New Autoimmune Treatment Removes Rogue Immune Cells Without Suppressing the Immune System


New preclinical experiments by scientists at the University of Pennsylvania have established that genetically engineered T-cells can drive severe autoimmune diseases into remission without suppressing the patient’s immune system. If the principles applied in this study also prove to be true in human patients, they can potentially revolutionize the treatment of autoimmune diseases.

Autoimmune diseases result when your immune system recognizes your own cells and tissues as foreign and mounts and immune response against them. Autoimmune diseases like systemic lupus erythematosus (also known as “lupus”), rheumatoid arthritis, scleroderma, multiple sclerosis, celiac disease, Sjögren’s syndrome, polymyalgia rheumatic, or ankylosing spondylitis can deeply affect the health of an individual and can also cause large amounts of tissue damage.

Treatment of autoimmune diseases usually requires high doses of drugs that suppress the immune system, such as corticosteroids, or various types of biological agents that also cause a host of undesirable side effects.

This new study, however, by scientists from the Perelman School of Medicine at the University of Pennsylvania have adapted an already-existing technology to remove the subset of antibody-making cells that cause the autoimmune disease. This strategy removes the rogue immune cells without harming the rest of the immune system.

In these experiments, the University of Pennsylvania team examined an autoimmune disease called pemphigus vulgaris or PV. PV results when the immune system recognizes a protein called desmoglein-3 (Dsg3) as foreign and attacks it. Dsg3 helps form attachment sites called “desmosomes” that normally adhere skin cells together to form tight, tough sheets. Desmosomes are also found between epithelial cells, myocardial cells, and other cell types.

desmosomes

Current therapies for autoimmune diseases like PV use drugs like prednisone and rituximab, which suppress large parts of the immune system. Consequently, prednisone and rituximab can leave patients vulnerable to potentially fatal opportunistic infections and cancers.

To treat PV, University of Pennsylvania researcher Aimee Payne and her colleagues used a mouse version of PV that is fatal in mice. Their experimental treatment, however, successfully treated this otherwise fatal autoimmune disease without causing any unintended side effects, which might harm healthy tissue. The results from these experiments were published in the journal Science.

“This is a powerful strategy for targeting just autoimmune cells and sparing the good immune cells that protect us from infection,” said Dr Payne, who serves as the Albert M. Kligman Associate Professor of Dermatology at the Perelman School of Medicine.

In collaboration with Dr. Michael Milone, assistant professor of Pathology and Laboratory Medicine, Payne and her colleagues adapted the Chimeric Antigen Receptor T-Cell (CART-Cell) technology that is being successfully used to experimentally treat malignant cells in certain leukemias and lymphomas. “Our study effectively opens up the application of this anti-cancer technology to the treatment of a much wider range of diseases, including autoimmunity and transplant rejection,” Milone said.

Aimee Payne, Michael Milone, Christoph Ellebrecht, left to right
Aimee Payne, Michael Milone, Christoph Ellebrecht, left to right

CART-Cells are T-lymphocytes that have been extracted from the peripheral blood of cancer patients and then genetically engineered to express a receptor that specifically recognizes a protein on the surface of tumor cells. These chimeric antigen receptor (CAR)-expressing cytotoxic T-lymphocytes have the ability to recognize and destroy tumor cells, which shrinks the tumor and potentially cures the patient.

CAAR technology

The core concepts behind CAR T-cells were first described in the late 1980s. Unfortunately, technical challenges prevented the development of this technology until later. However, since 2011, experimental CAR T cell treatments for B cell leukemias and lymphomas have been successful in some patients for whom all standard therapies had failed.

Antibody-producing B-lymphocytes or B-cells can also cause autoimmunity. A few years ago, a postdoctoral researcher in Payne’s laboratory named Dr. Christoph T. Ellebrecht came upon CAR T cell technology as a potential strategy for deleting rogue B-cells that make antibodies against a patient’s own tissues. Soon Payne and her team had teamed up with Milone’s, which studies CAR T cell technology. Their goal was to find a new way to treat autoimmune diseases.

“We thought we could adapt this technology that’s really good at killing all B cells in the body to target specifically the B cells that make antibodies that cause autoimmune disease,” said Milone.

“Targeting just the cells that cause autoimmunity has been the ultimate goal for therapy in this field,” noted Payne.

Because an excellent mouse model existed for PV, Payne and Milone decided to examine pemphigus vulgaris. Since PV consists of a patient’s antibodies attacking those molecules that normally keep skin cells together, it can cause extensive skin blistering and is almost always fatal. PV is treatable with broadly immunosuppressive drugs such as prednisone, mycophenolate mofetil, and rituximab.

