DNA

Researchers Are Using Viruses to Make Superbugs Commit Suicide

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The gene-editing technology called CRISPR has its origins as a bacterial immune system against viruses, a feature which could be turned against them in the future.

By arming bacteriophage viruses with the tools to force bacteria into falling on their own swords, scientists hope we will be able to develop powerful new ways to defeat antibiotic resistant pathogens and perhaps even shape our body’s microflora.

Research presented at the CRISPR 2017 conference in the US described the progress that has been made in modifying viruses that target specific bacteria with genes that make the host’s enzymes cut into its own DNA.

Clustered regularly interspaced short palindromic repeats – CRISPR for short – are sequences of DNA made of a repeating codes that form a long palindrome.

Bacteria produce them as a kind of immune system against viruses called bacteriophages, slipping bits of the virus’s genes scavenged out of the environment into the repeating codes.

With the viral DNA stored away in CRISPR sequences, any future infections can be detected quickly and a CRISPR-associated system (or cas) enzyme can then use the sequence as a beacon, latching onto the infecting virus genes and either snipping them selectively or tearing them to shreds.

About 25 years ago, researchers realised this cut-and-paste system of CRISPR sequences and cas enzymes could be used in the lab to edit sequences artificially, and a new engineering toolkit was born.

The technology has been in the news quite a bit in recent years as advances have been made in applying it to cancer treatments and even eliminating HIV infections.

While it might not be without certain risks, CRISPR gene editing has sparked a something of a minor revolution.

Bringing it back to its roots and turning it into a weapon against its creators has a sense of serendipity about it.

“I see some irony now in using phages to kill bacteria,” said the chief scientific officer of Locus Biosciences, Rodolphe Barrangou, at the CRISPR 2017 conference.

Using bacteriophages as a form of therapy to treat infection isn’t all that new, with trials dating as far back as the 1920s.

The use of phages is appealing because they are far more specific than antibiotics, targeting only specific types of bacteria and therefore posing no risk to our own health. The viruses can also penetrate the coatings of sticky film bacteria produce for protection and adherence.

Russia experienced a fair degree of success with phage therapy behind its Iron Curtain during the Cold War, but unable to patent the naturally occurring viruses and with the bacteria quickly adapting, red tape and limitations in technology have made it far easier to focus on antibiotics in the west.

With looming epidemics of superbugs on the horizon, attention is returning to bacteriophages as ways to kill bacteria, and CRISPR has put a new spin on the old idea.

A spin-off company from North Carolina State University, Locus Biosciences is testing the limits of CRISPR technology, including giving bacteriophages CRISPR sequences containing codes for antibiotic resistance genes.

Targeting bacteria with the genes, the CRISPR sequence would form a target for the bacteria’s own cas enzymes, effectively blocking resistance or even prompting the bacteria into chewing up its own DNA and self-destructing.

In recent years our eyes have been opened to how complex our relationship is with bacteria in our environment, and how dull our tools are for dealing with them.

Variations in our gut microflora has been linked with everything from Parkinson’s disease to autism to obesity, suggesting the species of bacteria we harbour could have major ramifications on many aspects of our health.

With its razor-honed surgical precision, it’s possible the technology could one day be used to select specific strains of bacteria in our gut, deleting them from the ecosystem and allowing us to edit our microbiomes.

Given we’re practically at the dawn of both CRISPR technology and our grasp on the complexity behind our body’s bacterial ecosystems, we can only speculate for the time being.

As antibiotics slowly lose their shine it’s probably worth paying close attention to radical new solutions such as these.

Source: 1

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China on the verge of re-writing HUMAN DNA!

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Next month, Chinese researchers will edit adult human DNA using the revolutionary CRISPR/Cas-9 tool, commonly known as CRISPR, for the first time anywhere in the world.

The researchers will attempt to cut faulty DNA out of the cells of lung cancer patients who have failed to respond to all other conventional treatments.

Chinese scientists have previously used CRISPR on non-viable human embryos, without much luck, but this is the first time any researchers, anywhere in the world, will use the tool to edit DNA in an adult. 

If successful, the hope is that it could lead to further CRISPR treatments – CRISPR/Cas-9 allows researchers to effectively cut and paste DNA in cells, and, in animals, it’s already been shown to treat genetic diseases such as Duchenne muscular dystrophy.

The new trial will begin at Sichuan University’s West China Hospital next month, according to Nature, and will involve patients who’ve already gone through chemotherapy and radiation therapy – in other words, are out of options.

