Gene scissor

[liam2424]

Hi,
Have in the german area they sspeak from a gene scissor. I don't find informtion here in english. It seems it works and has been presented in Vienna.

Here a german link:

http://www.oe24.at/gesund/Schere-entfernt-HIV-erfolgreich-0745534.ece

[fortuneseeker]

German researchers cut out HIV-infected cells genetic material of the virus proves that.

Für erhebliches Aufsehen sorgten im Jahr 2007 Meldungen aus Deutschland, wonach es mit Enzym-Scheren (Tre-Rekombinase) erstmals gelungen wäre, im Labor aus HIV-infizierten Zellen das Erbgut des Virus heraus zu schneiden. Jetzt sind die Forscher so weit, dass sie das Prinzip bei Labormäusen mit menschlichem Immunsystem erfolgreich erprobt haben. For considerable created a stir in 2007, reports from Germany that it is enzyme-scissors (Tre recombinase) was the first time succeeded with in the laboratory from HIV-infected cells, the genome of the virus to cut out. Now the researchers so that they in laboratory mice with human immune system have successfully tested the principle. Dies erklärte Helga Hofmann-Sieber (Heinrich-Pette-Institut/Hamburg) Montagnachmittag beim Internationalen Aids Kongress (AIDS 2010) in Wien. This explained Helga Hofmann-Sieber (Heinrich-Pette-Institut/Hamburg) Monday afternoon at the International AIDS Conference (AIDS 2010) in Vienna.

"Hat bisher noch keiner geschafft" "Has not been done yet"
Der Hintergrund: Das HI-Virus integriert bei der Infektion seine Erbsubstanz in jene der angegriffenen Zellen. Background: The HIV virus integrates its genetic material during infection in those of the attacked cells. Bisher gibt es keine Möglichkeit, sie wieder von der Erbsubstanz der Viren zu befreien. So far there is no way to return the DNA of the virus to get rid of them. Einmal HIV-infiziert heißt lebenslang infiziert. Once infected with HIV is infected for life. Die Entfernung des HIV-Erbguts wäre deshalb der beste Weg zu einer Heilung der Aids-Infektion. The removal of the HIV genome would therefore be the best way to cure AIDS infection. Vor zwei Jahren gelang den Forschern um Joachim Hauber vom Heinrich-Pette-Institut in Hamburg und Frank Buchholz vom Max-Planck-Institut für Molekulare Zellbiologie und Genetik in Dresden eine Weltpremiere. Two years ago, the researchers at Joachim Hauber of the Heinrich Pette Institute in Hamburg and Frank Buchholz from the Max-Planck-Institute for Molecular Cell Biology and Genetics in Dresden, a world premiere. "Wir wurden das Virus in den Zellen wieder los, das hat bisher noch keiner geschafft", sagten die Wissenschaftler. "We have the virus in the cells to get rid of, so far has not done yet," the researchers said. Dazu wurde mit Hilfe der Gentechnik eine spezielle Rekombinase hergestellt, ein Enzym, das wie eine molekulare Schere arbeitet. This was with the help of genetic engineering produced a specific recombinase, an enzyme that acts as a molecular scissors.

Rekombinasen spalten und organisieren DNA-Sequenzen neu. Recombinases cleave DNA sequences and organize new. Natürlich vorkommende Rekombinasen eignen sich jedoch nicht, um die Gene des Virus aus dem menschlichen Erbgut herauszuschneiden. Naturally occurring recombinases are not, however, the genes of the virus from the human genome in order to cut out. Sie funktionieren nur bei den für sie angepassten Basenabfolgen. They only work when they adjusted for base sequences. Daher stellten die Wissenschafter eine Rekombinase her, die das HIV-Erbgut erkennt und gezielt entfernen soll. Therefore, the scientists put forth a recombinase that recognizes the HIV genetic material and is intended to remove programs. Sie nannten dieses künstlich geschaffene Enzym Tre-Rekomibinase. They called this artificial enzyme Tre-Rekomibinase.

"Keine Toxizität" "No Toxicity"
Nach den ersten Versuchen an menschlichen Zellen im Laborversuch haben die Wissenschafter die Tests weiter geführt. After the first tests on human cells in laboratory tests, the scientists, the continued. Sie brachten das Gen für die Tre-Rekombinase in menschliche Zellen (Jurkat-Zellen) ein und prüften, ob das giftige Effekte haben würde. Helga Hofmann-Sieber: "Wir beobachteten binnen 15 Wochen keine Toxizität." They carried the gene for the Tre recombinase in human cells (Jurkat cells) and examined the effects would have toxic if. Helga Hofmann Sieber: "We observed no toxicity within 15 weeks."