However, to treat PV without causing broad immunosuppression, the Penn team designed an artificial CAR-type receptor that would home the patient’s own genetically engineered T-cells exclusively to those B-cells that produce harmful anti-Dsg3 antibodies.

Payne and Milone and their colleagues developed a “chimeric autoantibody receptor,” or CAAR, that displays fragments of the Dsg3 on their cell surfaces. Since the Dsg3 protein is the target of the PV-causing B-cells, the CAAR acts as a lure for the rogue B cells that target Dsg3. The CAAR effectively brings the cells into fatal contact with the therapeutic T cells.

After testing a battery of different cultured, genetically engineered T-cells, these teams eventually found a CAAR that worked well in cell culture and enabled host T cells to efficiently destroy anti-desmoglein-producing B-cells. These cultured cells worked so well that they even killed B-cells isolated from PV patients. The engineered CAAR T cells also performed successfully in a mouse model of PV. The CAAR T-cell effectively killed desmoglein-specific B cells, prevented blistering, and other manifestations of autoimmunity in the animals. “We were able to show that the treatment killed all the Dsg3-specific B cells, a proof of concept that this approach works,” Payne said.

Not only were these treatments devoid of undesirable side effects in the laboratory mice they studied, but they maintained their potency despite the presence of high levels of anti-Dsg3 antibodies that might have swamped out their CAARs.

Next, Payne plans to test her treatment in dogs, which can also develop PV and often die from it. “If we can use this technology to cure PV safely in dogs, it would be a breakthrough for veterinary medicine, and would hopefully pave the way for trials of this therapy in human pemphigus patients,” Payne said.

Penn scientists would also like to develop applications of CAAR T cell technology for other types of autoimmunity. Organ transplant rejection, which is also related to autoimmunity, complicates organ transplants, and normally requires long-term immunosuppressive drug therapy, may also be treatable with CAAR T cell technology.

“If you can identify a specific marker of a B cell that you want to target, then in principle this strategy can work,” Payne said.

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SanBio, Inc Moves Forward With Clinical Stem Cell Trial for Traumatic Brain Injury in Japan


Traumatic brain injuries can result from a variety of causes, ranging from car accidents, falls, occupational hazards, and sports injuries. The cause of traumatic brain injury (TBI) differs from that of ischemic stroke, but many of the clinical manifestations are somewhat similar (motor deficits). Such injuries can cause lifelong motor deficits, and there are currently no approved medicines for the treatment of persistent disability from traumatic brain injury.

SanBio, Inc., has completed the regulatory requirements to conduct a clinical trial using their proprietary SB623 regenerative cell therapy to treat patients who suffer from TBI. The obligatory 30-day review period of clinical trial notification by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) was completed on March 7, 2016. No safety concerns were voiced, and the trial can proceed.

SanBio’s clinical trial is entitled “Stem cell therapy for traumatic brain injury” or STEMTRA, and it will study the safety and efficacy of SB623 cell therapy in treating patients who suffer from chronic motor impairments following a TBI.

Enrollment in this clinical trial started in the United States in October, 2015. The trial will include clinical sites and patients in Japan and will enroll ~52 patients. The enrollment of Japanese patients is expected to accelerate the overall enrollment of human subjects.

SanBio spokesperson, Damien Bates, the Chief Medical Officer and Head of Medical Research at SanBio, said: “SanBio’s regenerative cell medicine, SB623, has improved outcomes in patients with persistent motor deficits due to ischemic stroke, and our preclinical data suggest that it may also help TBI patients.  This is the first global Phase 2 clinical trial for TBI allogeneic stem cells, and the approval to conduct the trial in Japan, as well as in the United States, brings us one step closer to determining SB623’s efficacy for treatment whose who suffer from the effects of traumatic brain injury.”

SB623 are modified mesenchymal stem cells that transiently express a modified human Notch1 gene that only contains the intracellular domain of the Notch1 protein. This activated gene drives mesenchymal stem cells to form a cell type that habitually supports neural cells and promotes their health, survival, and healing.  When administered into damaged neural tissue, SB623 reverses neural damage. Since SB623 cells are allogeneic (from a donor), a single donor’s cells can be used to treat many patients. In cell culture and animal models, SB623 cells restore function to damaged neurons associated with stroke, traumatic brain injury, retinal diseases, and Parkinson’s disease. SB623 cells function by promoting the body’s natural regenerative process.

