inflammasomes and autoimmune diseasesfmf.igh.cnrs.fr/issaid/doc/fmf said...
TRANSCRIPT
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Michael McDermott([email protected])
Section of Musculoskeletal Disease,Leeds Institute of Molecular Medicine,
University of Leeds, UK
Inflammasomes andautoimmune diseases
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Definition of autoimmunity
• Breakdown of mechanisms for self-tolerance - inductionof an immune response against components of self
• Aberrant B and T cell responses lead to breaking of tolerance - immune reactivity towards native antigens
• Adaptive immune system plays predominant role in the eventual clinical expression of autoimmune disease
• Organ-specific autoantibodies may predate clinical disease expression by years (e.g CCP, dsDNA, ICA)
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Antigen presentation, T cell function,including B cell help
MHC associationsMost autoimmunediseases
Regulation of T lymphocyte activation
Regulation of T lymphocyte activation
CTLA-4/CTLA-4
PTPN22/PTPN22
SLE, T1D, AITD
RA, SLE
Polygenic Autoimmune Diseases
Thymic epithelium/neg T cell selectionRegulatory T cells/Immunomodulation
Widespread/lymphocyte apoptosis
AIRE/AIREFOXP3/FOXP3
FAS/FAS
APS-1/APECEDIPEX
ALPS
Monogenic Autoimmune Diseases
Cellular Distribution/DefectGene/ ProteinInflammatoryDisorder
Genetic and Cellular basis forAutoimmunity
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Problems encountered with the autoimmunityparadigm in certain diseases
• Some diseases lack specific autoantibodies –ankylosing spondylitis
• Difficult to prove role of cell-mediated immunity -Behçet’s Syndrome
• Autoantibodies may be secondary e.g. apoptosis• Diseases lacking MHC associations – Crohn’s
Disease• Lack of efficacy of therapies e.g multiple sclerosis• Heterogeneous clinical disease expression – sero-
negative forms of rheumatoid arthritis (RA)
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Rare Monogenic Autoinflammatory DiseasesFMF, TRAPS, HIDS, PAPABlau Syndrome
Polygenic Autoinflammatory DiseasesCrohn’s Disease, Ulcerative ColitisDegenerative diseases e.g. osteoarthritisGout/Pseudogout/other crystal arthropathiesSome categories of reactive arthritis and psoriasis (no MHC associations)Self-limiting inflammatory arthritis including diseases clinically presenting as RAStorage Diseases/Congenital Diseases with associated tissue inflammationNon-antibody associated vasculitis including Giant Cell ArteritisIdiopathic Uveitis, Acne and Acneform associated diseasesErythema Nodosum associated disease, including Sarcoidosis
Mixed Pattern Diseases with MHC associations and autoinflammatory componentsAnkylosing SpondylitisReactive ArthritisPsoriasis/Psoriatic ArthritisBehçet’s SyndromeUveitis (HLA-B27 associated)
Classic Polygenic Autoimmune Diseases (Organ Specific and Non Specific)Rheumatoid ArthritisCoeliac Disease, Primary Biliary CirrhosisAutoimmune gastritis/Pernicious anaemia, Autoimmune Thyroid DiseaseAddison’s Disease, Pemphigus, Pemphigoid, Myasthenia GravisDermatomyositis/polymyositis/sclerodermaVitiligo, ANCA-associated VasculitisType 1 diabete, Systemic Lupus Erythematosus
Rare Monogenic Autoimmune DiseasesALPS, IPEX, APS-1/APECED
Innate ImmunityAdaptive Immunity
Anti-B cell andAnti-T cell Therapy
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
NALPs in vitiligo and hypertension
Jin Y et al. NALP1 in vitiligo-associated multipleautoimmune disease. N Engl J Med 2007 356:1216-22
• NALP1 SNPs associated with several autoimmune and autoinflammatorydiseases, implicating innate immunity in the pathogenesis of these disorders• these diseases include autoimmune thyroid disease (Graves' disease andautoimmune hypothyroidism), Addison's disease, rheumatoid arthritis,psoriasis, pernicious anaemia, and SLE among patients with generalised vitiligo• NALP1 expressed in T-lymphocytes, granulocytes and monocytes
T. Omi et al. An intronic VNTRs of the cold-inducedautoinflammatory syndrome 1 (CIAS1) gene modifies geneexpression and is associated with essential hypertension.Eur J Hum Genet. 2006 14:1295–1305
• inflammation oxidative stress-related genes in development of hypertension
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
PYDCCSPRY bZIPPyrin
PYD NACHT LRR
NALP1
CARD Caspase-1
CARD
Caspase-1
FIIND CARD
MDP
PYD
CARDASC
Pro-caspase-1
NALP1 Inflammasome earlier
IL1βPro- IL1βIL-1β activation
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
NACHT LRR
Kinase
CARD
NOD2 signalasome
CARD
CARD
NF-κB
MDP/DAP?
