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AIRE-PHD1. Thymoma. AIRE in mTEC. Role of AIRE in Thymoma-associated Myasthenia Gravis ?. Alexander Marx, MD. University Medical Centre Mannheim. University of Heidelberg. EuroMG Paris, 01-12-09. APECED/APS-1 and AIRE. The Autoimmune regulator (AIRE) - PowerPoint PPT Presentation
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Role of AIRE in Thymoma-associatedMyasthenia Gravis ?
University Medical Centre Mannheim
Thymoma
AIRE-PHD1
AIRE in mTEC
Alexander Marx, MD
University of Heidelberg
EuroMGParis, 01-12-09
APECED/APS-1 and AIRE
• The Autoimmune regulator (AIRE) is a gene mutated in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy or APECED
• Several autoimmune (endocrine) diseases (highly variable)
Hypoparathyroidism & Addison’s disease
Type 1 diabetes mellitus
Gonadal dysfunction (e.g. premature ovarian failure)
Autoimmune hepatitis, Alocecia, Autoimmune Thyroid Disease...
• Mucocutaneous Candidiasis (often first & leading symptom)
Thymus
EuroMG, Paris01.12.2009
• Virtually 100% of patients have auto-Ab to type I interferons
AIRE is mainly expressed in keratin-positive medullary thymic epithelial cells (mTEC), less commonly in dendritic cells
Aire
Pan-Cytokeratin (mTEC)
EuroMG, Paris01.12.2009
Regulation of > 1000 genes
Aire
Thyroglobulin
Aire
p450_c17
Pärt Peterson
Aire drives „promiscuous“ expression of „tissue-specific antigens“ (TSA)
and some other genes mainly in medully thymic epithelial cells
AIRE-dependent TSA: Insulin, TPO, casein , -subunit of AChR, p450, S100 A8
EuroMG, Paris01.12.2009
Mathis & Bennoit, ARI, 2009
Functional effect of AIRE-driven autoantigen expressionin medullary thymic epithelial cells (mTECs)
mTEC
Cross-presentation
by dendritic cells (DC)
Promiscuous expression
and improved prentation
of autoantigens & MHCII
DC
Apoptotic mTEC
Tolerance Induction
EuroMG, Paris01.12.2009
-200 0 200 400 600 800 1000 1200
Hassall n
-200
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200A
IRE
n
Significant Correlation between Prevalence of HCs and Prevalenve
of AIRE+ Cells in Normal Human Thymus
r = 0.81p< 0.00001
EuroMG, Paris01.12.2009
qHassFläch NT Ausreisser qAIRE_Fläch NT Ausreisser
1 2 3 4 5 6 7 8 9
Dekade
-2
0
2
4
6
8
10
12
14
16
18
20
22
24
Age-dependent decline of Hassall‘s Corpuscles and
AIRE+ cells in normal human thymus
Age, Decades
Ha
ss
all
‘s C
orp
us
cle
s &
Air
e+
Ce
lls
p
er
Are
a
HCs Aire+ Cells
Mean HCs per area NTOutlier (HCs)Mean Aire+ per area NTOutlier (Aire+)
Aire/HCs ~ 2 - 3 (0 - 40y)
~ 1 -1.5 (41- 90y)
EuroMG, Paris01.12.2009
A AB B1 B2 B3 „C“
„Medullary“ Mixed „Cortical“ TSCC
Among WHO-defined Thymomas Hassall‘s Corpuscles are common only in Type B1 Thymomas („predominantly cortical“)
WHO-Classification: 1999, 2004
Histogenetic Classification: Marino & Müller-Hermelink, 1985; Kirchner, 1992
EuroMG, Paris01.12.2009
>95% of thymomas, including all type A & AB thymomas do not express AIRE* (Ströbel, 2007)
AIRE---
Thymus Type B1§
§ ~50% of type B1 thymomas are Aire+
*AIRE, Autoimmune Regulator
Loss of AIRE and AIRE-related self-antigen expression
in >95 of thymomas
Ströbel et al. J Pathol 2007
Mathis & Bennoit, ARI, 2009
Does AIRE-deficiency in thymomas elicit autoimmune diseases, including APECED ?
mTEC
Cross-presentation
by dendritic cells (DC)
Promiscuous expression
and improved presentation
of autoantigens & MHCII
DC
Apoptotic mTEC
Autoimmunity
NO
NO
ImpairedClonal Deletion
EuroMG, Paris01.12.2009
Minimal overlap of clinical and serological autoimmune features in APS-1 patients and patients with AIRE(-)
thymomas
anti-insulinanti-GAD65anti-Cyp1a2anti-Cyp17anti-Cyp21
ANAanti-AChRanti-striationalanti-TPO
overlap:anti-IFNtype I
MG
EuroMG, Paris01.12.2009
Generation and export of CD4+ T-Cells is the „sine qua non“ of MG development in type AB and B Thymomas (Ströbel; Buckley)
CD
45
RA
FIT
CC
D4
5 R
A F
ITC
NT / Thymitis
CD4 RA CD4 RA16,0 % 26,7 % 2,5 %
CD 8 PE
18,3 %
CD8 RA25,3 %
CD8 RA4,5 %
CD8 RA
CD 4 QR
MG-negative Thymoma (AIRE----)
CD4 RA
MG+ Thymoma(Aire ----)
% C
D4
+C
D2
5+
(g
ate
do
n C
D4
+ C
D8
-ce
lls)
Thymus MG(+) MG(-)
100 101 102 103 104
100
101
102
103
104
CD
4
CD25
Thymus
Thymoma
100 101 102 103 104
100
101
102
103
104
0
8
16p < 0.05
Thymomas
Production of Regulatory T-cells is Impaired
in Type Ab and B Thymomas (Ströbel, