Pathology Grand Rounds: January 12, 2023
January 13, 2023The Pathophysiology of Multiple Sclerosis, by David Hafler, MD, FANA
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- 00:00At all to this nice, auspicious start
- 00:03of the new Grand Round series for 2023.
- 00:07And I'm happy to have Doctor David
- 00:10Hafler here is our speaker today.
- 00:13So since 2009, Doctor Heffler has
- 00:16been the William S and Lower Styles
- 00:18actually professor and chairman
- 00:19of the Department of Neurology,
- 00:21Professor of Immunology, Immunobiology
- 00:23here at Yale and his neurologist
- 00:25and chief of the hospital, David.
- 00:28He's a he's a clinical research scientist
- 00:30with an interest in understanding the
- 00:32path of pathogenesis of inflammatory
- 00:34CNS diseases by studying
- 00:36both basic properties of.
- 00:38Due to regulatory pathways in humans
- 00:40and they run this function in patients.
- 00:42But as went on, I won't show you all
- 00:44the ruminations over the 20 odd years,
- 00:46but with 47,000 patients,
- 00:4968,000 controls by identified,
- 00:51233 genetic variants,
- 00:53all these have been replicated.
- 00:55All the original ones are
- 00:57similarly replicated,
- 00:57which counts for about half the
- 01:00estimated heritability for Ms.
- 01:02So that's great.
- 01:04You can show these wonderful little figures,
- 01:06but how did the variants cause the disease?
- 01:09And I think this remains one of
- 01:11the major challenges for you,
- 01:12not modern medicine as it's relatively
- 01:15easy with these technologies.
- 01:17It wasn't so easy in 2000 where we are
- 01:20now with different aluminum athlete
- 01:22technologies to identify genetic
- 01:24variants with big patient cohorts.
- 01:27I think the challenge is how to
- 01:29go from variance to disease.
- 01:31So this is an effort.
- 01:32Collaborate effort with Alex Morrison,
- 01:34Kyle Farr and Brad Bernstein.
- 01:36We together did genetic and
- 01:38epigenetic fine mapping of autoimmune
- 01:40disease variants and these data up.
- 01:42They'll publish about 5-6 years ago.
- 01:45I think it's still hand up, pulled up.
- 01:48So what we did we turns off for a second.
- 01:50So you all know DNA goes to RNA
- 01:53goes to protein, you'll learn that.
- 01:56And so to go from DNA to RNA,
- 01:58DNA has done wine very well and
- 02:00there has to be ways so that poll
- 02:03two another enzymes can get to the
- 02:05DNA so you can have transcription.
- 02:08Well you can then use things like
- 02:10K27 installation,
- 02:11K4 methylation maps to identify where
- 02:14this open chromatid on different cell types.
- 02:17One can then take those data and
- 02:19overlay them with genetic variants,
- 02:21arguing that if a genetic variant,
- 02:24it's a region where there is
- 02:26no open chromatin,
- 02:27that variance is not going to be
- 02:28playing a role that's help with
- 02:30every place there's a genetic
- 02:31variant for chromance,
- 02:32it's open,
- 02:33then it's likely to be an influencing
- 02:35that cell type.
- 02:36That's what we did as part of the
- 02:38ENCODE project with Brad Bernstein.
- 02:40Our lab participated in generating the K27K4
- 02:44methylation maps of human immune cells and.
- 02:47We have different diseases.
- 02:49We have neurologic diseases over here.
- 02:51Here is urate levels,
- 02:53renal function, kidney disease,
- 02:55cholesterol and here the autoimmune diseases.
- 02:58We'll concentrate on Ms.
- 02:59If you look at Ms.
- 03:01We found the genetic variance,
- 03:04the P values of less than 10 to the minus 30.
- 03:07We're hitting immune cells.
- 03:09That wasn't surprising T cells.
- 03:11Macrophages T regs.
- 03:13But also what was a bit surprising
- 03:15is there were hitting B cells,
- 03:17and more so in Ms.
- 03:19most any other diseases.
- 03:20If you look at other autoimmune diseases,
- 03:23it wasn't the case,
- 03:25say for lupus and primary biliary serositis,
- 03:29suggesting that B cells play a
- 03:32critical role in the disease.
- 03:33Somewhat unfortunately,
- 03:34around the same time my dear friend
- 03:37and colleague Steve Hauser made the
- 03:39observation paper published New England.
- 03:41Channel,
- 03:42if you perform B cell depletion,
- 03:45this is the two different
- 03:47studies offer one opera 2
- 03:48compared to the standard treatment
- 03:50that time barred interferon.
- 03:52The 9897% decrease in new lesions dramatic
- 03:55effect and I would just say clinically
- 03:57will we see a patient we start them on
- 04:00B cell depletion when we have a patient
- 04:03who doesn't respond usually isn't Ms.
- 04:05that's how good that drug is right now.
- 04:08So these data fit in very
- 04:10nicely with our observation.
- 04:12All of these cells in the disease,
- 04:14but those are those in your
- 04:16biologist and neuropathologist.
- 04:17I apologize,
- 04:18we did not get hits in the brain.
- 04:22Now I will say, and I won't share Tom
- 04:24and show the data today with the paper
- 04:27that is going to be coming out in
- 04:29nature from our from our consortium,
- 04:31identifying 2 haplotypes associated
- 04:33not with the risk of developing Ms.
- 04:37but with progression.
- 04:38And these are helpful types which
- 04:40are found in neuronal cells.
- 04:42So it's a separate question
- 04:43of what causes the disease,
- 04:45what leads to disease progression.
- 04:46If you have the risk capital type,
- 04:48your likelihood of progressing
- 04:51is significantly increased.
- 04:53So how do you go from Snips
- 04:56to to functionality?
- 04:57So we found hits the enough Capital Region.
- 05:01There are part of the far paper we
- 05:04found that steps on the NF Kappa B
- 05:06binding sites across the genome.
- 05:08And there's snips happen in the
- 05:10haplotype social NF Kappa B.
- 05:12Now it's about 10 to the minus 12,
- 05:14so they're genetic variance here.
- 05:16However, the odds ratio is about 1.1,
- 05:19so not a big effect.
- 05:21So I want to show you.
- 05:23Just even though the odds ratio is low.
- 05:26It has a major biologic fact.
- 05:28In fact, about 1819% of eugenic kits Ms.
- 05:32are in the NF Capital B and the
- 05:35TNF NF Capital B signaling region.
- 05:38So this is published now 7-8 years
- 05:41ago by will housing our laboratory.
- 05:43But basically about 20% of these
- 05:46healthy subjects.
- 05:47About 20% of you here are GG's.
- 05:51Do you know enough to know who you are?