mutations in the LRRs leads to
CROHNʼs DISEASE
mutations in the NACHT leads to
BLAU SYNDROME
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
NALP3 Inflammasome
PYDCCSPRY bZIPPyrin
PYD NACHT LRRNALP3
CARDCaspase-1
CARD
Caspase-1
FIIND
CARDCardinal
MDPUric AcidATPCytosolic DNA
PYD
CARDASC
Pro-caspase-1
IL1βPro- IL1β
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
NALP3 is upregulated in synovium of RApatients compared to OA
Rosengren et al. (2005), Ann Rheum Dis. 64: 708-714.
NALP3 (cryopyrin), ASC, andpyrin mRNA expression wassignificantly raised in RAcompared to OA
Detection of NALP3 mRNA in synovialtissue by in situ hybridisation
A. NALP3 expressed in both lining andsublining in RA synovium
B. Negative control using NALP3 senseprobe
A B
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
DAS28 response criteria and methods
Bingham et al (2004), Rheumatology 43: 364-368
Wk 0 Wk 2 Wk 6 Wk 14
PBMC
mRNA
cDNA
qRT- PCR
ASC NALP3
Infliximab regime / sample collection
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Pre-therapy baseline levels of NALP3were predictive of response to treatment
Lower baseline NALP3mRNA levels in RApatients subsequentlyresponding to infliximabtreatment compared tonon-responders
Mann-Whitney U test.
Responders Non-Responders 0
10
20
30
(n=12) (n=11)
p=0.04
NA
LP
3 e
xp
res
sio
n
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
NALP3 mRNA levels were furtherdecreased from baseline in response to
infliximab treatment
Week 0 Week 2 Week 140
5
10
15 p=0.007n=12
Time
NA
LP
3 e
xp
ressio
n
Wilcoxon signed-rank test
Week 0 Week 2 Week 140
10
20
30 n= 11
TimeN
AL
P3
ex
pre
ss
ion
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Preliminary data suggest that infliximab alsoreduces NALP3 expression in the synovium
NALP3 mRNA fromsynovial tissuebiopsies pre- andpost- infliximabtreatment
Mann-Whitney U test.
Pre Post0
10
20
30
Non Responders (n=2)
Responders (n=3)
NA
LP
3 e
xp
res
sio
n
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Infliximab Responders
Wk0 Wk2 Wk140
20
40
60
80
100
n=9p=0.036
AS
C e
xp
ressio
n
Infliximab non-responders
Wk0 Wk2 Wk140
50
100
150
n=10
AS
C e
xp
ressio
n
ASC mRNA increased during infliximabtreatment in responders
ASC
ActinWk0
Wk2
Wk14
Protein expression inone representativeRA patient whoresponded to therapy
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Summary
• baseline NALP3 a potential predictor of response toinfliximab in RA patients - levels further reduced inthose who respond to therapy
• ASC mRNA levels are increased in patientsresponding to infliximab after week 14 of treatment
• Future work• examine ASC and NALP3 mRNA in synovial tissue
• determine the changes in different leukocyte populations
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Etanercept Infliximab
VariableNo changeProtein
Variable+mRNA
No change++Protein
No change++mRNA
ASC
Pyrin
Different effects of infliximab and etanercept onASC levels in PBMCs of RA patients
Pronounced changes inASC mRNA and proteinexpression wereobserved in RA patientsreceiving infliximab, butnot etanercept
(EWRR 2007)
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Mutations in genes encoding the RNASEH2complex and TREX1 cause AGS
TREX1
Ch. 3 AGS1
RNASEH2B/FLJ11712
Ch. 13 AGS2
RNASEH2A
Ch. 19 AGS4
RNASEH2C/AYP1
Ch. 11 AGS3
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Aicardi-Goutieres syndrome (AGS) is a genetic encephalopathywhose clinical features mimic acquired in utero viral infection.
