All posts tagged epstein-barr virus

Could the Epstein-Barr Virus – Autoimmunity Hypothesis Help Explain Chronic Fatigue Syndrome?

( Find a ‘quick’ summary at the  bottom of the blog)

 

The Epstein-Barr Virus Question in ME/CFS

We recently saw evidence suggesting that  increased viral loads of EBV (in whole blood) may be common in Chronic Fatigue Syndrome.We also saw that  ME/CFS patients  antibody responses to some proteins produced by EBV may be are impaired as well.

Those findings made sense given anecdotal evidence from doctors and study evidence from Dr. Lerner and Dr. Montoya indicating that  antivirals can be very helpful in some patients. Dr. Montoya’s recent review of anti-herpesvirus antivirals  indicated he believes they play a role but these results conflict with the Lipkin/Chronic Fatigue Initiative study which found almost no active herpesvirus infections in either Dr. Montoya’s or in the CFI’s study groups.

smoldering fire

Some researchers think the tests used by Dr. Lipkin are not sensitive enough to pick up the kind of ‘smoldering’ infection they believe is found in ME/CFS

How to reconcile these findings ? Kristin Loomis of the HHV-6 Foundation and Dr. Chia have stated that while the method Dr. Lipkin used to detect herpesviruses (in plasma) works very well in people with highly active herpesvirus infections, they do not believe it would pick up the type of smoldering, lower-level infection suspected in ME/CFS.

The existence of that ‘smoldering infection’ is, of course, controversial. It’s possible, even probable,  that most researchers outside this field including Dr. Lipkin do not believe that such a small infection could have such serious consequences.

Indeed, the ‘increased viral loads’ in the German study did not indicate a highly active infection was present, but they were still significantly higher in the ME/CFS patients than in the controls. Dr. Lerner, Kristin Loomis and others believes that’s significant and that’s the result they believe Dr. Lipkin would have received if he had used a different technique.

After XMRV it’s no surprise to see controversy in the pathogen field. The bottom line is that EBV is still a possible culprit in ME/CFS. Given that and the Rituximab findings suggesting that an autoimmune component may be present in ME/CFS, let’s look at a fascinating hypothesis that ties EBV infections and autoimmunity together and could have implications for ME/CFS.

Epstein-Barr Virus and Autoimmunity

CD8+ T-Cell Deficiency, Epstein-Barr Virus Infection, Vitamin D Deficiency, and Steps to Autoimmunity: A Unifying Hypothesis. Pender MP. Autoimmune Dis. 2012;2012:189096. doi: 10.1155/2012/189096. Epub 2012 Jan 24.

If this hypothesis is right, Epstein Barr Virus – still the virus most closely associated with ME/CFS – has a very, very close connection to autoimmune disorders.

EBV

Pender believes an EBV infection of B-cells sets the stage for autoimmunity in people with impaired T-cell responses

About a decade ago Michael Prender proposed being exposed to EBV is a prerequisite for having autoimmune disorder. In doing so he tossed aside the usual EBV mimicry hypothesis; that proteins found in EBV confused the immune system into attacking the body and put forth a much encompassing idea. He proposed that EBV’s residence in B-cells – which are ground zero for an autoimmune response – was responsible for most types of autoimmunity. His hypothesis, a decade later, remains alive  and well.

B-cells produce antibodies and autoantibodies. As we learned in the Rose autoimmune talk, the production of autoantibodies primed to attack the body is a natural outcome of an immune system that must defend the body against microbes containing proteins that are very similar to those found in humans. The immune system has ways to deal with these autoantibodies and in most cases it succeeds. When it doesn’t you have an autoimmune problem.

An Admiring Look at a Virus

In some ways you’ve really got to give it up to Epstein-Barr Virus (EBV). EBV  just happens to be the only virus known to survive in B-cells. In fact, EBV doesn’t just survive in B-cells they are its home. Somehow B-cells have managed to thrive survive in the  very cells that are designed to attack them.  That takes a special kind of viral hutzpah..

Every time EBV infects a B-cell it tells it to reproduce and when the cells does, EBV inserts itself into the B-cell’s ‘germinal center’ where it will reside, largely untouched, for the rest of the B-cells life. Every time the B-cell replicates EBV hijacks its reproductive machinery to produce more EBV virions.

