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2 News Reports on this story - Researchers have eliminated HIV in mice for the first time. Is a cure for humans next?
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1. Researchers have eliminated HIV in mice for the first time. Is a cure for humans next?
see below - "That's why we believe this technology is working because the LASER ART is reducing the virus significantly and then the CRISPR comes in and it's able to be more effective," Gendelman said. "They work at different stages, but put together they're kind of buddies."
Gendelman emphasized that the process "only is successful if we get rid of every virus in the body." The treatment worked on 9 of the 23 mice involved.
"We had to be highly efficient and getting a third of these animals cured is amazing considering what we were up against."
HIV eliminated from the genomes of living animals - "Sequential LASER ART and CRISPR Treatments Eliminate HIV-1 in a Subset of Infected Humanized Mice" - (07/09/19)
LASER ART alone cannot rid the infected host of latent HIV-1 no matter how successful the drugs may prove to be at restricting viral infection. Thus, in parallel, we develop CRISPR-Cas9 based gene editing technology using AAV9 delivery that specifically and efficiently excises fragments of integrated HIV-1 proviral DNA from the host genome19,20,21,22,23,24. We realize that CRISPR-Cas9-based technologies could be most effective in the setting of maximal viral restriction and substantive reductions in the absolute proviral DNA load. Thus, the two approaches are combined to examine whether LASER ART and CRISPR-Cas9 treatments could provide combinatorial benefit for viral elimination. Here we demonstrate elimination of replication competent HIV-1 in an experimental model of human infectious disease. Viral clearance is achieved from HIV-1 infected spleen and lymphoid tissues as well as a broad range of solid organs from documented prior infected humanized mice treated with LASER ART and AAV9-CRISPR-Cas9. This is confirmed in those mice using ultrasensitive HIV-1 nucleic acid detection methods by the absence of post-treatment viral rebound; and by the inability to transfer virus from those infected and dual-treated mice to replicate uninfected untreated mice. We conclude that viral elimination by a combination of LASER ART and gene editing strategy is possible. The advantages of LASER ART over native ART include rapid entry across cell membranes of both CD4 + T cells and macrophages (due to drug lipophilicity); accelerated antiretroviral drug entry into viral reservoir sites (including the brain, gut, lymph nodes, liver, bone marrow and spleen); increased intracellular drug delivery; and stable plasma concentrations observed over weeks to months. The ART were selected in order to produce sustained plasma concentrations 4X the protein-adjusted 90% inhibitory concentration. Notably, a single parenteral dose of NMDTG at 45 mg DTG equivalents/kg to mice provided plasma DTG concentration of 88 ng/ml at 56 days32. Liver, spleen and lymph node DTG concentrations were 8.0, 31.2 and 17.6 ng/g, respectively at 56 days following single treatment. At 14 days after NMABC and NM3TC given at 50 mg ABC or 3TC equivalents/kg to mice, ABC and 3TC plasma concentrations were 21 and < 7 ng/ml, respectively12,13,14. In summary, there was little to no residual ART in plasma or tissue at the time of animal sacrifice reflecting the robust viral rebound found in all infected mice treated with LASER ART alone. Further, significant efforts were made by us to demonstrate that one month after LASER ART was discontinued, viral rebound was detectable. All of this highlights the rationale for use of LASER ART over native ART. Most importantly, our research12,13,14 demonstrated that ART levels in plasma were undetectable during the period of measured viral rebound. LASER ART was developed in an attempt to eliminate these limitations and was shown effective in establishing drug depots in macrophages with sustained antiretroviral activities and reductions in HIV-1 proviral load beyond ART alone15,38,47,49,50,51,52,53,54,55. The success in these prior studies led to the use of LASER ART in the current report in order to maximize ART ingress to cell and tissue sites of viral replication enabling the drugs to reach these sites at high concentrations for sustained time periods. The maintenance of slow drug release for times measured in weeks or longer provided optimal settings for viral excision17,39,47. ART particles coated with poloxamers enabled lipophilic hydrophobic prodrug crystals to readily cross cell and tissue barriers, aiding precision drug release to viral sanctuary sites12,13,14,37,39,46. These claims are reinforced by our prior studies demonstrating up to a 10-fold increase in viral restriction at two independent multiplicities of infection in CD4 + T cell lines with LASER ART when compared to conventional native drugs12,13.
Generation and pharmacokinetic (PK) testing of LASER ART.
