Montpellier Ecology and Evolution Seminars (SEEM). Seminar by Dr. Alejandro Cabezas-Cruz (UMR BIPAR (INRAE, Anses, EnvA), Maisons-Alfort, France) on “Microbiota-targeted vaccines: Paving the way to vector-borne disease eradication”.
Supported by the Labex CeMEB: http://www.labex-cemeb.org/fr/recherche/seminaires-en-ecologie-et-evolution-de-montpellier-seem
For okay welcome everybody uh welcome to today’s same webinar as every week it is a webinar mode so for people on Zoom uh you won’t uh be allowed to talk during the seminar but you can ask questions in the Q&A and we will open your microphone
At the end of the seminar during the discussion session uh you can also report problems in the chat I’m alone today but I have to be on board to uh verify that everything is okay and now I let thece to this Tokyo hello good morning everybody it’s
A pleasure to me to introduce Dr Alejandro Cabas R uh he graduated as a doctor in uh veterinary medicine in 2006 and then he joined this genetic center of the of uh engineer and biotechnology in Lavana where he was a part of developing some uh vaccines uh for the anti for the ti
For tis after that in 2012 he secured a maruy fellowship and he joined the Institute of parasitology in the Czech Republic where he completed a master on parasitology and in 2003 he uh enrolled Sim Sim simultaneously in two PHD programs one in Spain related to TI biology and one in France related to
Epigenetics on on um on parasites he completed the master of Spain in 2014 and the in 2016 the ma the sorry the the PHD program in 20 in France after that in 2017 he joined the Institute of national research agriculture in France as a principal investigator and he uh M
His own group called micro KCK he introduced the concept of antimicrobial uh vaccines as an Innovative approach to block uh tricks uh transmission diseases and since 2012 aleexandra have outter more than 200 uh 200 papers and he was he has been Award with the odil brain memory prize uh for his standing
Contribution on parasitology so it’s a big pleasure to me the floor is yours thank you thank you everybody for coming thank you s for the invitation Nicola for your help setting up uh so everything goes smoothly so today we are going to be talking about antimicrob
Vaccines and and Tis so I am going going to wrap up a lot of um Concepts I am going to try to challenge the current Concepts we are using for developing vaccines and towards disease eradication first we have to say that for major Vector bone diseases that we have transmitted by
Different vectors we have failed to develop vaccines that allow us to eradicate diseases so concept of vaccination that we use for classical infectious diseases or non Vector bones that has helped us for example to eradicate potis so we can vaccinate the population and we eradicate eradication
Means zero cases of uh people sick in a population uh we have not been able to do so for Majors Vector bone diseases even for malaria which is a flagship um uh disease caused by by or transmitted by vectors caused by plasm mod which we have put billions of of uh
Euros doar whatever Co you want to use and I’m a lot of Minds to try to find a vaccine we have a vaccine now that have 70% efficacy was the last report I have I have read but for the others there is no vaccine that allow us eradication my
Standpoint start by saying that the com set we are using for vaccine development are failing so we have already a lot of years of evidence that something we have to develop new Concepts and be radically Innovative so I hope in this presentation I’m going to convince you
Of that or I would show Arguments for that first of all the model we use is scks so this is the life cycle of a typical three host THS in this case could be Exodus reinus in Europe the main th in Europe and exodus scapularis in the United States for example what is
Important in this life cycle that goes from eggs to adults is that in each of these red H circles the TS needs a blood Mill and in each of these feeding points they can acquire or transmit pathogens even the larva that come from X there are pathogens that are transovarially
Transmitted so even the larva can transmit a pathogen an important thing of this cycle is that it can last for resus for example five six years of which these dots are account only for 15 days so most of the time tis are in the environment crawling in the plants in
The soil so PS become during this life cycle hubs of pathogens so high prevalence of Co infection in THS and this is a map that we have uh we summarized the major distribution of th born diseases in the in the on on Earth what is challenging now is that with the
Climate climatic climate change the the distribution of diseases will change in unpredicted ways now we are seeing for example in Norway in which scks this sck in particular was never a problem now because of the increasing temperature we have in Norway have been reported a lot
Of of presence of EXO resinos tis in the south of France the other day was the report ofan Kong hemorragic fever virus in tis collected in France and before that was a problem only in African countries mainly so the the landscape that have take 30 years to understand
Will change in the next years dramatically in unexpected ways this is the problem um so first of all before going into microbiome anything let’s talk about thos P interaction so everything start from the interaction of tis and pns and we can we have exract two paradigms on these interactions the
First Paradigm is that the pathogen exploit the THS so how the paan exploit the Tis the discoveries of Patricia Nal that were published in a paper in science in 1987 she chose with her group that these THS can transmit the pathogen from one to the other without