EBV

EBV – A remarkable virus

Because B-cells aren’t long-lived and because EBV can’t replicate in them when they’re pumping out antibodies, EBV has found ways to keep B-cells alive and in a state of latency for longer and longer periods of time.

EBV has found ways in induce B-cells to undergo what’s called ‘clonal’ expansion in which B-cells produces EBV infected clones of themselves. One way EBV does this is by tricking the immune system to believe an pathogen is present, thereby causing it to ramp up B-cell production.

Keeping the immune system on high alert, though, can cause problems. Think of our missile defense system. If it’s on high alert the risk of a catastrophic mistake  increases greatly, and here is where Pender and his hypothesis comes in.

Cytotoxic T-cells and A Numbers Game

“CD8+ T-cell deficiency would appear to be a general feature of human chronic autoimmune diseases. ” Pender et.al.

EBV infections in the body are usually tightly controlled by killer or cytotoxic T-cells (CD8+ T-cells). These CD8+ T-cells kill EBV infected B-cells when they proliferate.

cytotoxic t-cell

Pender believes reduced cytotoxic T-cell functioning plays a key role in EBV triggered autoimmunity. Some evidence suggest cytotoxic T-cell functioning is reduced in ME/CFS.

Pender and other researchers believe an inherited defect in cytotoxic T-cells that prevents them from controlling EBV may be behind a lot of autoimmunity. (A Simmaron Research Foundation project involves looking for inherited problems in T-cells, B-cells and NK cells killing capacity.) It turns out that a long list of autoimmune disorders are, in fact, characterized by low cytotoxic T-cell levels.

In what is essentially a numbers game, Pender believes that poorly functioning cytotoxic T-cells allow more EBV infected B-cells to proliferate. Because EBV induces these B-cells to proliferate at a higher than normal rate the outcome of a less controlled EBV infection is simply more and more B-cells. That means more autoantibodies (remember they’re a natural feature) for the immune  system to filter out, and more possibility of a catastrophic mistake being made; i.e. a full-blown autoimmune or autoinflammatory disorder.

Cytotoxic T-cells and Chronic Fatigue Syndrome

CD8+ T-cells have not received a lot of attention in ME/CFS, but early evidence suggests they’re not working too well. A recent German study found a reduced frequencies of an EBV specific T-cells  in people with Chronic Fatigue Syndrome and an Australian  group found reduced cytotoxic T-cell (and NK cell) killing capacity in ME/CFS.

In fact, given the similarity in the killing systems in cytotoxic T-cells and NK cells, it wouldn’t be surprising to find the same dysfunction in both NK cells and CD8+ T-cells.  (If your NK cells aren’t doing so hot, it’s possible your cytotoxic T-cells aren’t doing so well either.)

If that’s true, your cytotoxic T-cells may not be taking out as many EBV infected B-cells as normal. That fits Pender’s hypothesis to a T.

Another Numbers Game

Timing could be everything in EBV, ME/CFS and autoimmunity.   An EBV infection in young children usually doesn’t cause symptoms. It turns out that infants have very high levels of cytotoxic T-cells that allow them to stop the virus in its tracks.

By age sixteen, however, those cytotoxic T-cell levels are a third of what they were at age two. That means that an infection which most infants wouldn’t even notice often causes infectious mononucleosis (glandular fever) and a greatly increased risk for ME/CFS and multiple sclerosis in adolescents.

from youth to old age

Being exposed to EBV later in life greatly increases the difficulty the body has in fighting it off. How many people with ME/CFS were first exposed to EBV later in life?

It appears that the Western fanaticism with cleanliness is pushing the date most children are exposed to EBV further and further forward. In the developing world most children are exposed to EBV by age three, and almost 100% are exposed by age ten, but some studies suggest about half the children in the developed world  have not been exposed to EBV by the time they’re ten.

As many as 50% of these children may come down with a symptomatic, infectious mononucleosis-like illness and during that illness as many as half of B-cells in their blood may become infected with EBV  –  producing a huge reservoir of highly active EBV infected B-cells.

The Jason Northwestern ME/CFS study estimates as many as 10% of college students will come down with infectious mononucleosis. The increased IgM antibody rates in the ME/CFS patients in the German study suggested they may have been suffering from a primary (first-time) infection as well.

Data is lacking on date of first time EBV infection in ME/CFS, but the German study with its high IgM levels  suggests a substantial number of ME/CFS patients may have encountered EBV later in life when their immune systems are less prepared to deal with it. Could ME/CFS in some people simply be the consequence of encountering EBV later in life?