Dann gingen die Wissenschafter in ein Mausmodell: Sie besiedelten sozusagen genetisch immungeschädigte Nager mit menschlichen CD4-positiven Zellen, den ersten Opfern von HIV. Then the researchers went into mice: They settled so to speak genetically immungeschädigte rodent with human CD4-positive cells, the first victims of HIV. Die Mäuse waren damit aus immunologischer Sicht "humanisiert". The mice that were immunological point of view "from humanized". Dann fügten die Forscher in die Tiere mit einer Lentivirus-Genfähre die Erbsubstanz für Tre-Rekombinase ein. Then the researchers added in the animals of a lentiviral gene ferry the genes for Tre recombinase with. Und schließlich wurden die Nager künstlich mit HIV infiziert. And finally, the rodents were artificially infected with HIV. Bei anderen Tieren geschah das selbe, ohne sie vorher mit dem Tre-Rekombinase-Gen versehen zu haben. In other animals was that they bear the same recombinase gene provided without first having Tre.

"Gen-Schere" erfolgreich "Gene shears" successful
Die Ergebnisse, die doch etwas Hoffnung auf Entwicklung von Therapien geben könnten, welche HIV endgültig besiegen könnten: Die Mäuse mit Tre-Rekombinase hatten nach zwei Wochen um das Hundertfache weniger HI-Viren im Blut als jene, die HIV nicht durch die "Gen-Scheren" entfernen konnten. The results, something on development of therapies might be hope yet, could finally defeat the HIV: The mice with Tre recombinase had two weeks to one hundred times less HIV in the blood than those who are HIV not through the "Gen- Scissors could remove. " Sie hatten laut der Zusammenfassung der Arbeit auch anhaltend deutlich mehr CD4-positive Zellen im Blut als die "Kontroll-Mäuse". They had, according to the summary of the work also sustained significantly more CD4-positive cells in the blood as the "control mice.

Die Wissenschafter in ihrem Fazit: "Insgesamt betrachten wir maßgeschneiderte Tre(Rekombinase, Anm.) als essenziell für die Entwicklung von neuen antiretroviralen Therapien für die Ära nach der hoch aktiven antiretroviralen Behandlung (mit herkömmlichen Medikamenten, Anm.)." The researchers in their conclusion: "Overall, we consider tailored Tre (recombinase, note) as essential for the development of new antiretroviral therapies for the era of highly active antiretroviral after treatment (with conventional medicines, note)."

[Boze]

This Google translation may be easier to read


German researchers cut from HIV-infected cells genetic material of the virus proves that.

For considerable created a stir in 2007, reports from Germany that it is enzyme-scissors (Tre recombinase) was the first time succeeded with in the laboratory from HIV-infected cells, the genome of the virus to cut out. Now the researchers so that they in laboratory mice with human immune system have successfully tested this principle. This explained Helga Hofmann-Sieber (Heinrich-Pette-Institut/Hamburg) Monday afternoon at the International AIDS Conference (AIDS 2010) in Vienna.

"Has not been done yet"
Background: The HIV virus integrates its genetic material during infection in those of the attacked cells. So far there is no way to return the DNA of the virus to get rid of them. Once infected with HIV is infected for life. The removal of the HIV genome would therefore be the best way to cure AIDS infection. Two years ago, the researchers at Joachim Hauber of the Heinrich Pette Institute in Hamburg and Frank Buchholz from the Max-Planck-Institute for Molecular Cell Biology and Genetics in Dresden, a world premiere. "We were in the cells of the virus to get rid of, so far has not succeeded yet," the researchers said. This was with the help of genetic engineering produced a specific recombinase, an enzyme that acts as a molecular scissors.

Recombinases cleave DNA sequences and organize new. Naturally occurring recombinases are not, however, the genes of the virus from the human genome in order to cut out. They work only when they adjusted for base sequences. Therefore, the scientists put forth a Recombinase, the HIV genome is to recognize that and remove programs. They called this artificial enzyme Tre-Rekomibinase.

