Review of Biotech/Translational Talks #ISSCR2015: StemCells Inc, Semma, ViaCyte, & Le Blanc

By Heather Main

The path to the clinic is a slow and arduous activity, frustrating not only to the researcher and patient, but investors. Successful clinical translation of technologies requires a balance of science, streamlined translation and funding. To develop fantastic science and then realise the most important components cannot be adapted to the clinical environment is as disastrous as having a great product but no cash to get it past the post. The fruitful interaction of researchers, companies and clinics will save a lot of pain in streamlining technologies to patients. Thus, it was nice to see an ISSCR 2015 plenary session on stem cell therapies including companies StemCells, Inc. and ViaCyte, Inc. The topics were a good spread of autologous and allogeneic cell sources as well as therapies directed at inflammation and immune reactions versus integrative cell replacement technologies.stemcellsinc-logo

StemCells, Inc. presented progress in clinical trials with allogeneic neural stem cells in brain, spinal cord and eye disorders. As is the reality for companies giving talks some data and beautiful pictures is not disclosed. Though there were no revolutionary data sets on efficacy, what was clear was that grafts could persist 1.5 years post removal of immunosuppression (this was determined with HLA-mismatch begging the development of a Shinya Yamanaka style allogeneic HLA cell bank). It should not be a surprise that there were no amazing efficacy leaps in these first trials. There would be a lot of luck in getting the right cell, the right dose and the right transplantation method in the first go. Even the development of reliable measures of graft behaviour and efficacy will take time to develop and standardise.

Semma TherapeuticsDoug Melton was clear to state that they “haven’t (just) done an academic study”. That while they are not yet in the clinic and even though they present a more classical academic study, showing a complex defined differentiation and detailed functional analyses, that they recognise the importance of not just talking the talk but walking the walk. Doug presented their in-vitro beta-cell body technology that show functional characteristics equivalent to, if not better than, cadaveric islets. They were able to upscale this technology and are now on the prowl for encapsulation technologies to move into the clinical space, which will happen through their new start-up Semma Therapeutics.

ViaCyte New LogoIt’s always nice to hear an Aussie accent ;), giving additional benefits to listening to Alan Robins present the progress of ViaCyte in clinical trials of their pancreatic progenitor and encapsulation technologies. Following on from Doug, Alan made a couple of comments to assure the audience that there was a lot of vigorous science behind their technology, the curse of not being able to disclose and thus somewhat unfairly being seen as less careful. The ViaCyte technology is based on the major phase of expansion in pluripotent cells followed by mass differentiation and subsequent encapsulation. Interestingly in their pre-clinical animals studies the grafts were able to regulate insulin levels at the standard human blood concentrations, indicating not only functionality but also species specific functionality.

Katarina Le BlancKatarina Le Blanc presented her work on MSCs for GVHD, diabetes and vocal cord scarring. Somewhat disappointingly I heard the comments of someone leaving this talk with the all too common disregard that MSC technologies are inferior to pluripotent technologies rather than recognising them as complementary technologies. Katarina showed epithelial cell death and inflammatory markers were reduced with maximal effect at 3 weeks after IV injection for GVHD, even though they also prove that IV infused cells have mostly disappeared already at 3 days post infusion. She also showed that while coagulation and complement cascades are activated in response to IV infusion of MSCs blood clotting is not a common occurrence. The risk of clotting was cell number, dose and passage number dependent, which is a little scary when many autologous therapy clinics do not standardise the cell number they IV inject.

It’s great to see both academics and companies being recognised as the drivers of cellular therapies. Working in a stem cell company myself, I was surprised 2 years in a row to see talks from academics about skeletal muscle differentiation protocols that do not come close to our technology. It’s somewhat understandable that when it is not possible to disclose a lot of details of your research, the companies are often not taken seriously and are relegated to paid presentations during the lunch break. It is fantastic however, to see positive movement in reputable exposure for the companies attempting to drive research to patients.

