhaps given the convoluted world of the CFS this is not that surprising. One of the main activators of NF-kB, protein kinase R (PKR), is upregulated in many CFS patients. This suggests an upregulated PKR could play a significant role in p100 activation and RNase L fragmentation.)

http://aboutmecfs.org/Rsrch/2-5OASRNaseLBackgroundCFS.aspx

 

[Cort]

Maes

Maybe the most significant connection, though, is with Dr. Maes - he believes NF-kB plays a key role in producing the inflammation and the 'psychosomatic' symptoms in ME/CFS and he has documented this in several studies.

http://www.ediver.be/ediver/latest%20news/Chronic%20fatigue%20syndrome%20-%20review%20-%20inflammation.pdf

Purpose of review

Inflammatory and oxidative and nitrosative stress pathways underpinning chronic fatigue, somatization and psychosomatic symptoms Michael Maes

The aim of this paper is to review recent findings on inflammatory and oxidative and nitrosative stress (IO&NS) pathways in chronic fatigue and somatization disorder.

Activation of IO&NS pathways are the key phenomena underpinning chronic fatigue syndrome (CFS): intracellular inflammation, with an increased production of nuclear factor kappa beta (NFkb), cyclo-oxygenase-2 (COX-2) and inducible NO synthase (iNOS); and damage caused by O&NS to membrane fatty acids and functional proteins. These IO&NS pathways are induced by a number of trigger factors, for example psychological stress, strenuous exercise, viral infections and an increased translocation of LPS from gram-bacteria (leaky gut).

The ‘psychosomatic’ symptoms experienced by CFS patients are caused by intracellular inflammation (aches and pain, muscular tension, fatigue, irritability, sadness, and the subjective feeling of infection);damage caused by O&NS (aches and pain, muscular tension and fatigue); and gut-derived inflammation (complaints of irritable bowel). Inflammatory pathways (monocytic activation) are also detected in somatizing disorder.

‘Functional’ symptoms, as occurring in CFS and somatization, have a genuine organic cause, that is activation of peripheral and central IO&NS pathways and gut-derived inflammation. The development of new drugs, aimed at treating those disorders, should target these IO&NS pathway

 

[Cort]

Maes II

Here's the biggie from Maes. To bad its in a very small journal that's hard to get. He was even able to associate increased NF-kB levels with symptom severity.

http://www.ncbi.nlm.nih.gov/pubmed/17693979

Neuro Endocrinol Lett. 2007 Aug;28(4):456-62.

Not in the mind of neurasthenic lazybones but in the cell nucleus: patients with chronic fatigue syndrome have increased production of nuclear factor kappa beta.
Maes M, Mihaylova I, Bosmans E.

There is now some evidence that chronic fatigue syndrome is accompanied by an activation of the inflammatory response system and by increased oxidative and nitrosative stress. Nuclear factor kappa beta (NFkappabeta) is the major upstream, intracellular mechanism which regulates inflammatory and oxidative stress mediators.

In order to examine the role of NFkappabeta in the pathophysiology of CFS, this study examines the production of NFkappabeta p50 in unstimulated, 10 ng/mL TNF-alpha (tumor necrosis factor alpha) and 50 ng/mL PMA (phorbolmyristate acetate) stimulated peripheral blood lymphocytes of 18 unmedicated patients with CFS and 18 age-sex matched controls. The unstimulated (F=19.4, df=1/34, p=0.0002), TNF-alpha-(F=14.0, df=1/34, p=0.0009) and PMA-(F=7.9, df=1/34, p=0.008) stimulated production of NFkappabeta were significantly higher in CFS patients than in controls.

There were significant and positive correlations between the production of NFkappabeta and the severity of illness as measured with the FibroFatigue scale and with symptoms, such as aches and pain, muscular tension, fatigue, irritability, sadness, and the subjective feeling of infection.

The results show that an intracellular inflammatory response in the white blood cells plays an important role in the pathophysiology of CFS and that previous findings on increased oxidative stress and inflammation in CFS may be attributed to an increased production of NFkappabeta. The results suggest that the symptoms of CFS, such as fatigue, muscular tension, depressive symptoms and the feeling of infection reflect a genuine inflammatory response in those patients. It is suggested that CFS patients should be treated with antioxidants, which inhibit the production of NFkappabeta, such as curcumin, N-Acetyl-Cysteine, quercitin, silimarin, lipoic acid and omega-3 fatty acids.