The animal develop bmia or paremia it was a groundbreaking discovery because the background of that Discovery was mosquito born diseases in which you have to develop parasitemia bmia for the next mosquito to get the pathogen here the thi transmit from one thi to the other without the animal developing bmia
Paremia but it hints at a special property of the saliva of the th that could assist pathogen transmission and this has been called nowadays saliva assisted transmission and it took 18 years to have the most beautiful example of this saliva assisted transmission for the ban boria
That one of the maor suface protein it has is osc is very antigenic immunogenic so when it enter the host antibodies against this protein can kill the speedet however there is a thick protein in the saliva that is called Sal 15 that covers opy so anti antibodies against
The opsy cannot kill corelia so that is essential for perpetuating boria life cycles in nature so and and and H the very strong Association from the THS and the pathogen so the pathogen exploit the THS this one is quite obvious because you can imagine why first of all they
Have Vector Bor so they need the vector for something but the other one that is less obvious is that PS exploit the pathogens to and the first example of this one of the most beautiful also examples were report by the group of aeropic in jail University in which they
Show that PS infected with an a plasma focil which is an intracellular pathogen induces a protein a thick protein that is an antifreezing protein so these scks that were infected with anaplasma resist better a choke a a temperature choke of minus 20 degrees and when you extrapolate this result to eological
Environment you can imagine that THS infected with soplas foph they could over winter better than THS that are not so THS and what is remarkable here is that it’s a th protein that is activated very well when the pathogen infect the THS but the THS by itself cannot
Regulate it soon enough and activate this mechanism of Defense another evidence has been provided Professor Jose lafuente which is one of the big um persons working on the in tis and tibon po interactions he found that when the anaplasma the same pathogen infect the DI they have up regulation of many genes
One of them suine and down regulation of porine the Gen involv in apoptosis subolesin is a transcription factor of TI so up and down induced by an a plasma infection when so they silent the both genes to see what happened in the tis when they silence subolesin
Which is here the ti could Feit less you have mortality and pathogen transmission is imper but when you silent pting nothing happen so the ti trans feed normally and transmission of pen happen normally so the pathogen up regulate genes that are essential for the th and downregulate genes that are not
Essential for Di completing feeding and the life cycle now what have we done so far to control ticks so first is vaccines so we have developed vaccines against Tis the first vaccine I will refer to two vaccines are just two examples but they are many in the literature using different strategies
That we are going to summarize after the first one on the flagship is bm86 which is an intestinal antigen uh I was disc discovered in 1989 uh and it’s the component of two vaccines one Australian vaccine and one Cuban vaccine that is called gak and it’s the only commercially available
Vaccine against it is the Cuban vaccine because these guys they Dro that project and then in 2005 I going to mention 64 antigen by Patricia Patricia nutal so this was the first paper that they discovered that the immunological control of thick infestation is possible this was a breakthrough
1989 and that open up this General scheme that provide rationality for vaccines against THS so you have antigens you have the immune response you you have antigens of the of the vector you vaccinate you induce an specific response that includes antibodies and then with the blood Mill
A lot the antibodies are introducing the deck body and Target the molecular the molecule they are specific to this open up this Paradigm host antibodies targeting thick proteins can protect against thick infestation then an interesting thing happened what is the the technological context of this discover 1980 that was
Very early so the first recombinant protein used for treatment in in humans was the recombinant insulin 1982 and if seven years later the first recombinant vaccine against SS jump into the into the into the research so we the community was able to translate these discoveries very early into the control of uh
TI and there was a Race So this trigger a race between very interesting two parties Australia and Cuba to develop a recombinant vac against SS the qan team was LE led by Jose LA fente and they has well as early in the 90s as 1994 they developed an own recombinant version of
That antigen but they use a different expression system so they could patent the same antigen with the different technology of vaccination to the Australians and this is the vaccine that exists today so what was the main results of this vaccination reduction in think abundance vaccination of associated with
The reduction of certain th B pens and the reduction of AAR sites this is one of the main results how you can represent these uh red bars represent the the amount of bath you have to give in a year to treat a certain cattle her that this supposed to to t infestation
When you introduce vaccination in this rthm so is one per month so there are 12 red bars you can reduce this treatment to two per year so vaccination just this and the reduction of environmental impact that have the use of aite vaccination by itself in this is very
Essential I I let the question open we could discuss why vaccines are not entering into the market for the control of scks we could discuss reasons for that but technically from the scientific point of view a problems that this vaccine didn’t address first it was a concealed antigen
So it was in the mid gut so when the DI bites you the host immune the host immune system is not exposed to the antigen so you don’t develop antibodies naturally so you have to be constantly vaccinating the animal to keep certain level of protective antibodies and the
Second thing problem was that this protein have sequence variation in the population and that escaped the possibility to have a universal uh vaccination as I mentioned then Patricia Nali introduced another antigen 64p that’s that solve some of this problem so 64p was a conceal
Antigen so it was in the Mig but also in the salivary gland and the cement so now every time the T bite you develop antibodies and you have the three of the immune response by the infestation and also it was shown that blocked the transmission specifically of th balitis
And there is a lot of scientific data supporting this now these paradigms of the antibodies of the host being used to reduce th infestation permeate also vaccinate strategies against Vector bone pathogens in this case boria so the vaccines that fiser and Beva which is a French company are developing today and
Is Phase H clinical phase three at this moment is using one protein from boria o that is expressed by the pathogen only when is in the tigmi gut so it blocks the transmission of the pin targeting the pin within the midgut of the DI and this is an essential thing to consider
Later in the antimicrob vaccines and this vaccine this category are being named transmission blocking vaccines so today we have categories of vaccines against THS we have vaccines targeting th secret salivary protein so so salivary proteins we have vaccines targeting membrane proteins like bm86 and also vaccines targeting cetto solic
Proteins of the th like subolesin subolesin is the base of one vaccine which is one of the best characterized antick vaccines and somehow by mechanis that we don’t understand the host antibodies enter the cells of the THS and can Target intracellular Targets in the THS this is an open area of research what
Are the mechanism by which these antibodies are internalized into the the cells in 2020 in 2020 we introduce a new category of vaccines which are antimicrob vaccines but before going into the antim microbiota vaccines we have to introduce the concept of microbiome and microbiome ER perturbation of those old
Paradigms of thick pathogen interactions the two paradigms that I revised and summarized before this Revolution and the discovery of a microbiome in tis an important player in the T physiology and Vector competence affects our capacity or or Force us to rewrite the book of what we understood between th and P
Interaction so the th microbiome has been found so far that changes during the life cycle there was a work um developed by Alejandra it was a PhD student of mine very ironic the name then we have the the the host that the t f fit on they also
Affect the microbiome the soil microbiom is expected to affect considering that this s can spend 99% of the time of the life cycle crawling in the floor temperature Etc different factors the th immunity has been also shown that shapes the microbiome of the THS so this microbiome uh it’s become an important
Player in understanding thick B interaction but I have a problem with the definition of microbiome how do we when we say microbium all of us are we considering the same exact thing and I I I am still struggling to Define microbiome because for example when you
Go to the literator one of the concept of microbiome you go leaving microorganism within animals including bacteria Fung protozoa virus uh virus there is a lot of lature that says that virus are not leaving microorganism so there is a a group of people that would argue that virus and
The living there is a problem there another problem that I see what what we consider microbium we are using massively 16s sequencing which are sequencing DNA but DNA could be contained in living bacteria but also dead bacteria so what we are calling microbiome could be considering by the technology we are
Using which is the most standard I am not saying that RNA sequencing cannot be used contradict also this Living Concept another concept is like what do I include in the microbiome do I include thck bone pathogens within the microbiome of the TH or only non pathogenic microbes within the tis for
The vertebrae in one uh the the literature when you revise this topic in the literature you find apparently that there are researchers that put both nonpathogenic and pathogenic within the concept of microbiome however others have developed Concepts as the pathum in which they say the nonpathogenic microbes plus the pathogens this mean
That for this group of researchers the microbiome does not include the pathogens so the problems skip a mountain in which what are we consider with there are people study endos syion and they are studying the microbiome of the th however they do not really look at the complexity of commensal bacteria
At chire not vertically has the endo symbion and the long evolutionary history of millions of years sometime of coevolution between the th and the endos symbion and they neglect these environmentally acquired commens that concerns only the generation that this question but not vertically transmitted in our group
Um we are considering the microbiome as a complex system that can be better described by networks complex system that not because it’s complicated by complex system that have a lot of components that interact simultaneously with each other and this conceptualization which I would show that have also some problems allow us to