"No Toxicity"
After the first tests on human cells in laboratory tests, the scientists, the continued. They carried the gene for the Tre recombinase in human cells (Jurkat cells) and examined the effects would have toxic if. Helga Hofmann-Sieber: "We observed no toxicity within 15 weeks."

Then the scientists went in a mouse model: they settled, as it were genetically immungeschädigte rodents with human CD4-positive cells, the first victims of HIV. The mice were so immune vision "of humanized". Then the researchers added in the animals of a lentiviral gene ferry the genes for Tre with a recombinase. And finally, the rodents were artificially infected with HIV. In other animals that happened, they bear the same recombinase gene provided without first having Tre.

"Gene shears" successful
The results, something on development of therapies might be hope yet, could finally defeat the HIV: The mice with Tre recombinase had two weeks to one hundred times less HIV in the blood than those who are HIV not through the "Gen- Scissors could remove. " They had, according to the summary of the work and sustained significantly more CD4-positive cells in the blood as the "control mice.

The researchers in their conclusion: "Overall, we consider customized Tre (recombinase, note) as essential for the development of new antiretroviral therapies for the era of highly active antiretroviral after the treatment (with conventional drugs, note)."

[liam2424]

Thanks a lot for your translations.
As it works with humaniced mices, why shouldn't it work with human. Even if it's not a cure, seeing reduced the viral load by 100 would be great! This would increase life expectancy and make HIV definitively a chronic disease!
But the problems are always the same I guess; when can this therapy be available, do they continue studying on this persistently, do they have the money to do this....

I think that even if it's not a cure, it would be very important  to offer this therapy to help the people. But I know, it's not like a pharma company that discover, develop, pass testing and then are happy to sell their pills... And I know that means a certain cost to ¨the industrial countries, probably unavaibility to the countries in development and no end of the virus.

What do you think???

Perhaps Andy can tell us more as he was on the conference in Vienna.

[Inchlingblue]

It's good to know the Germans are still working on this.

More on Ter recombinase:

http://forums.poz.com/index.php?topic=21656.0

http://www.queerty.com/hiv-cure-20070629/

If I am understanding this correctly, it would potentially wipe out reservoirs.

[liam2424]

Yes it would keep hiv at low level. But not eliminate all as it seems. But better a low level than nothing at alll!

What do you think about the avaibility of such a therapy? In how many years?

[liam2424]

And thanks for the interesting links, Inchlingblue!

[Inchlingblue]

What do you think about the avaibility of such a therapy? In how many years?

Even with the English translation supplied by Boze, it's difficult to tell where they are in the research. If they are finished with the animal studies maybe they're ready for clinical trials? Hard to say.

[coolstone25]

I have been following their research. It was a part of the PhD work by indrani sarkar(an indian girl) working with dr. Frank buchholz, Dr.joachim hauber and dr.ilona hauber in Hamburg. The work took months to evolve the topoisomerase enzyme(so called because it works on the topology of the dna- by cutting dna strands, cutting certain genes and recombining the ends of the strands - hence the word for the enzyme, "recombinase") that exists in bacteria(which excises base pairs between CRE and LOX sequences) to an evolved TRE recombinase so it recognizes HIV proviral gene sequences that have been integrated in the host cell nucleus and genes. They succeeded in making all HeLa cells(Henrietta lachs lab cancer cells) infection free but it took 150 evolutionary steps to get the enzyme of minimum desirability and 3 months to clear the infection in the cells.

Currently, they worked on immunologically challenged mice by injecting them with human immune cells or "humanized mice" by then giving them the "ability" to use the recombinase or "armed them" so to say, with tre recombinase. ****The results were very encouraging.****

They are currently working on optimizing the tre recombinase enzyme even more - so its highly effective and efficient in removing the infections - they have isolated even better recombinases today since those they were working on for the mice study!!!

The enzyme works beautifully and makes every cell, in which it exists and goes to work, infection free. However their biggest stumbling blocks at this point were:
1. cytotoxicity
2. delivery of the enzyme.
3. Targetting intended cells.

Especially, delivery(point two). How together the enzyme inside each actively or latently infected cell.  And ofcourse, targetting too: Considering its difficult to deliver the enzyme to every "latent reservoir" or "silent infection", - after all, its estimated 1 in 1million Tcells are latently infected.