- 05:53Is your homozygote for
- 05:55this particular variant?
- 05:57About 20% of you were A and the
- 05:59rest of you are had to reside in.
- 06:01If you are G,
- 06:03you have about a 20 fold increase
- 06:06in P50 NF Kappa B.
- 06:08Activity where if you're a it's
- 06:10significantly less and we every time
- 06:12we've looked at a genetic variant,
- 06:14this is what we find that the biology
- 06:16of these are quite striking and even
- 06:19though maybe 1.11 point one to the 233
- 06:23power becomes a very major effect.
- 06:29So in summary of the genetics big picture,
- 06:32the genetics of autoimmune
- 06:34disease dictates lower activation
- 06:36threshold of different cell types,
- 06:37including TH 17 cell B cells and T regs
- 06:41in the dozen or so genes we've looked at.
- 06:45I also say we've just started a
- 06:47collaboration with Steve Robbins just
- 06:49recruiting here from the Broad Institute.
- 06:51We had these wonderful techniques
- 06:53of looking at genetic variants
- 06:54and different cell types look
- 06:56into effect on motor function.
- 06:57So there are tools emerging which allows
- 07:00us to take a whole genome approaches.
- 07:02So getting back to the question
- 07:03I started with,
- 07:04you know the cause of multiple sclerosis,
- 07:07here's our working model.
- 07:10That's the genetically,
- 07:11as I said earlier, it's a genetically
- 07:13mediated autoimmune disease.
- 07:15It's initiating the periphery by T
- 07:17cells and macrophages that traffic
- 07:19into the central nervous system.
- 07:22So the the idea is that there are
- 07:24microbial antigens likely cross reactive
- 07:27with myelin that something happens to
- 07:29activate these antigen presenting cells.
- 07:32Probably be sales, probably EB though
- 07:35there's no biology behind that yet.
- 07:37There's expression of
- 07:39costimulatory molecules.
- 07:40We have activation of viral
- 07:42reactive T cells now we all have
- 07:44autoreactive T cells in our blood.
- 07:46I could clone mold reactive T
- 07:48cells from menu in this room.
- 07:50And a number of years ago,
- 07:51back in in the late 80s,
- 07:53we developed technologies for looking
- 07:55at autoreactive T cells were able to
- 07:57show for the first time that there are
- 08:00in fact autoreactive T cells in humans.
- 08:02Highly robust response and we identified
- 08:05a dominant epitope Amal and basic
- 08:08protein are recognized as 84102 region
- 08:10which went on to to find how it
- 08:13bounded MHC in a form post doc in the lab,
- 08:16kyouka fennick with Don Wiley went
- 08:19down to crystallize this these clones
- 08:22recognizing this epitope with the T
- 08:25cell receptor and MHC but was more.
- 08:28Interesting to me was the fact that we
- 08:31also found reactivity in healthy individuals.
- 08:34Significant reactivity
- 08:34led to decades of work.
- 08:37Why do we have autoreactive
- 08:38T cells in their circulation?
- 08:40This is work done by will count here,
- 08:42published in STM about seven years ago.
- 08:46This is principal component analysis
- 08:48looking at T cell reactivity using a T
- 08:51cell library approach against published.
- 08:53Just point out that the paper no peptide
- 08:55control anger can the myelin peptides.
- 08:58You can see that the red is Ms.
- 09:00patients that they tend to go off to GMCSF
- 09:04gamma in 17 whereas healthy individuals.
- 09:08The main reactive T cells need
- 09:10aisle 10 suppressive soda comma,
- 09:12which makes terrific sense.
- 09:14And if you do single cell cloning
- 09:16rather than the library approach,
- 09:18you can see that and help the individuals.
- 09:21They tend to make aisle 10 with single
- 09:24cell they tend they make all ten,
- 09:27that is Ms.
- 09:28patients making 17 GMCSF less gamma.
- 09:31So suggest that these aisle 10 secreting
- 09:33cells and all of us may play a role.
- 09:36For example one has damage.
- 09:38The brain stroke other factors that
- 09:41these cells may circulate into the
- 09:43nervous system involving scar formation.
- 09:46So.
- 09:48What we find is,
- 09:49so we have this situation,
- 09:51we have aisle 10 secreting cells
- 09:53in healthy individuals,
- 09:54but you also have regulatory T cells.
- 09:56Look to both TR1 and Fox V3 cells which
- 09:59are preventing this from happening.
- 10:02But multiple sclerosis is a loss of
- 10:04these Fox P3 regulatory T cells.
- 10:06I'll show you some recent unpublished
- 10:09data related to PRDM one.
- 10:12So the hypothesis is that
- 10:14in healthy individuals,
- 10:15these T regs prevent activation of
- 10:18autoreactive T cells where's Ms.
- 10:20patients are defective.
- 10:21This is work done by Dizzy Begleiten,
- 10:23Claire Batch Allen,
- 10:25published now almost 20 years ago,
- 10:28which was the first demonstration
- 10:29of T Reg dysfunction in the human.
- 10:31Autoimmune disease,
- 10:32these are all new ones that untreated Ms.
- 10:35patients or healthy donors and
- 10:37this is the presence of oppression
- 10:39perforation different ratios of T
- 10:42regs and you can see this market
- 10:45demolition diminish chip of Reg
- 10:47function in vitro in patients with Ms.
- 10:50and the same thing been found in type one
- 10:53diabetes everyone to arthritis went on
- 10:55to show that the T regs and patient Ms.
- 10:57work done by Margaret Dominguez
- 10:59Pierre is that these T regs and MSN.
- 11:02Making games that Fearon.
- 11:03Here we took T Reg,
- 11:05stimulated for four hours of PNA on a
- 11:07mycin and measured gamma secretion,
- 11:09purified populations and using
- 11:12sample control,
- 11:13aisle 17 versus gaming can see this gamma.
- 11:16They all express.
- 11:17Foxp 3 is a summary of these data
- 11:20that these T regs were making.
- 11:22Gamma,
- 11:22and I'll just point out I'll show
- 11:24a little bit in a few minutes
- 11:26that dysfunctional T Rex.
- 11:28What's happening is they go from
- 11:30suppressor cells to effector cells.
- 11:32And start making game interferon.
- 11:34So an Ms.
- 11:35is not just bad genes, not bad environment,
- 11:37but the bad interaction between
- 11:39genes and the environment.
- 11:40It's very interested again
- 11:43in environmental influences.
- 11:44The instance of Ms. stops at 2000,
- 11:47but it's continued to increase.
- 11:49Ms.
- 11:49Crohn's disease, type one diabetes,
- 11:51continues to increase.
- 11:52And of course that can't be genetics.
- 11:55So the pathophysiology of Ms.
- 11:58will involve genetic environmental
- 12:00factors which lead to the immune response.
- 12:05So well just give background on this about.
- 12:09We started looking at microbiome
- 12:11versus TH 17 cells in the blood and
- 12:15we started looking at dietary history
- 12:17and we found that if you ate at a
- 12:20fast food restaurant more than twice
- 12:22a week you had increased dial 17 cells.
- 12:25Statistically significant.
- 12:27We said really and said,
- 12:29well wasn't the golden
- 12:31arches provide that and salt.
- 12:33So we did an incredibly simple experiment.
- 12:36This work done by Marcus Kletzel,
- 12:38we added salt to the culture.
- 12:40And the same time,
- 12:42my dear friend and colleague Vijay Kutru
- 12:44was looking at TH 17 cell induction,
- 12:47identified SGK one as critical
- 12:49inducing TH 17 cells.
- 12:51We are very we do lab things together.
- 12:54We're very closely he told that SGK one,
- 12:57I told him that salt and we
- 12:59did the papers in parallel.
- 13:00I'll just do a little just on terms
- 13:02of we couldn't have started competing
- 13:04who could get this out first?
- 13:06But we're much more clever than that.
- 13:08We worked in parallel, sent the papers.
- 13:10Back-to-back to a weekly journal.
- 13:14And when the editor said, well,
- 13:16did you know about each other's work,
- 13:17we said no, not really,
- 13:20but no one would have believed
- 13:22that salt did this,
- 13:23but having two laboratories
- 13:24showing the same thing at a much
- 13:27more credence to the work.
- 13:28So it was and we've gone on to
- 13:31look at the effect of of salt and
- 13:33other factors in terms of fat
- 13:35in terms of T Reg function.
- 13:37So I'll just show you some of these data.
- 13:39They're really quite remarkable.
- 13:40If you add 40 milliequivalents
- 13:43of salt to a culture,
- 13:44you have logarithmic increases,
- 13:46dial 17 and M RNA and and secretion.
- 13:50They may be saying yourself,
- 13:51this is artificial right concentration.
- 13:54Salt and blood is about 150,
- 13:56which is what sea water is, turns out
- 13:59the concentration of salt in tissues.
- 14:02Is higher, it's about 18190 and
- 14:05blood is a suppressive condition.
- 14:08You don't want T cells being
- 14:10activated in the peripheral blood.
- 14:11So when T cells traffic into the tissue,
- 14:14they're in the condition of leading to more
- 14:17activation which is what we were seeing.
- 14:19I also say that a recent paper by
- 14:22another group in Germany showed
- 14:24increased salt concentration using MRI
- 14:26magnets in tissue skin tissue of Ms.
- 14:29patients compared to the controls.
- 14:31So we also this work done.
- 14:33By the talented graduate student
- 14:34of the NADPH Mandatory Hernandez.
- 14:36And she showed that if you add
- 14:38salt to T regs.
- 14:39So here we have T Reg effector cells,
- 14:41we load them with a green dot at the very
- 14:43green that stimulates them not dead.
- 14:44With the dye at T regs to go
- 14:46from here to here,
- 14:47they suppress entering the cell,
- 14:49cycle through the same thing
- 14:50with sodium chloride,
- 14:51they lose functionality.
- 14:55And the mechanism, if you look at SGK
- 14:58one would solve it goes up in the T regs.
- 15:01You can knock down the SGK one with the
- 15:04short hairpin RNA and then if you look
- 15:07at function here's effective function.
- 15:10If you knockout SGK one you go from
- 15:12control to here and restore function.
- 15:15So it was happening so also inducing
- 15:17SGK one with gamma difference secretion
- 15:20and T regs leading lots of function.
- 15:22So I'm presenting to you the importance
- 15:25of SGK one as a central factor.
- 15:28And loss of T Rex function.
- 15:31So come back to that in a moment,
- 15:32one of the great surprises in my life.
- 15:35So then the question what's the
- 15:37transcriptional circuit driving
- 15:38dysfunctional foxies through positive
- 15:40regulatory T cells in autoimmunity?
- 15:42That's can we identify a master
- 15:44regulator of T cell dysfunction.
- 15:47Let me just say this is work
- 15:49done by Thomas Sabita,
- 15:50who started as a postdoc is now in the system
- 15:52professor and there's really represents his,
- 15:55his original work.
- 15:56So what we basically did was performed a
- 15:59comprehensive transcriptomic and epigenomic.
- 16:01Profiling doing bulk and
- 16:03signals of RNA seek attack.
- 16:06Seek for epigenetic regulation genome
- 16:08wide for chromatid accessibility.
- 16:11He did transcription factor footprint
- 16:13analysis and accessible chromatin regions and
- 16:16look to the E QTL effects of Automeris Lucci.
- 16:18I'll just just show data on the 1st 2:00.
- 16:21This is a whole one hour talk in itself.
- 16:24And then we did a CRISPER activation
- 16:26based validation of this.
- 16:28It's regulatory elements getting
- 16:29at the molecular mechanism.
- 16:31So it's amazing what we can
- 16:32do in human biology now.
- 16:34It's unimaginable years ago.
- 16:35So first of all let me show
- 16:37you what we found.
- 16:39Found increases in PRDM 1.
- 16:42Now for those of you who are mouse
- 16:44people who say this doesn't make sense.
- 16:47It's it's well known that PRD one
- 16:49increases T Reg function announce
- 16:51T cells and I'll show you what
- 16:54what it was and that it we found
- 16:56that it drives a dysfunctional
- 16:58sheets something like program.
- 17:00But what's happened is not the
- 17:02long form that's increased it's
- 17:03a short form which inhibits the
- 17:05long form and here's the kicker,
- 17:07it drives SGK one of all the kinases and
- 17:11proteins that could have been induced by
- 17:14the shore former PhD one it was the SGK 1.
- 17:17So let me now I showed you the results,
- 17:19let me show you the data.
- 17:20See here we looked at T Reg,
- 17:22this is doing vulgar in DC looking at
- 17:26overlapping differential expressed genes
- 17:28between memory T regs and seating for itself.
- 17:31So you can see this market
- 17:34increase in PRDM one,
- 17:35BCL 3 pin three will also regulated.
- 17:38These are all induced by PRDM one and genes
- 17:41are downregulated by PRDM one like ID 3,
- 17:44LBH were down regulated.
- 17:45So we had this increase in.
- 17:47PRDM one did a replication of the set of
- 17:51patients and showed here that the PRDM
- 17:54one is upregulated in patient with Ms.
- 17:57but again confusing because
- 17:59of the mouse data.
- 18:01It's all about mice of course,
- 18:03but then we learned that there are two
- 18:06isoforms in humans that don't exist in mice.
- 18:09Dry nosed mammals do not express a
- 18:12short form of PRDM one and so the
- 18:16short form the dominant negative.
- 18:18When we looked in normal cell types,
- 18:20we found that the short form is what's
- 18:23expression memory cells and T regs,
- 18:24but not in B cells.
- 18:27So then we looked at the short
- 18:29former period you want by PCR,
- 18:30and indeed it's this short
- 18:32form that's increased NS,
- 18:33not the long form.
- 18:36And we rapidly perform Western
- 18:38blotting to show that indeed the
- 18:41short form is what's induced.
- 18:43We then looked at the data sets in
- 18:46particular set by oted all that's
- 18:48published in cell and we found that
- 18:51the PRD one isoform PRD one is also
- 18:54increased in most autoimmune diseases.
- 18:56So appears to be a common regulator of in
- 18:59T regs among different autoimmune diseases.
- 19:02And of course PRD one drives the
- 19:04blimp one and we looked at blimp
- 19:06one expression and MST regs it was
- 19:08in and it was it was increased.
- 19:10So it wasn't memory T Rex and memory T Rex.
- 19:13By flow. By both PCR and flow.
- 19:18So then here's the experiment
- 19:20where we transfected PRD one into
- 19:22T regs and integer cat cells.
- 19:24We have the induction of SGK one and here's
- 19:27measuring SGK one and primary union T Rex.
- 19:30See this? When we overexpressed
- 19:31the short form of T regs,
- 19:34you had an increase in SGK one expression.
- 19:39And then if you go in and do all the
- 19:40other experiments, not get SGK one,
- 19:42you lose the loss of T rate function but the
- 19:45short form in T Rex become dysfunctional.
- 19:48The whole story came together.
- 19:50So this suggests to us that the short form
- 19:52of PD one may be critical in different
- 19:55autoimmune diseases and driving dysfunction.
- 19:58And again we believe it's related to
- 20:00salt and to genetic factors that will
- 20:03show the data particular CD toward the
- 20:05genetic variant in CD28 who drives a P1.
- 20:10Now switch gears and show some public,
- 20:13recently published work looking at
- 20:15T cell traffic between blood and
- 20:17the CNS and the single cell work.
- 20:19So.
- 20:20T cell traffic into the CNS is very tightly
- 20:23regulated and CXCR 3 positive cells
- 20:25are the ones that get into the brain,
- 20:28crossing the correct plexus
- 20:30near great interest,
- 20:32and they get into the brain.
- 20:34And what I'll show you is a T cells
- 20:36in the central nervous system are
- 20:38CXCR 3 positive and express Tibet
- 20:41and make gamma interferon.
- 20:43We believe that this relates to the
- 20:45fundamental observation by the late
- 20:47Ben Barris that astrocytes are driving
- 20:49homeostatic communication would not.
- 20:51This is Michael Glee up but also are
- 20:54driving through secretion of cholesterol
- 20:56and TGF beta are driving this T bet
- 20:59induction that isn't the T cells go
- 21:02into the nervous system then they'll
- 21:04you in the brain drives this function.
- 21:07So give them on the knowledge of
- 21:09particular genre pop or Lotto submitter.
- 21:11Our Krishnaswamy and David Vandyke and Lee
- 21:14sang together did this worker with us.
- 21:17And basically we took spinal
- 21:20fluid group of patients,
- 21:21isolated the spinal fluid homonuclear cells,
- 21:25perform 10X the usual way that
- 21:28most you're familiar with now.
- 21:30And then we perform this on 6 healthy donors,
- 21:34get the bed in the moment, 5 patient with Ms.
- 21:36And looked at over 100,000 cells
- 21:39into 50,000 T cell receptor.
- 21:41Now does show high level summary
- 21:43of the of this work.
- 21:46So first in terms of blood
- 21:48versus spinal fluid,
- 21:49what we found wasn't surprising that the
- 21:51majority of cells in the spinal fluid
- 21:54or T cells what we observed before.
- 21:56So we started first bikes adding a
- 21:58spinal fluid from patients with Ms.
- 22:00right blood spinal fluid.
- 22:02We found the spinal fluid was very inflamed.
- 22:05I love this picture and we're sitting
- 22:07at the immunology repeat this change
- 22:09that we need to do controls goes that
- 22:12means we have to do spinal taps on age
- 22:14match 20 something year old students
- 22:17to do that. So Full disclosure.
- 22:20I do not know who would spinal taps, I said.
- 22:25I do not want to know because I
- 22:27do not want to be accused
- 22:29of coercion, collusion.
- 22:30So only Jenna knows who volunteered.
- 22:33They're all de identified.
- 22:35But at the I acknowledge all these wonderful
- 22:37students who had Spinal Tap stuff.
- 22:40So these cells acquire an
- 22:42inflammatory signature.
- 22:43So just quickly the menu now fate
- 22:46where the cell progression of
- 22:48blood and CSF release fate maps.
- 22:51This is a fading out.
- 22:52The red is blood, the blue is CSF
- 22:55via very different characteristics.
- 22:58They sense potential of heat diffusion,
- 23:00if any based transition embedding.
- 23:03I love the words they come up with and
- 23:05that world, but it's a way of looking at it.
- 23:08Unsupervised visualization that looks
- 23:10at geometric distance between data points.
- 23:14So here's the original tissue
- 23:15on the fate map.
- 23:16We can define the CD.
- 23:188 cells are here,
- 23:20CD4 cells are here.
- 23:22And we were able to describe we took
- 23:24the top 10 differential expressed
- 23:26genes in each cluster and to find
- 23:29different populations naive cells,
- 23:31naive CD4,
- 23:32CD 8 and really three different
- 23:34populations CSF cell we called CSF
- 23:371/2 and three in memory CD8 cells.
- 23:41So one could do something very interesting,
- 23:44which is looking at the continuum
- 23:46between blood and spinal fluid,
- 23:48getting back to the point of how T
- 23:51cells change function going to tissue.
- 23:53So we merge the fate to fusion
- 23:56operator with the original identity
- 23:57of itself come up with a tissue score
- 24:00which is basically the probability
- 24:02of transitioning from one form to
- 24:05another in a random walk and you
- 24:07can see the Tisha score that their
- 24:09cells are very blood like over
- 24:11here CD4CD8 cells in transition
- 24:13and cells is very CSF like.
- 24:18And so I did have a reality test.
- 24:21Ensuring that tissue
- 24:22score captures no biology.
- 24:23ITG Force is the LA4CD49D and
- 24:27requires this T cell traffic
- 24:28into the into nervous system.