Study the system has a complex system that have emerging properties something that you cannot realize when you study the part separately one of the emerging properties of network for example is robustness modularity ETC that you cannot study if you do not consider this framework also network has allowed us to
Identify kyone taxa so taxa that have nodes that have very high centrality in the network and we have we may argue that this concept may not be good enough or this k taxa based on this that this an abstraction I’m going to say is not good enough but then we validate this
Concept by vaccination so we take the Kyon taxa we vaccinate against the kyone taxa and we see a major reaping in the microbiome and not with other taxa that are not kyone so by we we close the loop of validation of the concept of the nwor has a good approach identification of
Keystone and to identify targets for antim microbiota vaccines the network has been uh we publish this year is a for us it’s a fruitful approach to the study of microbial ecology this is an study published by apoline and we can see here the networks of current networks of two
Th speeches so a one thi speeches B another one and you see in green and and uh Pink here two clusters that are equivalent so there is a high similarity of the composition of bacteria here and bacteria here and we were tracking Ria pathogens interestingly in this th
Speeches Ria is nested into this community in the other one is nested into this community so Network allow us to understand the system at this level of complexity and for us is a free strategy for the search of candidate for vaccines and also for the study of
Microbial ecology in t now networks have a problem of themselves it’s an it describes an abstract microbial Community why an abstract microbic community so networks you have different samples 10 samples 15 samples so you have sample one and in mind this is a grid that describe taxa that are
Appearing in the sample one so you have this blue taxa appearing here sample two some disappear some stay but new appear sample three something change and then you develop the cooccurrence patterns in which you describe some interactions between These Guys these guys they don’t have Pro because they are randomly heing
So this community is a summatory of 15 ticks so it’s an abstract definition of a community we don’t know really how this complex system interact with each other at the individual level so we are just we need the population to study to describe the the microbial community so that’s a limitation of
Uh Network however we we consider this as a free a strategy for the description of the community as a complex system then we propose the use of microbiome susr susr is an Strat was was not an idea I had um he was developed by one philosopher Algerian born French this Al
His work here is called Jack Dera and he proposed the use in other problems in gr grammatology to signify words that are um requir but not enough to describe a certain thing so we cannot assume something very easily we have to highlight the complexity of signifying the concept with the word
We are star introducing now this in some of our paper to see how the reviewers get it just once in the paper to to see uh to to chieve this uh to highlight the complexity of defining the microbiome one property that have this microbial composition in THS of the microbiom in
Tis is the filos symbiosis so we have found in this paper that we did a philogen of some exod ex Exodus tis and then we describe the diversity of the microbiome you using jackar dist distance and then you see that there is an almost perfect overlapping or matching between the genetic philogen of
The THS and the composition of the microbiome however is the the sign of coevolution between the full community and thi speeches there we cannot conclude by this fos symbiosis that there is a Evolution this nany Moran which is a one of the top uh researchers in U microbial ecology in the United
States have a very good paper in plus biology that she described that these patterns can emerge by different type of mechanism that does not necessarily involve Co Evolution between the two but definitively we can say that there is a certain microbion composition assigned to every th species now there are two
Tendencies today in the microbium research in TI there there is a group of researchers that say that the ti microbiome is very diverse so you have high Spees richness and there is all another group of researchers saying that there is a pool microbiome it’s not significant it’s
Just few bacteria some people call the tis sterile they have not found microbes in the ti then the same group argue also that there is an impact of microbiome in the pathogen and Vector competence and this also is kind of associated with the neglection in the interaction of th bone
Pathogens with the microbiome saying that that sever antique bone P has L gen of bacteria bacteria interaction Etc is not is not needed not necessary to to account for so in our group we are biased of the evidence we have generated of our understanding of this problem
Towards a rich microbiome and a very strong impact in thi p and interactions so one important another property of this microbiome has I mentioned before is high diversity in high taxonomic diversity but low tax functional diversity per th individual in this analysis you have tax account
Here and path weight count here and this you start removing the samples so when you have all the samples 100 samples you have this amount of taxa you start removing samples and then you start decreasing the diversity so the sample of force is associated with more diversity in the microbiome however the