• early-onset disease with calcification of basal-ganglia, white-matterabnormalities, and a chronic cerebrospinal fluid (CSF) lymphocytosis
• raised levels of antiviral cytokine interferon alpha (IFN-α) in the CSF
• nucleases defective in AGS (TREX1 and RNASEH2A, 2B and 2C)remove endogenous nucleic acids during normal cellular processes
• possibly act on a common substrate, and failure of nuclease activityresults in an (inappropriate) activation of the innate immune system
• heterozygous missense changes and frameshift in 6/218 SLE patients(UK), 6/199 (Germany) compared with 0/200 and 2/1,512 in controls
• dual role of TREX1 as DNA-degrading enzyme in granzymeA–mediated apoptosis and cytosolic DNA sensor induce autoimmunitywhen this nuclease is mutated
Aicardi-Goutieres syndrome (AGS) and SLE
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Virus
ss/dsDNA ssRNA dsRNA
Endosomal nucleic acid sensing TLRs
TLR9 TLR7(8) TLR3RIG-1
‘Self’ nucleic acids
Type I IFN induced antiviral state
Virus
MDA5DAI
Inflamma-some
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Receptors of the innateimmune system
TLR
2
TLR
4
TLR
5
TLR
3
TLR
7
TLR
8
TLR
9
Endosome
Caspase-1/ -5
Pro-IL-1βPro-IL-18
IL-1βIL-18
MyD88 dependent/independent pathways
Pathogen clearance
IKK
NF-κB
Proinflammatory cytokines
Toll-like receptors (TLRs)
NA
IP5
IPA
F
Nod
1/2
NA
LPs
Intracellular pathogensendogenous signals Danger
Nod-like receptors (NLRs)
Leeds Institute of Molecular MedicineLeeds Institute of Molecular MedicineIFN-α
PlasmacytoidDendritic cell
MyD88
TLR-9
Nucleosomes (Host derived)DNA Protein
Role of TLRs in Lupus
TLR-7ssRNA
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
TLR-9
MyD88
YY
Y Y Y Y
Nucleosomes (Host-derived)
AutoreactiveB cell
Autoantibodies
DNA
Self IgG2aRF
Protein
IgG2a = immunoglobulin G2a; RF = rheumatoid factor.
TLRs as Therapeutic Targets:TLR-9 and Autoantibodies
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
INDUCTION OF CO-STIMULATORY MOLECULES CD80/86INDUCTION OF TNF
Courtesy of Steffen Gay and colleagues
sense control probeanti-sense probe
Expression of TLR2 mRNA in RA synovialtissue
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Toll-like Receptors
10 TLRs
MyD88 Mal Trif Tram
Products ofinflamed tissues
Modulation of immune and inflammatory genes
Immune and inflammatory effector mechanisms
Microbialproducts
NLRs
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Cytokines and chemokinesAnti-viral proteinsproIL-1 and proIL-18
Mature IL-1 and IL18
Anti-viral proteins
MyD88MalTrifTram
MICROBES
TLRs
NLRs
RLRs
NF-κBIRFsMAPKs
Caspase-1
IRFs
MyD88
MAVS/IPS-1/VISA/Cardiff
SENSOR SIGNAL RESPONSE ADAPTER
The Innate World as we Know it:Host Defence
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Why is Autoimmunity paradigmso strong?
• Approx 1,000,000, 000 T cell receptors in man• T cell clones expand x 64,000 in 4 days• Each activated Th1 cell attracts up to 1,000
macrophages• T cells stimulate macrophages to make IFN etc
• Repertoire- an almost unlimited number of epitopes
• Memory with secondary responses: occur sooner,steeper, faster, higher and with a lower lowerthreshold
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Aicardi-Goutières syndrome (AGS)
Leeds Institute of Molecular MedicineLeeds Institute of Molecular Medicine
Adaptive vs innate immunity in rheumatoidarthritis
• Rheumatoid arthritis (RA) has traditionally been describedas an adaptive immune response, but, more recently, therehas been a gradual appreciation of the role of the innateimmune system
• The innate immune system recognises-microbial pathogen associated molecular patterns (PAMPs)-endogenous signals; danger associated molecular patterns (DAMPs)
• The detection of DAMPs and PAMPs is through Toll-likereceptors (TLRs) and Nod-like receptors (NLRs)