Heather Main on Carla Kim & Hans Clevers talks on organoids at #ISSCR2015

By Heather Main

Organoids are pretty big in stem cells right now. The last couple of years have attracted a lot of media attention on mini lungs, mini brains, mini kidneys, mini guts and more, giving the impression that scientists know how to specify and organise cells into mini functional organs in the lab. Organoids have become a hot topic in a stem cell environment where our understanding of disease is limited by studying only cell autonomous effects in single cells. If Thursdays ISSCR 2015 plenary is anything to go by, 2 of the 5 talks were on organoids, the first from Carla Kim on lung organoids and the second Hans Clevers on gut and liver organoids.

Carla Kim started with a seemingly irrelevant summary of the fact that just about every cell type in the lung seems to have some sort of stem cell or regenerative capacity but then continued to discuss their work on formation of lung organoids from Sca1+ BASCs (Bronchio Alveolar Stem Cells). Culture of bodies from these sorted stem cells leads to a mixed population of organoids, 20% representing bronchiolar, 60% alveolar and 20% mixed structures. Carla’s research has now shown that Tsp1 increases the proportion of alveolar organoid formation. This is relevant to an increase of Tsp1 seen due to alveolar injury and works towards defining the reactions of lung stem cells to different types of lung damage. I must say however that what caught my attention from a purely human view was Carla’s movie on unidirectional mucin flow in bronchiolar organoids, demonstrating the level of complexity of these structure but also just giving you the school yard giggle of producing snot from pluripotent cells.liver organoid

Hans Clevers talk was such a mass of animation that you found yourself amazed that they have the funding for all of this and a little cheated at the same time that it is the animation that sticks in your mind rather than the data. Hans began with his gut organoids and then moved onto liver organdies (note added from Paul; see image of a liver organoid from one of the Clevers lab papers with the wonderful Meritxell Huch, Hans’ former postdoc as first author, who now has her own lab ).

It was fascinating to see that at least to some extent the gut organoids were capable integrating to gut tissue when transplanted in vivo. The animation showed the organoid splitting to expose its apical surface and then integrating into the tissue through its basal surface. It was unclear to me, but possible I just missed it, if the body was capable of integrating to normal tissue or if some type of damage was required to allow the basal surface to implant in the tissue. Hans also showed forskolin induced swelling of these bodies and rescue of swelling in CRISPR modified Cystic Fibrosis cells. As a progression Hans discussed their developments in liver organoids. These bodies were established from dissociation of liver, which left EPCAM+ bile duct cells that could be programmed to a stem cell state through Wnt and RTK regulation. These liver organoids were used to test responder behaviour of different individuals to drug treatments.

The organoid talks are always beautiful. They always have amazing staining patterns of impressive structural complexities, but what makes them any more interesting than a biopsy in understanding disease? Will they be more powerful for cellular therapies than single cell populations or transplantation of the relevant stem cell of origin? The cost of producing and culturing these organoids needs to be balanced against the benefit of the application over existing and alternative technologies. It was nice to see Hans’ application in responses to chemotherapy, which should be a field that would benefit out of such techniques. The cost to the patient of undergoing a cancer treatment that does nothing to the cancer but ravages their body is huge and will have implications in the number of other treatments that they are able to endure. Chemotherapy treatments themselves have a large financial cost not only for the drugs but the time in hospital, which would further validate the cost of organoid diagnostics.

However, it is not time to throw away autonomous cell studies. The direct effects of genetic diseases on primary affected cell types are essential to understanding the origin of disease. Treating secondary effects will not be as effective, or long-lived, as rescuing the primary effect. Organoids give a second level of understanding which will no doubt lead to increased complexity of autonomous ‘single cell’ cultures towards absolutely defining mechanisms for efficient targeting of therapeutics.

Back to the public, one may imagine that while being a little exciting these ‘mini organ’ studies also seems a little scary to the public and may make them scared of what else we are capable of if we are now growing mini functioning organs. What may need to be a little clearer, at least for the sake of the public, is that while different labs can produce structures with more or less complex hallmarks of structures within particular organs, at this stage we have very little understanding of the processes involved and thus have extremely limited control. It seems that both the starting cell and the culture conditions are important in driving the complexity of tissue formation, but the field is still quite primitive in understanding the complexity of the programs these starting cells undergo. We are also far from the public impression of growing ‘functional’ organs in the lab.