One of my requests for Mary Schweitzer was to get Dr. Maes to the April Workshop. I hope they can.

 

[Mark]

So...to attempt a translation of the NCI/NIH abstract...

We identify two NF-κB binding sites (designated κB-1 and κB-2) in the long terminal repeat (LTR) U3 region of XMRV, and demonstrate that both sites bind to the NF-κB component p65/RelA.

XMRV's LTR contains two sites to which NF-kB (immune regulator) binds.

Mutation of the κB-1 site, but not the κB-2 site, impaired responsiveness to TNFα and LMP1 in reporter assays.

If you knock out the first of these NF-kB binding sites - denoted kB-1 - then XMRV is inhibited from replicating as it otherwise would do in response to TNFα (inflammatory cytokine and immune regulator) and EBV LMP1.

A mutant XMRV at the κB-1 site replicated significantly less efficiently than the wild-type XMRV in the prostate carcinoma LNCaP, DU145 and PC3 cell lines, HEK293 cells, the EBV-immortalized cell line IB4 and the Burkitt's lymphoma cell line BJAB.

When grown in all these cell lines - prostate cancer and B-lineage cells - the mutated XMRV, with the kB-1 site impaired, replicated less efficiently.

These results demonstrate that TNFα and EBV LMP1 enhance XMRV replication in prostate carcinoma and B-lineage cells through the κB-1+ site in the XMRV LTR, suggesting that inflammation, EBV infection and other conditions leading to NF-κB activation may promote XMRV spread in man.

[Note: EBV LMP1 (Epstein-Barr virus (EBV) latent membrane protein-1) "plays a critical role" for for EBV-induced B-cell transformation and in the lytic cycle of virus production. - http://jvi.asm.org/cgi/content/full/79/7/4415]

This shows that TNFα (inflammatory cytokine) and EBV LMP1 (Epstein-Barr virus) promote XMRV to replicate in prostate cancer cells and B-cells, by using the κB-1+ site.

Thus: Inflammation, EBV infection, and anything else that activates the immune regulator NF-κB, causes XMRV to replicate in prostate cancer and B-cells.

 

[Mark]

Hmm...so then: the kB-1 site of XMRV is exploiting the immune regulation function in order to replicate itself. NF-kB is intended to promote an immune response to infection or inflammation - but it also promotes XMRV to replicate. Could this perhaps be the mechanism that we have been calling "auto-immune"? Is it in fact XMRV that causes the immune system to get locked into a cycle, by provoking an immune cascade? How does the body respond to this XMRV replication it's provoking?

This feels like a really solid jigsaw piece fitting in perfectly and linking up two (or three, or four) big sections of a puzzle...

 

[leaves]

this is a list of all nf-kb inhibitors http://people.bu.edu/gilmore/nf-kb/inhibitors/index.html

 

[Cort]

Thanks for clarifying that Mark. Isn't that a tricky little devil....

This suggests to me that XMRV could be activated by any other pathogen that activates NF-kB....it might not be XMRV activating them - it could be them activating XMRV! As you point out we don't know what happens when XMRV then starts replicating - that might be another link in the immune cascade.

A patient of Dr DeMeirleir's reported that hormones do not appear to be a key trigger for XMRV; if that's true then maybe it is inflammation - from a pathogen, from gut problems, from methylation problems, etc.

Then you have NK-kB apparently helping to trigger RNase L problems in CFS -- a very interesting conjunction occurring there as well.

Other pathogens also exploit immune activation as well, I believe. I believe EBV replicates when B-cells are activated. I imagine other people know of other pathogens as well that do that.

 

[Mark]

EBV, HTLV, HIV, Hepatitis B and C, influenza virus, all promote NF-kB activation.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC199181/

It seems not unlikely that XMRV also promotes NK-kB activation, but I'm not sure which other viruses exploit NK-kB itself for their own replication, like XMRV does.

"This activation may serve several functions: to promote viral replication, prevent virus-induced apoptosis, and mediate the immune response to the invading pathogen."