- 24:30It's a treatment for Ms.
- 24:32blocking T cell traffic and you can see
- 24:35that it's expressed predominantly in the T
- 24:38cells and transition CSL against the XR3,
- 24:41KEMA concord and fatty cell
- 24:43entry predominant expressed.
- 24:45It's expressed only really
- 24:47in PCNSL CR7 Express 9 T.
- 24:51So she excluded from the brain
- 24:53and you can see that it's almost
- 24:55exclusively in the peripheral blood.
- 24:58So we've found nine clusters
- 24:59of T cells and spinal fluid.
- 25:01We use the gene expressions imputed
- 25:04with something called magic because
- 25:06basically looked at gene expression
- 25:09across the gene expression patterns.
- 25:11You see different patterns
- 25:13across different tissue scores.
- 25:14Again,
- 25:15all the details in the paper have
- 25:16the 9 clusters and I want to start
- 25:18with the teach one cluster and
- 25:20think about single cell data.
- 25:22There's so many things you
- 25:23can explore with it.
- 25:25So to me,
- 25:26I find a few interesting stories,
- 25:27validate them biologically,
- 25:29get the data out in the literature,
- 25:31and I've been so pleased by how many
- 25:33others have taken our data and use
- 25:35it for really important experiment.
- 25:37That's what we're trying to do.
- 25:38So even treat bothers TH1 cluster.
- 25:41So if you look at the TH with the CD
- 25:44four cells to different populations,
- 25:47the CSF 3 populations particular
- 25:49and high amounts of gabito Ferrum
- 25:52tibets CXCR 3 run 3 stat.
- 25:544, so an aisle 12 receptor,
- 25:57another CD4 population of tissue
- 26:00resident markers like lag 3CD-69
- 26:03and PRDM 1 interestingly enough
- 26:06and markets have soda toxicity,
- 26:08a grandson and grandson K,
- 26:10which is interesting.
- 26:12Colleague Michael Brenner at Harvard
- 26:14recently identified grandson Kay
- 26:16as being involved in complement
- 26:18deposition and finally CDA population
- 26:20markets at tissue residence and,
- 26:22not surprising cytotoxicity.
- 26:26So to summarize a lot of data,
- 26:28what do we find in the blood cells
- 26:31excluded from entering the CSF and
- 26:33we found cells that are rich for
- 26:36for traits necessary for entry
- 26:38and then finally markers for CSF
- 26:41entry and tissue dependent changes.
- 26:44So in CSF we found gamma interferon
- 26:47signature rest in T cells,
- 26:49cholesterol homeostasis,
- 26:50TGIF beta pathway and these
- 26:53cohabitated receptors will get
- 26:55to that in just a moment.
- 26:57So then the question is,
- 26:58do we actually see gamma difference
- 27:00creating T cells from spinal fluid?
- 27:03So first we looked at PPD one.
- 27:05So this is from another three healthy
- 27:08subjects looking at blood versus CSF.
- 27:10This is no stimulation,
- 27:114 hours of stimulation with PM out of
- 27:14mice and see this market expression of PD1.
- 27:17And see itself compared to blood
- 27:20with stimulation goes even higher.
- 27:22So there is very high expression of this
- 27:25Co inhibitory stepter in spinal fluid cells.
- 27:28We then looked at that together,
- 27:29interferon response with blood and
- 27:31you can see this major gamma signature
- 27:34recapitulating what we found with
- 27:37the RNC data and compared to blood.
- 27:40So this is major gamma signature
- 27:42and T cells from spinal fluid.
- 27:44I'll show you another experiment
- 27:46which I found interesting.
- 27:47This is work we've done.
- 27:48We did looking at PD1 glioblastoma
- 27:51and basically we took the PD1 high,
- 27:54PD1 intermediate,
- 27:55PD one negative and total T cells
- 27:58stimulated them and not surprisingly
- 28:00PD1 high cells do not enter cell cycle.
- 28:04But they did make gamuts to pharon.
- 28:073% to 50 to over 50%.
- 28:10So it suggests to us it's phenocopies,
- 28:13what we see in the brain,
- 28:14the cells in the brain,
- 28:15they're condition in the brain have
- 28:18high amounts of combinatory molecules
- 28:20that make gaming jefferon and we wonder
- 28:23is this what immune privilege is?
- 28:25Is that what if you privilege
- 28:27the high expression?
- 28:28Comunitar molecules can enter the cell cycle,
- 28:31but they are functional.
- 28:33So now we know normal spot on the floor.
- 28:35What about multiple sclerosis?
- 28:36Did the single cell analysis
- 28:39say looking at the populations
- 28:41between healthy blood and Ms.
- 28:43or no difference?
- 28:44Not surprising.
- 28:45We never found any differences before.
- 28:48But if we look at log fold changes,
- 28:49I'll just highlight some of them
- 28:51were just beginning to work out
- 28:53what these different factors being.
- 28:54We're intrigued by mallet.
- 28:56Mallet one which is involved in
- 28:59gene expression and epigenetic
- 29:01modulation of gene expression.
- 29:03We found I 32 it's a pro
- 29:07inflammatory cytokine induces
- 29:08TNF alpha associated with Ms.
- 29:11And we found June a part of the AP1 bonding.
- 29:16I won't show all these
- 29:17dates to talk in itself,
- 29:18but we looked at healthy Ms.
- 29:20versus non expanded versus expanded itself.
- 29:24It's tremendous clonal expansion
- 29:26these cells and again looking at
- 29:29the different populations within
- 29:32the aisle 32AP1 and there was
- 29:34more distinct in the clone expand
- 29:37itself both in CD4 and CD8 cells.
- 29:39I think the next decade will
- 29:41be taking these various.
- 29:42A fact is we found replicating
- 29:44them by protein and then seeing
- 29:46how they involved in Ms.
- 29:48induction.
- 29:49But this is really a road map as genetics
- 29:52work road map for what drives and drives
- 29:55autoimmunity in the nervous system.
- 29:57And of course,
- 29:57what about the brain?
- 29:58I couldn't resist being a pathology group.
- 30:02So here we did characterize T cells
- 30:05in normal human brain prank them up
- 30:08here different cluster patients.
- 30:09Some of these involve fresh RNC from
- 30:13brain that provided by Jack Intel
- 30:16doing epilepsy surgery and here
- 30:19are the T cells over here at the
- 30:21very end and different populations.
- 30:23While summarizing here we're
- 30:25looking at the tissue residence and
- 30:27functional gene expression and T cell
- 30:30with normal brain prank comma and.
- 30:32You know,
- 30:33I mentioned we saw this game
- 30:35interferon signature.
- 30:36In the spinal fluid and we see here
- 30:39in the brain this is RNA seek up
- 30:42T cells right out of the brain.
- 30:45Here is with Duke seek his major
- 30:47gaming different signature.
- 30:48So these data indicate that the gamma
- 30:51different signature is there in the brain.
- 30:53Speculate at the end what that
- 30:56might be doing also Joe work from
- 30:58Tomo samita done with Andrew Wang
- 31:01out loud that's predominant humans,
- 31:03we do mice, we work with vice people.
- 31:06And this is data from a few months ago and
- 31:08she's getting barrage of write her thesis.
- 31:11But basically we wanted to look at T cells
- 31:13isolated directly from the house brain.
- 31:16So we saw this in humans.
- 31:17The question is to see it in mouse brain.
- 31:20And so here we're looking at T cells
- 31:23isolated directly from parenchymal tissue.
- 31:25We wash out the vessels
- 31:27and work with HomeGoods.
- 31:28Lander suggests he T cells
- 31:29are in the prank him up.
- 31:31He's gamma to Fearon on the X axis.
- 31:36Case in the CD three you can see this
- 31:38prominent cabinet different signature in
- 31:41CD4CD8 cells as we saw in the brain with
- 31:4440% that cells are making game interferon.
- 31:47You can see this here,
- 31:48but you don't see it,
- 31:50you don't see it in the
- 31:51in the peripheral blood,
- 31:53you only see it in the nervous system.
- 31:55So it suggests that these Gavin
- 31:57difference between T cells are
- 31:59physiologic and won't show that the data.
- 32:02But if you put if you do this
- 32:04experiments and germ free.
- 32:06Animals work done with Noah Palm,
- 32:08they don't make these cells.
- 32:10These gamma different secreting T cells
- 32:12are being driven by gut microbiome
- 32:15and if you label these T cells.
- 32:17In the gut with the dye that turns
- 32:20color with the fluorescent probe,
- 32:22you can show that all these cells in
- 32:24the brain are coming from the gut,
- 32:26similar to what BJ's Country did.
- 32:29And E model.
- 32:30But this is normal Physiology,
- 32:33so we can speculate why is it that T
- 32:36cells in normal central nervous system?
- 32:39Our country from the cotton
- 32:40what are they doing there?
- 32:41Nature doesn't do this for no reason.
- 32:44I'm sort of speculate that maybe at
- 32:46night when you have the lymphatics and
- 32:48you clean your brain out these T cells
- 32:51that surfing along secreting gamma
- 32:53influencing the microglia experiments
- 32:54were battery to begin it's to look
- 32:57at Tibet gamma knockouts to see what
- 33:00happens to synaptic pruning and what it
- 33:03does to the microglia influencing the
- 33:06neuronal excellent interactions and by.
- 33:08In summary,
- 33:09so is there.
- 33:11Is there glial tea sub
- 33:13communications circuits?
- 33:14This is again from light
- 33:15Ben Barris sowing TGF.
- 33:17Beta and cholesterol drove these together.
- 33:20And after I drive TJF,
- 33:22painting classes are required for my
- 33:24survival and these sizeable factors are
- 33:26produced by astrocytes including cholesterol,
- 33:28lipoprotein which are found in CSF.
- 33:31I won't show the data but if you take
- 33:33spinal fluid or cholesterol and TGF beta,
- 33:36it drives gamma interferon
- 33:37almost as much as Isle 12.
- 33:39So we think the cholesterol in the
- 33:42brain brains what mainly cholesterol
- 33:44is driving this gamma driving this
- 33:47gamma and what it's unknown function.
- 33:49Gamma interferon in the CNS.
- 33:52It's known to involve in chemical
- 33:55production record Plexus.
- 33:56Gamma has known neuroprotective
- 33:58function like glutamate clearance,
- 34:00neuronal survival.
- 34:01We speculate synaptic pruning
- 34:04and work done by Yoni Kipness
- 34:06published a few years ago in nature.
- 34:09So if you knock out gamma to Ferron in mice,
- 34:12they developed depression.
- 34:13How do you measure depression mice?
- 34:14I don't know, but they clearly had changes
- 34:17in behavior until they meet them working.
- 34:20That with a number of individuals
- 34:22and psychiatry department I can
- 34:23tell you that if you put animals the
- 34:25germ free environment and get rid
- 34:27of these games to creating cells
- 34:29that market changes in behavior.
- 34:31So it is psychiatrist one field,
- 34:33neurologist another.
- 34:34But what's beginning to happen feels
- 34:37are colliding of course centered
- 34:39around their inflammation but to me
- 34:41the normal Physiology the discovery
- 34:43of gamma difference between T cells
- 34:45that are normal Physiology which arose
- 34:48from studying disease is actually.
- 34:50More interestingly enough,
- 34:51observations please to how how things work.
- 34:56And one other experiment again which
- 34:58I didn't show the data for is you can
- 35:01ask the question well what if he's
- 35:02teased cell receptor as a barcode?
- 35:04To look at this identical T cell
- 35:07in spinal fluid versus the blood.
- 35:10Does it change or is there
- 35:12a selective migration?
- 35:13The answer is it changes.
- 35:15The T cells in the blood that share
- 35:18the same T cell receptor sequence with
- 35:21cells in the CSF have very different
- 35:24characteristics the CSF cells.
- 35:26Have the gamma signature and other PD.
- 35:29One signature with the identical
- 35:31T cell in the blood does not
- 35:33have markets knife cells,
- 35:35so this provides strong evidence that
- 35:37what's happening as the T cells migrate
- 35:39into the central nervous system,
- 35:41they're acquiring these phenotypes.
- 35:44So in summary,
- 35:45all immune disorders are complex
- 35:48complex genetic diseases where genetic
- 35:50variants mapped to the immune system
- 35:52in MSB cells drive the inflamed
- 35:55Mon reactive CD4 cells instead.
- 35:57Let me just comment on EB for a moment.
- 36:00May have heard that beautiful paper
- 36:02by Alberto Mascaro clearly showing
- 36:05that if you are a he looked at
- 36:081,000,000 recruits in the army.
- 36:10Identified individuals are EB
- 36:12negative and follow.
- 36:14Deerfield their light chains come CPK
- 36:16the brain shows brain damage and he
- 36:20showed that the on the serial samples
- 36:22they collected that when NFL went up
- 36:25in the serum followed by diagnosis of Ms.
- 36:28it was 49 and 50 ton
- 36:31preceded by EB infection.
- 36:32You have to look at a million
- 36:34people to find that.
- 36:35But incredibly provocative
- 36:37data that's EV trigger Ms.
- 36:40what's the experiment we need to do.
- 36:42There's one key experiment.
