You are witnessing a scientific
breakthrough develop from theory to public health practice.
In November 1994, Dr. Will Taylor, Associate Professor
in the Department of Medicinal Chemistry at the University
of Georgia, explained his hypothesis that opened new inroads
into possibly controlling many viruses including AIDS,
Ebola and even several "more-routine" viruses.
Last month, Dr. Marianna Baum of the University of Miami
discussed her published results with selenium and HIV/AIDS.
We didn't discuss her latest results because they had not
yet been peer-reviewed for publication, but I can tell
you that they are very exciting. Dr. Orville Levander of
the USDA has published his latest findings with selenium
and viruses. These three aspects of research with selenium
and human viruses recently gained interest at an International
Conference on the subject held in Germany in April.
As one who has conducted laboratory
research with selenium and other antioxidants for more
than 35 years, I can attest to the scientific and public
health importance of this "new direction" in
virus research. I don't believe that I have used that terminology
to describe completely new concepts since my 1973 publication, "Cancer:
New Directions," in which I reported my laboratory
research showing that selenium and other antioxidants reduce
the incidence of cancers. [American Laboratory 5(6) 10-22
(1973)] By the way, an upcoming chat with Dr. Larry Clark
will discuss his clinical trial which found that selenium
supplements can cut the cancer death rate in half.
Let's chat again with Dr. Taylor
to see how his new theory has had an effect on AIDS and
viral research. It is not necessary to understand the technical
aspects of the theory, just that, as his analogy illustrates,
that selenium can be a birth control pill to some deadly
viruses. If you are interested in the details of his theory,
please refer to our November 1994 discussion which describes
it in detail.
Passwater: Dr.
Taylor, it has only been two years since we discussed your
exciting new theory about selenium and HIV, but thanks
to your new concept, a lot of important and exciting related
findings have resulted in that relatively brief time as
research goes. Not only has selenium and AIDS research
leaped ahead, but research with selenium on many viruses
from the rare Ebola to the common flu has produced dramatic
findings.
Are you pleased with the way
in which some researchers are comprehending the significance
of your research on the role of selenium in limiting the
spread of at least some viruses? Or are you disappointed
that more scientists have failed to look into this relationship?
Taylor: There
certainly are a lot of exciting developments about selenium
and viruses, some of which is new work and some of which
is research that is only now gaining the attention it deserves,
even though it was done a few years back. I am referring
to the use of selenium to treat an Ebola-like hemorrhagic
fever that broke out in China in the late 1980s. Hemorrhagic
fevers can kill up to 90 percent of those infected, but
this study showed that selenium supplementation can reduce
that mortality rate dramatically. But let's talk about
that later.
From my perspective, however,
I'd honestly have to say that despite the accumulation
of supporting evidence, it has been somewhat frustrating
to me that few major virology groups have made any attempt,
let alone a serious effort, to rigorously prove or disprove
what I now call the "viral selenoprotein theory." In
essence that hypothesis, first proposed in my 1994 paper,
is the idea that certain viruses (initially HIV, other
retroviruses, and also some strains of Coxsackievirus)
may interact directly with selenium in host cells by incorporating
selenium into viral proteins. This would mean that the
role of selenium deficiency in some viral diseases might
be far more complex than previously thought - and believe
me, the potential roles of selenium and other antioxidants
in the body's defenses against infectious disease are already
very complicated, even without this possibility.
On the positive side, a number
of studies have recently come out or are being prepared
for publication (Allavena et al. 1995, Constans et al.
1995, Look et al. in press, Baum et al. in preparation),
confirming that low serum or plasma selenium is a highly
significant correlate of HIV disease progression, and a
risk factor for mortality. While this does not prove anything
about the MECHANISMS involved, there seems to be more going
on here than a simple nutritional effect, and these observations
are consistent with my 1994 prediction, based on theoretical
genomic evidence, that dietary selenium might inhibit HIV
replication and slow disease progression. Of course, based
on his studies of the mouse mammary tumor virus (MMTV),
a retrovirus relative of HIV, Dr. Gerhard Schrauzer had
already predicted over ten years ago that selenium would
have an anti-HIV effect. So he has had to be far more patient
than I have so far, in waiting to see his idea rigorously
tested.