Pathways do not follow the same Trend so you have a robustness in path in Pathways metabolic path paway associated with the microbiome that could lead also while developing vaccines against the microbiome that is highly diverse may be challenging by maybe we could find proteins that are conserved across scks
Across microbiomes that can be used as vaccine candidates now I introduced the microbiome Revolution and now going to introduce why we consider that the microbiome is important in thick B interaction because I say that that concept permeate the the paradigms of thick pow interactions and the experiments I will present are the one
By ER of P first he describ he discover that the pathogen infection modulate the microbiome and then he use anaplasma ftoon as a model and he found that pigs that were infected with anaplasma this one here they have a reduction in the diversity of the microbiome they go
Further so this is the pns paper and they describe the mechanism they show that the ti the antifreezing protein that I mentioned before has also antimicrobial activity and reduce the capacity of this microbiome to produce biofilms this is an intracellular pathogen so it debilitate the biofilms associated with the peritrophic membrane
And access the cells to infect so pathogens influence the microbiome also he develop another set of experiments is now we he modulate the microbiome of the tis by raising the tis in an esile environment or by exposing the tis to antibiotics and then he exposed the two group of tis treated and
Untreated to boria those that have high diversity in the microbiome they have higher boralia compared to those that were treated either with antibiotics or rais in an ester environment so from these two set of experiment we conclude that the relation this is our examples if you find the litera you will find
Many more examples representing these and that that the relation between pathogen and the microbiota is bidirectional in which pathogen modulate the microbiota but at the same time the microbiome modulate pen infection and Vector components based on this study we could one abstraction one conceptualization of the stage of the microbiome in which all
The possible states of the microbiome could be the circles so all the Open Circles you have a certain set of microbiome that are infection permissible states to accept the development of the PA within them but others that would be infection refractory State and others that are the blue here that are impossible State
Because of the community doesn’t accept the conation mention of immune system doesn’t accept this bacteria here or there and that open the window for vaccination and manipulation of the microbiome towards infection refractory States then in 2020 I had an idea which I call syntactic ontic
Idea I had we had we have published this paper that have this title in the dream in the dream it was in the lockdown so 2020 we were in the lockdown and I was sleeping and I have this title it comes to my head and then in the in the dream
The words in Black start disappearing and stay only the those in red th microbiome anti- thck vaccines and in that moment I wake up and I reorganized the wor the word sorry and I realized that nobody working on Vector bone diseases mosquito he of vaccinating against the microbiome and in the last
30 years we have accumulated a lot of evidence that the microbiome is essential for any Vector P interactions even the mosquito Community because the mosquito Community all the time 30 years ahead the de community so they have the trenic mosquito they have usak already and we are like 30 years before after
Our syst is more complicated than the mosquito but here for the even the mosquito community that have an intense Community working on microbial ecology they didn’t use the Paradigm of antibod host antibodies of the host to manipulate the microbiome and induce infection refractory States so we
Develop uh in the lab to to to test this hypothesis at that time it was an hypothesis that we could modulate the microbiome through vaccination against the microbiome with theel which is a microbial ecology in University of welp in Canada ludes which is a post doog in
My lab and Jennifer which is an specialist in auuan so we were discussing brainstorming to see how we design the vaccines first of all we identify kyone bacteria in the microbiome using networks so first CR for identification of the Keystone was that they have high centrality in the
Networks second that they were ubitus across the samples so they were everywhere in the samples and then that they have high abundance so using this three three criteria sorry we identify kyone tax EXO res and then we vaccinate the mice so price we obtain 40% of
Mortality now if we we take it for granted like one little bacteria floated in the midguts of the th you vaccinate against it comensal not an endosym we have not moved to endion which could be an improvement of those vaccines and you kill 40% of the th for us this was
Something really relevant and we move to other experiments now to show for example that when we vaccinate we modulate the microbiome and we set up an experiment we we vaccinate against different bacteria and what we found for example this is the tis that fed in green on animals that were not
Vaccinated against this Keystone taxel and in red the animals that the Ts that fed on the animals vaccinated with the Keystone tax what you found in the reduction in the alpha diversity because you can imagine if you understand the microbium has a network you can understand a cascading effect if you
Target one of the netk of the nodes of that Network this one positively affect this one negatively affect this one so if you affect one of the notes you can have a cascading effect in the community that in this case we show that result in the reduction in the alpha diversity but
