 Kia ora kato kato, very good evening to you. My name is Sam Blanchett and I'm a PhD student at the Faculty of Medical and Health Sciences, where my research is supervised by Associate Professor Thomas Profft and Dr Jason Lohm. And what we're interested in in our lab group and with my research in particular is looking at whether or not we can use these hairy bacteria that we find in the wild as the basis for vaccine development. So just to put this into a bit of context, I thought I'd talk a bit about vaccines to start off with. So there's many diseases out there where there's absolutely no vaccine available and what that means is we can't prevent these diseases. Whether or not that disease is a major exotic disease you hear about on the news like Ebola or malaria, or something a lot closer to home, something much more familiar like a sore throat or a skin infection. We can't prevent any of these diseases so why would we want to? Well aside from the fact that nobody really wants their throat looking like that because it looks incredibly painful, vaccines are the most cost-effective and efficient way of treating and preventing a disease within a community. They're so successful that they're actually able to eradicate diseases. You would have only heard about smallpox in a historical context. A successful worldwide vaccination program eradicated that disease from the face of the earth. Another thing you might have heard about is rising antibiotic resistance and what that means is that a lot of these diseases are no longer able to be treated with antibiotics. So what that means in terms of treatment sorry is that it's a lot better to prevent these things than to actually have to treat them especially when we have no options left. So vaccines themselves have developed quite significantly over time. The first vaccines were essentially live pathogenic pathogens that were put into people and as you can imagine injecting people with live pathogens isn't a particularly great idea. So we've learned quite a bit since the 1700s. We've learned you don't need the pathogen to be at full strength. You can give it a bit of a kick in the guts and weaken it so that the body is more guaranteed to overcome it. And we see this in modern day vaccines with the measles, mumps, rubella vaccine as well as the chickenpox vaccine. We've also learned a little bit more. We've learned we don't need the whole bacteria at all. We can just use a portion of it and we can use a protein found on the surface and we see that in subunit vaccines like with the hepatitis B vaccine. We can take that another step further. We don't even need the whole protein. We can use just a small section of that protein and that's called a peptide. And peptide vaccines are at the leading forefront of modern vaccine research. So peptide vaccines offer a number of major advantages. The fact that there's absolutely no infectious material involved because it is just a small portion of a protein. We're able to specifically target the immune response with this very small peptide. And because it's such a small amount of foreign material there's a very little risk of allergic reaction. Now like everything, peptides do come with a bit of baggage. There are some disadvantages. So peptides, the biggest disadvantage, they don't actually do anything. There's no response in the body. The body ignores it and basically disposes it into the rubbish. Because of this to get a response, other previous peptide vaccines have combined these peptides with potentially toxic products and these are expensive and its cost is always a factor in modern medical development. So to overcome this, the process we're planning to do in our lab is using bacteria. So there are good bacteria and there are bad bacteria. And the fact that our bodies contain 10 times more bacterial cells than our own is probably a good thing that there are some good ones out there. So we find a lot of these good ones in food products like dairy products where we find this one called lactococcus lactus and he becomes important later on. He's a friendly bacteria. He's not going to cause us any harm. There's also bad ones. We see this in the ones that causes the sore throat, the groupiae striptococcus. And as you can see he's got these hairlike projections coming off the surface of his cell. He's going a little bit bald but he's got these hairlike projections. So when we look down the microscope do we see these hairy bacteria at all? Well it's actually a little bit more boring. Bacteria look like this on the microscope and what we see is these hairlike projections protruding from the surface of the cell and these are called pillow. And what they are are essentially little arms and hands reaching out to grab onto the body to help them adhere to us and make it harder for the body to remove them. Now this pathogenic bacteria has these pillow and if we take a closer look at these pillow we see that they're essentially just one building block repeated over and over again. Now the body knows this building block. It's seen it a lot of times in the past. It's learned that this building block is bad for us so it mounts an immune response. So if we contain our peptide within that building block you can see that our peptide is now all over the building block of the protein, oh sorry all over the pillars. And because we're getting an immune response to the building block our peptide gets caught in the crossfire and we get a response to that peptide which overcomes that disadvantage with peptides not doing anything. So to put this into a more elegant picture basically what we've done is we've taken the gene responsible for this hair-like