128 - Nigel McCracken & Sean Knight - Research into T-Cell Exhaustion

Episode 128 of the Long Covid Podcast is a chat with Nigel McCracken, COO of Virax Biolabs & Sean Knight, Clinical research fellow at the University of Manchester. Nigel and Sean are working together in collaboration on a study to dive deeper into T-Cell exhaustion in people with Long Covid.

We take a deep dive into T-Cells, immunology and the quest for a biomarker!

Virax Biolabs
Long Covid research at Manchester

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(music - Brock Hewitt, Rule of Life)

Transcript

****This transcript is unedited - my apologies! Should be updated early next week when I'm back from my holiday!****

Jackie Baxter  
Hello and welcome to this episode of the long COVID Podcast. I am delighted to be joined today by Nigel McCracken and Shaun Knight. And we are going to be diving a little bit into the research world. And I'm going to let them introduce themselves. So a very, very warm welcome to the podcast today.

Nigel McCracken  
Hello, Jackie, thanks very much. This is Nigel McCracken and a wee bit of background about myself. I'm actually Scottish and live in Edinburgh at the moment, sort of background in Clinical Pharmacology and have worked in drug development for the last 30 years. And recently, it's taken up a role at chief operating officer for a company called Virax BioLabs who are actually interested in developing immune profiling solutions, as well as T cell diagnostics.

Shaun Knight  
Hi, Jackie, I see this is Shaun Knight, I'm an academic clinician, I grew up a long way from Scotland, as I actually grew up in Africa. I'm an academic clinician. So I do that means basically, I spend half of my time doing research and half of my time looking after patients, and My clinical specialty is respiratory medicine. So that means looking after people who have lung diseases, including people who have infections, and basically anything that's that's gone wrong with the lungs really do affect. And

Jackie Baxter  
yeah, we are kind of diving into the world of long COVID research. Is it too soon a question to ask, like, what brought you guys together? Or is that kind of further down the story?

Speaker 1  
Well, I can answer that one. So as I said, I've been doing drug development for a long time and worked across many indications. And certainly over the last 15 years or so I've been be sort of heading up groups around translational medicine. So I've always been interested in understanding the immune component of a lot of diseases, and particularly infectious disease in oncology. So actually, my previous job as Chief Scientific Officer, we were actually had a, you know, a molecule that was targeting a specific target that for actually COVID it as well as oncology because it was actually the targeting that microenvironment. And we'll go into that a little bit, the importance of that. So from our own background, I we did to actually run a couple of COVID studies, and in doing so, and came across the University of Manchester, because we were doing an awful lot of research around I just so happened that the target that I was looking at reduced the interferon gamma levels will go into that, around that that general chronic inflammation part. And in doing so, I was introduced to Professor chasing hustle, who I know that a show and sort of works with so rolling on to the next sort of, you know, role, which was more around diagnostics, and that early diagnosis, or all these conditions, and whatever, you know, was really quite nice. We reached out to Tracy and then from Tracy, we got introduced to Shawn because Shawn had actually this ongoing study that he was involved in, and now I'll hand that over to Shawn.

Speaker 2  
Yeah, yeah. So it's been, in fact, like a lot of the COVID work I've been involved in, it's all been sort of fortuitous, in chance encounters that have kind of led to these interactions happening and driving a lot of the research forward. So yeah, so I actually much like margin underwear, sort of going further back, I was actually more interested in in lung cancer and immunology of lung cancer before the pandemic. So I'd actually around sort of late 2019, early 2020, I'd taken time out of my clinical work to set up my laboratory with Tracy hustle over at patologia Becker institutes in Manchester. And it's amazing in hindsight, when you go back through the days, to see how quickly things changed with COVID, and how it went from sort of an esoteric thing that was in the news to, you know, rolling all the way out and realizing that it was going to have such a massive impact on on everyone sort of around the world. So we were sort of very much in that, that whole sort of stage of disbelief, and then and then working out what we could do to I guess, to use the resources from, you know, the research perspective that we had to try and help people with COVID. So, Tracy and I, together with some other investigators in Manchester, set up this longitudinal COVID-19 study. And it had very broad objectives at the beginning in the sense that, at that stage, we knew nothing about the virus and how it affected the immune system. So what we planned to do was pretty much invite people to take part as they came into the hospital with COVID-19. And many patients donated their their blood for our research. And we basically looked at almost every immune cell, and we tried to work out what they were doing in acute COVID-19. So obviously, that was before we knew what the now To sort of cause the infection would be, and certainly at that stage, we had no idea that long COVID was going to be, you know, such a prominent thing coming out the other side. So that study essentially involved into a long COVID study, because a lot of those patients that we recruited when they came into hospital, we followed up after they left hospital, and they continue to donate samples for us. And I guess at that stage, the group started to separate out in that some people made a full recovery. And then it became clear that some people weren't making a full recovery. And what was interesting about that was that it wasn't always driven by how severe their infection was. So that was the thing that sort of, I guess, stood out for me, really. So I've met some people who were in intensive care with their COVID-19. And when we saw them at outpatients, you know, three months after they recovered, they were pretty much back to normal. Now, that wasn't everyone's story, there was obviously lots of people who, you know, didn't have a very protected recovery. And then there were other people, you know, who maybe hadn't been as, as civilian effective whilst they were in hospital, but had a much, much more difficult trajectory in the recovery phase. So basically, we sort of adapted our research to look at that. And that study sort of reached the natural conclusion that we're just about to publish. And I guess I'll work with Nigel is sort of the next step, we're now what we're looking at is we're focusing on Don COVID. And we're just about to start recruiting patients to a new study that basically will follow those patients with lung COVID, over a course of two years, and we'll be looking at their immune system changes, and how that correlates to how their symptoms change. So much like sort of hearing the story at the beginning about how many years it can take to recover from COVID-19. The idea is, if we catch people while they're symptomatic now and sort of see what changes as they get better, it might give us a better idea of what I guess how we consider to track the natural trajectory of long COVID And, you know, identify things that we might be able to change to make things better for people.