Also in the significant change in the abundance of sever taxa taxa including the one that we use for vaccination which was the Gena another thing important trade that we observed was that the centrality meture has a network of the Kon taxa that we use was reduced after vaccination so the importance of the
Taxa we Target in the community decreases after vaccination so we could Target we CH we can modify the abundance of Taxas we can modify the diversity of the microbiome and the centrality the jarch of nodes within that Community or taxa into that community in that Community we also found that a
Modulation in the metabolic pathways of THS that fed on the antim microbiota vaccinated and in this case we identify genes associated with the degradation of lysin that were reduced in the tis that fed on the vaccinated animal so we could modulate not only the taxonomic composition and understanding of the
Microbium but also the functions associated with the microb we validate this concept with canaris and AIA malaria in collaboration with vas palow which is one of the world leaders in in Avia malaria in which we vaccinate the birds with different bacteria and then we challenge them with mosquito infestation and then we collect
Samples and then we did the same we classify we characterize the microbiome so you see here let’s just focus on this one on the top left this is the PBS the community of the of the network of mosquito that f on animals that were just vaccinated with the mo vaccine PBS
And here the one that we vaccinate with the chicha you see just topologically without entering into the mathematic description of that Network that this network is completely different to this one and also different to the one of mosquitoes that were feeding on birds infected with plasmo so the antimicrob
Vaccine modulate the modulation that the pathogen induce in the microbium but more interesting so again the centrality of the bacteria that we used to vaccinate changes as we observed before but more importantly the loads of plasmodium within the mosquito reduce significantly this is the frequency of OC frequency here we are understanding
Yes or no say they were they were or no in the control group we have around 70% of mosquitoes that were positive for they have all in the mid gut but look at the vaccinated groups so a reduction of half in the amount of OES this is C yes
Or no and then those that were positive the amount of osis was significantly lower than those in the control group and we observe something similar in the frequency of sporos in the salivary glands of the mosquito this one is in particular with this bacteria the control group was around 30% and this
Bacteria less than 5% op so you can imagine that if you make an experiment in those mosquitoes to test transmission you have a significant reduction in the transmission of the P then we publish this year similar results with boria in ex Reus we vaccinate the T we vaccinate
Animal sorry against one microbiome the taxa and then we have antibodies against this Keystone taxa and then we reduce we observe a reduction in the amount of boralia in the midgut of the tis here that was the reviewer have a very interesting question are you sure the antibodies you
Raise against a chicha are not close reacting with boria ah good question so we develop an experiment we were back to the lab and we develop an experiment which we remove aera recognition of the antibodies so we remove by absorption and we did an experiment an experiment with mro inject with those antibodies
Depleted from recognition of boria and challenge with boria and again we saw a reduction in the boria so the effect in the reduction of theia was mediated by the modulation in the microbiome and not by any direct action of those antibodies against boria so we keep happy with this and
Then we set up a collaboration with CLA bente which is from the University of Leon in which we test this concept against mosquito alus we set up a dual lab collaboration that they have bacteria that they isolate from the mosquito we vaccinate rabbits against the bacteria
And send the blood for then and they meure parameters of the of the of the mosquito reproductive parameters and we OB ve here we we we observe the different thing what we want to see but the anti mosquitoes that fed on the antimicrob vaccine have an increased
Peity and egg hatching rate so again you imagine that you have a bacteria you target with antibodies and you can have such important impacting the traits of the life U life trait of one mosquito then we quantify also the impact of the vaccine on the microbioma
Look at here you see that the networks in the control group are completely different to the nwor on mosquito that fed on animals vaccinated with one of the bacteria in a toac topologically you see that you have your induced chift and a change in the topology and the
Assembly of the microbiome then now we could think about engineering if we can go to the cream with the help probably of artificial intelligence and we can we could engineer expected outcomes in the metabolomics of a microbiome you mind that we design a vaccine that we can expect certain modulation in the
Microbiome that increase bacteria that produce lactus lactate so maybe lactate increase would reduce the ph and pathogens need certain pH to have optimal conditions for optimal development so we could even modulate maybe this is now something we have not uh tested yet but the physical chemical properties of the vector mut using this
Approach and of course the rationality is that antibodies enter with the blood meal and interesting in addition to what I just said before with the Paradigm that developed from the th infestation vaccination against th infestation those antibodies are also they access all the tissues of the of the vector they last
