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Dr. Pathak: We became interested
in working on XMRV
because when we started we
thought this could be a
pathogenic virus that's causing
prostate cancer,
chronic fatigue syndrome,
and perhaps other diseases
in humans.
And we really wanted
to determine,
whether that's true
and if that's true,
can we find ways to treat people
that have this virus.
We've done studies to look
for the virus's ability
to replicate in people
and we find that it doesn't.
There's a cell line that's
derived from a prostate tumor
called 22RV1,
that makes XMRV virus
that is essentially identical
to all of the viruses
that have been reported.
So the assumption was
that this cell line was derived
from a prostate tumor
from a person
who had been infected with XMRV.
We were looking
to see how this virus got
into this cell line.
We wanted to look at some
of the earlier tumor cells,
as close to the beginning
as we could get.
We were working
with these tumor cells,
tumors from the immunodeficient
mice and we found a virus
that looked kind of like XMRV.
And we worked hard
to clone the whole virus,
so we had the entire sequence
of the virus.
And, while this was going on,
we were collaborating
with John Coffin, who has a lab
at Tufts University.
He was chasing
down another virus
that looked like XMRV.
But we didn't know the
relationship
between these two viruses.
In about mid-December,
we had just completed the
sequence of our virus,
John and his student, Oya,
had gotten almost all
of the sequence of their virus.
And John kind of looked
at our virus and said,
"You know, this virus looks a
lot like the opposite
of our virus.
So let me take a closer look."
So I sent him the sequence.
My wife and I were going to go
to Egypt for a two week vacation
that evening, I was late,
so I went home,
by the time I got home,
John had emailed me already
and had compared the two
sequences and had said, "Oh,
these viruses are exact
compliments of each other,
with just a few
crossover events.
They will generate XMRV,
which is nearly identical
to the XMRV
that we know so far."
So I got this on my I phone
and I was so excited,
I kept thinking,
oh this is so cool,
this is so cool.
But I was running around packing
and we got in the car,
I didn't have a chance
to email him back.
So we rushed to the airport,
we were late getting
to the airport.
We got in, we got
into the plane, got our seats,
and I took my I phone out
and I emailed him and said,
that's awesome and that's
when they said 'turn off your
electronic devices'
and then I was
out of email contact
for almost two weeks, so,
but it was a very exciting
moment because generally
scientific discoveries are kind
of a gradual process.
You get a clue,
you get another clue,
and you kind of,
it happens sometimes
of over weeks or months.
And this was not like that;
this was just immediate, bam.
This is the answer,
and we knew it right away.
So it was one
of those eureka moments.
We've found
that the virus actually was born
in the mid 90s
in a laboratory experiment,
which pretty much tells us
that the virus cannot be causing
any of these diseases.
So the obvious conclusion is
that it must have spread
through
laboratory contamination.
Dr. Le Grice:
I think we're seeing now
that tools that we use
in the lab,
reagents for everyday research
are contaminated with mouse DNA,
these are things we never knew
at the time.
The other thing is that,
as scientists, we share reagents
that we maybe didn't know were
contaminated
and that's how things can pass
from lab to lab.
That's what we do as scientists,
we share reagents,
we hope we don't share problems,
but it may be in this case
that XMRV circulated
in certain cell lines
that it had infected and so on.
Dr. Pathak:
I think it's certainly a
cautionary tale, that people,
as new pathogenic agents are
discovered and thought
to be associated with diseases,
people really have
to be diligent to make sure
that it's not due
to laboratory contamination.
Above all, the results need
to be independently confirmed
by multiple investigators before
people can draw the conclusion
that, yes, this particular virus
or bacteria is causing
or is even closely related,
associated with a disease,
let alone the cause
of the disease.
Dr. Le Grice:
There has simply been a mounting
body of evidence
that suggests this
was contamination.
But the work of Drs.
Phatak and Coffin, this for me,
as a scientist was the icing
on the cake.
To see exactly
where this virus came from,
to be able to trace its history
almost twenty years
and to be able to show,
I believe, conclusively
that XMRV is a recombinant virus
and it's never been in patients
and it's never been isolated
from patients.