structure for this pillar. We've modified it a little bit so that now our peptide of interest is contained within that pillar. Because we can't administer a vaccine in a pathogenic bacteria we have to take it out of the bad bacteria and put it into the friendly one, this lactococcus lactose that we find in dairy products. And so what we get we get this friendly bacteria that's now expressing these immunogenic hair-like projections with our peptide of interest and we've called this pillvax short for pillus vaccine. And if we go back to our advantages and disadvantages of peptide vaccines and think about it in the context of pillvax what we now have is most of these disadvantages basically removed by putting our peptide in that immunogenic structure we're now getting an immune response and it's also protected from degradation within the body and we no longer need to couple it to anything else. We also get a number of extra advantages so bacteria very cheap and very easy to grow. So like I said earlier cost is always a factor and that is why this is such a major advantage. Another major advantage is that most vaccines at the moment they're delivered with needles. A lot of people don't like needles i'm a little bit iffy on them myself but because this bacteria is found within food products we have the potential to put it into food products. So imagine being able to go down to Queen Street after this maybe treat yourself to some ice cream and get vaccinated just by eating that ice cream it'll be the most delicious vaccine you've ever had guarantee that one. So we know that this works this isn't all talk and theory we've carried out a pilot study within our lab group and that pilot study shows that this works so on the y-axis what we have is a level of antibody response and mice that have been immunized and on the x-axis it's just the different controls that we carried out. So the first column where there's no response is just where we've contained uh vaccinated mice with our peptide our test peptide put over and over as you would expect as a peptide doesn't cause any response so we don't see any antibodies whatsoever. Our next column the blue one is our overpeptide contained within the pilvax construct and what we get is a reasonable antibody response. Now the the third one the green one is our positive control in a sense so it's our peptide immunized with cholerotoxin B which is a more traditional adjuvant they've been mixed together and we've immunized mice with that mix and we do get a reasonable antibody response to that as well. The reason the pilvax one is a lot more exciting and a lot better is because the pilvax construct contains 10 000 times less peptide and as I said earlier the less foreign material put into the body the better it is. So this comes along to the aims of the rest of the aims of my project and what we're looking at is whether or not we can use this construct in models of infectious disease we want to pull apart the immune responses that we get we want to see what cell types are involved and what interactions are involved between those cells and we also want to see if we're able to offer protection with this vaccine. So the disease we've chosen to target is mycobacteria tuberculosis and that's been described by the World Health Organization as a global health emergency and they're not just being dramatic when they say that this bacteria has killed more people than any other bacteria in the history of humankind so it's quite a significant threat to human health. This is all despite the fact that there is a current vaccine available the BCG vaccine but it's largely ineffective and the New Zealand Ministry of Health no longer prescribes this on the vaccine schedule because it is rather controversial as to whether or not it works. So how we're going to target mycobacteria tuberculosis is by targeting this protein this Esat 6 protein. Now the name not particularly important but it stands for early secreted antigen and the six just indicates the size of the protein. So what this protein does is it's essential for virulence if you take this protein away from the bacteria it's no longer able to cause any sort of disease in humans so if we can target this protein and prevent it from having any effect perhaps we can prevent this bacteria from being able to cause disease in us. So because this is a peptide based process we're targeting three portions of this protein these three peptides circled here and why we're targeting these three peptides is because in the real life situation these are the three areas of the protein that are exposed to the immune system. The spirally bits in the middle are hidden away with a cell membrane so we're not actually going to have the immune system seeing those in a real life situation so there's no point targeting them. Now where this project is at is in a very watch this space in terms of in terms of progress we've got a lot of very exciting future work ahead of us with our collaborators Dr Joanna Kerman and her lab group at the University of Otago and down there we're going to vaccinate mice with our three pullbacks constructs and we're going to pull apart the immune response we're going to see what the cell types are doing all the different cell types of the immune system all the different signaling molecules and really see what's going on if this vaccine is effective and eventually able to determine if it offers protection. So finally I'd just like to acknowledge my lab group for all their help and support as well as our collaborators at the University of Otago and thank our funding bodies the University of Auckland and the Marsden Fund and we're welcome any questions.