For weeks and months within the vector and in the case of THS they are Ched back to the host so the antibodies enter go the all the mid guts go to the Emin salivary L and they are they enter again in the host so somehow they escape the protolytic
Machinery of the th and there is a significant amount of active antibodies within the de which is our weapon of to fight uh the microbiome so with these antibodies we could Target symbion pathogens like the blocking transmission with boria but also depleting depleting kiston taxa as we have uh shown and use
Of course for the classical vaccines which is targeting specific protein within the mid of the of the de so what conceptualize what uh I have just said when you have to have pathogen Transmission in any Vector bone disease you need to have a a match between the microbiome of the vector the pathogen
And the vector itself so the genetic of the vector the microbion composition and the genetic of the pathogen because there are some strains of pathogen that not transmited for the vector or strin of the vector doesn’t transmit the P Etc and the idea is that we could
Induce we could indu shift in the composition of the microbiome towards infection refractory State and decate this triat to a state that are unsuccessful for the vector to transmit the pathen and this could be applied to any hematophagous um arthropod now there is room for Innovation here we I I have described the
Antimicrob vaccines however when every time we Face a microbiome there is high diversity what is the best Target for example in the vaccine with the mosquito that we did we increase reproduction and number of X this what we don’t want for sure so we need certain algorithm
Certain way that we could identify and pinpoint the right bacterias that we could use to Target to develop antim microbiota vaccines that help us to reduce pathogen infestation pathogen infection s in the THS probably th Fitness reduce Etc and we consider that artificial intelligence could be brought in to
Fit the data that we could develop in in the lab and then develop algorithm that help us to identify what are the best candidates for this one we are proposing an study that in which we could study the Assembly of the microbiome and we could do a tomography
Of the community so if you start sampling tis in different time points so you could start seeing how different taxa start interacting with them in time and then the dynamic of this assembly so you could identify early taxons and notes that disallowed the Assembly of a community that is compatible with pthen
Transmission this is a still we have not done this but we will be moving to um to using these tools to identify this um early bacteria that are key for the Assembly of the microbiome and then this could be one of the approach that we could use to develop Noel
Vaccine so we could analyze the microbiome in a certain region for example for for Animals we can identify Keyon taxs that we develop the vaccines we can test in the lab the efficacy against the pathogen that of interest and then we could the test vaccines in
The field so now we are using we are doing one project like this in Corsica so where we take PS from the cattle in Corsica and we are in this uh this stage it would be difficult for the testing the in the animals but we we will try to
To set it up and that’s me so uh thank you for your attention so you may remind this aene from jic Park when they discovered the mosquito that they have this blood that they used to to to do the dinosaurs so Recent research showed that this was not the mostos it was
A thank you very much thanks for the talk I was wondering um on a bit on a bit more long longer scale than what you show for example say you have a nymph and you have a vaccine targeting bacteria and then you remove the Hub and then it modifies all the interaction and
Then you have less infection of boria whatever and then because of also of the functional composition of the microbiota which is very similar you then expect that one of the other bacteria will take the role in the next year infection of the adults if the N survive of course and
Then you will need a different vaccine for that so I are you thinking about a bit longer term that one generation or of course this is first step to if if it works whe it works and how it works but then for more bit evolutionary perspective you have this switch
Directly to a different community directly in the thick if that screwed Hub basically yeah um it could happen but the I think the selection pressure on the taxa that we vaccinate have to be quite strong to to select for the substitution so at that time we have been implemented antimicrob vaccine at
Large Scale Etc but and that could be an outcome um that can happen uh we need to see how this um unfolds in the time but this could be one of the things what happen please it’s maybe a naive question but do you have the same like a TI uh uh
Feing on a CLE will will it have the same microbiota as a take fitting on mice so is it relevant to like uh go and uh test in cats and then test on mice or would you have to do on same species every time yeah that’s a that’s a a good
Question but that’s I mean that’s a problem that concerns not only antimicrob vaccines when we develop drug for cancer we start with the mice we start in be with the mice and then we extrapolate to clinical trials and most of the fail failure in clinical context has been assigned to what you testing
The mice that the mice is uh eight weeks old very young very strong then you go to the patient that have diabetes is dying with the cancer so complicated so here we are going to we need to this translation is always a challenge so you need to start the