 In the past, scientists have spoken out about the ethical concerns surrounding the use of CRISPR, which is capable of causing genetic changes to sperm and egg cells that can be passed down to future generations.

There are also concerns that it could lead to the development of ‘designer’ babies – where parents pick and choose certain traits to write into their child’s DNA.

But it’s important to note that the new Chinese study will only edit patients’ immune system T-cells, and not affect gamete cells that could be passed down to offspring.

In other words, the changes made by CRISPR will be limited to the patient involved in the trial – a number that hasn’t been disclosed as yet.

We do know what the process will involve, though.

In the trial, the Chinese scientists will extract T-cells from patients’ blood and delete a gene that produces a protein called PD-1, which stops T-cells from targeting and killing cancer cells, from their DNA.

The team will then multiply these new CRISPR-modified T-cells in the lab, before injecting them back into the patients to flood their immune system.

The hypothesis is that, with PD-1 inhibited, the T-cells will be able to track down and wipe out lung cancer cells naturally.

While CRISPR/Cas-9 is capable of also inserting new DNA into a cell’s genome, in this study, genetic information will only be deleted, not added.

This is a similar process to immunotherapy studies that are already common around the world – researchers take immune cells, genetically modify them, and insert them back into patients. In fact, gene editing has already saved the life of a girl with ‘incurable’ leukaemia.

But what’s different in this case is the use of CRISPR, which is incredibly simple and versatile.

While in the past it’s taken years for scientists to develop the right molecular ‘scissors’ to cut out specific genes, CRISPR simply needs to be programmed and can then work for any part of the genome – no costly development required.

Last month, the US National Institutes of Health (NIH) approved a similar trial in the states – although the American research will also add an extra gene to help combat three types of cancer: melanoma, sarcoma, and myeloma. 

The research could begin as early as this year, but if reports are anything to go off, China will be the first to try out this incredibly powerful tool in humans.

Source: 1

 

DNA-based monoclonal antibody technology to cure HIV

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Inovio Pharmaceuticals, Inc., an immunotherapy company,  announced that its novel DNA-based monoclonal antibody technology will be deployed to develop products which could be used alone and in combination with other immunotherapies in the pursuit of new ways to treat and potentially cure infection from the HIV virus.

In a recently published article, Inovio demonstrated that a single administration in mice of a highly optimized dMAb DNA, which targets HIV, generated antibody molecules in the bloodstream that possessed desirable functional activity including high antigen-binding and HIV-neutralization capabilities against diverse strains of HIV viruses.

Funding for Inovio’s effort to treat and potentially cure HIV is part of a $23 million grant from the National Institutes of Health to The Wistar Institute, an Inovio collaborator. This grant brings together Inovio and more than 30 of the nation’s leading HIV investigators to work on finding a cure for the virus. The grant, called BEAT-HIV: Delaney Collaboratory to Cure HIV-1 Infection by Combination Immunotherapy, is one of six awarded by the NIH as part of the Martin Delaney Collaboratories for HIV Cure Research.

“A simple, safe and scalable cure for HIV would accelerate progress toward ending the HIV/AIDS pandemic,” said National Institute of Allergy and Infectious Disease (NIAID) Director Anthony S. Fauci, M.D. “Through the leadership of talented investigators with a diversity of expertise, the Martin Delaney Collaboratory programme will accelerate progress in this key research endeavor.”

Dr. J. Joseph Kim, Inovio’s president & CEO, said, “With 37 million people infected with HIV still awaiting a cure to HIV, we are pleased that our new HIV dMAb products are expanding our initiative alongside our breakthrough DNA vaccine products to potentially help these patients.”

Inovio has demonstrated experience in advancing HIV product candidates. Inovio completed initial clinical studies of its HIV immunotherapy PENNVAX-B, targeting clade B viruses, to achieve proof of principle in generating potent immune responses using its SynCon immunotherapy technology. In two published phase I studies, PENNVAX-B immunization generated high levels of activated, antigen-specific CD8+ killer T cells with proper functional characteristics. This ability uniquely positioned PENNVAX as an important vaccine candidate to prevent and treat HIV infections.

Using a $25 million grant from the NIAID, Inovio designed its universal, multi-antigen PENNVAX-GP vaccine targeting the env, gag and pol antigens to provide global coverage against all major HIV-1 clades. PENNVAX-GP is Inovio’s lead preventive and therapeutic immunotherapy for HIV and is being evaluated in a phase I clinical study (HVTN-098) involving 94 healthy subjects as a preventive vaccine.