Overview of Yamanaka Talk at #ISSCR2015 by Heather Main

Heather_MainISSCR day one

By Heather Main

The day of plenary is the most enjoyable in my view. You don’t need to make the choice between sessions and the judgement on the viability of shifting sessions versus staying put and listening to the slightly less relevant.

ISSCR 2015 plenary was, as to be expected, full of the big names, the affectionately known Rusty (Fred Gage), Jonas Frisen (one of the smartest MD PhDs I have ever met) and of course Shinya Yamanaka. In deciding which talk I wanted to highlight it is somewhat cliché to go for the Nobel Prize winner but I just can’t help it, he is just such a great guy.

I first met Shinya at Karolinska Institutet, Stockholm, Sweden, when he was giving a presentation (no doubt an interview for his Nobel Prize). In association with this trip he was interviewed in our lab space where he divulged that he got into research as he didn’t think he was a very good orthopaedic surgeon, he wanted to do something where he could help people!

So, I was very pleased to see that his ISSCR 2015 talk was divided into 3 sections;

  • immune matching of pluripotent cells
  • differentiation and purification of desired cells types
  • pre-clinical testing of stem cell therapies

What this tells me is that Shinya is truly devoted to helping people. That he is not just thinking about the first step or the last step of stem cell therapies but the entire process, each step as important as the next and the previous. It is not enough that he has a Nobel Prize and could spend the rest of his career studying the mechanisms of reprogramming, he wants to drive his technology to the patients. What a star!

The first part of the talk outlined his work into HLA haplotype matching with regard to homozygous individuals. With a current Japanese focus, just one donor homozygous for the most common HLA haplotype would be sufficient to provide immune matched cells to 10% of the Japanese population. 10 homozygous donors with other common haplotypes would cover 50% of the population and 140 homozygous donors would cover 90%. With 1:1000 individuals showing a homozygous phenotype AT LEAST 140,000 individuals would need to be HLA screened, with this number falling drastically short on the fact that a specific repertoire of HLA haplotypes would be needed. So Shinya and his team are scanning the blood donor and cord blood bank stocks to find their golden donors. A huge task, with huge reward.

For differentiation and sorting Shinya’s team have developed a method called miRNA switch. The technique is mainly aimed at those cell types for which we do not have good cell surface markers for FACS sorting. Basically expression of two fluorescent proteins indicates transfected cells, which upon differentiation to the desired cell type, will lose expression of one of the fluorescent indicators under the control of a cell type specific miRNA. These single positive cells can then be sorted or selected with chemical resistance. Simple and elegant though may require significantly larger numbers of cells, dependant on transfection efficiency.

Finally, my favourite iPSC master showed data from a pre-clinical study into Parkinson’s Disease transplantation of Corin+ dopaminergic neurons. For this section Shinya was very careful to acknowledge his collaborator Professor Jun Takahashi, and continued through the section to present the work as ‘he did’ rather than ‘I did’ or ‘we did’. In the study they were able to show that sorted iPSC derived Corin+ dopaminergic neurons transplanted into monkey brain gave functional recovery of Parkinson’s Disease and survived for at least one year without a reduction in graft size and without tumor formation. Interestingly, whether the original iPSC were from diseased or non-affected individuals, similar rescue was seen, arguing for autologous therapies from the diseased individual. These results were setting up for the exciting step of testing these human cells in human clinical trials beginning within the next 2 years.

While Shinya may be the big name, his humility and genuine desire to make a change in the lives of patients is a great inspiration. His continued dedication to the cause in light of his earth shattering appearance onto the stem cell stage is a testament to a great guy. Japan is definitely the space to watch for a dedication to stem cell therapies (including liberal regulatory standards), and I’m sure along with Shinya they will continue to drive the field forwards both at the basic and clinical level.

Top 10 Insider Trends on Stem Cells to Look Out for at ISSCR 2015 Stockholm

isscr meetingThe annual ISSCR meeting has started in Stockholm.

This is always a great annual meeting both for the science and for connecting with people including new friends and colleagues as well as old friends.

Another element to the meeting is the insider conversations in the halls, restaurants, and bars that tell a behind the scenes story of the stem cell field.

Below are my top 10 things to look for that might be discussed over a beer or coffee this year. Also be sure to check out the wonderful guide to Stockholm from Heather Main and if you are there at the meeting enter our stem cell contests to win up to $100.