Pender ties in other autoimmune factors, many of which are found in Chronic Fatigue Syndrome as well.

Heritability

Autoimmune disorders are have a higher degree of heritability than most disorders – an intriguing factor given that cytotoxic T-cell functioning is largely governed by heredity.  The heritability factor in ME/CFS and Fibromyalgia has not been the subject of many studies, but one study suggests that heritability may be even higher in these disorders than in autoimmune disorders.

Location and the Vitamin D3 Connection

Living further from the equator also increases the risk of autoimmune disorders such as multiple sclerosis and rheumatoid arthritis. Reduced sunlight and vitamin D3 could aggravate  cytotoxic T-cell problems thus imperiling control of EBV. It turns out that cytotoxic T cells contain more vitamin D3 receptors than any other immune cell.

Dr. Bateman was astonished at how low the Vitamin D3 levels were in her ME/CFS and FM patients but people with ME/CFS and FM probably get less exposure to sunlight than do healthy people. People who are bedridden, of course, get very little exposure to sunlight.

Gender

Cytotoxic T-cells are believed to be hormonally regulated (with increasing estrogen reducing Tc levels) and women tend to have fewer cytotoxic T-cells than men. The gender imbalance found in FM and ME/CFS as another.

Reduced cytotoxic T-cell functioning, high heritability, reduced vitamin D3 levels, and female predominance all appear to be present in ME/CFS and all fit Pender’s paradigm for an EBV induced autoimmune disorder.

Treatment

Rituximab

Rituximab is high on Pender’s list of treatment options for people with EBV induced autoimmunity

Pender’s treatment recommendations for EBV triggered autoimmune disorders are enticing given what we know about Chronic Fatigue Syndrome. They start with none other than Rituximab.

“Improvement of an autoimmune disease with rituximab therapy would be consistent with an essential role of EBV in the development of the disease”

Pender asserts an EBV triggered autoimmune disorder could be treated in two ways.

(1) Depleting B-cells with monoclonal antibodies such as Rituximab would reduce total B-cell levels which would reduce the levels of EBV infected B-cells and autoantibody production. ( Since Rituximab would also reduce the levels of non-EBV autoreactive B-cells a successful course of Rituximab does not constitute proof.)

(2) Boosting immunity to EBV – Getting EBV under control is another option.

  •  the gp350 vaccine – vaccinating young adults with recombinant gp350 has been shown to stop the development of infectious mononucleosis after EBV infection. If Pender is right, gp350 vaccination could be one way of cutting down ME/CFS rates in adolescents. This would simply require determining which adolescents have not been exposed to EBV and vaccinating them. Given that Jason expects perhaps as many as 10 percent of college freshman to come down with some form of infectious mononucleosis this would seem to be a really good idea.
  • using monoclonal antibodies against gp350.
  • Intravenous infusion of autologous EBV-specific cytotoxic CD8+ T cells after expansion in vitro
  • interleukin-7, which expands the population of functional virus-specific CD8+ T cells in chronic viral infection

Summary

  • Michael Pender, has proposedthat exposure  to Epstein-Barr virus, a virus that takes up residence in the B-cells, is required for autoimmunity.
  • All B-cells produce autoantibodies that would, if the immune system didn’t filter them out, attack the body.
  • EBV prompts B-cells to produce EBV infected B-cells which live longer and produce more B-cells than usual. Their longer lifespan and higher productivity means EBV infected B-cells also produce more autoantibodies than normal B-cells.
  • Pender believes high numbers of autoantibodies produced  by these B-cells overwhelm the immune system causing an autoimmune disorder.
  • The key problem in autoimmunity Pender believes, then, is large numbers of EBV-infected B-cells.
  • Since cytotoxic T-cells kill EBV-infected B-cells, a poor cytotoxic T-cell response may be the key, and indeed reduced cytotoxic T-cell responses appear to be common  in autoimmune disorders.   (Two studies suggest reduced cytotoxic T-cell responses are present in ME/CFS  as well.)
  • Because cytotoxic T-cell responses decline over time, someone exposed to EBV as an adolescent typically has a much more difficult time fighting off EBV than a young child does. (Could late exposure to EBV be a common feature in Chronic Fatigue Syndrome?)
  • ME/CFS shares  factors like low Vit D3 levels,  a high degree of heritability and gender predominance with autoimmune disorders.  All these plus the increased EBV viral loads, the reduced antibody response to the latent stage of EBV and the possibly reduced cytotoxic T-cell functioning suggests ME/CFS could very well fit Pender’s hypothesis of an EBV triggered disorder.