Jackie Baxter  
And I guess what's cool about that original study, and if you want to give me a link to that, I can drop it in the show notes as well as that you have that data right from the start. Because I think what a lot of studies, and I suppose what your second study is going to be doing, and it's picking up people sort of longer along the road. So you know, the COVID infection has in the past, they've done the whole thing where they thought they were getting better, and then they weren't getting better. And then maybe they weren't getting Oh, no, but then they weren't and that kind of start of the wiggle of lung COVID. And then they start tracking their symptoms, and they start logging things, because that's kind of what you do. But your original study had that data right from the start whether they ended up having long COVID or not. So I suppose that's very cool.

Speaker 2  
Yeah, so it was interesting, I guess as as, as ever with research is, when you look back at it, there's always that inclination to think Well, what did we have for that study as well? So I think that the major question which is running through our minds, but we haven't really had a way of answering as well as, as a step before that is that we've seen some changes, I guess, in people who have ended up with long COVID. But were those people before they had infections, but they're different in some way. So, you know, before the pandemic came around with it, almost predetermined, I guess that those people were going to end up with long COVID. And all that they were looking for was the right sort of stimulus if you like, which happened to be the COVID-19 illness. So yeah, so I guess in short, it has been really helpful to track, you know, all the way from acute infections to recovery. But that I guess there's also some, some unanswered questions that I guess we have ideas that we want to sort of put into practice in the future. But yeah, I guess we're having all of this is sort of an ongoing piece of work, I guess.

Jackie Baxter  
And I guess that's the thing where the research, isn't it, you know, you, you find an angle and you get an answer. And then, you know, that just leads to more questions, which then gives you more answers, which then leads to more questions. So it's like, the more you know, what is it the thing that the more you know, the more you realize, you don't know, is that the saying, or did I just make that up? It's something like that, isn't it?

Unknown Speaker  
But it certainly feels like that.

Speaker 1  
So a complicated business, you know, when you think about the adaptive immune system, and the interplay, in different indications that know, the interesting thing around viruses or even oncology because again, I come from an oncology background, as well, you know, what viruses do very well, as well as oncology, they adapt the microenvironment they adapt the, you know, the, the want to keep growing, so they the turn things on and the turn things off, to allow them to grow. And the, in this instance, you know, when we're coming at, you know, with respect to the T cells, and in particular, T cell exhaustion or T cell dysfunction is a term that's been about in oncology for many years. So you can imagine most of the immunology compounds are the big sort of sellers like Pember lism, AB and stuff and things like that. That's what they're doing. They're targeting receptors that cause T cell exhaustion, and they're the same receptors that cause the T cell exhaustion, and viral syndromes. So to the point why some people get along COVID, or an MV, it could be that you've been exposed to certain viruses in the past, like epstein barr, or CMV, or herpes. And that's source code, even though it might not be a really bad episode of is enough to tip the balance is enough to bring on this T cell exhaustion. And in doing so, you know, the symptoms sort of come from that, which is super, I mean, it's very interesting, both, but as you said, it's very complicated, as well. And, and a lot of the research that's been done, because there's been an awful lot of long COVID studies that have been conducted, and the data's just starting to come out on that, I think that we're, you know, we're trying to be in a situation that we can react to that data, but also provide meaningful tests. Because as you know, you know, there is no diagnosis for lung COVID is self diagnosis, or there's a questionnaire and I think, what we would like to do through the research, you know, with, with Shawn, within the respiratory stuff that he's doing, as well as the other work that we're doing, is to hopefully provide, you know, tests that actually help with that early diagnosis of that in relation to that T cell dysfunction or T cell exhaustion.