- 36:44Which we're working on,
- 36:46which is to vaccinate patients at risk.
- 36:49So there's no EV vaccine out there now?
- 36:53Ohh Danner GSK have one and I'm on a
- 36:55group of devices trying to convince
- 36:57GSK to do a subset with the clinical
- 36:59trial patients at risk that we
- 37:01can vaccinate and prevent disease
- 37:03as we prevented SP with measles
- 37:05vaccination that be the defendant
- 37:08rather definitive evidence we've
- 37:10not been able to find any biology
- 37:12B we've looked in the brain of Ms.
- 37:15patient just interviewing our graduate
- 37:17student he said you haven't published
- 37:19much on EV why haven't you go we've
- 37:21been looking we haven't found any.
- 37:23In your own publishing that data right.
- 37:25But what we have your IRB approval
- 37:28to do now and start shortly it's
- 37:31a do tonsil aspirates it,
- 37:33wants it in this patience.
- 37:34EB lives in the nasal pharynx.
- 37:37Then you have any ideas how to
- 37:39do this but we do singles RDC can
- 37:41do CV expression so we can fund
- 37:43the EB signature we once and Ms.
- 37:45patients but of course there may
- 37:47be gone by the time we do it.
- 37:49So once again summary of the
- 37:52talk autoimmune disorders.
- 37:53Particular mass or complex genetic diseases,
- 37:56genetic variance mapped to the
- 37:58immune system and MSB cells.
- 38:00We believe Dr.
- 38:01Inflame months specific CD4 cells in the CNS.
- 38:05Also mentioned that we're doing
- 38:07single cell RNA sequencing pre
- 38:08post treatment THC stated about
- 38:10two weeks all we've been spending
- 38:12now year analyzing the data but
- 38:14the most promising we're seeing
- 38:16would be cell depletion myeloid,
- 38:19express myeloid, induction of TNF.
- 38:22You might say, are you kidding me?
- 38:24It's working by inducing
- 38:27inflammatory cytokine.
- 38:28But go back to the clinical trial,
- 38:30anti TNF makes Ms.
- 38:32work works great in IBD and RA.
- 38:35So the data is now suggesting that
- 38:37TNF induced by the B cell depletion
- 38:40is leading to TNF secretion which
- 38:43then induces increased T Reg
- 38:45function with TNFR 2 receptor
- 38:47doing the single cell analysis.
- 38:49So we'll see where that goes.
- 38:51Yeah I showed you the T cell
- 38:53traffic between blood and spinal
- 38:54fluid and brain tightly regulated
- 38:56showed the TH one signature and
- 38:58that the blood and sees that for
- 38:59functionally different indicating
- 39:01the CNS shapes homeostatic T cell
- 39:03states that happens all the tissues
- 39:05at T cell center in the tissues.
- 39:08This is phenotypic difference
- 39:09in healthy and masks and control
- 39:11particularly more expanded cells and
- 39:13we're beginning to explore what these
- 39:15are what they mean and this help us
- 39:17teach one signature seen healthy
- 39:19brain and of course with the PRT.
- 39:21And positive teabags think we may have
- 39:23identified a major transcriptional
- 39:25factor driving autoimmunity.
- 39:28So let me end by thanking I I put
- 39:31here the members of the lab who made
- 39:35major contributions work Jenna Pappalardo,
- 39:37who is now out in West Coast,
- 39:40an industry.
- 39:41Tomo, who's assistant professor Tomia,
- 39:43graduate student,
- 39:44please thank assistant professor
- 39:46in our department.
- 39:47Others in the lab now is the former lab
- 39:49members who contributed the work I discussed.
- 39:52Today,
- 39:52Matt Lincoln and the PRD one projects
- 39:55computational Margot who did the
- 39:57work with the TH1 T Rex phone
- 39:59contact and the Center colleagues
- 40:01of the Broad Institute.
- 40:02In particular Brad Bernstein
- 40:04analyst Kellison,
- 40:05Chuck Epstein who worked with us,
- 40:07the PRD one project collaborators
- 40:09at the MI Year in Yale Genetics and
- 40:12Marcelo and Yang who we feel are
- 40:14part of our Neuro inflammation group.
- 40:17So thank you for your time and just
- 40:19say here's my e-mail and here's
- 40:21our last picture of our.
- 40:22Ms.
- 40:22Group if we have a lot of meetings
- 40:25every week, all winter, not really.
- 40:27But anyway,
- 40:28thank you for giving me the
- 40:29opportunity to talk to.
- 40:30I really appreciate it.
- 40:43So do we know who's in the chat?
- 40:46That is OK. Good story here.
- 40:55OK, question.
- 40:58Thank you for a great thank you.
- 41:01What about this are those? Who
- 41:05are they?
- 41:11You should ask.
- 41:13Unable to defrag the hard problem.
- 41:18Here's how to approach.
- 41:19Do you have a collaboration?
- 41:23Change. And what we're doing is we're
- 41:27taking the T cell receptor, thousands of
- 41:29T cell receptors, popping them into
- 41:31reporter cell lines and then using
- 41:33antigen libraries see what they react to.
- 41:36We're also have tetramers loaded with
- 41:39different peptide libraries barcoded.
- 41:42We do single cell and pull them
- 41:43out and see what they're reacting
- 41:45with so far, guess what?
- 41:46Answer we're finding the spinal fluid
- 41:48across different patient, anything else?
- 41:52Beebe. Whether it's primarily I
- 41:56don't know but we also see that the
- 41:58activity and what we're doing you
- 42:00know we can I can tell you that
- 42:02team cell rachamim based approach
- 42:04that's and tells me one thing right.
- 42:06So you'd like non hypothetical need
- 42:08approaches so we're halfway in the
- 42:10project and hopefully hear so the
- 42:12better idea to do the same thing
- 42:13with cancer antigens or they'll know
- 42:15and guess what they're recognizing.
- 42:18Don't just rent apart.
- 42:24The train.
- 42:31Yeah, the traffic.
- 42:36Of the possible.
- 42:41Requires.
- 42:48Or.
- 42:50Stop it.
- 42:56Sure.
- 43:07What happens with the message? All Star.
- 43:19K1 did not qualify. In the South. So.
- 43:27But since it's increased solid,
- 43:30expect to see it. But you know.
- 43:35And then?
- 43:38And yes, it's laughing.
- 43:43Disease.
- 43:45That's where we had she is thought
- 43:48to subtractive stuff because
- 43:50these papers the post office.
- 43:54How much is that?
- 43:57That there's whereas I think
- 43:59we have a good working model
- 44:02for relaxing the EMS not yet to
- 44:04discover but a good model I have
- 44:06no idea where cost of progressive.