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2. Scientists eliminate HIV in the entire genome of lab mice for the first time ever: Breakthrough paves the way to a human cure - with clinical trials set to start next year
"While standard ART is a soluble drug that dissolves into the blood and gets to work, the drugs in LASER ART are packaged inside nanocrystals, which the immune system recognizes as foreign and carries it up to tissues where HIV hides. Once inside those reservoirs, the nanocrystals slowly dissolve, releasing ART into the hardest-to-access spots over a longer period of time. it would only need to be taken once a year, and because it releases slowly, it would be a gentler experience, with fewer ups and downs that the body experiences from a daily hit of medication. ......Eventually, after years of trial and error, they arrived at LASER ART first, followed by CRISPR-Cas9 to eliminate the virus in a third of mice engineered to produce human T cells susceptible to HIV infection. First, they eliminated it in two out of seven, then in three out of six, then in four out of 10. They then sequenced the entire genome of the mice to make sure that the virus was completely gone, and there were no chromosomal side effects of the gene-editing"
• The study documents the first time HIV has been eliminated from the entire genome of a living animal
• Researchers in Nebraska and Philadelphia used a two-pronged approach to corner HIV then use gene-editing to attack it
• They eliminated HIV in a third of their lab mice who were engineered to produce human T-cells
• The team is now starting to test the technique in macaque monkeys, and hope to start human clinical trials in summer 2020
By Mia De Graaf Health Editor For Dailymail.com
Published: 11:01 EDT, 2 July 2019 | Updated: 11:14 EDT, 2 July 2019
https://www.dailymail.co.uk/health/article-7205169/Scientists-eliminate-HIV-entire-genome-lab-mice-time-ever.html
Scientists eliminated HIV from the entire genome of lab mice for the first time ever using a slow-acting drug and gene-editing.
The feat, revealed in a publication today, suggests this two-pronged technique could be the basis for the first universal cure in humans, with human clinical trials slated to start next summer.
Only two people have been cured of HIV, both had terminal blood cancer and underwent a risky bone marrow transplant that obliterated both diseases.
But the transplant technique has not worked in anyone else - proving fatal in some - and it effectively requires that the patient have both HIV and cancer.
Now, a team spearheaded by an HIV expert in Nebraska and a gene-editing expert in Philadelphia has presented the unprecedented fruits of a five-year project: using a slow-acting drug called LASER ART that corners the virus, followed by CRISPR Cas9 gene-editing that blitzes it.
In a new paper, they reveal this approach successfully eliminated HIV from the entire genome of a third of their lab mice.
Even they were surprised.
'We didn't believe it,' Dr Howard E Gendelman, Director of the Center for Neurodegenerative Diseases at the University of Nebraska Medical Center, told DailyMail.com.
'We thought it was a fluke, a problem with the graphs; that the cells carrying HIV had died; that our assay system was wrong.
'It was only after we repeated it a couple of different times,' he says, that they accepted they had hit the veritable jackpot.
What's more, journals didn't believe it.
'After we got it right, we submitted it for publication and it was rejected from many different journals,' Dr Gendelman said.
'They had a hard time believing HIV could be cured.'
He and his co-author (and 'best bud') Dr Kamel Khalili, of Temple University in Philadelphia, added no less than 20 supplemental figures to their paper - far more than usual - to prove that their results were not a fluke, finally getting the green light from Nature Communications.
'There was a lot of frustration, self-introspection, denials, reaffirmation, and just laborious day by day activities to prove it,' Dr Gendelman said.
HIV is so hard to obliterate because it is a virus that infects the genome.
It buries itself inside hidden reservoirs, ready to mount a resurgence at any point.
These days, we have incredibly effective drugs (called ART, or anti-retroviral therapy) that suppress the virus to such an extent that it is undetectable, and cannot be transmitted to another person.
It means people who have HIV can live a long, healthy life without the virus turning into AIDS.
But ART cannot get at the hidden reservoirs where HIV's reserves lie.
A couple of years ago, Dr Gendelman developed a technique called LASER (long-acting slow-effective release) ART with Benson Edagwa, PhD, Assistant Professor of Pharmacology at Nebraska.
While standard ART is a soluble drug that dissolves into the blood and gets to work, the drugs in LASER ART are packaged inside nanocrystals, which the immune system recognizes as foreign and carries it up to tissues where HIV hides.
Once inside those reservoirs, the nanocrystals slowly dissolve, releasing ART into the hardest-to-access spots over a longer period of time.
It means HIV is held at bay for extended periods of time.
Dr Gendelman and colleagues have showed that the technique could be used as an easier-going drug for people with HIV: it would only need to be taken once a year, and because it releases slowly, it would be a gentler experience, with fewer ups and downs that the body experiences from a daily hit of medication.
Meanwhile, Dr Khalili, a named inventor on patents that cover the coveted gene-editing technology CRISPR-Cas9, was trying to use CRISPR to wipe HIV from the genome of mice - without success.
The main problem is that HIV replicates too fast for CRISPR to do its work.