Jackie Baxter  
Yeah, so it could be the sort of the straw that breaks the camel's back sort of thing, you know, a collection of viruses over time. And then boom, COVID happens to be the one, I suppose the question. I mean, I'm going off on a tangent here, which is totally not like me. But why is it COVID? For so many people? Is it just the sheer volume of infections all at once that, you know, there were a lot of people that were kind of primed for it, so to speak? Or was there something special about that particular virus that added a particular load on that made so many people kind of topple over into this kind of state? Yeah,

Speaker 2  
I guess you could pick that up, and probably give you slightly different variations on maybe a similar theme. But I guess my impression of it is that, I guess the first few waves of the pandemic were, sort of before we had a vaccination. And before the Omicron variants sort of emerged, the syndrome of at least in hospital that the patients we were seeing was was quite different, I guess, what we usually see with a lot of other respiratory viral infections. And the main difference really was the amount of inflammatory load and damage within the lungs. And I guess in terms of the tools that we have to look at that in the hospital, it's basically what you can see on a chest X ray. And even so from our study, and others like it, almost all the patients that came in, regardless of the severity of their infection, had some visible changes on their chest X ray, meaning that they had inflammation to a degree that there was, you know, collections of fluid within the lungs that we usually wouldn't see. So, you know, with viruses, I guess they've commonly come in winter periods, like influenza, and respiratory syncytial virus. Usually with those, there's only a very small portion of patients where we see those changes. But yeah, those changes were just a lot more widespread. And of course, then there was the numbers, numbers of people coming in. So what's still puzzles, puzzles, me now is in the first wave, how we stopped seeing everything else for a while in the hospital. So all the other presentations that we normally see, you know, people come in with heart attacks and stroke, everything just seemed to stop and we just got COVID for a while. So I think to answer your question, I think it was sort of a new virus with perhaps very little residual immunity in the population. And what that means is that the way that our immune systems handle that virus is probably quite different to how it usually would handle other viruses that it's more familiar with. And that may be led to sort of more damage within the lungs. And I guess, leading on from that, it could be that as a result of that damage, and the longer process to heal that damage, that that sort of changes the immune system and lots of other systems in the body as well, in a certain way that gives someone a protected recovery.

Speaker 1  
Yeah. And just moving on from that and with that damage that Shawn had mentioned, you know, and when you get that acute inflammatory response, what you do get is you get a lot of oxidative stress on the actual system and oxidative stress, you will know all about things like reactive oxygen species, because they're that's the sort of thing that he uses. but it's also you know, when we, when we have an inflammatory response, there is quite a lot of reactive oxygen species that's generated. And the oxidative stress is self is a balance between Hi rose as the as they call it, and the antioxidant sort of proteins that keep it in balance. And with that, you know, when you have high levels of oxidative stress, it does actually have an effect on the adaptive immunity, as well as the cellular microenvironment. So to that point, it actually gets to the point where your your adaptive immune system is not working properly, but also, and will most probably get on to this because, you know, around the commonality around the symptoms of something like long COVID And something like me, there's been a boat for an awful long time sort of thing about that effect, or that downstream effect on something like the mitochondria, which is that the mainstay of the energy, you know, this supplies, you sort of thing and what have you on the effect on that. So, it's not a simple thing. And I think what we're trying to do here with the research within this study, and in general is to try and understand is there some sort of signature from your T cells in your T cells are things that are there to sort of help kill the virus as part of your adaptive immune? Is there some sort of signature that you can actually look to see that, you know, you've got either that early diagnosis, or you've got this T cell exhaustion, and is there anything that you can do, whether that's a dietary thing, or whether it's antioxidants, or whether there's some treatment is coming up, that you can actually have that intervention, to help prevent getting to the stage where maybe your adaptive immune system rewires itself into a different sort of stage. And that's, I think, where we would like to sort of come at