SanBio recently completed a US-based Phase 1/2a clinical trial for SB623 in patients with chronic motor impairments six months to five years following an ischemic stroke. The results of this trial demonstrated that SB623 can improve motor function following a stroke. On the strength of these results, SanBio initiated a Phase 2b randomized, double-blind, clinical trial of 156 subjects began enrollment in December 2015.  This trial is entitled ACTIsSIMA (“Allogeneic Cell Therapy for Ischemic Stroke to Improve Motor Abilities”).

Since the therapeutic mechanism of action of SB623 cells and the proposed route of administration are similar in the two trials (the stroke and TBI trials), the results of the TBI trial should be similar to those of the stroke trial.

The Japanese regulatory agencies grant marketing approval for regenerative medicines earlier countries as a result of an amendment to the Pharmaceutical Affairs Law in 2014. This particular amendment defined regenerative medicine products as a new category in addition to conventional drugs and medical devices, and the conditional and term-limited accelerated approval system for regenerative medicine products has started.

Two regenerative medicine products have already gained marketing approval under this new system, and the government-led industrialization of regenerative medicine products has gradually been realized.

SanBio has begun the preparation of clinical trial facilities in Japan and expects the launch of the clinical trial in 2016. the company hopes to market the medicine in Japan by taking advantage of the accelerated approval system.

New Gene Therapy Treatment Stops Deadly Brain Cancer in its Tracks


Brain cancers called Diffuse Intrinsic Pontine Gliomas (DIPGs) are often a death sentence. These aggressive, fast-growing, drug-resistant tumors are deadly and they originate from glial cells in the brain.

However a recent report published in the journal Cancer Cell details an experimental gene therapy that stops DIPGs in their tracks. This study included researchers from several different institutions, but was led by scientists at Cincinnati Children’s Hospital Medical Center. The study examined human cancer cells and a mouse model of DIPG.

DIPGs seem to require a gene called Olig2 (which encodes a transcription factor) to grow and survive. The majority of gliomas express the protein encoded by the Olig2 gene and removing this gene halts tumor growth and liquidating Olig2-producing cells inhibits tumor formation. This collaborative team designed a technique scientists found a way to use a gene therapy to shut down Olig2 expression.

“We find that elimination of dividing Olig2-expressing cells blocks initiation and progression of glioma in animal models and further show that Olig2 is the molecular arbiter of genetic adaptability that makes high-grade gliomas aggressive and treatment resistant,” said Qing Richard Lu, PhD, lead investigator and scientific director of the Brain Tumor Center at Cincinnati Children’s. “By finding a way to inhibit Olig2 in tumor forming cells, we were able to change the tumor cells’ makeup and sensitize them to targeted molecular treatment. This suggests a proof of principle for stratified therapy in distinct subtypes of malignant gliomas.”

DIPGs originate from supporting brain cells called oligodendrocytes. Oligodendrocytes make the insulation that surrounds the axons of various nerves in the central nervous system. Olig2 expression appears at the early stages of brain cell development, and is also present in the early-stage dividing and replicating cells in tumors. Olig2 also participates in the transformation of normal oligodendrocyte progenitor cells (OPCs) into cancer cells that divide uncontrollably. Olig2 also facilitates the adaptability of gliomas that helps them evade chemotherapeutic regimens. Indeed, clinically speaking, DIPGs may initially respond to chemotherapeutic agents, but they tend to quickly adapt to these drugs and develop high-levels of resistance to them.

Lu and his colleagues and collaborators eliminated Olig2-positive dividing cells from DIPG tumors that were still in the early stages of tumor formation. Lu and his colleagues used an ingenious technique to remove Oligo2 expression: by genetically engineering a herpes simplex virus-based vector, they delivered a suicide gene (Thymidine kinase) into replicating Olig2-positive cancer cells. Since herpes simplex viruses (HSVs) have the ability to grow in neurons that do not divide a great deal, the HSV-vectors are well suited to this purpose. After infecting the early DIPG cells with the HSV vectors, they administered an anti-herpes drug already in clinical use, ganciclovir (GCV), which kills any cells that have the thymidine kinase gene. The Olig2-deleted tumors were not able to grow.

In follow-up work, Lu and his colleagues observed a fascinating fate for the Olig2- tumors. These cells differentiated into astrocyte-like cells that continued to form tumors, but expressed the epidermal growth factor receptor (EGFR) gene at high levels. EGFR is an effective target for several chemotherapy drugs. In repeated tests in mouse models, Olig2 inhibition consistently transformed the glioma-forming cells into EGFR-expressing astrocyte-like cells. Then these tumors were treated with an EGFR-targeted chemotherapy drug called gefitinib. These treatments stopped the growth of new tumor cells and tumor expansion.