The most encouraging development
on the clinical side is the long-overdue initiation of
some rigorous clinical studies of selenium supplementation
in HIV patients. These include a study by Dr. Marianna
Baum in Miami, and a study in African AIDS patients that
is being set up by Prof. Luc Montagnier of the Pasteur
Institute, who recently told me that he thought the data
on selenium and HIV are now sufficiently compelling as
to justify such a study. I find that very gratifying, particularly
since most AIDS patients in impoverished nations in Africa
and elsewhere are unlikely to receive any of the expensive
new antiviral drugs, like the HIV protease inhibitors.
In those countries, all they can realistically hope for
is inexpensive ways of slowing down the disease until a
vaccine is found- and there is nothing I know of that can
do this that is cheaper than selenium!
Passwater: Dr.
Montagnier is the discoverer of HIV. Our readers may wish
to review his research in the September 1995 issue. When
I visited Dr. Montagnier in his Pasteur Institute Laboratory,
I handed him our 1994 article and he became very interested
in your theory. Also, I used that article to introduce
your theory to Dr. Baum and she became very interested
in your theory as she commented in last month's column.
Are clinical researchers better
understanding the significance of the role of selenium
acting directly on viruses themselves, as opposed to protecting
the host via such mechanisms as stimulating the immune
system?
Taylor: It
has been my impression that there has been a lot of interest
in my research among practitioners of holistic or alternative
medicine, and M.D.s who appreciate the value of prevention
and nutritional approaches to therapy, but that "mainstream" HIV
clinicians are less likely to have heard of it, or indeed
to place much hope in any type of nutritional supplementation
approach. Thanks to a story in Dr. Jonathan Wright's excellent
newsletter, "Nutrition and Healing", I have been
invited to present these concepts to a large group of M.D.s
at a meeting of the "American College for Advancement
in Medicine" in Tampa, Fl, next spring.
There is no doubt that part
of what is catching these people's attention is the idea
that selenium may have a direct effect on some viruses,
rather than merely a non-specific immune-boosting effect.
However, it's the whole story - putting my findings in
the context of the various Chinese selenium studies, the
work of Drs. Levander and Beck, Dr. Schrauzer, and so on
- that is so intriguing.
Passwater: There
is no doubt that you will have an interested audience at
the ACAM Conference. These medical practitioners are very
familiar with selenium. In addition to the clinical studies
that you mentioned, linking selenium status to HIV disease
progression, what are some of the specific new developments
that you can point to as support for your "viral selenoprotein
theory"?
Taylor: There is not as much
as I'd like, because in many ways the theory has hardly
been tested. However, we can say with considerable confidence
that there is now virtually no doubt that some viruses
can make selenoproteins - it's more a matter of which viruses
can do it. This statement is possible because Dr. Bernard
Moss, a scientist at the National Institutes of Health
(NIH), recently reported the complete DNA sequence of a
common wart virus, the pox virus Molluscum contagiosum.
This virus appears to encode a gene that is 80% identical
to the known mammalian selenoprotein glutathione peroxidase
(GPx). So far he's only done what I have for HIV: show
the potential gene is there by theoretical analysis. But
with such an unmistakable match to a known selenoprotein,
there's no reason to doubt that this is a real GPx gene.
Similarly, we have now demonstrated
GPx-like sequences in Coxsackie B virus, the viral cofactor
for Keshan disease, and the subject of the now famous Levander
and Beck studies. If our readers will bear with me for
just a moment, I want to point out to our technical readers
that other developments include a published experimental
verification of an RNA "pseudoknot" that we predicted
in HIV, in vitro experimental verification in my lab of
a novel frameshift site in HIV associated with a conserved
UGA codon, and most recently, from the lab of a collaborating
virologist, immuno-histochemical evidence in patient samples
for some novel HIV protein variants that I predicted. Finally,
in the test tube, selenium has been shown to be a potent
inhibitor of HIV reactivation from latently infected cells.
In summary: still no absolute direct proof that a virus
can make a selenoprotein, but an increasingly strong body
of favorable circumstantial evidence.