"Transcriptional regulators of the NF-kB/IkB family promote the expression of well over 100 target genes, the majority of which participate in the host immune response (1). These proteins include a multitude of cytokines and chemokines, receptors required for immune recognition, proteins involved in antigen presentation, and adhesion receptors involved in transmigration across blood vessels walls. Because of this extensive role in immune action, NF-kB has been termed the central mediator of the immune response. Gene knockout and other studies establish roles for NF-kB in the ontogeny of the immune system but also demonstrate that NF-kB participates at multiple steps during oncogenesis (2) and the regulation of programmed cell death"


Actually, if I remember correctly, this is where I originally came in to this forum, when I first posted with the observation that a virus that could hide and only come out when your immune system was under stress from another invader, would be occupying a cunning little niche...

 

[Cort]

I didn't know such an innocuous name hid such a key factor......NF-kB is a major player in autoimmune disorders and cancer as well.

http://www.abcam.com/index.html?pageconfig=resource&rid=11255&pid=10629

The role of NFkB signaling in disease

Asthma is a chronic inflammatory disorder. The pathogenesis of asthma involves the persistent expression of pro-inflammatory cytokines, chemokines and other such inflammatory mediators. Many of these genes contain the kB site for NFkB within their promoters, suggesting that NFkB plays a vital role in asthma (Yamamoto and Gaynor 2001; Christman et al., 2000). Indeed, increased NFkB activity has been observed in the airways of asthmatic patients (Hart et al., 1998). NFkB is also implicated in inflammatory bowel disease such as Crohn’s disease and ulcerative colitis (Neurath et al., 1998; Schreiber et al., 1998). NFkB activation is evident in biopsies from such patients and treatment of patients with steroids decreases NFkB activity in biopsies as well as reducing the clinical symptoms of disease. Furthermore, NFkB is involved in the pathophysiology of the autoimmune disorder rheumatoid arthritis (RA).

In addition to the roles that NFkB plays in inflammatory diseases, constitutive activation of the NFkB pathway is involved in some forms of cancer such as leukemia, lymphoma, colon cancer and ovarian cancer (Rayet and Gelinas 1999). However, more commonly it is thought that changes in the upstream pathways that lead to NFkB activation become deregulated in cancer.

Given that I wonder why Maes's paper got buried in Neuroendocrine letters when it found evidence of upregulation of such a key immune factor.

Herpesviruses

This paper suggests though that herpesviruses do better when NF-KB production is suppressed not increased. I'm sure this is an evolving field, though.

Scientists Discover How Herpes Viruses May Lead to Cancer

Researchers have discovered that some herpes viruses can reduce the ability of cells to shut themselves down or die, which is critical to halting the development of cancers such as lymphoma and Kaposi’s sarcoma (KS). Their findings are published in the April 2 issue of The EMBO Journal.

It is well known that certain common gamma herpes viruses are associated with the development of cancer, such as the Epstein-Barr virus with Burkitt’s lymphoma and human herpesvirus-8 (HHV-8) with KS. Until now, however, scientists have not been able to explain how the viruses could cause cancer.

To examine the potential mechanisms by which gamma herpes viruses could cause cancer, Lnia Rodrigues, from the Universidade de Lisboa, in Portugal, and her colleagues investigated proteins produced by the murid herpesvirus-4—a virus related to Epstein-Barr and HHV-8. Specifically, Rodrigues and her team looked at a specific protein produced by the herpes virus called ORF73.

The team found that ORF73 was able to suppress the ability of cells to produce NF-kappa B (NF-kB), a protein critical to the growth and proliferation of new cells, and the dying off of defective cells. While some cancers and inflammatory diseases are caused by too much NF-kB activity, other cancers caused by viruses may be caused by the suppression of NF-kB.

The authors explain that viruses like HHV-8 and Epstein-Barr can live on in the body and multiply more easily when NF-kB is suppressed.

 

[Mark]

This suggests to me that XMRV could be activated by any other pathogen that activates NF-kB....it might not be XMRV activating them - it could be them activating XMRV!

Exactly, and this appears to me like a crucial cause-and-effect question answered...

As you point out we don't know what happens when XMRV then starts replicating - that might be another link in the immune cascade.