Speaker 2  
it from if I could just come in on that as well, because I think it's probably useful to kind of also discuss at the moment how I guess up until now, we've been talking about long COVID, like, it's one sort of thing. But the other thing to mention is that I guess we still don't really know 100%, what long COVID is, and in truth, it's probably a couple of different things coexisting in the same space. And the reason I think that's important to say is, I think one of the reasons I was really keen to work with Nigel, and how sort of collaboration came about was, it would be really helpful for us to have some diagnostic tests and maybe identify particular people who may be having a problem with their immune system in long COVID, which may be different from other people who may be having different problems. And, you know, there's lots of things that happened in the pandemic, we spoken about how the virus was different, and how that that sort of maybe changed the inflammation that people would have had compared to other viruses that were more familiar with. But on top of that, there were all the other changes that happened around the pandemic, in terms of the lockdowns and the changes in social situations, and all of that, and all of those things would have impacted people as well. You know, so I guess to put it this way, there probably is a subset of people who have an issue with their immune system that sort of changed as a result of SARS, cov, two infection. But then there may be other people who've had other things that have happened as well. And I think at this stage where we we've just got one sort of a amorphous blob that we're calling long COVID It's really important to try and tease those things apart and try and identify patients who maybe have an actionable thing that we can do to help them along the way.

Jackie Baxter  
Yeah, absolutely. I think that's a really good point, the sort of underlying cause sort of Holy Grail, isn't it almost. What is that? I think, what might be really useful, I think, Nigel, you've mentioned T cells a couple of times now, would it be okay to just take a dip into sort of science lessons, and you tell us what, what are T cells? And why are they relevant? You

Speaker 1  
when you talk about the immune system, you talk about the innate immune system and the adaptive immune system. So usually, when you're exposed to some sort of virus, that Innate system kicks in and it and you talk about white cells, and we've got the lymphocytes and macrophages. So, what they do is they basically mop up things that they can do they create these antigens, that then basically, you know, the the adaptive immune system utilizes it because it recognizes these these antigens. Now, when we talk about the adaptive immune system, we talk about B cells and T cells, the B cells tend to generate antibodies sort of against that, that neutralize but also stimulate cytokines for the T cells and the T cells and mentioned to you before are really sort of killer cells. So they're, they're basically used, you know, to actually kill that virus. So what happens is when your body can't deal with the initial virus, then it will kick they'll kick the adaptive immune system and to deal with At No, usually within infection, you know, a lot of people tend to get a fever and stuff like that 42 hours later. And that's because that inflammatory part is kicked in, and it starts to, to kill those those specific that virus or, or that pathogen and what have you. So when we talk about the T cells, we're talking about, you know, helper cells, and there's regulatory cells, and there's memory cells. So if you remember, sometimes, and this is the whole thing around the vaccination is that you're vaccinated. And then when you get exposed later on, you have these memory T cells that this game really targets, it's more of a targeted effect on the actual immune system. So that's what we're talking about. So usually what happens, you know, when somebody's exposed to a virus, the T cells do a good job, and the immune system does a good job of getting rid of that. Now, in some instances, the body just can't do that. Now, that could be because it's been exposed to some previous virus. And because it doesn't want to remove it, because in removing it is going to have to then attack its own tissues. So in many instances, what will happen, then is, and this is where this thought around the exhausted T cell is the T cell is not efficiently working in doing what it's supposed to do in its, what it's doing is it's keeping at a level that will keep it a B, but it won't actually get rid of it. So maybe when you're exposed to something else, then it tips it all over the edge. And that's what what we're potentially sort of talking about here, when we talk about that T cell exhaustion, or that inefficiency of the adaptive immune system to get rid of that virus. So it means that you've got this antigen presentation, which is just present. And in doing so you've got that more chronic inflammation. And with that chronic inflammation can have repercussions on the cellular microenvironment. Now also include something like oxidative stress that we talked about. And then when you think about that, how would that then affect something like a symptom like chronic fatigue, or some of the symptoms that we're seeing? Well, that can cause dysfunction and the likes of the mitochondria? And as we mentioned before, something like that, because it's 90 95% of the energy, you know, that we regard comes from there, you can then imagine it manifests itself in some sort of potentially in some sort of some symptoms. Now, do we understand that, you know, that that T cell exhaustion, or that oxidative stress with the symptoms of chronic fatigue with brain fog, it's not 100%. But certainly, there's definitely links there, and I think, you know, T cell dysfunction, and a link to to mitochondrial dysfunction, and some of the symptoms that we see, in these post viral syndromes, including, you know, one COVID, you know, I think the way present and quite relevant to specifically look at,

Jackie Baxter  
yeah, and does this play into the sort of bio persistence theory, then. So you say, if the T cells aren't working as well as they should, they might be sort of knocking it down keeping it at bay a little bit, but not properly eradicating it. So this is why some people clear the virus and some people don't,