  • Clinics make an appearance? It’s a long shot, but I keep wondering if some of the stem cell clinic folks will show up at ISSCR some day to try to legitimize themselves even if they don’t speak, etc. Maybe they’ll sneak in with some posters or even just attend to make some connections. Unlikely, but if it happened could prove very interesting.
  • I’ll be curious if the Hanna-Silva feud of a sorts continues persist over ground state pluripotency, MBD3 and NuRD.
  • Does anyone still believe in VSELs?  A scandal is still smoldering there.
  • Anybody know what happened to Vacanti and the assumed to exist Brigham & Women’s/Harvard investigation over STAP cells? Last year in Vancouver at ISSCR STAP cells were one of the hottest topics.
  • Will Mitalipov continue to assert that NT-hESC are better than IPSC after the more recent paper (on which he was an author seemed to show otherwise)? More broadly will the SCNT/human therapeutic cloning folks continue to claim a clear path to the bedside?
  • Any news on Masayo Takahashi’s IPSC trial? More preliminary data?. I’m excited to see how that goes.
  • I keep hoping also that more biotechs will present at ISSCR and be given plenary talks.
  • Is ethics/policy given sufficient attention at the meeting?
  • Will CRISPR-Cas9 editing of stem cells be the talk of the meeting? The explosive trend of this amazing gene editing technology in science overall has really gripped everyone’s attention.
  • How many reports of clinical trial data will be given? Sometimes in the past ISSCR meetings have had a sizable tilt towards basic science. Could that be changing?

A 250,000-fold oversight on 3-person IVF mitochondrial transfer?

Remember the debate over so-called 3-person IVF?

The goal of this technology, also referred to as mitochondrial transfer and 3-parent IVF, is to prevent mitochondrial disease through nuclear transfer in oocytes or one-cell embryos.

The resulting genetically modified (GM) human embryos and ultimately children if it works could have dodged mitochondrial disease, but also could have serious or even fatal problems due to the technology itself.

The fact that 3-person IVF would create GM people and the concerns over the limited amount of data on the safety and efficacy of this technology, have sparked a rousing debate.

One of the subplots in this debate has been the assertion by many that modification of nuclear genes (e.g. CRISPR-mediated modification of as little as a few base pairs of a single nuclear gene) is far more of a concern than 3-person IVF. Nuclear genes and the nuclear genome are in their way of thinking dramatically more important than the mitochondrial genome.

It seems to me that in this discussion we’ve missed a hugely important factor that may tip the balance in the other direction.

All nuclear genes are present in only two copies per somatic cell and only one copy per gamete such as an egg. For a fertilized egg there are two copies.

mitochondrial DNAIn contrast, there can be thousands of separate mitochondria in every single somatic cell and every single mitochondrion has an entire genome.

If we start looking at the relevant cells for 3-person IVF things get even more super-charged for mitochondria.

In fact, human eggs have the most mitochondria of any known type of cell with the number estimated at 100,000-600,000 per cell. I’ve seen other estimates around 500,000.

That means in one human egg there are let’s say 500,000 mitochondrial genomes and that same number of copies of all the mitochondrial genes and other genomic elements such as non-coding RNAs.

This means that in any one given fertilized egg there are 2 copies of any nuclear gene, but that same cell might have 500,000 copies of any given mitochondrial gene.

What this means is that the potential impact of any one given mitochondrial gene is amplified in a fertilized egg by having 500,000 copies relative to the only 2 copies of nuclear genes. Further, this also means that the potential impact of 3-person IVF technology (where the entire cytoplasm and all mitochondria are changed via nuclear, spindle, or polar body transfer) must be multiplied perhaps by 250,000 relative to a change in a single nuclear gene in a fertilized egg.

So for example to those who say that the mitochondrial genome “only” has 37 protein coding genes versus the perhaps 25,000 human genes in the nucleus, you should at least take into account that all those nuclear genes are only present at 2 measly copies per zygote whereas there might be 500,000 copies of any given mitochondrial gene in that same single cell. That’s a 250,000-fold difference.

That’s a very big number and confers a potentially equally huge impact on how 3-person IVF could work out in terms of risks.