Conclusions

The role Epstein Barr virus or autoimmunity plays in Chronic Fatigue Syndrome is unclear, but Pender’s hypothesis suggesting that poorly controlled EBV infections cause many autoimmune disorders is intriguing given recent study evidence of increased EBV viral loads in ME/CFS.  Time will tell but the  reduced cytotoxic T-cell functioning, gender imbalance, the low Vit. D3 levels, the high heritability factors, and the positive response to Rituximab reported all suggest Pender’s EBV/autoimmune hypothesis is something we should keep an eye on.

EBV I: A Deficient Immune Response, Increased Levels of Epstein-Barr Virus Opens Up EBV Question in Chronic Fatigue Syndrome Again

A Long History

Although altered EBV-specific antibody titers have been repeatedly demonstrated in CFS, no clear evidence for chronic EBV replication has been obtained so far. Authors

Perhaps the most common viral trigger for chronic fatigue syndrome (infectious mononucleosis, aka glandular fever) or Epstein Barr Virus (EBV) is a herpesvirus almost all adults have been exposed to and carry, usually in latent form in their cells.

conflicting signs

Conflicting results have made it difficult to determine the role EBV plays in ME/CFS. Will this German study signal a change?

EBV infection was proposed as the cause of chronic fatigue syndrome not long after the disorder became prominent in the 1980s, but inconsistent study results in the 1980s and 1990s followed by Straus’s 2000 paper (which suggested the search for herpesvirus infections in ME/CFS was over) put a damper on EBV research efforts.

From 2000 to the present only Dr. Lerner with his stream of positive studies (but sometimes challenging study designs) and Dr. Glaser published fairly consistently on EBV in ME/CFS. Recently Dr. Lipkin stated (unpublished) he found no evidence of active EBV infection using high throughput sequencing in the plasma of hundreds of ME/CFS patients.

Despite study inconsistencies, EBV has remained a pathogen of interest in ME/CFS. Both Lerner and Glaser have produced evidence suggesting that a defective form of the EBV virus may be causing the symptoms in some people with ME/CFS. Recent studies suggesting that EBV triggers autoimmune disorders are intriguing given the successful ME/CFS Rituximab treatment trials.

EBV’s ability to reactivate during stress and in hypoxic conditions may have implications for its possible role in ME/CFS as well. A recent laboratory study suggesting that high rates of oxidative stress can reactivate EBV and that antioxidants (including NAC, catalase, and L-glutathione) might be helpful in reducing EBV reactivation is intriguing given the high rates of oxidative stress found in ME/CFS.

Now, in a surprising turn, German researchers have not only put the spotlight back on EBV, but have dug deeper into EBV, ME/CFS, and the associated immune response than any group has before.

The Study

“Taken together, our study provides clear evidence that deficiency of EBV-specific immune response is present in CFS” The authors

The adaptive part of the immune system, the one that takes time to kick in, comes in the form of B-cell produced antibodies that lock onto proteins the virus produces and cytotoxic T-cells that attempt to the kill the virus. (B-cell’s attack the virus in the blood and cytotoxic T-cell attack virally infected cells.)

broken

Ohio State researchers believe a defective form of EBV that is spewing out proteins may be causing ME/CFS

Noting some unusual findings in their lab, these researchers looked at these antibodies and T-cells to see if people with chronic fatigue syndrome were mounting an effective immune response against EBV. They also looked for direct evidence of an active EBV infection.

EBV replication occurs when the virus produces proteins in a sequence that allows it to build another virus. One theory, developed by Dr. Lerner and a group at The Ohio State University (that includes Drs. Ariza, Glaser, and Williams), proposes that EBV undergoes ‘abortive replication’ in some people with ME/CFS. In abortive replication, a defective form of EBV produces early proteins, but is unable to produce later ones. The Ohio State group believes continual production of these proteins is causing a chronic inflammatory state in some people with ME/CFS.