Speaker 1  
exactly I mean, if you think about if you're exposed the virus, you get this fever, maybe 40 liters, liters, because you've created this, there's an awful lot of inflammation. And that inflammation is caused by the T cells killing the virus and stuff like that, if for instance, is not functioning, that properly, you're not necessarily going to get that same clearance of the actual virus. So again, but something else comes up, you know, you know, then it becomes a problem because you've just got this persistence of a chronic inflammation and wherever you're not chronic inflammation is then manifesting itself in some some downstream things on targets that might actually produce some immunocompromised environment. So in oncology, they talk about a tumor microenvironment, which is immunosuppressed. You know, and it could be a similar type of thing, not in the tumor, but certainly within the cellular environment. I

Speaker 2  
guess the other thing to say with that is even if eventually your T cells did clear the virus, so let's say that you had you had that process that Nigel was, was was outlining there. And that process took a little bit longer than it went to sort of PSA influenza or another virus that maybe we're more familiar with. What can happen then, which which happens to lots of people is is actually surprising how much function you can lose from being inactive for a short period of time. So if you have a protracted illness, even if you've cleared the virus, and you know your immune system, if you like has gone back to normal. But if that process has taken too long, then there's lots of changes in your body that we call deconditioning. Meaning that your muscles are less able to you know, control how you walk around and they sorts of things, your energy levels are lower, then that can sometimes also lead to people getting into a negative loop. So it might be that actually started with an immunological problem that seems resolved, but then you're left with sort of the functional deficit, if you like that, that having a protracted illness is caused. So that's another thing that can kind of factor into long COVID, which I think does make it more complex, because I guess you've got all these bits that are kind of meant to work together that and if one thing isn't quite working, then sometimes you can have effects sort of beyond that, beyond that organ, beyond that sort of system within the body,

Speaker 1  
sort of building on that, and then go back to this sort of oncology sort of point of view, when we talk about PD, one PD, one's a big thing. And targets like, you know, pages and stuff. They're all targets that a lot of oncology, immunological, drugs, target. Now, to the point what what Shawn was sort of seeing, see, for instance, you have that initial sort of insult, obviously, something like SARS, cov, those expression levels are increased. And, you know, when you increase the PD one levels, you know, whether it's in a tumor or or within the actual sort of system, then what it's actually going to do is actually going to have an effect on are these cytotoxic T cells, either not going to be able to do that. So the question is, is, once that virus has gone through the expression levels of PD one and those receptors that are known to be easily affected? You So did they go back to a normal state? Or do they stay within that expression, level knee don't go down? And because of that, then you're going to have this general problem moving forward? And that's certainly something you know, that we would want to specifically look at No, of course, you know, to use your immunology drugs and stuff, and something like, you know, viruses and stuff like that can be a wee bit extreme, because obviously, that the side effects associated with that, but there's certainly something you know, that we could potentially look at, in between. And certainly, I know that there's lots of cytokines that are associated with long COVID. And there's also cytokines that are associated with exhausted T cells. And there are certain things that we can do, without necessarily taking specific, you know, drugs to potentially sort of, you know, alleviate that to a certain extent. But I think when we think about, you know, developing, you know, a diagnostic, of course, we want to catch the diagnosis early, you know, because the later we catch it, the chances are, it may take longer to get back to sort of a normal state. But what we also want to do is, is to provide, you know, insightful research to developers and drug companies who are actually developing therapies to target those specific whether it be a cytokine, or whether it be a specific receptor this up regulated.

Jackie Baxter  
Yeah, this is fascinating. Now, you just touched on that sort of diagnosis. And I think one of the sort of many frustrations of lung COVID, I was gonna say that the main and I'm not sure that's true, because there are so many. But one thing that is very difficult is that it's kind of it's a clinical diagnosis, there's no biomarker, you know, you don't go to your doctor and get a blood test. And they're like, Aha, you have lung COVID. You know, it's not that simple. And, you know, nowadays, you know, so few people are actually taking tests that actually, you know, people who might be developing lung COVID, sort of on from now, may not even know that they've had COVID to start with. So I suppose this is where things like this come really useful. Partly, you know, we shouldn't need to have some sort of diagnosis, some sort of test in order for people to believe that you have symptoms. But unfortunately, that is the case, in some circumstances, that you will not be believed, unless you actually have that kind of that test and a bit of paper. But also, you know, maybe more importantly, that actually, you know, in order to make that diagnosis have having a test that you can do, where you can say sort of without any doubt, yes, this is one COVID, or yes, this is a post viral condition. You know, it will help to rule out other things as well, I suppose, because what the process at the moment is, is a diagnosis of exclusion, isn't it? You go and get tested for literally everything else under the sun. And you know, it's only once all of that has come back negative that then it's like, oh, well, it's the only thing left kind of thing. So yeah, how does this work, I suppose

Speaker 2  
perhaps might come up just from from the clinical angle on that. So I think one of the things that's different maybe about having an immunological test is that it's a bit different to just saying like, yes or no, you have a condition in the sense that what we would be defining as is an immunological state. And where that's different is that it kind of gets See some insight into what might be going on inside that patient. So they've come in with some symptoms, they've said, you know, I'm feeling fatigue, brain fog, and all of those sorts of things. And then this blood test would say, yes, so I guess you, you know, you've got one of those things going on. And we've can see that your immune cells are doing this, which is perhaps different to what we might be expecting. And that that concept, although at the moment, I guess, when you're thinking of anything that might develop into a clinical intervention, it takes many, many years to go all the way from your idea to kind of actually having you know, something that's very protocolized and delivered in the NHS, and then guidelines and all the rest of it. But I guess this does put you on a path in that you can start to see how things are going wrong. And you can start to think about interventions that might be able to influence that, that test. So it's a bit different to like a test. I'm trying to think of an example. Well, you know, so if you if you were having a test to see if you had cancer or not, and you had a scanner, and they said, Yes, we've got cancer, or no, you don't you don't have cancer, it doesn't tell you how to treat the cancer, it just says it's there or not. So that I guess that's that's where this test is maybe a bit different to just having a sort of a yes or no answer.

Speaker 1  
And as you mentioned, Jackie, currently, the you people are usually diagnosed based on a questionnaire, and based on your score, you would get diagnosed on that. So looking forward, and as we were looking to develop the ESL diagnostic, and what we'd be looking at, you know, as part of that, we will be looking at specific cytokines that we will start with the certainly the non suspect. So, you know, if you look at the literature, you know, people who have long COVID seem to have lower levels of of cytokines, il two TNF alpha interferon gamma. So there's things that are sort of known about however, there are other cytokines that are super important specifically to that, and understanding because it could be a number of different things that are causing these symptoms. You mentioned this whole thing, how do you know it's specifically SARS cov. And it's not something like, you know, Epstein Barr something like some other viral of type of thing. So I think we are thinking about developing this, and we are developing, being this sort of a T cell diagnostic, you can come at it from a couple of points of view, you can come at it about, you know, an antigen related to this specific sort of a variant of SARS, kava, you can call or you can look at the how the actual, you know, virus itself is broken the epitopes. And you can actually have a specific epitope mix, which is specific for that virus, which when it released with your blood cells, or your PBMCs, as we would call your interest, it will actually activate the T cells specific to that virus. So, as Sean was saying that, what you would then get is a specific phenotype, which is associated specifically with that virus. Now, if you provide a test, we'll go back to this questionnaire thing, because the only thing that's potentially available is that you've got this questionnaire, which is approved, and is used by clinicians, you know, based on symptoms associated with long COVID, which are very similar to a lot of other post viral syndromes. But then you're going to test which is specific to that virus, then you can use that phenotype, you know, especially if you if you if you do that association with the symptoms, and the actual signature, that you can then utilize that moving forward about, you know, right, we have a diagnosis or long call is associated with no T cell dysfunction or T cell exhaustion, because, as Sean was saying, there's many different symptoms. And to think that you can come up with one test that will answer all the things I think we're we're coming out is, we believe that the adaptive immune system has got a central role and a potential signature that can help gate around that early diagnosis. And I think the early diagnosis is super important. Because yes, people have been in our living with long call wouldn't have been for a while, but but SARS cov hasn't gone away. And vaccinations are most probably not going away, either sort of thing. So people will be exposed to SARS, cov. In the future, it could be a slightly different variant, and whatever, you know, so there is the potential that you're going to get new people and wherever, you know, who are going to get these symptoms. And the question is, is if you can identify early, you can maybe actually have an intervention or some sort of treatment management to help with the one COVID symptoms, but you could also potentially pinpoint a level where, you know, you don't really want to go on before maybe it affects the actual adaptive immune and it prevents it from rewiring into a different, a different sort of stage sort of thing and I think that's We see the value in such a test. And as you mentioned, you know, if you have something like, you know, some peptide mix, which is specific to the virus, you can do the same things for other post viral syndrome See, like Lyme disease, or psycho mega virus, or epstein barr, or something like that, or influenza sort of thing. So again, you can provide that sort of information, because the biggest problem and people with me have been living with this for 4050 years about this have been not being diagnosed and not being believed. You know, it's good. All of this research has been done a long COVID. You know, people who and I know many people, so I think is crucial, as you see, to get that early diagnosis or get a diagnosis of that actual problem.