- 44:10Before we had trees
- 44:11that will be 50%.
- 44:15Now the most important question
- 44:18here is that we have a plan.
- 44:23Question.
- 44:26The station.
- 44:29Progressive disease.
- 44:31But that's a major question by suspected
- 44:34to be progressive disease cells stay
- 44:36there trapped in the back and forth
- 44:39that we might see on the sausage.
- 44:42Is it really correct?
- 44:43That's terrific questions and
- 44:45we'll go back and then you have to.
- 44:48The second version.
- 44:51This is really interesting people,
- 44:53normal people have T cells are going.
- 44:56They're making their gambling responsibly.
- 45:02Yeah, So what are the time scales involved?
- 45:07T cell recognizes something
- 45:09that wasn't changed.
- 45:10You might not know, obviously, but you.
- 45:12Visioning that it's terms of making
- 45:15a change there and then having
- 45:16some response back afterwards,
- 45:19well, I I could do it my side.
- 45:24New brand. I can get
- 45:26spinal fluid but drain it.
- 45:29But now that it's very
- 45:30radically so, it happens. If
- 45:31we so pre, we don't see them at
- 45:34the time of reading when you start
- 45:37acquiring the microphone and
- 45:39that's when we started seeing it.
- 45:40That happens very quickly.
- 45:42So we label them,
- 45:43I can answer that question.
- 45:44We might label them in
- 45:47the gut within 2-3 days.
- 45:49So, so the experiment I did as
- 45:51as a postdoc.
- 45:53The terrific experiment.
- 45:54There's some new thing called
- 45:57monoclonal antibodies and we
- 45:58want to put them into people.
- 45:59No one has really done
- 46:00that yet. So we're kind of cowboy.
- 46:03Please stop the recording now. So I've got 5.
- 46:09So what we did was
- 46:10we had invited.
- 46:15Two and I did it with my 5.
- 46:21Make these. And we said, Gee,
- 46:24if we don't find material across state lines,
- 46:27that would be Massachusetts.
- 46:29You don't need that TA approval.
- 46:32That now, but you know IRB approval.
- 46:35So we're very careful what we did,
- 46:37we had RV approval and what
- 46:39we do and so we injected.
- 46:43And to our patients and we showed
- 46:46that major biological effects
- 46:48but they're now sanctified
- 46:50after one child human anti mouse
- 46:52antibody would deactivate them. So
- 46:55we only had to make.
- 46:58But 11 experiments that anti CD 2
- 47:02N IG23 coded all the T cell but
- 47:04did not cross into the central
- 47:06nervous system showed that.
- 47:08So I would do this thing.
- 47:10That's a new call, Microsoft you guys.
- 47:13There was one solicitation to
- 47:15Harvard Medical School at the
- 47:16time and I did the first thing
- 47:19pretreatment did with respondent.
- 47:20Few days respond that did the same thing.
- 47:23We got anti mouse and everything but.
- 47:25Then we did this that it's standing
- 47:28after the treatment and majority of
- 47:30cells lit off the coat anti mass and
- 47:32said what's going on here? Let's just
- 47:33screw it up again.
- 47:37Oh my God they're covered with
- 47:39antibody with mouse antibody.
- 47:40So we use this way of labeling all
- 47:43the peripheral blood T cell and that's
- 47:46being traffic into the CNS policy.
- 47:48And because everyone looked
- 47:50at the blood brain barrier,
- 47:5180% of the cells traffic within three days.
- 47:56How did they do it?
- 47:59Found the entry right before crossing.
- 48:01Well, because when we took
- 48:03that we couldn't find the party even though.
- 48:10No.
- 48:13Now that doesn't listen all
- 48:16the circulating T cells.
- 48:23Invite them. So it's suggested
- 48:26you can follow the connection.
- 48:30So it's suggested and that nice people
- 48:33have gone to replicate that more output.
- 48:36So the traffic of T cells from the blood
- 48:39to the nervous system side is very fast.
- 48:42And I think it's continuing this intro data,
- 48:43but there are three different
- 48:45scenes of population in CSF.
- 48:47One and three are about basically residents.
- 48:50LCF 2 looks like sales and traffic,
- 48:54so one opposition doesn't have CD-69
- 48:57was like a population is garden.
- 48:59We have a question in chat. Yes, yeah.
- 49:03What's the concordance of Ms.
- 49:05and identical twins?
- 49:06That might be a good group in
- 49:07which to consider prophylaxis.
- 49:09And a second related question,
- 49:10is there any handle on what
- 49:11causes spontaneous remission?
- 49:13And by these days goes untreated,
- 49:15Nope, no one goes and I want to
- 49:17comes to Yelp goes untreated.
- 49:18Well occasionally they don't
- 49:19want to do a patient want.
- 49:21So the answer Jeff is about
- 49:233040% and yes that would be a
- 49:25great group to consider for
- 49:27prophylaxis but it's a small number,
- 49:30it's two small numbers.
- 49:31So what we're doing in the Rs
- 49:33study is developing the tools
- 49:35to develop to identify average
- 49:37patients of intake first.
- 49:38So the question is what is the incident Ms.
- 49:41in daughters of patients with Ms.
- 49:43about one in.
- 49:4430 It's quite high and we can do
- 49:47polygenic risk score and increase
- 49:48it even more so and then we can
- 49:51use NFL we were fully light chains
- 49:53to follow them so that's why I'm
- 49:56proposing GSK first as a subset take
- 49:595000 and first degree relatives
- 50:01children at risk before they become
- 50:03EB positive seriously follow them
- 50:05with NFL NFL go up MRI them I think
- 50:09that's attractable study to do.
- 50:10That's how we're going to try to
- 50:12do it will cause spontaneous.
- 50:14So what So what relapse,
- 50:15it's a really good question.
- 50:17What happens I think in Ms.
- 50:19is that it's there's an acute
- 50:21event there's the attacks occur
- 50:23very quickly within a day within
- 50:26forty 2448 hours they come on,
- 50:27it's T cell trafficking into the CNS.
- 50:30There is Dima that breakdown,
- 50:32the barbarian barrier,
- 50:34gadolinium enhancement.
- 50:35I think it's the edema that's
- 50:37causing neurologic symptoms with
- 50:39time there is retraction,
- 50:41edema goes away,
- 50:41the blood brain barrier is closed
- 50:43and rather than having a big lesion.
- 50:45With a tiny scar,
- 50:46like it's just just normal Physiology
- 50:49of of the lesions resolving as
- 50:51edema goes away and steroids
- 50:52makes that happen faster.
- 50:54I think that's what's happening.
- 50:58That one. Alright.
- 51:02Well, thank you very much to David.