 My name is Yves Chiswili Chabu, and I'm a professor in biological sciences here at the University of Missouri-Colombia. And I guess to answer the question, how did we get to the story that we recently published in Onko Target? So when we first started, we really started from the concept that in clinics, one of the significant challenges is to identify therapeutics that are highly selective. And so by that I mean having an agent that can selectively kill the cancer cells without killing the normal cells. So a lot of these cancer therapeutics, especially when you talk about chemotherapies, they don't not only kill the cancer cell but also call the normal cells. So this can generate considerable toxicities and mobilities for the patients. So we started from the sort of need to come up with a different way to target these cancer cells, but also to do it in a way that's not necessarily required in a priori understanding of the molecular landscape or the molecular drivers of that cancer. So let me just take a step back. So we now know with the precision medicine approach, one can obtain biopsies from the patients and then from those biopsies define the molecular landscape, at least identify genes that are driving the cancer. And that knowledge will then inform the physician's decision as to which therapy is better suited for that patient. So that's your precision medicine space. So and that has led to significant improvements in terms of patient outcome. What we wanted to do was to also think about ways that are not that selective, in other words, to find the strategies that can target cancers more broadly. Now, about a century ago or more, there was this realization that bacteria can target cancer cells. And we had already some data showing that this specific cellular strength that we had could target cancer cells, basically killing cancer cells by leaving the normal cell largely unaffected. So we then reasoned that maybe we can utilize that and go into any vivo model to really test the efficacy of that approach or how good that approach was. So and we turned to prostate cancer because that's where we had most of this data. So we turned to the prostate cancer and there's a mouse prostate cancer model. And as you probably know this, prostate cancer can develop resistance to treatments and the therapeutic landscape for that indication is limited. So immunotherapy also doesn't work there and hormone therapy eventually leads to relapse for those patients. So we took that specific indication and meaning that specific cancer type and ask, does this bacteria that shows tumor tropism in vitro, that shows selectivity in vitro, can also generate similar effects in an animal model? So that was really where we started. That's really the initial question that we went after. So during the course of the study, what was really unexpected was that although we saw these targeting, so we can see the biologic or bacteria homing into the cancer tissue very specifically, so they're colonizing the cancer tissues and not only they're colonizing the cancer tissue, but they are staying there and they're staying there for at least a couple of days. And that finding is relevant because normally these bacteria get cleared away really fast in the host. But what we saw is that he was able to go into the cancer tissue and stay in the cancer tissue. So that is really important. So you can now have the bacteria that is going to the tumor and then it is colonizing, I mean they have to divide in these tumors and evade clearance. So that was really encouraging for us. So then we asked, so if the bacteria is staying in the tissue, can we, I guess you can let me put it this another way. So if the bacteria is staying in the tissue, you also want to make sure that the bacteria itself doesn't accumulate additional genetic mutation that will make it lose its characteristics. And the characteristics that I have in mind here is really the safety, right? So we had shown that the bacteria itself was quite safe in this animal model. So we didn't see some really significant toxicities in these mice and we had also evaluated it in dogs where it was well tolerated. So what you want then is to have a biologic, I mean a bacteria. So I'll use the word biologic and bacteria almost interchangeably. But what you want is that not only you're targeting the cancer tissue and it is stable in the cancer environment, but you want to make sure that bacteria doesn't accumulate additional genetic lesion such that it loses all its characteristics, i.e. its ability to persist in the tomaco environment and to kill off the cancer cells. So then what we decided to do was, okay, let's then evaluate its genomic stability. And in so doing we could see clearly that it was also genetically stable. So then we had a series of characteristics and quite frankly what attractive characteristics. So we had a biologic that was safe and in addition to that it was able to target the cancer tissue and three it was genetically stable even after it colonized the tissue for days and weeks. So that was very encouraging. So then we asked what are the consequences of these targeting effects? What are the consequences of having the biologic going into the cancer cells? And one area that we really wanted to focus on is the ability of these cancer cells to now release immunogenic molecules. So you want the cancer cell to release molecules that can now attract the immune cells to the tomaco environment. Why