Jackie Baxter  
Yeah, and as you say, you know, post viral stuff is not just long COVID, it's been around for much, much longer, I suppose. What would be interesting, and I don't know, if there's something you even know yet, you know, these immune responses, this T cell exhaustion, that you're looking to be able to test for? Does this look the same in lung COVID? As it does in people with say, MECFS, with Lyme with any of these others? You know, are you seeing commonalities across there? That's

Speaker 1  
exactly what we see is the the combination of cytokines. I've mentioned, you know, il to an NF alpha, wherever it is not the same as it would be for Lyme disease, you know, or or me? Or is it slightly different, because if it is the same, and when we think it, let's just see, in a general term, you've got T cell exhaustion, and that T cell exhaustion is having an effect on glycolysis through its effect in the mitochondria, which is having a problem around the energy, general energy production, which could be causing symptoms of chronic fatigue? And what have you know, is there a commonality? No, if there is a commonality, it may well be, we will find out, but ultimately, you know, the test itself, although the virus might be slightly different, and whatever, you know, the result will most probably be the same. And that's certainly something that we would specifically look at. So if I was looking in the future, you know, could you get to the point where you would have an 86, well plate, different peptide mixes, you know, for the different viral syndromes, but with the ultimate seems sort of cytokines, which are associated with that T cell exhaustion, which you know, what, we're obviously linked in some way sort of thing to that sort of chronic fatigue, that would be the way to go. So you would go to the GP, and they would test you for the different sort of, and then you will do the interesting thing about the peptide mix that's specific to that virus. The question is, is when you're using that to stimulate the T cell cells, is that stimulation and the release of the cytokines? Is it different? And we don't know yet. But we will find out.

Jackie Baxter  
And I guess this kind of takes us into the research that brought you guys together. And indeed, all of us here today together. So this is an extension or a kind of relaunch the next bit, I suppose, of the research that you described at the start, Shawn. So maybe I just kind of throw it out there and say, Tell us about the research.

Speaker 2  
Yeah, I guess, like we've been saying throughout. So this study for us is is sort of like the second phase of things. And that we I guess the first study was that we did right at the beginning of the pandemic ended up being called the Surco study, which was just to emphasize it was sort of a Greater Manchester collaboration. And there were lots and lots of people involved in that. And one of the things that we found, which we've sort of published in pass along the way, like I was just saying, now our current paper is currently just being put together is, is that that there were some specific phenotypes that seemed to drop out in patients with long COVID. And some of those. So there is a story of T cell exhaustion, which we spoken about once a lot today. But there were also some changes in the B cells that we saw as well. So Nigel was mentioning the B cells are the cells that make the antibodies if you like. And we did see that there was some differences in terms of how the B cells in patients with long COVID, I guess, generally sort of produced their their antibodies. So what we looked at was the other B cells, because what's quite extraordinary about the adaptive immune system is the extraordinary variation that you have in the 70s of genetic makeup. Because maybe if we dive back a little bit into science, I guess when when you're growing up at school, you're kind of told that you have the same code of DNA and all of your cells. But what's really is that doesn't really hold true when you get into the adaptive immune system. Because what happens is that your T cells and your B cells randomly mutate bits of your DNA So that gives them all a slightly different genetic makeup that enables them to detect things that you haven't even seen yet. So if you like you would have had from early on, you know, all of us would have had some T cells that were sort of born to recognize SARS, cov. Two, even though we hadn't seen it yet, and, you know, they had sort of emerged as certainly as a pandemic. So within that, we can see that in our patients with lung COVID, the way that those cells refined their their specificity to being able to recognize COVID, is slightly different to patients who've made a full recovery. So I guess one thing that we want to do alongside the work with the T cell exhaustion is to look at that process as well, again, in a longitudinal sense, so the idea is that you recruit, we would ask people with long COVID, to take part, and enough people to get some variation in that. So we get some people who had maybe very disordered sort of B. So what we call affinity maturation, where you get the B cells sort of becoming more specific, I guess, to the target that they're sort of trying to protect against. So we would get sort of a range of people who sort of have a very good response, saying, and those who don't have a good response, and then seeing how those change over time, how that correlates with symptoms. And I guess the expectation is that everyone will get illnesses like we all do, across each winter period. So over that two years, we'll be able to see what sort of infections people are getting, and how they're responding to those as well. So it's maybe slightly more refined, and that we have more data, then we did when we started our first COVID-19 study. But it is still fairly broad, and that there's still lots that we don't understand. And like we've been saying throughout this, I guess there's lots of work that we need to do to really understand what long COVID is, this is sort of part of that work is to try and try and maybe get closer to that sort of question.