According to Dr. Lu, with additional testing, verification, and, of course, refinement, this experimental therapy that he and his colleagues have designed, could help prevent the recurrence of brain cancer in patients who have undergone initial rounds of successful treatment. Lu also added that these new treatments would probably be used in combination with other existing therapies like radiation, surgery, other chemotherapies and targeted molecular treatments.

Lu and his team will continue their research with other human cell lines and “humanized” mouse models of high-grade glioma. Such mouse models use genetically engineered mice that can grow brain tumors derived from the tumor cells of specific human patients. These tumor cells come from the tumors of patients whose families have donated biopsied tumor samples for research. This allows researchers to test different targeted drugs in their therapeutic protocol that may best match the genetic makeup of tumors from specific individuals.

The entire research team cautions the experimental therapeutic approach they describe will require extensive additional research. Therefore, this type of treatment is years away from possible clinical testing. Having said that, Lu said the data are a significant research breakthrough, since this study identifies a definite weakness in these stubborn cancers that almost always relapse and kill the patients who get them.

First Patient Randomized for ACTIsSIMA Trial for Chronic Stroke


SanBio, a regenerative medicine company in Mountain View, California, has announced the randomization of the first enrolled patient in the ACTIsSIMA Phase 2B clinical trial. This trial will examine the efficacy of SanBio’s proprietary SB623 product in patients who suffer from chronic motor deficits as a result of strokes. SB623 consists of modified adult bone-marrow-derived stem cells. A secondary purpose of this trial is to evaluate the safety of SB623 in these patients.

Ischemic strokes account for about 87 percent of all strokes in the United States. Ischemic strokes occur when there is an obstruction in one or more of the blood vessels that provide blood and oxygen to the brain. On the order of 800,000 cases of ischemic stroke occur in the United States every year, and it is the leading cause of acquired disability in the United States. Present drug treatments for stroke either try to prevent strokes or address patients who have recently suffered a stroke. Unfortunately, there are no medical treatments currently available for people who live with the effects of stroke, months or even years after suffering a stroke.

SB623 cells are derived from bone marrow mesenchymal stem cells extracted from healthy donors. These cells are designed to promote recovery from injury by triggering the brain’s natural regenerative ability. SB623 cells have been genetically engineered to express a modified version of the Notch gene (NICD) that conveys upon the cells the ability to promote the formation of new blood vessels and the survival of endothelial cells that form these new blood vessels (see J Transl Med. 2013, 11:81. doi: 10.1186/1479-5876-11-81).

SB623 was tested in a Phase 1/2A clinical trial in which SB623 was implanted into stroke patients and produced some improved motor function.

This follow-up trial, ACTIsSIMA, will treat stroke patients with SB623 cells in order to examine the safety and efficacy of SB623 cells. All patients in this trial have suffered from a stroke anywhere from six months to five years. Also, all patients must exhibit chronic motor impairments.

Damien Bates, M.D., Chief Medical Officer & Head of Research at SanBio, said, “Our previous trial suggested there was potential for SB623 to improve outcomes for patients with lasting motor deficits following an ischemic stroke. Randomization of the first subject marks an exciting step toward further evaluating this treatment as a promising new option for patients.”

For this trial, SanBio is collaborating with Sunovion Pharmaceuticals, Inc. Sunovion is a wholly owned subsidiary of Sumitomo Dainippon Pharma Co., Ltd., and SanBio and Sumitomo Dainippon Pharma have entered into a joint development and license agreement for exclusive marketing rights in North America for SB623 for chronic stroke.

The ACTIsSIMA trial will include approximately 60 clinical trial sites throughout the United States, and total enrollment is expected to reach 156 patients.

VM202 is a Safe, Beneficial Treatment for Limb Ischemia


The Korean biotechnology company ViroMed Co., Ltd. has announced the publication of a Phase 2 study that evaluated their VM202 product in patients with critical limb ischemia. This study involved 52 patients in the United States and showed that VM202 is not only safe, but also produced significant clinical benefits.

VM202 is a plasmid (small circle of DNA) that encodes the human hepatic growth factor (HGF) gene. When injected into muscles, VM202 is readily taken up by nearby cells that then quickly synthesize the two isoforms of HGF. Heightened HGF concentrations can treat ischemic cardiovascular diseases by inducing the formation of new blood vessels (angiogenesis). These new collateral vessels increase blood flow and tissue perfusion in the sick tissue, which effectively treats any tissue ischemia.