is that important? It is important especially in the case of prostate cancer because the prostate cancer environment is immunosuppressive. So prostate cancer has enact mechanism to suppress immune cells and exclude really immune cells from the cancer tissue. And because of that even your immunotere therapeutics that have shown great results in say skin cancers they don't work on a prostate. So for prostate cancer there is a need for strategies that can remove that immune barrier so that these immunotere therapeutics can actually work in that setting. So we then reasoned we now have a bacteria that we know is immunogenic. It's a bacteria after all and it goes to the tumor, colonized the tumor and then it is genetically stable in that tumor. Now we will say let's see if it's test the hypothesis that these bacteria can also have a immunogenic effect. That is it can cause this cancer cell to release all these hemokine into the tomaco environment and in so doing recruits immune components in the cancer cells and it did. So that was really satisfying. So we could see from those experiments that animals that were treated with the bacteria there are cancers and this again the prostate cancer mouse model. There are cancers that add a lot more infiltration of immune cells. So you had timing immune components in the tomaco environment and they were there in a higher frequency or quantity if you will than the control mice that were just treated with the buffer. So we thought well this is really this is great right so we are getting an immune stimulation we are recruiting immune components now into in the tumor tissue. That's the case we should expect to see an increase of cancer killing immune cells as well. So we saw a series a different type of immune cells in the cancer macro environment right so cd4 positive cells which are required and critical to activate the cytotoxic cd8 positive cells. So we saw an increase of cd4 positive cells in a cancer micro environment and then we asked if we could also see these cd8 positive or cytotoxic t cells and unfortunately whatever we saw there was really transient right so we'll see some cd8 positive cells but then they'll rapidly those numbers will basically well that's what dwindle down and you get a decrease. So that hinted us it really hinted that perhaps what is happening the cancer cells are deactivating these cd8 positive cells. So they are deactivating the cytotoxic t cells and one mechanism is essentially through these pdl and pd1 mechanism. So we then thought if we could couple the user the bacteria with blockades of the signaling axis so that is we're now preventing cancer cells from inhibiting cd8 t cells we will see a decrease in disease burden so that was the hypothesis that we went in. It was very rewarding to see that indeed when we couple now these immunogenic and tumor targeted bacteria with antibodies that block the pd1 pdl signaling axis we could now decrease disease burden in these animals. So for us that was really and I think that's the novelty of the paper right so that is to use something that one wouldn't even consider using right so you're using a bacteria genetically attenuated bacteria uh nonetheless but it's still a bacteria and and utilizing its immunogenic capabilities to then engage immune components and activate these cancer fighting immune cells definitely a some merit and in this case we could actually see a decrease in disease burden in these mice. So that was really really for us it was really proof of principle that one can use these immunogenic biologic to now break down the immune barrier we talked about at the beginning and allow the immune components or the immune cells or the host immune cells to surprise or to kill of the cancers. So it's a proof of principle and and my hope is that the rest of the fields and all the other researchers out there the community will manage to summon sort of uh to get past this this concept that it is a bacteria and really see what else we can how you can better functionalize it to achieve better clinical outcomes right because that's what we're all into this we're all into this to help our patients so if we can come up with strategies that can leverage these characteristics of this biologic to indeed generate some durable clinical benefit for patients then it's a win-win situation. Now so what is next really so what will be the next chapter so I would think that in addition to and I really hope this happens that the entire community picks this up and try to see better ways of functionalizing it it's a much better outcome. Another benefit of this biologic right so you can use it as a immune or tumor immune activating agent but you can also use it as a vehicle right so you can envision leveraging is tumor targeting capacity to deliver therapeutic loads into cancers right and so you can pack therapeutics into the cells and you can do this it doesn't have to be small molecules but you this is a thing that can be genetically engineered in the bacteria and be delivered specifically at least with preference preferentially delivered into the tumor tissues so that is also a I would think a clear application for this biologic. I think I should also note that there is a potential here to expand this to other cancer types where immunotherapy does not work right and here we have started looking at pancreatic cancer with pancreatic cancer has the same limitation meaning that it's an highly immunologically suppressed