It seems the future holds for multiple therapies that restore complete immunological function:
Histone deacetylase inhibitors that "expresses" and ferrets out latent HIV; using RNAi therapy i.e., anti-hiv siRNA laced on to peptides conjugated to tcell specific antibodies, to keep the uninfected cells free of all infection and the tre recombinase to excise all infection and make all cells infection free. There are some other therapies under development which are therapeutic (not preventative!)... such as zinc finger nucleases, gene therapy and gene interrupt therapy, etc.

The tre recombinase next faces preclinical trials within infected and noninfected human subjects after successful studies in mice that exhibited no toxicity. Testing within few humans in pre clinical trials would take 2 years and are in stages of being planned and conducted.
Clinical trials would take about 10 years and might need a "holiday" from medications.
There are significant legal ethical and reasonable concerns to bringing any therapy prematurely to the table.

More details to come....

[Inchlingblue]

coolstone, thank you for that very good explanation.

[coolstone25]

FYI. for those interested.

=========
Innovative Methode zur HIV-Ausrottung?
Virus-Genom einfach aus dem Zellkern schneiden

BERLIN – Mit herkömmlichen Therapien wird sich HIV nicht aus dem Körper entfernen lassen; es würde einfach zu lange dauern. Deutsche Forscher haben jedoch eine molekulare „Schere“ entwickelt, die das Virusgenom fein säuberlich herausschneiden kann.


Vor zehn Jahren glaubten Optimisten noch, zwei bis drei Jahre hochaktive antiretrovirale Therapie (HAART) könnten ausreichen, um HIV zu eliminieren. Inzwischen weiß man es besser: Angesichts der Halbwertszeit von latent infizierten Zellen zwischen sechs und 44 Monaten müsste die antiretrovirale Behandlung mehr als 70 Jahre dauern, bis alle virusbefallenen Zellen ausgetauscht sind. Haupthindernis für eine Heilung sind latent infizierte ruhende CD4-Gedächtniszellpopulationen, die integrierte, aber transkriptionsinaktive provirale DNA enthalten, erläuterte Prof. Dr. Joachim Hauber vom Heinrich-Pette-Institut in Hamburg auf den 12. Münchner AIDS-Tagen. Die Tücke dabei: Latent infizierte Zellen sind für das Immunsystem unsichtbar. Aus dieser „biologischen Bibliothek“ kann HIV daher nur entfernt werden, wenn die Zellen wieder aktiv werden und die Virusreplikation in Gang setzen.

Rekombinase Tre soll HIV besiegen
Der Versuch, die schlafenden Zellen mithilfe von IL-2 zu wecken, um sie dann von dem rekonstituierten Immunsystem vernichten zu lassen oder in die Apoptose zu treiben, gelang nur zur Hälfte. Aber eine globale T-Zell-Aktivierung induziert nicht nur die Virusreplikation, sondern erhöht auch die Zahl der Zielzellen und damit die Virusausbreitung in einem Maße, das durch die derzeitige hochaktive antiretrovirale Therapie nicht beherrschbar ist.

Prof. Haubers Team hat gemeinsam mit Forschern des Dresdner Max-Planck-Instituts ein Instrument entwickelt, das einen wichtigen Beitrag zum endgültigen Sieg gegen das Immunschwächevirus leisten könnte: Tre ist eine hochspezifische Rekombinase, die gezielt genau den Abschnitt aus der Zell-DNA herausschneidet, der das Virusgenom enthält. Die Vorstellung geht dahin, dass die Information für Tre mittels eines Lentivirus-Vektors in CD34-Zellen – unreife hämatopoetische Stammzellen – eingeschleust wird, die dann dem Patienten reinfundiert werden und im Körper die Rekombinase zusammenbauen.

Prof. Hauber ist sich darüber im Klaren, dass Tre nur ein Baustein bei der Viruseradikation sein kann, die ohne rekonstituiertes Immunsystem ohnehin nicht funktionieren kann: „Mit unseren Therapien schaffen wir vielleicht 90 Meter dieses 100-Meter-Laufs, die letzten zehn Meter muss das Immunsystem leisten.“

Dr. Manuela Arand

[Matts]

Prof. Hauber got 2,5 million € from the government to found a company developing the gene scissors for the market. Trials and development are ongoing; maybe in 10 years it will be available.

http://www.biotechnologie.de/BIO/Navigation/EN/Funding/foerderbeispiele,did=71684.html