Results

First, the German researchers found evidence of primary EBV infection or reactivation (increased IgM antibodies to a late EBV protein in @15% of patients vs 3% of controls) in significantly more ME/CFS patients than controls. The fact that this could be a ‘primary infection’; i.e. it represents the first time these patients are exposed to the virus is intriguing. A primary infection of EBV early in life usually leads to nothing more than a cold; a primary infection later in life can have serious consequences including infectious mononucleosis.

Having found evidence that an active EBV infection was more common in people with ME/CFS than controls, they looked to see if a reduced immune response was responsible for that.

The first hint of a reduced immune response to EBV in ME/CFS came in the form of a lack of antibodies to EBV-produced proteins VCA and EBNA1.

But first, a short antibody primer:

antibody

Antibodies attack pathogens in the blood; cytotoxic T-cells attack them in the cell

Antibody Types

  • IgG antibodies are ‘memory antibodies’ that travel through our system looking for evidence that a pathogen is present. Once your B-cells have mounted an attack against a pathogen, they are always present in our system. Therefore, IgG antibodies are not evidence of an ongoing infection.
  • IgM antibodies are attack proteins associated with a pathogen. High IgM titers to a viral protein generally reflect a primary infection.

With two types of antibodies being manufactured against a range of viral proteins the situation becomes complicated, but a healthy immune system should produce an array of both IgG and IgM antibodies that can detect (IgG) and inhibit (IgM) pathogens (found outside cells) at different stages of their lifecycles.

As they dug deeper, the German researchers found holes in the immune response to EBV in ME/CFS patients.

Immune Holes to Epstein-Barr Virus Found

Immune Hole #1 – reduced antibody response

Evidence of a impaired B-cell response to EBV first came in the form of missing IgG antibodies to VCA and EBNA in 13% of ME/CFS patients compared to 4% of controls. This indicated that 13% of their ME/CFS study population did not have some of the memory B-cells needed to detect an EBV infection.

Increased IgM antibody responses in ME/CFS (17.5% in ME/CFS vs 4% in controls), on the other hand, suggested active and perhaps primary EBV infections were more commonly found in ME/CFS patients.

All told, 30% of the ME/CFS patients either had reduced IgG (EBNA-IgG) or increased IgM (VCA) responses to EBV.

That finding prompted a deeper look, and a much larger study that found no IgG response to a protein expressed during latency by EBV (called EBNA-1 protein) in 10% of IgG positive ME/CS patients. This indicated that the immune systems of approximately 10% of the ME/CFS group were unable to detect a very early stage of EBV latency.

EBV

The EBNA-1 protein featured in many of the tests helps EBV maintain its latency in B-cells

Latency – For EBV to maintain itself in the body over time, it needs to be able to maintain itself in B-cells in a process called latency. EBNA-1 is a protein that helps maintain EBV’s viral genome in the earliest stages of latency.

The authors noted that people with severe infectious mononucleosis and chronic active Epstein-Barr virus disease have similar findings (although it’s not clear why, given that EBNA-1 is not involved, so far as we know, in replication).

That brings up the question of how many people with ME/CFS would have fit into the category of severe mononucleosis at the time they got ill. The Dubbo studies found that more severe infections greatly increase the risk of coming down with ME/CFS.

Immune Hole #2 – reduced frequencies of two B-cell antibody producing cells

Intrigued by the findings, the German researchers dug deeper into the immune response to EBV. They took blood (PBMCs) from ME/CFS patients and then stimulated it with CpG, SAC, and PWM for seven days, and found reduced frequencies of B-cells producing antibodies against VCA and EBNA-1, and for the first time they found evidence of immune deficiencies in most people with ME/CFS.

No less than 59% of ME/CFS samples had a diminished response to a later stage EBV protein (VCA) produced during the late stage of lytic replication, and a whopping 76% of ME/CFS samples had a diminished response to the EBNA-1 protein. With the VCA finding we have evidence suggesting many people with ME/CFS may have trouble controlling EBV replication.

Calling the findings ‘remarkable’, the authors suggested that either the memory B-cells associated with these EBV antigens had been lost or had failed to develop into antibody-secreting cells.

Immune Hole #3 – Reduced T-cell response to EBNA-1

A similar deficiency in the T-cell response to EBNA-1 indicated that both arms of the adaptive immune response to Epstein-Barr Virus, the B-cells and the T-cells, had difficult recognizing and responding to this protein.