environment so these are considered immunologically homologically cold in bar cancers so we are now using that in that indication in pancreatic cancers and we are seeing really beautiful responses in the host we're doing this in mice but we can see from this plane you can see a nice activation of the immune components in animals that are treated in animals that are both that the cancer entered it with these bacteria so you can see an elevation of these cd8 cells in the spline we do see just like in the prostate cancer study we see that it does not always translate right so when you will the splining activation that we're seeing does not necessarily translate into a durable colonization of the tumor by these cd8 positive cells right so it's similar to what we saw in the prostate it's a transient colonization and then I think you have these suppressive mechanisms are enacted by the cancer to keep the immune cells away but now you can imagine even for that specific indication coupling checkpoint locates or immunotherapy with the biologic we can now also then surprise at least that's the hypothesis that we are pursuing we can also press these really deadly and again this the therapeutic landscape for that indication is a really meager and needing additional agents so we would like to see that maybe these biologic these bacteria coupled with with immunotherapy will generate some benefits in animal models and here we're talking about shrinking of the cancers and ideally extending the more life so those are the sort of the spaces where I can see opportunities and again the pancreatic cancer space we we were definitely exploring opportunity for this biologic in that context but I really hope that the entire community and can leverage some of the characteristics of this bacteria to help out to our patients now I should also say that it's not that wild the concept right so people have used athletic viruses and in fact there are trials people using on coletic viruses to essentially generate immune response and therefore kill eliminated cancers so here is a similar approach just like people are using coletic viruses in clinical trials in clinical studies here we're using a bacteria and and is generating some killing locally but also activating the release of these immunogenic factors which then recruits immune cells to the cancer so I think it's definitely a good proof of principle it's a good place to start it's a good place to be and and I think a further development is needed to really even further refine this technology and see if we can evaluate more broadly across different type of cancers right so we are using it you know immunotherapy setting but this we also have some additional data in the context of chemotherapy we're seeing some really interesting interaction between chemotherapies and hormone therapies also in the prostate cancer space so chemotherapy hormone therapy immunotherapy in the prostate cancer space there is some clear interaction between these agents and those therapeutics I think it's very important to mention I don't think there I could say it's in more stronger terms but I'm a big proponent of collaborative research and and this work will not have been possible without the collaboration and in fact if you look on the manuscript it's people across institutions right so we have researchers like a Yale that performs some of these immunological profiling all this profiling the immune landscapes in in all these mice and we also have my colleagues here at MU that played an important role in modeling right so you see we actually integrated all these different aspects of research so we had immunologists contributing we had people that were modeling all these genomic data that we had so all that came together to make this story possible so again I really think that this paper I mean this manuscript really exemplifies the utility and the value of collaborative research across different disciplines right so again so it was genomics it was some mathematical modeling and we had basic cell biology and then you also had people in animal science helping with this and this people in radiology and radio imaging helping with this so it was really team efforts where everybody brought to the table some unique aspects of their strengths and that's how this this paper really came into being so I want to thank every single one of my collaborators and people in a lab I want to thank Bakul a co-author on the paper for their hard work I want to thank Rob who's also first author on that paper and again they worked tirelessly so there was a postdoc and they worked tirelessly to really make sure that everything was done to the highest standard so that was really great those fantastic and of course I want to thank all my colleagues on the manuscript Elke Goulden like a Yale and and our imaging facility here so he was really a team effort and Dr. Stroeber also for his modeling on the manuscript but that was really fantastic and we had a lot of fun with it so so he really the modeling really started as a casual conversation and it really evolved and it was something that we started over the phone and then so Dr. Stroeber and myself our families play soccer together so we will play soccer and at the end of the soccer we start talking about these these concepts how we can model this and then we followed up with phone conversations and again with more soccer and the rest is history so it was it was really nice it was really pleasant