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Elimination of HIV-1 Genomes by CRISPR/Cas9 Gene Editing
- giarc 11y ago"...potentially serve as a novel and effective platform toward curing AIDS." Researchers are usually quite conservative and the media are usually the ones to sensationalize titles. Given the above quote, this is likely a major step forward.
- falsestprophet 11y ago"potentially serve as a novel... toward curing.." is academic speak for "well, anything's possible"
- deleted 11y ago[deleted]
- agumonkey 11y ago'still better than nothing'
- mikexstudios 11y agoNo, that's standard boilerplate these days in papers. You have to "sell" the science a bit to reviewers and connect your work to the broader picture. Those in the field usually ignore statements like this.
- fluxquanta 11y agoWhen I was a research assistant in college I was encouraged for one of my presentations to emphasize safe hydrogen storage as a vehicle fuel source, when really the research was all about how minuscule amounts of hydrogen change the electrical/optical properties of thin metallic films (and desorption was on the order of days). Selling it as a building block for safer hydrogen storage was necessary to get people engaged.
- refurb 11y agoYup! I published a paper on organoselenium chemistry and was asked to add commentary about potential "anti-cancer" properties. Sure my work could be extended in that direction, but I had done zero work to pursue it.
- giarc 11y agoEven in Nature?
- mikexstudios 11y agoThis paper is in Scientific Reports, which is published by Nature but is not regarded as a top-tier journal. It has an impact factor of 5.5 vs. 41 of Nature. But I would say that "selling the science" occurs more often for high-profile journals because the authors need to convince the reviewers that the paper has a significant impact. Papers in more field-specific journals tend to write conservatively.
- giarc 11y agoOh you're right, I didn't notice that. Thanks for pointing that out.
- astazangasta 11y agoIf you're going to deliver enough lentivirus into an HIV patient to edit all the HIV out of their T-cells, you're going to provoke a massive immune response. This is not the first time people have demonstrated the ability to excise HIV from the genome - I recall a cool system that involved evolving a novel endonuclease that recognized the HIV LTRs. Aha, here: http://www.ncbi.nlm.nih.gov/pubmed/17600219 http://www.ncbi.nlm.nih.gov/pubmed/17600219 This is 2007 - doing this again with CRISPR is, frankly, just using a flashy new toolkit. The fundamental problems with gene therapy remain and are, as usual, the major hurdle to any of this shit being effective. It's easy to edit genomes in a dish; doing it in the human body is orders of magnitude harder.
- fndjdh 11y ago>If you're going to deliver enough lentivirus into an HIV patient to edit all the HIV out of their T-cells, you're going to provoke a massive immune response. Not if the HIV infection has progressed to AIDS. Even with a regular HIV infection the immune response would be diminished.
- astazangasta 11y agoNo; HIV targets CD4+ T cells; you will still have CD8s being activated by the lentivirus all over the body and killing cells in response.
- outworlder 11y ago> If you're going to deliver enough lentivirus into an HIV patient to edit all the HIV out of their T-cells, you're going to provoke a massive immune response From a layman's point of view: isn't that exactly what HIV does in the first place, only faster? As I understand it, on initial infection there can be a major immune response, causing skin rashes or worse.
- noname123 11y agoReading the methods section, it looks the T-cells infected with HIV-1 that are used for targeted for gene editing came from a cell line and incubated in a cultured medium. For people who are involved in dealing with CRISPR/Cas9, what is the effective rate of gene editing done in vitro vs. in vivo? Would the molecular machinery of CRISPR/Cas9 encounter any natural defense mechanism of the human immune system when attempting to mutate target sites on T-cells in say, lymph nodes of adult humans (contrasting to changing DNA in the germ-lines of bacteria or even human embryo's)?
- noipv4 11y agoThis link might be useful for answering your question: http://www.nature.com/nature/journal/v514/n7522/abs/nature13589.html http://www.nature.com/nature/journal/v514/n7522/abs/nature13...
- cryoshon 11y ago>For people who are involved in dealing with CRISPR/Cas9, what is the effective rate of gene editing done in vitro vs. in vivo? Difficult question. CRISPR is ironclad in vitro, but in vivo it's not well understood. For reference, other methods of gene transfer/editing are almost exclusively for in vitro use, with the exception of lentiviral vector-based transduction. >Would the molecular machinery of CRISPR/Cas9 encounter any natural defense mechanism of the human immune system when attempting to mutate target sites on T-cells in say, lymph nodes of adult humans (contrasting to changing DNA in the germ-lines of bacteria or even human embryo's)? Yes. The cell membrane, the nuclear envelope within the cell, and the chromatin/chromosomal structure of the genetic material within the nuclear envelope are huge barriers that can't be skipped across easily when in vivo because many of the convenient work-arounds aren't suitable for in vivo use. Bacteria are always much easier.