Monoclonal antibodies (mAb) were a transformational scientific innovation designed to enhance the immune system’s ability to regulate cell functions. They are designed to bind to a very specific epitope (area) of an antigen or cell surface target and can bind to almost any selected target.

The paradigm shift of Inovio’s technology is that the DNA for a monoclonal antibody is encoded in a DNA plasmid, delivered directly into cells of the body using electroporation, and the mAbs are “manufactured” by these cells. Using this newly patented approach, Inovio published that a single administration of a highly optimized DNA-based monoclonal antibody targeting HIV virus in mice generated antibody molecules in the bloodstream possessing desirable functional activity including high antigen-binding and HIV-neutralization capabilities against diverse strains of HIV viruses. The potential of this technology was further demonstrated in two additional published studies where dMAb products for Chikungunya and dengue viruses were able to completely protect the treated mice from lethal exposure to these viruses.

All of these feats were not previously achievable with other DNA-based or viral delivery technologies. Inovio’s transformational approach could be applied to develop active monoclonal antibody products against multiple therapeutically important diseases including cancers as well as inflammatory and infectious diseases. Combined with favorable pharmacokinetic characteristics and cost structure compared to conventional monoclonal antibody technology, Inovio’s active in-body generation of functional monoclonal antibodies in humans has the potential to significantly expand the range of targetable diseases.

Monoclonal antibodies as a product class have become one of the most valuable therapeutic technologies of recent years. In 2012, global sales value of monoclonal antibodies exceeded $50 billion. Among the top 10 best-selling drugs in 2012, six of them were monoclonal antibodies, each with annual sales exceeding $5 billion.

Source: 1, 2

AbbVie begins phase III study of Veliparib in patients with advanced breast cancer

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AbbVie announced the initiation of a Phase III clinical trial evaluating the safety and efficacy of its investigational compound, veliparib (ABT-888), when added to carboplatin and paclitaxel, two chemotherapeutic medicines, in patients with advanced breast cancer. Specifically, the combination of veliparib, carboplatin and paclitaxel will be compared to treatment with carboplatin, paclitaxel and placebo in patients with human epidermal growth factor receptor 2-(HER2) negative metastatic or locally-advanced breast cancer, containing BRCA1 and/or BRCA2 gene mutations.

“Our Phase III programme for veliparib represents an innovative approach to developing this type of anti-cancer compound. By adding veliparib to DNA-damaging therapies, such as carboplatin and paclitaxel, we can evaluate its potential to provide incremental benefit to existing treatments,” said Michael Severino, M.D., executive vice president, research and development and chief scientific officer, AbbVie. “This is the third Phase III trial evaluating the efficacy and safety of veliparib, and the second evaluating the addition of veliparib to chemotherapy for the treatment of patients with difficult-to-treat forms of breast cancer.”

The randomised, double-blind, Phase III clinical trial will recruit approximately 270 patients. The primary efficacy outcome of the trial is progression-free survival (PFS). The secondary pre-specified outcome measures include overall survival (OS), clinical benefit rate (CBR), objective response rate (ORR) and duration of response (DOR).

Veliparib is an investigational oral poly (adenosine diphosphate [ADP]–ribose) polymerases (PARP) inhibitor being evaluated in multiple tumour types. PARP is a naturally-occurring enzyme in the body that repairs damage to DNA, and in certain types of cancers, repairs cancer cells. Discovered and developed by AbbVie researchers, veliparib is being developed to help prevent DNA repair in cancer cells and increase the effectiveness of common DNA-damaging therapies like chemotherapy or radiation. Veliparib is currently being studied in more than a dozen cancers and tumour types, including Phase III studies in non-small cell lung cancer and breast cancer.

Breast cancer is the second most common cancer in the world and the most commonly diagnosed cancer in women worldwide.1 The HER2 gene, which normally helps cells in the breast remain healthy and function normally, can play a role in the development of breast cancer. Specifically, in approximately 25 per cent of breast cancers, the HER2 gene does not work properly, causing cells in the breast to grow and divide in an uncontrolled way. This process, known as HER2 gene amplification or over expression, results in HER2-positive breast cancer. HER2-positive breast cancers tend to grow faster, metastasize more quickly and are more likely to recur, compared to patients diagnosed with HER2-negative breast cancer.