Citing other disorders such as HIV, they suggested that persistent EBV reactivation in ME/CFS had driven the T-cell response in ME/CFS into ‘exhaustion’. (A similar suggestion has been made with regard to natural killer cells that attack pathogens early in an infection, which use killing methods similar to those employed by T-cells.)

Further analysis suggested that T-cell suppressor cells which decrease B-cell responses were not responsible for the B-cell suppression found. Normal B-cell responses to herpes simplex and cytomegalovirus suggested that the deficient B-cell responses were associated with EBV and not other herpesviruses.

cytotoxic T-cell

Lower cytotoxic T-cell responses to EBNA-1 could be associated with an increased risk of autoimmune disorders

Immune Hole #4 – reduced T-cell response to EBNA-1, reduced T-cell responses to EBV

Next they explored T-cell induced cytokine production. The T-cells should produce an array of cytokines against EBV. About 20% fewer ME/CFS patients (70% of controls vs 50% of ME/CFS patients) were able to mount an IFN-y response against EBV.

Looking specifically at the latency associated EBNA-I protein, they found the startling result that no ME/CFS patients mounted an IFN-y response against it.

They also found that ME/CFS patients produced significantly lower amounts of the pro-inflammatory cytokine TNF-a in response to EBV. Finally, a lower percentage of patients produced IL-2 as well. The reduced cytokine production suggested cytotoxic T-cells, one of the big guns of the adaptive immune response, were not being strongly activated in response to EBV.

Immune Hole #5 – Reduced frequencies of EBNA-1 specific T-cells

The researchers dug deeper still. Next they stimulated the blood (PBMCs) of ME/CFS patients and healthy controls (n=40) with the EBNA-1 protein, expanded the cells in the presence of IL-2 and Il-7, and then checked the T-cell response to them. Specific types of T-cells should be produced to attack EBV, but reduced frequencies of EBV-specific T-cells occurred in about 50% of the ME/CFS samples. That again suggested the cytotoxic T-cell response to the EBNA-1 protein was substantially reduced in ME/CFS.

Direct Evidence of Active EBV Infection

“Remarkably, in line with this finding we could provide evidence of enhanced viral load of EBV by detection of EBV DNA in a significantly higher proportion of patients compared to healthy controls.” The authors

Using a real-time PCR test in the whole blood that looked for ‘low-copy’ numbers (<1,000-2930 copies/ml) they found evidence of increased EBV viral load in 7.2% of 290 ME/CFS patients. When they dug deeper and did the same test in PBMCs in a subset of patients, they found that a whopping 55% of patients (vs 13% of controls) tested positive for EBV.

The viral loads were far below those found in other EBV associated illnesses such as infectious mononucleosis or post-transplant EBV infections, and there was no evidence of lytic replication (i.e., full replication of the virus), but something the authors called ‘latency-associated replication’ was common in people with ME/CFS, yet not in healthy controls.

The Lipkin Study

Using PCR the German researchers found much higher rates of EBV infection in PBMCs vs whole blood and no evidence of EBV infection in plasma.

plasma-blood

Was looking for EBV in plasma somehow a mistake?

Neither the Lipkin CFI ME/CFS pathogen study nor the CFIDS Association of America BSR study found evidence of EBV infection in ME/CFS. According to Russell Fleming’s transcript of the Lipkin talk, the CFI study looked in the plasma of both the Montoya and the ME/CFS experts’ samples.

Whole blood contains plasma, red blood cells, white blood cells, and platelets. Plasma makes up 55% of blood volume and contains water (90%), proteins, nutrients, waste products, clotting factors, hormones and carbon dioxide. It does not contain red or white blood cells or thrombocytes.

EBV DNA has certainly been found successfully in plasma before and plasma has been used to track EBV activation. Serum/plasma EBV PCR kits are available for purchase. Researchers search and find EBV in plasma frequently.

Dr. Chia, however, reportedly stated he believes the use of plasma rather than blood was a serious mistake, and the Germans were able to find evidence of EBV activation in blood but not in plasma.

EBV (and CMV and HHV-6) are ‘cell-associated viruses. The only times their DNA escapes the cells is when the cell dies (and the DNA goes into the plasma) or when the virus is replicating. Otherwise the virus sits in a latent or semi-latent state in the cells
Medical dogma states if you can’t find EBV in the plasma, the infection is not active. EBV DNA can be found in the plasma when EBV replication rates are high, as sometimes occurs in transplant patients, but it’s not likely to be found in the smoldering infection believed present in ME/CFS. Many researchers do not accept the idea of a smoldering infection that pumps out proteins which trigger an inflammatory response.