- L_Rahman 11y agoThe study used Lentivirus as the delivery mechanism, but ex vivo. I imagine an in vivo study would be the next step, and I'm interested in seeing its outcome.
- 11y ago
- benjismith 11y agoAwesome. I've been avidly following the CRISPR/Cas9 developments over the past five years or so, and the possibilities seem astonishing. I can't wait to see where this all leads!
- azinman2 11y agoSome cool stuff combined with very scary stuff, like eugenics and large scale food chain modifications with unpredictable effects (already being planned with mosquitos).
- sghodas 11y agoThat's also true for most major breakthroughs like this one.
- azinman2 11y agoThere's never been a breakthrough like this -- what you edit dominantly gets transferred to offspring. Previous gene therapies didn't necessarily get propagated, which means any mistakes are permanent.... the potential for disaster is huge.
- foxylad 11y agoUntil we completely understand the risks, perhaps we should make a rule not to breed after genetic manipulation. If you want kids and gene therapy, kids first.
- duaneb 11y ago> eugenics Well, in this case CRISPR wouldn't make much sense for negative eugenics—i.e. trimming the gene pool—vs positive eugenics—purposely introducing or manipulating existing genes. While the latter is still scary, it's not exactly close to the mass sterilization people think of.
- azinman2 11y ago
- nonbel 11y agoFigure 1D is said to show "Detection of Cas9 protein by Western blot analysis", so what does "bp" stand for in that figure (above the ladder)? Usually it stands for base pair but that doesn't make sense when looking at protein.
- kyberias 11y agoThat's an obvious error. The scale in the figure is kilo-daltons (for proteins). Bp scale is used in figure 1C (RNA). Perhaps they copy pasted that image when fabric... I mean polishing the images.
- leemailll 11y agoNot knowing hacker news and pubpeer overlaps
- cryoshon 11y agoBase pairs. I don't know the exact math and haven't ever done Westerns, but there's almost certainly a way of converting protein size (typically expressed in kDa) to base pairs, since theoretically a large enough quantity of bp would weigh as much as a protein of a given size. The trick here is to understand that Western blots use gel electrophoresis to detect protein size, meaning that heavier proteins will not traverse as far as lighter proteins.
- kyberias 11y agoCome on. Having actually done Westerns, there is absolutely zero chance that the "bp"=base pair in that figure is on purpose. Western blot is a protein blot and they are always measured by their molecular weight (kDa). Base pairs would make no sense here. The numbers in the image are obviously kilo daltons. How do we know the numbers are kilo daltons? Well, they say they're using β-tubulin as a loading control. β-tubulin's molecular weight is about 50kDa and that's what you can see in the image. Also, look how the headers are not aligned properly in the image. As if the image is a draft.
- zymhan 11y agoApparently this doesn't only diminish the infection, but can supposedly confer resistance? "When evaluating a therapeutic strategy based on CRISPR/Cas9, it is critical to understand that not only will HIV-1 be eliminated from latently infected cells, but the majority of uninfected cells will become resistant to HIV infection. Thus, there is a high likelihood that rebounding viral infections will be contained by the resistant cells."
- L_Rahman 11y agoThis confused me as well. Based on my skimming, the paper doesn't speculate on why this appears to be true, but it's very interesting that the researchers observed this phenomenon at all.
- jameskraus 11y agoHIV is a virus whose genes are rapidly mutating, even in a single individual (due partially to its genome being based on RNA, not DNA). Due to random chance, it's highly likely that an individual will already have a resistant strain of HIV in their body before they underwent this treatment, so after the treatment, only that strain would be left.