VM202

Severe obstruction of the arteries that feed the extremities (hands, feet and legs) is the cause of critical limb ischemia (CLI). The term “ischemia” refers to the starvation of a tissue for oxygen. The lack of sufficient blood flow to an organ or tissue can cause severe pain and even skin ulcers, sores, or gangrene. CLI-induced pain can awaken the patient during the night, and, therefore, is called “rest pain.” Rest pains often occur in the leg and is usually temporarily relieved by dangling the leg over the bed or getting up and walking.

CLI does not improve on its own. It is a severe condition that requires immediate by a vascular surgeon or vascular specialist.

Look at the right side of these angiograms and you will see that a vessel is obstructed and blood is not flowing through it. This is an example of Critical Limb Ischemia.
Look at the right side of these angiograms and you will see that a vessel is obstructed and blood is not flowing through it. This is an example of Critical Limb Ischemia.

In this Phase 2 study, patients were divided into three groups, one of which received a placebo treatment, the second of which received a low-dose treatment VM202, and a third group that received a high-dose of VM202.

Both patient groups that received VM202 showed improvement compared to the placebo group, but patients in the higher-dose group showed significantly better ulcer healing and higher tissue oxygen levels than the placebo group. For example, 62 percent of the ulcers healed in patients treated with high-dose VM202 compared to only 11 percent of ulcers in patients who were treated with the placebo. Also, 71 percent of patients who received the high-dose VM202 showed improved oxygen concentrations in their tissues, compared to only 33 percent of patients who were treated with the placebo.

Emerson C. Perin, Director of the Stem Cell Center at the Texas Heart Institute and the principal investigator of this Phase 2 study, said: “These positive results are exciting, and VM202 shows great promise for treating patients with this debilitating disease who often have limited therapeutic options. We are looking forward to conducting a phase III trial to better understand the potential of this novel approach, especially in treating non-healing ulcers, which is a serious symptom that often leads to amputation because of the lack of medical therapies available.”

ViroMed has already been granted an IND or Investigational New Drug approval by the USFDA to initiate a Phase 3 study in diabetic patients who suffer from non-chronic ischemic foot ulcers. This study will enroll 300 subjects who will be divided into a VM202 group and a placebo group. The treatment regiment will mimic that of this smaller Phase 2 study and will only follow patients for seven months. This time, ViroMed is interested in determining if VM202 helps wound closure, which will constitute the primary efficacy endpoint on this new study.

Godspeed ViroMed!!

Noninvasive, Targeted, and Non-Viral Ultrasound-Mediated GDNF-Plasmid Delivery for Treatment of Parkinson’s Disease


A growth factor called Glial cell line-derived neurotrophic factor (GDNF) has the remarkable ability to supports the growth and survival of dopamine-using neurons. Dopamine-using neurons are the cells that die off in Parkinson’s disease (PD). Providing GDNF to dopamine-using neurons can help them survive , but getting GDNF genes into the central nervous system relies on invasive intracerebral injections in order to pass through the blood-brain barrier.

Typically, genes are placed into the central nervous system by means of genetically engineered viruses. Viruses, however, are often recognized by the immune system and are destroyed before they can deliver their genetic payload. Therefore, non-viral gene delivery that can pass through the blood-brain barrier is an attractive alternative, since it is non-invasive. Unfortunately, such a high-yield technique is not yet available.

A new study by workers in the laboratories of Hao-Li Liu from Chang Gung University and Chih-Kuang Yeh from National Tsing Hua University, Taiwan has utilized a novel, non-viral gene delivery system to deliver genes into the central nervous system.

In this study, Lui and Yeh and their research teams used tiny bubbles made from positively-charged molecules to carry genes across the blood brain barrier. These bubbles formed stable complexes with GDNF genes, and when the skulls of laboratory animals were exposed to focused ultrasound, the bubble-gene complexes permeated the blood brain barrier and induced local GDNF expression.