The German researchers are deepening their study of EBV and ME/CFS and currently evaluating antibody responses against a broader variety of EBV peptides derived from 8 different proteins. They are also quantifying the levels of memory B-cells targeting EBNA-1 and VCA.

Conclusion

“We think the altered pattern of the specific immune response to EBV may be suitable as a diagnostic marker for CFS.” Authors

ball of string

The harder they looked, the more they found …

It was if these researchers kept pulling a string that got longer and longer. First their interest was piqued by some paradoxical antibody findings, then they found widespread deficiencies in some antibody responses and T-cell responses, and finally they saw evidence of an active EBV infection in the blood of 55% people with ME/CFS (vs 7% of controls).

Much is still unclear. The EBNA-1 protein that the immune systems of ME/CFS patients had trouble responding to is associated with ‘early latency’, not EBV replication. The authors’ reference to ‘latency associated replication’ is unclear given that latency is not usually associated with replication. When asked what importance their findings have for EBV reactivation or EBV survival or  more severe casesof infectious mononucleosis in ME/CFS, the authors stated they can’t answer those questions yet.

Some researchers believe, however, that reduced cytotoxic T-cell responses to EBV increase the risk for autoimmune disorders. (We’ll be covering that possibility in the next blog.) These findings also suggest that the proposal by Lerner and the OSU group of Drs. Ariza, Glazer, and Williams that an abortive lytic process (smoldering EBV infection) is present in many people with ME/CFS may be correct.

While it will take more work to determine what these findings mean for ME/CFS,  the broad range of dysfunction  found and the high rate of active EBV infection (in plasma) would appear to put this pathogen back into play in a meaningful way in ME/CFS.

Novel Approach to Herpesvirus Infections Could Reap Dividends for Chronic Fatigue Syndrome Patients

Liang Y, Vogel JL, Arbuckle JH, Rai G, Jadhav A, Simeonov A, Maloney DJ, Kristie TM. Targeting the JMJD2 Histone Demethylases to Epigenetically Control Herpesvirus Infection and Reactivation from Latency. Sci Transl Med. 2013 Jan 9. PMID: 23303604.

Common Infections..Sometimes Uncommon Effects

An uncommon common virus

Unlike most viruses once you’re infected with herpesviruses you’re usually infected for life.

Herpesviruses are fundamentally different from most other viruses we come into contact with.  Most viruses  get completely eliminated from our systems  but herpesviruses have found a way to stick around – usually effectively bottled up by our immune system – for a lifetime ride in our cells. Very common in humans, we’ve all been exposed to and almost all of us carry a  latent or inactive herpesvirus infection.

Usually contracted in childhood most herpesvirus infections produce nothing more troubling than a childhood cold but they have a dark side.   A Epstein Barr virus infection that causes a mild cold in childhood often produces  infectious mononucleosis in adolescents and increase one’s risk of later coming down with multiple sclerosis and ME/CFS.  A mild herpes simplex infection during childhood can turn into an  painful case of shingles when we’re older.

Herpesvirus infections may be ubiquitous and usually mild but they  can cause encephalitis, blindness, horrific neurological problems and inflammation if they hit the right person at the wrong time. Not surprisingly, people with impaired immune systems such transplant patients are at high risk of herpesvirus reactivation with sometimes deadly consequences.

Key Viruses in Chronic Fatigue Syndrome (ME/CFS)

herpesvirus

A significant percentage of people may have reactivated herpesvirus infection.

Herpesviruses may play a key role in ME/CFS as well. How many people with chronic fatigue syndrome have a reactivated form of the virus is still unclear but some doctors believe the percentage is substantial. Many people begin their experience with chronic fatigue syndrome (ME/CFS) with a herpesvirus infection in the form of infectious mononucleosis.

Dr. Lerner and Dr. Glaser believe an unusual form of Epstein-Barr  virus is wreaking havoc in many patients. Their model suggests proteins and enzymes produced by a  partial reactivation of the virus are sending  the immune system into a tizzy and causing fatigue and other symptoms. Because the current slate of  herpesvirus antivirals attack the virus in the later stages of it’s development they’re in effect missing the action in ME/CFS.  These drugs work to some degree.  As they slowly lower viral load, the cells harboring the viruses die off over time.