Raising then the next question, as you rightly say, as to whether this process drives a vicious cycle, or whether XMRV just responds to immune activation. Perhaps the answer is both - that there are circumstances where the process can become runaway - if the body notices XMRV replication, or its effects, and responds with more immune activation...

Other pathogens also exploit immune activation as well, I believe. I believe EBV replicates when B-cells are activated. I imagine other people know of other pathogens as well that do that.

...could this be the severe case, where additional co-infections which are similarly parasitic on the immune response are adding their own persistent effects in to the mix? The variety of 'states' of ME/CFS, and their apparent relationship to persistent co-infections, seems to suggest an answer...perhaps the immune system can stabilise in a state where the co-infections are also driving their own cycle of immune activation, together with XMRV - and ordinary infections become chronic?...

I'm imagining a diagram with a series of cause and effect arrows where you add both EBV and XMRV and get that vicious circle...

 

[Mark]

This paper suggests though that herpesviruses do better when NF-KB production is suppressed not increased. I'm sure this is an evolving field, though.

I think that's fine and just narrows down what it means that herpesvirus activate NF-kB: the NF-kB is getting activated in order to suppress them: it's an immune response, rather than the herpesviruses 'intending' (!) to switch on NF-kB...

The quote above:
"This activation may serve several functions: to promote viral replication, prevent virus-induced apoptosis, and mediate the immune response to the invading pathogen."
...I almost added that 'mediate the immune response' sounded most likely to me - all these viruses cause the immune regulator to be activated...and they don't generally like it...figures...

In terms of treatment this is the Catch-22 when you have co-infections: when the body's fighting them, XMRV is replicating; stop the body from fighting the other infections, and XMRV replication stops but the co-infections start back up...somebody posted something very much like that experience just the other day, sounds a familiar story...

 

[Gemini]

In terms of treatment this is the Catch-22 when you have co-infections: when the body's fighting them, XMRV is replicating; stop the body from fighting the other infections, and XMRV replication stops but the co-infections start back up...

Mark,

Do you think it's possible to develop an animal model--infected with XMRV and co-infections--to observe this and develop treatments?

 

[Cort]

The animal model idea is interesting...that is always a big deal in medical research and some researchers are stressing out lab rodents through exercise - and putting them into a state where they resemble CFS....that is their animal model for CFS as I remember. I hope to do a writeup on this....

I would think that would be a great step..instead of exercise them into CFS - infect them into it

 

[Gemini]

The animal model idea is interesting...that is always a big deal in medical research and some researchers are stressing out lab rodents through exercise - and putting them into a state where they resemble CFS....that is their animal model for CFS as I remember. I hope to do a writeup on this....

I would think that would be a great step..instead of exercise them into CFS - infect them into it

Cort,

Agree. Can Mary S. get animal models on the April Workshop agenda?
Possibly as a follow-up to the first XMRV animal model study? Also,
am I correct that a small animal XMRV model is now possible--
thought I saw something about it recently on PubMed?

Edit update:

J Virol. 2011 Feb;85(3):1205-13. Epub 2010 Nov 17.
Early Events in Retrovirus XMRV Infection of the Wild-Derived Mouse Mus pahari.
These data support the use of Mus pahari as a model for XMRV pathogenesis and as a platform for vaccine and drug development against this potential human pathogen

http://www.ncbi.nlm.nih.gov/pubmed/21084477

 

[taniaaust1]

Here's the biggie from Maes. To bad its in a very small journal that's hard to get. He was even able to associate increased NF-kB levels with symptom severity.

http://www.ncbi.nlm.nih.gov/pubmed/17693979


One of my requests for Mary Schweitzer was to get Dr. Maes to the April Workshop. I hope they can.

That's very interesting.

I agree this area would be a good area to be followed up more in some way. I'd never heard of Dr Maes before, kind of exciting to hear that he's linked it with symptom severity (and then its been linked with XMRV).
........

Thanks Mark for deciphering what that was saying some, helped me understand it a little more rather then being like chinese to me.
....

some researchers are stressing out lab rodents through exercise - and putting them into a state where they resemble CFS....that is their animal model for CFS

I hate that idea.. more like they'd then be studying over training syndrome some body builders and athletes get rather then CFS/ME