Passwater: When
we discussed the mechanisms you elucidated and presented
in your hypothesis, we also included a glossary for the
non-virologists. Just so our non-virologists don't have
to go back to that article or reach for their scientific
dictionary, a codon is a three-letter code in DNA or RNA
that directs insertion of an amino acid into proteins,
a frameshift is a shift into a new protein coding region,
a pseudoknot is an RNA structure that promotes frameshifts,
and UGA not only stands for the University of Georgia but
either a "stop" signal for protein synthesis
or for selenocysteine insertion.
As I mentioned, I have had the
pleasure of introducing your research to several clinical
investigators, yet, I am still struggling to get the concept
across to many nutritionists and clinical researchers who
are not overly familiar with stop codons, frame shifts
and pseudoknots. I have the advantage of getting help from
my youngest son, Michael, when it comes to complex modern
virology. You may recall that the fact that my oldest son,
Richard, graduated from the University of Georgia that
led me to your earlier research. Rich and I deal with antioxidants
more than viruses. Now I find it ironical that what seems
like just a few years ago that Mike asked, "Hey, Dad,
what's DNA?" Now, I have to ask, "Hey Mike, why
do RNA-based viruses mutate more than DNA-based viruses?
Or "Why do the HIV family of viruses have the highest
mutation rates among a family (retroviruses) of viruses
with high mutation rates?"
Mike pointed out that the fleets
of enzymes which check, double check, and transcribe DNA
are at least as important as the DNA itself. RNA is not
protected as well. Perhaps it would help clarify your findings
if I lead you through the same line of questioning that
Mike led me through when we first discussed your research.
Could you briefly explain the significance of UGA codons
in your findings on HIV, and how that may relate to the
role of the known Selenium-containing antioxidant enzyme
you mentioned earlier, glutathione peroxidase (GPx)?
Taylor: In
essence, the UGA codon is the selenium link because it
can direct the insertion of selenocysteine into proteins,
an alternative to its more common role as a "stop" signal.
We showed that in regions of HIV-1 that were presumed to
be inactive or non-coding, UGA codons are "conserved," i.e.
found in almost all isolates of HIV-1. Along with other
structural features we identified, these observations suggested
that the virus might encode selenoproteins in several such
regions.
That was a radical suggestion
because apparently no one had ever seriously considered
the possibility that viruses might encode selenoproteins,
which were believed to be very rare. Only about five mammalian
selenoproteins were known at the time, although several
more have already been found, and now some leading researchers
in this field of research believe that many more probably
exist. GPx is the prototypical selenoprotein, and is an
essential antioxidant enzyme in living systems, used to
break down harmful peroxides, to maintain cell membrane
integrity, and to generally reduce the harmful effects
of reactive oxygen species.
A deeper question is, what would
a virus - say M. contagiosum or Coxsackievirus - gain by
encoding a GPx? There could be many answers to that question.
One is that it is now known that the immune system uses
free radicals as part of the process of programmed cell
death (apoptosis), which is also one of the mechanisms
used to kill off cells infected with viruses. Thus, a viral
GPx could serve a defensive function for the virus, by
countering that process and at the same time keeping the
host cell alive - again reminding us that viruses don't
necessarily want their host cells to die.
Oxidative stress is also known
to activate the replication of many viruses, especially
HIV, so increasing the levels of either a host or a viral
GPx could act to inhibit viral replication. Thus, a viral
GPx could also serve as a repressor of viral replication,
similar to what I proposed for one of the hypothetical
selenoproteins in HIV, although that one is not a GPx.
Passwater: Regarding
the potential role of selenium in viruses such as HIV,
Ebola and Coxsackie, would a reduced level of selenium-containing
enzymes countering the transcription and/or integration
process contribute to the high mutation rate characteristic
of these RNA viruses?
Taylor: There
are several things going on here. First, as you mentioned,
RNA viruses lack the "editing" or error correcting
enzymes characteristic of the DNA based replication machinery
of higher organisms. Furthermore, RNA is more chemically
reactive and unstable than DNA. Thus, RNA viruses are inherently
more mutation-prone even than DNA viruses, and far more
than their DNA-based hosts. This can be advantageous for
a virus because by mutating it can increase its ability
to evade the host immune system.
Thus, anything that slows down
the replication rate of such viruses will reduce their
ability to mutate, because mutants are just "sloppy
copies": no copies, no mutants. That is why in the
chemotherapy of AIDS, high drug levels are used, to reduce
viral replication almost to zero: otherwise, resistant
viral mutants will rapidly emerge and the drugs won't block
them. As far as the potential role of selenoenzymes in
this, we do know that selenium somehow boosts the immune
system, and cellular immunity in particular, which should
help keep viral replication in check. But in regard to
how viral selenoproteins may act, this area is so new that
we don't have any hard data; all we really have are some "educated
guesses" like the repressor hypothesis I mentioned
earlier.
Passwater: Wouldn't
increasing the selenium concentration in a virally-infected
cell cause an increase in host selenoenzymes as well as
in viral selenoenzymes?
Taylor: Since
the same pool of selenocysteine is involved, one would
expect that levels of both host and viral selenoenzymes
would increase if more selenium was available. This touches
on an aspect of my findings that many people have had difficulty
with from the beginning. Many people wonder: if the virus
uses or "needs" selenium, then why would taking
selenium slow viral activity - wouldn't that "feed" the
virus?
The answer to this is, first
of all, selenium is more essential for us than it is for
the virus. So if selenium becomes depleted, we suffer far
worse consequences than the virus. Secondly, it also depends
on how the virus uses selenium in its selenoprotein. I
explained above how a viral GPx could act to inhibit viral
replication. Thus, I have proposed that in some cases a
virus might use such a protein in a negative feedback loop,
i.e. as a repressor. That would permit the virus to respond
to conditions of low selenium in the cell - which could
be a signal of impending cell death - by replicating at
a higher rate, to "escape" from that cell.
For example, under appropriate
conditions, HIV is known to remain in cells for long periods
of time, either in a latent state or only replicating at
a very low level. Selenium-based mechanisms could help
regulate that state.
Passwater: You
are right about many people asking why "feeding" the
virus selenium is a good thing. They wonder if it would
not be better to starve the virus. Nutritionists and clinicians
tend to think of selenium in terms of nourishment, but
in this case you are not talking about selenium for the
nourishment of the virus. Even cancer researchers sometimes
miss a similar point when they focus strictly on nutrients
and tumor status instead of the more important question
of nutrients and immune system status Your explanation
will help more scientists that are non-virologists get
the point!
In my lectures, I have used
your comment about it's really not in the best interest
of viruses to kill their hosts, because the viruses will
also die. That is, unless they can jump ship (host) by
spreading to their next victim. As you said, but I want
to repeat it, the important point is that selenium is not
really feeding the virus, but is used by the virus to determine
the health of the host. If the infected cell (and thus
the host) is well nourished and not in immediate danger
of dying there is no urgent need for the virus to invade
new cells.
Taylor: Perhaps
it would help some of our lay readers if instead of thinking
of selenium as nourishment or food for the virus, they
would think of selenium as being part of a birth control
pill for viruses. The viruses don't need selenium for survival
so much as for growth regulation.I already explained how
a viral GPx or other selenoprotein can inhibit viral replication
by reducing oxidant tone in the cell: remember that oxidative
stress activates HIV. So a very simple analogy would be
that a viral selenoprotein could act as a viral birth control
pill, inhibiting viral reproduction when selenium is abundant.
Of course, at the same time selenium is boosting the immune
system and having other beneficial effects in the host.
But when selenium levels are too low, we not only have
a weakened immune system, the viral birth control is reduced,
and the virus replicates at higher levels. This obviously
makes sense for the virus, because this is the best time
for it to break out - when the i
mmune system is weakened by selenium deficiency. Thus, by strengthening the
immune system with high selenium/antioxidant levels, the virus is forced
to maintain a low profile. In essence, this analogy explains what a repressor
mechanism is, using the "birth control" concept.
Passwater: Does
increasing the selenium concentration in the HIV-infected
stabilize the HIV genome?
Taylor: Slowing
viral replication rate reduces the opportunity to mutate,
which is what is meant by "stabilizing" the viral
genome. Since oxidative stress is known to activate HIV
transcription, selenium supplementation will reduce HIV
replication activity, simply as a consequence of increased
cellular GPx levels. That has been proved in cell culture
studies (Sappey et al. 1994). Furthermore, by protecting
against oxidative free radical damage to RNA and DNA, increased
dietary Selenium would directly reduce mutation rate. But
the possible contributions or roles of viral selenoproteins
in these processes still need to be elucidated.
Passwater: If
the HIV genome is stabilized, does this give the immune
system a more steady target that it can destroy with a "traditional" response?
Taylor: Certainly,
if the ability of the virus to mutate is impaired or slowed,
it will be easier for the immune system to neutralize it,
because it will be less of a "moving target".
Passwater: Does
increasing the selenium concentration in HIV-infected cells
stimulate the immune system? In uninfected cells?
Taylor: As
you know, there is a remarkably extensive body of literature
showing that dietary selenium is critical for a healthy
immune system, and that selenium potentiates various aspects
of cellular immunity, such as T-cell proliferation responses,
and the action of the cytokine interleukin 2. I think only
a part of this can be explained by known human selenoproteins
like GPx, and we really have a lot to learn about howselenium
produces its immune-stimulating effects. This statement
is supported by the fact that according to an early study
by McConnell using radio-labeled selenium in immune cells,
only about 20% of the total selenium content is contained
in GPx. So selenium is probably doing important things
in those cells that we still don't understand.
Passwater: I
believe it was a 1959 study by McConnell in which he subcutaneously
injected radioactive selenium (75Se) chloride in dogs and
measured the amount of selenium incorporated into the leukocytes.
This is the first reference to selenium being used in the
immune system that I am aware of. I don't believe that
anyone has published figures changing his finding that
about 20 percent of the selenium became incorporated into
the protein fraction of the leukocytes, which indeed may
be essentially one or both of the glutathione peroxidases.
That's a good point for me to check with Dr. Orville Levander.
Sorry to interrupt, I hope it didn't make you lose your
point.
Taylor: The
point that I was getting to is that in HIV-infected individuals,
I would expect this role of selenium in immunity to be
at least as important as in the uninfected. In addition,
since HIV targets the immune system, an important role
for selenium in the normal immune response could also help
explain why the virus might gain something by getting directly
involved in selenium biochemistry, as I have proposed.
Mimicry of host proteins and mechanisms is a common viral
strategy.
Passwater: Does
increasing the selenium level in HIV-infected cells increase
glutathione or oxidized glutathione levels?
Taylor: Selenium
increases GPx levels, and GPx uses glutathione (GSH) to
reduce peroxides, forming GSSG (oxidized glutathione) in
the process. So one might expect GSSG to increase when
selenium is increased. But another enzyme, glutathione
reductase, readily regenerates GSH from GSSG. So the total
amount of both forms of glutathione is what is really important.
Recently, French researchers showed that, counterintuitively,
selenium supplementation actually increases free GSH levels
significantly, which is good, because it is the reduced
GSH form that is needed for many important detoxification
reactions and free radical scavenging in the body. So some
complex homeostatic mechanisms must be involved, that act
to increase total glutathione levels when more selenium
and GPx are available.
Passwater: It
was recently noted that Keshan disease seems to have a
viral component rather than being strictly a selenium-deficiency
disease per se. Do you see your research as playing a role
in understanding this development?
Taylor: Actually,
this link was first noted by the Chinese in research published
as far back as 1980. Coxsackie virus, a widespread relative
of the common cold virus, was isolated from the hearts
of Keshan disease victims, and was also shown to produce
heart damage in selenium-deficient mice that was identical
to that seen in human Keshan disease. I think this is extremely
significant in terms of what I am saying about HIV, because
Keshan disease is clearly a selenium deficiency disease,
apparently with a viral cofactor. And I am saying: AIDS
is a viral disease with selenium deficiency as a cofactor.
And we now have compelling evidence for virally-encoded
selenoproteins in both HIV and Coxsackie virus.
Passwater: Dr.
Melinda Beck of University of North Carolina, Chapel Hill,
made an interesting observation about how a fairly harmless
strain of Coxsackie virus mutates within selenium-deficient
mice (and presumably in people as well) to become a more
harmful virus that can then spread and produce heart damage,
even in others who are not selenium deficient. Was she
aware of your research when she made her observation? How
does her finding complement your research findings?
Taylor: Dr.
Beck's work is an extremely important breakthrough in establishing
the selenium-virus link. She and her collaborator Dr. Orville
Levander were working independently in this area before
I was, developing their line of research based on the earlier
Chinese observations linking Coxsackie virus to Keshan
disease. When I discovered a potential HIV-selenium link
in spring of 1994, based purely on genomic analysis of
HIV, I was unaware of their selenium work because their
first paper showing increased virulence of Coxsackie virus
in selenium-deficient mice was not yet published, although
I had seen an earlier paper they did showing a similar
effect with vitamin E.
In a subsequent paper, they
showed that when passed through selenium-deficient animals,
the virus actually mutates into a more virulent strain,
that retains its virulence in selenium-adequate animals.
This has obvious implications in regard to "emerging" viral
diseases. In their published work, Drs. Beck and Levander
have focused on known mechanisms to explain their observations,
along the lines we have already discussed: low selenium
leads to weakened antioxidant defenses and reduced immune
surveillance, higher viral replication rates, and thus
to conditions favoring viral mutation. However, particularly
now that my group has demonstrated unmistakable GPx-related
sequences in the Coxsackie B virus strain that they studied,
I think they are seriously considering the possibility
of a direct virus-selenium link of the type I have proposed
for HIV. Obviously, if Coxsackie virus encodes a selenoprotein,
it would have to be involved in the mechanism underlying
their observations.
Passwater: After
publishing your selenium - HIV discovery, you proposed
a possible relationship between selenium and the Ebola
virus. What did you find and why did you think to look
for this relationship?
Taylor: Coincidentally,
I began to study Ebola less than a month before the 1995
outbreak in Kikwit, Zaire that brought this virus so drastically
into the public consciousness. I did so because of a poster
presentation I had seen that spring in Santa Fe, at a meeting
of the International Society for Antiviral Research. A
Russian group presented a world map showing the geographic
areas where various hemorrhagic viral diseases tended to
occur, and I was struck by the fact that the area shown
for the filoviruses Ebola and Marburg matched a region
in Africa that I suspected might be a low-selenium region.
What we found was striking: several gene regions in Ebola
contained large numbers of UGA codons, up to 17 in one
segment. We later published a paper showing that it might
be possible for Ebola to synthesize selenoproteins from
these gene regions, and proposed a mechanism whereby this
might induce artificial selenium deficiency and contribute
to the blood clotting characteristic of Ebol a pathology.During
the revisions to the final draft of that paper, we learned
of a 1993 paper in a Chinese journal that reported the
use of selenium to treat an Ebola-like hemorrhagic fever,
with remarkable results. Luckily, the English translation
of the abstract was available. Using the very high oral
dose of 2 mg selenium per day as sodium selenite, for only
9 days, the death rate fell from 100% (untreated) to 37%
(treated) in the very severe cases, and from 22% to zero
in the less severe cases. Apparently there were about 80
people involved in this outbreak. Dr. Hou of the Chinese
Academy of Medical Sciences, the author of this study,
has since told me that he thinks more lives could have
been saved if he had been permitted to give the selenite
by injection, because in many of the more severly affected
there is so much organ damage due to internal bleeding
that they may have been unable to fully absorb or retain
the oral dose of selenium. All in all, this is the closest
thing to a curative result in the treatment of hemorrhagic
fever that I have ever heard of.
Passwater: Dr.
Hou used selenite because quick and dramatic action was
required as the patients were dying in front of him. For
normal, long-range protection, organic selenium supplements,
such as selenium-rich yeast or selenomethionine, are preferred,
as discussed by Dr. Gerhard Schrauzer in the December 1991
issue, and by others as will be discussed later in this
series.
How do hemorrhagic fever viruses
cause hemorrhaging? Would selenium's effect on blood clotting
in the host play a role in such diseases, or is the effect
strictly an interaction with the virus itself?
Taylor: The
characteristic hemorrhaging produced by various "hemorrhagic
fever" viruses involves the production of blood clots
that ultimately block small capillary vessels, which rupture
under pressure to produce internal and even external bleeding
in severe cases. This is known as "disseminated intravascular
coagulation", or DIC. Thus, paradoxically, the bleeding
is produced by a pro-clotting mechanism, and anticoagulants
(which usually promote bleeding) have been used to treat
symptoms of the disease.