(A) Schematic of GDNFp-cMBs and mechanism for controlled gene transfection of GDNFp-cMBs into brain triggered by FUS. (B) Left: Microscope bright-field images; middle: TEM images; right: PI staining image of cMBs and GDNFp-cMBs. (C) Size distributions of cMBs, GDNFp-cMBs and nMBs. (D) Zeta potential of nMB and cMB before and after adding GDNFp. (E) DNA loading efficiency of GDNFp onto nMB and cMB. The left axis was the amount of GDNFp bound onto MBs (solid line). The right axis was the GDNFp loaded efficiency onto MBs (dotted line). Single asterisk, p < 0.05, versus nMBs. Data were analyzes by Student’s paired t-test presented as mean ± SEM (n = 6 per group).
(A) Schematic of GDNFp-cMBs and mechanism for controlled gene transfection of GDNFp-cMBs into brain triggered by FUS. (B) Left: Microscope bright-field images; middle: TEM images; right: PI staining image of cMBs and GDNFp-cMBs. (C) Size distributions of cMBs, GDNFp-cMBs and nMBs. (D) Zeta potential of nMB and cMB before and after adding GDNFp. (E) DNA loading efficiency of GDNFp onto nMB and cMB. The left axis was the amount of GDNFp bound onto MBs (solid line). The right axis was the GDNFp loaded efficiency onto MBs (dotted line). Single asterisk, p < 0.05, versus nMBs. Data were analyzes by Student’s paired t-test presented as mean ± SEM (n = 6 per group).

In fact, this technique outperformed intracerebral injection in terms of targeted GDNF delivery. The amount of GDNF expressed in these laboratory animals that received the GDNF gene/microbubbles + ultrasound protocol was significantly higher than those animals that had genes directly injected into their brains. Furthermore, these higher levels of GDNF genes increased the levels of neuroprotection from PD. Animals that had a form of PD and had received nonviral GDNF gene therapy showed reduced disease progression and restored behavioral function.

This interesting study explores the potential of using ultrasound-induced passage through the blood brain barrier to bring genes into the central nervous system. This noninvasive technique successfully delivered genes into the brain to delay the effects of, and possibly treat, a neurodegenerative disease.

This study was published in Scientific Reports 6, Article number: 19579 (2016), doi:10.1038/srep19579.

 

Accelerated Reprogramming and Gene Editing Protocol Can Make Fixed Cells Much Faster


Sara Howden and her colleagues at the Morgridge Institute for Research and the Murdoch Children’s Research Institute in Australia have devised a protocol that can significantly decrease the time involved in reprogramming mature adult cells while genetically repairing them at the same time. Such an advance is essential for making future therapies possible.

Howden and others demonstrated that genetically repaired cells can be derived from patient skin cells in as little as two weeks. This is much shorter than the multistep approaches that take more than three months.

How were they able to shorten the time necessary to do this? They combined two integral steps in the procedure. Adult cells were reprogrammed to an embryonic stem cell-like state in order to be differentiated into the cells that we want. Secondly, the cells must undergo gene editing in order to correct the disease-causing mutation.

By in this new protocol developed by Howden and her colleagues, they combined the reprogramming and gene editing steps.

To test their new protocol, Howden and her team used cells isolated from a patient with an inherited retinal degeneration disorder, and an infant with severe immunodeficiency. In both cases, the team not only derived induced pluripotent stem cell lines from the adult cells of these patients, but they were also able to repair the genetic lesion that causes the genetic disease.

This protocol might advance transplant medicine by making gene-correction therapies available to patients in a much timelier fashion and at lower cost.

Presently, making induced pluripotent stem cell lines from a patient’s cells, genetically repairing those cells, expanding them, differentiating them, and then isolating the right cells from transplantation, while checking the cells all along the way and properly characterizing them for safety reasons would take too long and cost too much.

With this new approach, however, Howden and others used the CRISPR/Cas9 technology to edit the damaged genes while reprogramming the cells, greatly reducing the time required to make the cells for transplantation.

Faster reprogramming also decreases the amount of time the cells remain in culture, which minimizes the risks of gene instability or epigenetic changes that can sometimes occur when culturing cells outside the human body.

Howden’s next goal is to adapt her protocol to work with blood cells so that blood samples rather than skin biopsies can be used to secure the cells for reprogramming/gene editing procedure. Blood cells also do not require the expansion that skin cells require, which would even further shorten the time needed to make the desired cell types.

The accelerated pace of the reprogramming procedure could make a genuine difference in those cases where medical interventions are required in as little time as possible. For example, children born with severe combined immunodeficiency usually die within the first few years of life from massive infections.

Howden cautioned, however, that she and her team must first derive a long-term source of blood cells from pluripotent stem cells before such treatments are viable and demonstrate the safety of such treatments as well.

See Stem Cell Reports, 2015: DOI: 10.1016/j.stemcr.2015.10.009.