Frequent detection of infectious XMLV in human cultures from mouse xenografts

[Jemal]

A new study, got this from the new sequence posted by Bob.

Volume 12, Issue 7 October 1, 2011
Yu-An Zhang, Anirban Maitra, Jer-Tsong Hsieh, Charles M. Rudin, Craig Peacock, Collins Karikari, Rolf A. Brekken, Victor Stastny, Boning Gao, Luc Girard, Ignacio Wistuba, Eugene Frenkel, John D. Minna and Adi F. Gazdar

Purpose: To investigate the frequency of xenotropic murine leukemia virus (MLV) presence in human cell lines established from mouse xenografts and to search for the evidence of horizontal viral spread to other cell lines. Methodology: We examined xenograft tumor cell lines from 7 independent laboratories and 128 non-xenografted tumor cell lines. Cell line DNA was examined for mouse DNA contamination, and by three Taqman qPCR assays targeting the gag, env or pol regions of MLV. Sequencing was used for viral strain identification. Supernatant fluids were tested for reverse transcriptase (RT) activity. Results: Six of 23 (26%) mouse DNA free xenograft cultures were strongly positive for MLV and their sequences had greater than 99% homology to known MLV strains. Four of five available supernatant fluids from these viral positive cultures were strongly positive for RT activity. Three of these supernatant fluids were studied to confirm the infectivity of the released virions for other human culture cells. Of the 78 non-xenograft derived cell lines maintained in the xenograft culture-containing facilities, 13 (17%) were positive for MLV, including XMRV, a virus strain first identified in human tissues. By contrast, all 50 cultures maintained in a xenograft culture-free facility were negative for viral sequences. Conclusions: Human cultures derived after mouse xenografting frequently contain and release highly infectious xenotropic MLV viruses. Laboratories working with xenograft-derived human cultures should be aware of the risk of contamination with potentially biohazardous human-tropic mouse viruses and their horizontal spread to other cultures.

https://www.landesbioscience.com/journals/5/article/15955/

 

[Jemal]

So we have multiple highly infectious mouse retroviruses that can infect human tissue in laboratories all over the world. Not all scientists might have been aware of the danger (weren't they about to test their own people?). I am sure everything is fine! Just move along...

The XMLV in the title wasn't a spelling mistake on my part, by the way. The title was XMLV on the source website as well...

Do we know if the WPI had anything to do with mouse xenograft products? I think not, but don't know for sure...

 

[Jemal]

Also, why this study does seem important to me, they use the term biohazardous (though in context they say potentially biohazardous).

Conclusions: Human cultures derived after mouse xenografting frequently contain and release highly infectious xenotropic MLV viruses. Laboratories working with xenograft-derived human cultures should be aware of the risk of contamination with potentially biohazardous human-tropic mouse viruses and their horizontal spread to other cultures.

Some definitions of a biohazard:

- A biological agent, such as an infectious microorganism, or a condition that constitutes a threat to humans, especially in biological research or experimentation.
- Biohazards are infectious agents or hazardous biological materials that present a risk or potential risk to the health of humans, animals or the environment.
- Biological hazards, also known as biohazards, refer to biological substances that pose a threat to the health of living organisms, primarily that of humans.
- Biological agents and materials which are potentially hazardous to humans, animals and/or plants.

It's getting more and more obvious that XMRV and MLV's are a threat to humans and who knows if they were contained...

 

[zzzz]

This research is dated Oct 2011 ?? I'M surprised no one else has commented on this thread. It indeed seems to me an important piece of information! Is Pandora's box finally opened?

 

[alex3619]

Hi zzzz, this is pre-publication. This article is open access, so there might not be any issues with pre-publication release. From the paper I found this interesting:

"The window during which both cell lines were maintained together in the same culture facility was only a few days, indicating that horizontal spread may occur rapidly. This XMRV-positive RKO culture probably represents the first report of horizontal spread of the XMRV virus."

They have also traced some contamination issues back to the 70s. I am still reading this article, just wanted to post some preliminary thoughts.

Bye,
Alex

 

[alex3619]

Hi all, this article is labelled "DO NOT DISTRIBUTE". This could be a problem. Bye, Alex

 

[zzzz]

Jeez, I'm stunned! Thanks for the update! Altough I wonder if we should keep this thread up seeing it is labelled.

 

[Jemal]

Hi all, this article is labelled "DO NOT DISTRIBUTE". This could be a problem. Bye, Alex

I think I found this article through Google, so if it's not for distribution, they messed up. It could also mean that the PDF shouldn't be distributed outside of their journal and website (copyright, which they also claim directly beneath "DO NOT DISTRIBUTE"). Also, the PDF download wasn't there when I found the article. The article is now linked from the homepage of the journal Cancer Biology & Therapy by the way, as the top download

So yes, this could be a mistake on their part, but I am not sure...

 

[Jemal]

I checked and other articles from this journal, from the current issue, also have the "DO NOT DISTRIBUTE" watermark. So I think it's just a copyright watermark.