This may be very significant
in regard to selenium involvement, because the biochemical
basis for an anti-clotting effect of selenium is very well
established. Severe selenium deficiency, usually artificially
induced in animals, is known to produce hemorrhagic symptoms.
Thus, the idea that hemorrhagic fever viruses might produce
a severe selenium depletion would be consistent with the
established pro-clotting mechanism of DIC. So there may
be an interaction here, where viral activity is having
a direct impact on host selenium status over the period
of one or two weeks, sufficient to cause serious pathology.
Alternatively, the results obtained
in the Chinese study could have been simply due to the
anti-clotting effect of selenium, or other mechanisms.
Dr. Hou apparently decided to try the selenium treatment
because of his own theories about the involvement of selenium
in complement activation, another feature of hemorrhagic
disease. So additional studies are badly needed, to determine
what the predominant mechanism of protection by selenium
really is.
Passwater: Then
do you see multiple roles for selenium against other viruses?
Taylor: At
this point, I've very optimistic about the potential of
dietary selenium as a broad-spectrum chemoprotectant against
various viral diseases. A lot of that may be entirely due
to the immune-stimulating and antioxidant benefits of selenium,
but I think that in a number of viral diseases, some degree
of direct interaction between the virus and selenium is
likely to be involved. We already have quite a few viral
diseases where a clinical correlation or definite selenium
benefit has been established: hepatitis B/liver disease,
HIV/AIDS, Coxsackie virus/Keshan disease, hemorrhagic fever,
MMTV/cancer, and a number of other animal viral diseases
where selenium has been used in veterinary practice. I
also strongly suspect that various herpes viruses will
prove responsive to selenium therapy, and the strongest
case of a selenoprotein in a virus to date is in a pox
virus. So the potential scope of this chemoprotection approach
is very exciting.
Passwater: Your
research is getting dramatic scientific support at least
by some researchers, what are you looking into now?
Taylor: After
spending much of my efforts over the last two years in
trying to extend the scope of our HIV findings in terms
of other viruses, and trying to establish some collaborations
in order to have the implications experimentally verified,
I am now focusing on building up the capabilities in my
own laboratory to do some of the necessary experimental
research. It's been slow getting started, because we have
been hampered by lack of financial resources, and only
now is the hard evidence coming in that will enable us
to convince Federal funding agencies that this research
merits support. Along with a few other labs, we have already
obtained evidence that some of the molecular features we
predicted in HIV are real. Our objective is to clone several
of the novel genes that we have found by genomic analysis,
including several from HIV and the GPx homologue from Coxsackie
virus, so the meantime we are trying to work with clinical
researchers like Dr. Marianna Baum to promote the seri
ous assessment of the potential benefits of selenium as a complementary therapy
in HIV disease.
Finally, I've also become very
interested in the biochemical roles of selenium in health
as well as in cancer and rheumatoid diseases, etc. My group
is now engaged in a search for new selenoprotein genes
in the human genome, and we are finding some rather intriguing
things. All that I can say at this point is that I strongly
suspect that selenium is playing a role in cell signaling
and attachment - very important in the immune system -
and that selenium is more than just indirectly involved
in gene regulation. So I'm sure I'll be keeping busy well
into the next millennium trying to find out if that hunch
is really true! Hopefully our readers will be able to say
they read it here first.
Passwater: Well,
we will all be looking forward to the selenium millenium!
Hopefully our readers will remember they read it here first.
The information that you have
deduced by examining genes to see what they can make is
a great help and gives great directions for the biochemists
to check out. Without this help we are more or less left
to "stumble around" trying to figure out biochemically
how selenium does all those things that our laboratory
studies show it does.
I am sure that the funding agencies
will soon understand the importance of your research. They
need time to fully understand its consequences. You have
been on the program of the International Conferences on
selenium and human viruses. Now let's see if we can get
you on the programs of some of the NIH virus researchers.
Remember NIH also stands for Not Invented Here -- and if
not invented here (at National Institutes of Health) it
takes longer to get the attention of the establishment
funders. Thanks for helping us keep up-to-date on your
exciting research.
For more information on Selenium,
please click below.
Selenium
Article 1, Selenium
Article 3