It is estimated that at least five percent of breast cancer cases result from inherited mutations or alterations in the BRCA1 and BRCA2 breast cancer susceptibility genes. Women with these mutations have a 40- to 85-per cent lifetime risk of developing breast cancer. Additionally, men with BRCA2 mutations carry an increased risk of breast cancer.

  Source: PharmaBiz

Inovio Pharma breakthrough DNA-based monoclonal antibody therapy protects animals from lethal viral challenge

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Inovio Pharmaceuticals announced that its novel DNA-based therapeutic monoclonal antibody targeting Chikungunya virus (CHIKV) completely protected mice from a lethal CHIKV challenge. In this preclinical study, a prototype DNA plasmid construct encoding for a monoclonal antibody for CHIKV envelope protein was created using Inovio’s patented DNA optimisation technology and delivered with its Cellectra device. The results were presented as a poster at the 17th Annual Meeting of the American Society of Gene & Cell Therapy in Washington, DC.

Chikungunya virus (CHIKV) has re-emerged as a serious mosquito-borne alpha-virus responsible for several recent epidemics in tropical Africa and Asia. Recent evidence suggests that CHIKV, which is primarily transmitted to humans from mosquitoes, could spread to other parts of the world.  There is no vaccine or therapeutic against this virus.

In this presented study, Inovio scientists and collaborators developed a novel DNA plasmid encoding a highly engineered immunoglobulin encoding a CHIKV monoclonal antibody (mAb) to directly generate in vivo production of an anti-CHIKV mAb in mice. They demonstrated that the serum of transfected animals exhibited the specific ability to bind to the CHIKV envelope antigen and this serum possessed CHIKV-neutralising activity. Importantly, the treatment of the animals with anti-CHIKV mAb plasmids protected 100 per cent of the treated animals from a lethal injection of CHIKV virus while 100 per cent of the control animals died. The treated animals were also spared of virus-related morbidity, as measured by dramatic weight loss and lethargy.

Monoclonal antibodies (mAb) were a transformational scientific innovation designed to enhance the immune system’s ability to regulate cell functions. They are designed to bind to a very specific epitope (area) of an antigen or cell surface target and can bind to almost any selected target. mAbs have the unique ability to alert the immune system to attack and kill specific cancer cells (as in the case of Yervoy) or block certain biochemical pathways (such as those leading to rheumatoid arthritis, as in the case of Remicade). However, mAb technology has limitations. Delivered by passive administration, meaning they are manufactured outside the body, mAbs typically require costly large-scale laboratory development and production. Additional limitations include the necessity for repeat administrations and their limited duration of in vivo potency.

The paradigm shift of Inovio’s technology is that the DNA for a monoclonal antibody is encoded in a DNA plasmid, delivered directly into cells of the body using electroporation, and the mAbs are “manufactured” by these cells. Using this patent-protected approach, Inovio previously published that a single administration of a highly optimised DNA-based monoclonal antibody targeting HIV virus in mice generated antibody molecules in the bloodstream possessing desirable functional activity including high antigen-binding and HIV-neutralisation capabilities against diverse strains of HIV viruses. This new work further demonstrates the capability of this technology using a CHIKV challenge model.

All of these feats were not previously achievable with other DNA-based or viral delivery technologies. Inovio’s transformational approach could be applied to develop active monoclonal antibody products against multiple therapeutically important diseases including cancers as well as inflammatory and infectious diseases. Combined with the significantly favorable cost structure of Inovio’s DNA-based technology in comparison to conventional monoclonal antibody technology, active in-body generation of functional monoclonal antibodies in humans has the potential to significantly expand the range of targetable diseases.

“Inovio continues to demonstrate that it is one of the most innovative and scientifically productive biotechnology companies in our industry,” stated Dr. J. Joseph Kim, President and cief executuiuve officer, “We have again shown that we can design a novel mAb construct capable of providing therapeutic benefit and are confident we can create DNA-based monoclonal antibodies against any infectious disease or cancer. These advancements represent a new area of value enhancement for Inovio stakeholders and we plan to develop multiple important monoclonal product candidates, alone or with new partners.”

Monoclonal antibodies have become one of the most valuable therapeutic technologies of recent years. In 2012, global sales value of monoclonal antibodies exceeded $50 billion. Among the top 10 best-selling drugs in 2012, six of them were monoclonal antibodies, each with annual sales exceeding $5 billion.

Source: PharmaBiz