 

[alex3619]

I checked and other articles from this journal, from the current issue, also have the "DO NOT DISTRIBUTE" watermark. So I think it's just a copyright watermark.

Hi Jemal, that is pretty much my take as well. Short comments or quotes at less than ten percent of the full paper should be within copyright permissions. Bye, Alex

 

[gregf]

Frequent detection of infectious XMLV in human cultures from mouse xenografts https://www.landesbioscience.com/journals/cbt/ZhangCBT12-7.pdf

was just tweeted by ...

Crikey. Is this saying what I think it is saying ?

MLV/XMRV is common in human-mouse xenografts and is a biohazard to staff.
Staff should be checked for infection.

Therefore, XMRV is doing everything we say, AND it is man made, a result of
lab research since the 1970s.

It would explain why governments are covering it up.
But I am not jumping to conclusions yet.

 

[Mya Symons]

Holy Crap!!!--"Human cultures derived after mouse xenografting frequently contain and release highly infectious xenotropic MLV viruses. Laboratories working with xenograft-derived human cultures should be aware of the risk of contamination with potentially biohazardous human-tropic mouse viruses and their horizontal spread to other cultures."

So what's going to be their next move to discredit these researchers? Once again they are going to say it could have happened but it did not and we are lucky it didn't.

I am trying to remember--Dr. John Coffin was involved in MuLv gene therapy experiments and is still getting grants money for this, correct? Or did I get this mixed up?

 

[gregf]

Cross link : http://phoenixrising.me/forums/show...og-on-Age-of-Autism-about-XMLVs-in-xenografts

 

[currer]

And look - they actually suggest in the paper that we should search for antibodies to XMLVs in those exposed to these agents!

Have they heard of the WPI's findings?

 

[currer]

I remember this problem being discussed in the 1990s. Virologists themselves were reluctant to admit to the contamination problem because their own research would be invalidated if it were subsequently found that ten years research had been done on a contaminated cell line. It could destroy their research credibility. It was a known problem that was shelved.

Now this paper is trying to open out this subject. It seems like whistleblowing to me, especially since these viruses are now being associated with disease. It ought to be widely discussed in the scientific and popular press.

Can anyone find any reference to it in the media?

There is also this paper by Sfanos et al. "Identification of replication competent murine gammaretroviruses in commonly used prostate cancer cell lines"
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0020874?

 

[RedRuth]

Table 4 lists


prostate LNCap Multiple MLV strains ND ++++

Doesn't the Mikovits lab use LNCap cells?

 

[ukxmrv]

It does Redruth, and I noticed that. We are getting a lot of evidence that many labs are contaminated.

The WPI have tested their LNcap and it is clear. I'm been asking them q's like this since the Science paper was published.

It appears that specific labs are infecting their own cultures but other labs are managing not to do this. I'd like to see an explantion of this and how it has impacted any experiments done on these tisues.

The question is how did the "contamination" get into patients like me.

 

[currer]

Just out of curiosity, redruth, and I can understand if you cannot answer this, but you said earlier that your lab had one of the infected cell lines.

Is it possible that this contamination has passed from this one cell line into other cell lines in your lab?

What steps should be taken to find out if this has happened?

Will these steps be taken?

Do you think staff are likely to be tested for antibodies to MLVs?

 

[RedRuth]

It's a possibility though it shouldn't really happen if you're careful. I work in a category 2 culture lab (I share a lab with a group who work on hematopoietic blood cells and we use lentiviral vectors) so we're aware of the risks, although all the blood is screened for HIV and HepB we're all aware we have to be careful. Given the low probability of retroviral infection from cell cultures I wouldn't think any of us will be tested for any retroviruses. I have though made sure everyone knows the particular cells I mentioned are probably infected with an MLV.

 

[currer]

Just a few quotes for you Redruth, from the CROI conference 2011.

Sort of following up on that, I think there's no doubt after this meeting that this virus arose from a recombination,,and as the original prostate tumor explants and propagated, and its extraordinarily infectious in vitro and is clearly demonstrasting infectivity in human explants and a variety of human cell lines, and transmitted to nonhuman primates..and I'm a little concerned..one, was this human-created in the laboratory, and its a highly infectious retrovirus...could it transmit to humans..could it have , subsequent to that event transmitted to humans?

We've been doing studies using pedigreed negative controls, some of whom happen to be lab workers working with this virus and intermittently score positive in one lab or another.
I've just ignored that, but now I'm beginning to be concerned that there might be transient infections in humans.
Has anyone embarked on studies to look at ..lab workers who have or are working with these cell lines?


.....Just to remember about this virus ...it's replication competent. Unlike most of the things your'e probably handluing. So there is a concern.


....Just quickly on that last point, there are in fact some lines of cells like LnCAPs which are also known to be infected with either XMRV or some other xenotropic |MLV and theyr'e quite infectious...not XMRV exactly but xenotropic MLVs that are almost certainly picked up during....There are a lot of them in laboratories. Many people or most people who work with them are unaware of their virological status.