Speaker 1  
And I totally agree with what Shawn was saying is that, you know, there's tests out there that measure cytokines, and certainly for many years, the, you know, the go to test, and I would imagine a know of the long COVID studies that were done previously. And they use Eliza and ally, you can have a panel of, you know, 60 cytokines and look at the cytokines. But the problem with something like Eliza is, you don't know the origin of that. So what Shawn's talking about, is the origin CD fours CDA cells, because again, they will give you some sort of guidance, if it's coming from B or T cells and stuff and things like that, is it dendritic? Now, unlike as working with something like serum or plasma, what we will be doing is we will be, you know, separating out the PBMCs, the peripheral blood, which is the intracellular components of that. So, you know, although we'd be measuring, you know, the cytokine release, we would also be looking at the origin of that, you know, is it coming from a bee or is it T cell or dendritic cell, because, again, we really do want to try and understand a little bit more around the adaptive immune system, when and all that, you know, as part of the collaboration that we've got with with Shawn in the group is that we even want to go a little bit farther and that, you know, to, to look at all of that, that those orange, look at the tape of sales, and the changes within those cells over time with these longitudinal samples. So although the research, I think when you do these things, certainly when you're talking about the adaptive immune system, you're talking about getting some sort of in vitro diagnostic out there, with drug development with anything, it's super important that when you develop that diagnostic, the science behind it is something that people and it's clinicians, GPS, who are going to be utilizing that, understand the value of that. And so, you know, for us to publish, and move the sign sign is super important, just as important as developing the actual in vitro diagnostic. So, although, you know, this is a two year study, where we're going to be sort of looking at that, and we'll be, you know, also hopefully, in moving the science on and understanding on, what we will be doing is we will be looking to get, you know, to develop the in vitro diagnostic, you know, most probably in conjunction with a questionnaire initially when we're looking at a signature, and we'll be going for full approval, and when we go for full approval, CE marking in IV D approval, you know, we will be working alongside the MHRA, or even in the US, the FDA, and hopefully partnering with them. So when you think about when you're, you're developing an IV D, you have to have a clinical validation study, you validate what it's supposed to do. We would look right from the beginning to have those early discussions with the regulatory authorities to define what those outcomes are within the clinical study, which would be you know, insightful and have utility with respect to that early diagnosis. And that's the sort Are journey that we will do. So the research and the work and the samples that we can generate from this study, we will use to develop that assay and understand that more. But ultimately, as we see development of IBD, and long COVID, and whether, you know, also potentially another post viral syndrome See, white line disease to be said, that's what we want to do, because with a full IV D approval to see Mark, you can make a clinical decision. And unless you actually have that, and it's, you know, the analytical performance and the clinical performance is done, you can inject that into that healthcare provider journey. So the ultimate goal for us is to get a fully approved regulatory diagnostic, which is approved by the likes of CNAs. Or at least we've been involved them in the early journey that it can actually be put into the healthcare system to help with that diagnosis, rather than, Oh, I have this test, how do I get it to GPS?

Jackie Baxter  
Yeah, and I suppose this comes back to the idea of like, you know, diagnosis is kind of the first step in actually getting something that helps, whether that's pharmaceutical or holistic, or whatever that looks like, you've got to understand what you're dealing with before you have any idea how to tackle it. But at the same time, a diagnostic is only useful if it actually leads to a pathway. So I suppose that is the next step, isn't it? Okay, we've got this diagnosis, we now know what's going wrong. All right. So what do we actually do about

Speaker 1  
that? You we talked early around antioxidants, and oxidative stress so so to your point, and you know, there are things that potentially we could do to reduce that oxidative stress, because we know that oxidative stress in general, is not a good thing, or chronic inflammation, unless you're trying to get rid of a pathogen is most probably not a good thing. So again, to identify even a signature to say that, you know, actually, you've got quite a high level of chronic inflammation. And whenever, you know, that signature, you know, the cytokines It's most probably related to some sort of post viral syndrome, like something like SARS, Cobra, long COVID and stuff in there's something you could potentially do something about that to reduce the potential symptoms, because you're reducing that oxidative stress. And then you're in doing so you're most probably helping with that energy thing with with respect to the mitochondrial dysfunction that a lot of these syndromes specifically have. So even though if there's not any drugs, specifically available at this moment in time, I think that inflammation that's such a 10 s would do, it would help gait, research and development about potential therapeutic interventions later on.

Jackie Baxter  
Great. Well, thank you so much for giving up your time to speak to me this afternoon. It's been an absolute pleasure hearing about all of this, and that you're working together to do this. It's amazing. So the study that you've mentioned on the study that is going to be launching, I'll make sure that links to that go into the show notes. So if there's anybody interested in that, then they can absolutely follow that up. So yeah, thank you so much. Good luck, and maybe you'll come back and talk to me once you have some results.

Unknown Speaker  
Yeah, I'd love to do that.

Transcribed by https://otter.ai