Help Needed 

“there remains a clear need to develop new antivirals”

The problem is that in this model  the road to recovery takes time and lots of it; often a year or more of taking expensive antivirals. Dr. Lerner’s  been looking for a treatment that will hit the virus just as it’s starting to replicate and he’s  not alone. Even when the full virus is present, the present slate of  antivirals still sometimes  arrive too late to prevent blindness, neurological problems, birth defects and inflammation. The current herpesvirus antivirals come too late to the scene to

  1.  block the production of mutant viruses that can give rise to resistant strains of virus
  2.  block the expression of early viral enzymes that effect  and can produce cancer in cells
  3.  block the product of viral proteins that can trigger a damaging immune response (Lerner/Glaser’s theory of ME/CFS)

A Possible Breakthrough

A new approach to treating herpesvirus infections could reap dividend for other viral infections as well. An entirely different way of treating herpesvirus infections could reap dividend for other viral infections as well.

A new approach to attacking hard to treat herpesvirus infections could reap dividend for other viral infections as well.

“Depletion of the JMJD2 members or inhibition of their activity with a new drug results in repression of expression of viral immediate early genes and abrogation of infection. This inhibitor also represses the reactivation of HSV from the latent state in sensory neurons”

That may be changing. Researchers working at National Chemical Genomic Center (NCGC) have a developed  a ‘probe’ that stops herpesviruses from replicating by  pouncing  on the early enzymes they use to build a new virus.   (Ironically the virus uses our genetic machinery to get our bodies to produce the enzymes to build another virus). These researchers were able to design this probe after they figured out what genes these herpesviruses activate early in their life cycle.  This ‘epigenetic’ approach – stopping a virus by targeting the genes it needs to replicate – may very well herald a new era in antiviral therapy.

It’s  death by small cuts. By continually stopping the virus from replicating the herpesvirus will eventually  die when the cell they’re  living in dies. The good news for ME/CFS patients is that this probe could also whack the very enzymes Lerner and Glaser believe are causing ME/CFS. That could  mean no more long, expensive and sometimes dangerous treatment regimens.

The Implications for Chronic Fatigue Syndrome (ME/CFS)

This study focused on two herpesvirus infections (cytomegalovirus (HCMV), herpes simplex) sometimes found in ME/CFS. In Dr. Peterson’s presentation in Paris on the successful treatment of HCMV infections in ME/CFS, he reported that a small subset of ME/CFS patients have an active herpes simplex infection, as did Dr. Montoya at the FDA Drug Development Workshop.

Epstein-Barr Virus and Human Herpesvirus 6?

 Continued elucidation of the mechanisms and components involved in epigenetic regulation of viral pathogens will lead to additional targets for antiviral development

Epstein-Barr Virus (EBV) and Human Herpesvirus 6 (HHV6) are the pathogens most commonly associated with ME/CFS, however. I was unable to determine if the  enzyme targeted by this probe is found in these viruses. The fact that the  herpesvirus family undergoes a process called chromatic assembly and modulation in which the enzyme plays a role  suggests the probe might be effective in other herpesviruses.The fact that the probe worked in both alpha and beta herpesviruses (EBYis a gamma herpesvirus) suggests it may have widespread application but we’ll have to see if it applies to these viruses as well.

Dr. Martin Lerner, a specialist in treating herpesvirus infections in chronic fatigue syndrome has high hope for this approach.

My own research suggest immediate early gene products initiate CFS.  I think this work has great promise in effectively inhibiting many herpesviruses. Dr. Martin Lerner

Even if it doesn’t this discovery provides a new approach to drug treatment  that could be duplicated in other herpesviruses. Indeed these researchers are already looking for other epigenetic targets, one of which is found in Epstein-Barr virus.

This ‘probe’ has still  long way to get to the marketplace. It’s demonstrated its effectiveness in cultured cells and now needs to be assessed in animal models and  humans.

outside the box

This same epigenetic approaches that are effective in cancer are effective with viruses as well.

A New Paradigm for Antiviral Drug Development

There is intensive focus on the development of inhibitors of epigenetic components for the treatment of cancers and other diseases. The study presented here demonstrates that epigenetic inhibitors can also function as antiviral therapeutic agents.

The success of a drug employing a epigenetic approach to infection was big news with the study appearing in the premier scientific journal Science and the authors urging other researchers to pour resources into developing more epigenetic tools to fight infection.