- cryoshon 11y agoI was in HIV research for a time. I was unimpressed by this paper's title, introduction, methods, etc, until the part where they discussed correcting infected cells derived from human donors. As a general note, a running joke in the field is that "anyone can cure HIV in vitro", so I practically tuned out the sections where they discussed the work in T-cell cultures. >Lentivirus (LV) mediated Cas9/gRNA delivery suppresses HIV-1 infection in human T-cells. That should be the actual headline of this paper. Yes, it's a big deal that researchers were able to use a lentiviral vector (HIV without the disease causing bits) to genetically alter infected CD4 T-cells. This is a shot at a cure. Simple infection of a person with the CRISPR-fortified lentiviral vector is a new therapy idea which has the potential to trump the current antiretroviral therapies because it can reduce or remove the HIV "viral reservoir"-- the places in the body where HIV can hang out and survive even when being suppressed by antiretroviral therapy. I can imagine a therapy in which the CRISPR-vector is injected into patient lymph nodes and other similar sites with the intent of curing HIV for good. Won't be cheap for another decade, though.
- gravypod 11y agoHow did they narrow down what section of DNA is removed? That sounds to me like the really hard problem here. I'm actually really interested in that kind of work.
- kyberias 11y agoKnowing the exact location in the genome, they amplified the target sequence from the DNA (using PCR) and sequenced it verifying the modification.
- return0 11y agoIf it does what it says on the box, it would be in nature, not scientific reports.
- jcoffland 11y agoIf this pans out I hope there won't be any nonsense where some pharma company charges ~$80k for a full treatment like with the hep C cure.
- roywiggins 11y ago$80k for an HIV cure is cheap compared to a lifetime of HIV treatment. "The most recent published estimate of lifetime HIV treatment costs was $367,134 (in 2009 dollars; $379,668 in 2010 dollars)." http://www.cdc.gov/hiv/programresources/guidance/costeffectiveness/index.html http://www.cdc.gov/hiv/programresources/guidance/costeffecti...
- jacobsimon 11y ago!!! Amazing
- atmosx 11y agoThats the best news I've had in a long time. Great time to be a molecular biologist.
- coryfklein 11y agoIt has been common experience for me to check my internet news feed and see "the cure" for HIV/AIDS/Cancer/Diabetes fairly regularly. This article does not appear to claim to be "a cure", but does seem promising. Can anybody comment on the significance of this and why the layman should care about it?
- azurelogic 11y agoMost HIV treatments center around suppressing the virus. For example, many antivirals used in treatment interfere with viral reproduction. These people are never cured, because part of what HIV does is it inserts itself into the DNA of the infected individual's cells. The technique proposed in this article would be revolutionary because it suggests that we may eventually be able to use CRISPR to selectively cut that HIV DNA out of infected cells, leading to a permanent cure, if 100% eradication of HIV DNA can be achieved. Unfortunately, doing it in a petri dish is much different than doing it in vivo, particularly with 100% eradication.
- x0x0 11y agoif we could create a reasonable number of healthy (uninfected) t-cells, would an individual be left infectious but otherwise asymptomatic (because of the retention of a working immune system)?
- azurelogic 11y agoThis would only make sense if you could make the uninfected t-cells totally resistant to infection. What this paper suggests is that even this would be unnecessary. The combination of antiretrovirals and CRISPR therapy would prevent replication and excise the embedded viral sources. With enough of this combined therapy, eradication may be obtainable, resulting in a properly cured patient.
- medymed 11y agoSeems like it could be effective to use CRISPR/Cas9 to insert the HIV resistance gene mutation (CCR5-delta32, to replace the normal CCR5 gene) into bone marrow stem cells and then inject those into the person after testing the created cells to be HIV negative (or cutting the HIV out by means in this paper). If HIV negative bone marrow cells available were sufficient to do this it could be a 'cure' for the hematopoietic system. Or use HIV-negative induced pluripotent stem (IPS) cell with hematopoietic potential derived from a tissue not normally infected by HIV. Such cells in principle would have a survival advantage over native cells and would effectively perform a bone marrow transplant, maybe helped along by some medicinal guidance. Pies in the sky, but using HIV-negative cells may avoid the problem of removing divergent sequences of HIV in different people and ineffective gDNAs.
- ogreveins 11y agoSo it cuts the genomes out, does it keep the cells alive while doing so? I heard that CRISPR/Cas9 doesn't rejoin the dna it cuts. I'm new to this and would love to know from someone more knowledgeable about this.
- jameskraus 11y agoCells are always poised to repair DNA breaks. For example: over your lifetime, your cells will have repaired thousands of DNA breaks due to gamma radiation. The breaks due to CRISPR/Cas9 are similar to the breaks caused by gamma radiation and likely to be repaired very rapidly. If the DNA break is not resolved, there are other biochemical pathways to lead to apoptosis (programmed cell suicide).