CRISPR carries a mugshot of the target it is seeking to destroy, which can work well if there is only one target, or a few. Trying to tackle HIV is like running into a festival of clones, and trying to get to every single one.
He approached his long-time friend and colleague Dr Gendelman to discuss using LASER ART to corner and control the HIV virus, giving CRISPR the space to do its work.
At first, they tried to combine the techniques to deliver them together, but that flopped.
Eventually, after years of trial and error, they arrived at LASER ART first, followed by CRISPR-Cas9 to eliminate the virus in a third of mice engineered to produce human T cells susceptible to HIV infection.
First, they eliminated it in two out of seven, then in three out of six, then in four out of 10.
They then sequenced the entire genome of the mice to make sure that the virus was completely gone, and there were no chromosomal side effects of the gene-editing - i.e. that their technique had caused some other problems in the genome. Everything looked good.
'We were pleasantly surprised,' Dr Khalili said.
To get at the other two thirds of mice who still had HIV, Dr Khalili said, they are exploring adding another CRISPR technique, targeting not just HIV but also the CCR5 gene, which, acts as a doorway to HIV. People who do not have CCR5, or have a mutation of it, (like the Berlin
Patient and the London Patient, after their transplants) are essentially immune to HIV.
The team is now starting to test the technique in macaque monkeys, and hope to start human clinical trials in summer 2020.
This is not yet a cure, but Dr Khalili and Dr Gendelman are bursting with relief and excitement.
'At the very least it's a proof of concept,' Dr Gendelman said. 'It shows it's possible that HIV could be cured.'
Their peers are also impressed, but call for a wider pool of animals - and, indeed, humans - before the technique can get the stamp of approval.
Dr Paul Freemont, Co-Director of the Centre for Synthetic Biology and Innovation, Imperial College London, said: 'This is an exciting study showing that it might be possible to use a chemical and genetic editing therapy in combination to eliminate HIV permanently from infected cells.
'HIV is very clever in that it embeds its own genetic code into cells which when activated can make more virus, and so methods to both kill active viruses and also eliminate HIV genetic code in infected cells are needed.
'However the number of mice used in the study is small and further trials will be needed to confirm this initial but exciting proof-of-concept study.
'However, it is still an open question as to whether such an approach would work in humans, particularly off-target effects.'
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2. Researchers have eliminated HIV in mice for the first time. Is a cure for humans next?
N'dea Yancey-Bragg, USA TODAY Published 10:13 p.m. ET July 2, 2019 | Updated 7:14 a.m. ET July 3, 2019
https://www.usatoday.com/story/news/health/2019/07/02/researchers-cure-hiv-mice-first-time-breakthrough-study/1635072001/
Researchers say they've successfully eliminated HIV from the DNA of infected mice for the first time, bringing them one step closer to curing the virus in humans.
Scientists from Temple University and the University of Nebraska Medical Center were able to eliminate the virus using a combination of gene-editing technology and a slow-release antiviral drug, according to a study published Tuesday in Nature Communications.
"The possibility exists that HIV can be cured," Howard Gendelman, chairman of UNMC's pharmacology and experimental neuroscience department and study author. "It's going to take a little bit of time but to have the proof of concept gets us all excited."
Nearly 37 million people are living with HIV, according to UNAIDS, which if left untreated can develop into AIDS. Current HIV treatment involves daily, lifelong antiretroviral therapy (ART) which suppresses the virus' ability to replicate, but doesn't eliminate the virus from the body.
If a patient stops taking the drugs, HIV is able to rebound because the virus is able to "integrate its DNA sequence into the genomes of cells of the immune system, where it lies dormant and beyond the reach of antiretroviral drugs," according to a press release.
Researchers used a new form of ART called LASER ART on 23 "humanized mice," animals genetically modified to bear similarities to the human immune response. They were able to control the release and metabolism of the drug which allowed it to suppress virus replication for longer period of time.
The team then excised the remaining integrated HIV genome using a gene-editing tool called CRISPR-Cas9 which allows scientists to operate on DNA to add or disable certain genes.
"That's why we believe this technology is working because the LASER ART is reducing the virus significantly and then the CRISPR comes in and it's able to be more effective," Gendelman said. "They work at different stages, but put together they're kind of buddies."
Gendelman emphasized that the process "only is successful if we get rid of every virus in the body." The treatment worked on 9 of the 23 mice involved.
"We had to be highly efficient and getting a third of these animals cured is amazing considering what we were up against."
Gendelman said its unclear how long it will take before clinical trials can begin noting that more research needs to be done into the potential of toxicity of gene modifying therapy and how to scale up the dose for humans.
"We're working on this day and night and we hope it'll be sooner than later, but we have some obstacles to overcome," he said. "There's a tremendous amount of effort to move this technology forward."
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