Clinical in the lab condition reduce reductionism science is important to understand what is going on probably a preclinical trial with CLE under control conditions and then before you move to the field but definitively there is a risk of translation that what you are seeing in M may not be what you will see
In the target definitively SAR you can ask your question now thank you very much so uh my question is whether you have a studied what’s the influence of your vaccines on the vertebrate host I mean on the microbiome of the the vertebrate host yeah that’s a question that is uh weaky to
And pervasive all the time the concern about safety of the vaccine and what is the impact on the host um we have two considerations there in the experiments that we did in mice and canaries we took fishes uh samples along the the study and we did not observe any major change in the
Diversity and composition of the microbiome of canies that were vaccinated against the contrs but if we go in depth probably with the network or maybe more fine-tune search we may find changes now the second point is the modification of the microbiome with vaccination is not a challenge that concerns only antimicrob vaccines but
Any vaccine we are using today to vaccinate ourself to vaccinate the animals they have an impact in the microbiome this has been reported there are several examples now that are coming out regarding this because the the modulation of the immune system that you induce with the vaccination have an
Impact in the microbiome you have for example gross reactivity some bacteria that you vaccinate against they are also taxa similar taxa in the microbiome of the host but also the the immune system by itself which is a area that has been explored how the immune system shape the
Microbiome so now with the vaccine we are modulating the immune system and that changed the microbiome an interesting question that emerged there is is the efficacy of vaccines associated with the modulation of the microbiome that induce the vaccine itself so is the efficacy that I
See of vaccination there is a is it the is it the proportion of that efficacy that belongs to the modulation I inducing the microbiome that did have a feedback on the efficacy of That vaccine that could be an interesting question to explore in the future but yeah to the to
The question we have not observed in experimental setting but that’s a challenge that concerns any vaccination um strategy I don’t know if so just a followup question there are you planning to do it I mean it it could be very easy to find candidates for your vaccines
That are not present in the in the host microbi yeah definitively this is one of the solutions to to that problem and even we could move to a subunit vaccines because now we are using live bacterial vaccines so we are vaccinated with the life bacteria and this is for the
Regulatory point of view to enter into application in veterinary medicine or human medicine challenging so we could move to a recant vaccine that targets A protein that is only in the microbiome of the vector in question so we remove a lot of risk definitively as you suggest by targeting refining the the approach
Definitively or we could Target for example symbion Endo symbion of the arthropod that is link explicitly with the arrod and it’s not in the in the vertebrae so it could also another way way to overcome that challenge thank you thank you a lot yeah thank you for the talk very
Interesting so I had a question about the the community and individual so population and individual you said that you cannot study the community inside an individual because is they have all different communities no so each individual has like his own bacteria populations but you can really call like
Community the one that you find then in the entire population if they are not really interacting with each other or or yeah or they you always find anyway some some some that are interacting like in the um using network analysis you always find an abstract community so you find a a an
Ideal Community from the set of samples microbiome that you use to fit the network so you don’t have information about the individual however there is no other way to understand that system in the complexity of the system I’m not saying that you can isolate bacteria and stud bacteria bacteria interaction see
Changes in abundance by PCR but in the complexity of very numerous interactions between then and Co associations and Etc the networks is the only way that you can understand but then it comes the validation with the antimicrobial we use this AB abstract community and we identify a
Keystone taxa Kon taxa that it might be important in the individuals because when you summarize you identify in the as Community it would be important so we you vaccinate against this one and then you have a read out so you change the community assembly you you reduce
Pathogen infection Etc so there is an effect of something that may happen when you identify a kiston taxa that came from that abstraction but it’s an abstraction it’s a community that exist it’s an it’s a mathematical abstraction but the beauty of of the network is what once associations are
Transformed in a network it’s a mathematical entity that in the same nwork I’m describing I can describe the interaction between us when we stand up and then we do an experiment we see who interacted with who you can check this many times and I can identify hisone person that interact with many people
And we are we be describing the microbial Community social interactions in FA in Facebook electricity GDs airplanes uh flowing the so this mathematical asra is powerful to describe a lot of complex systems so for us it’s really an successful strategy even if it’s an abstraction thanks thank you thank you very much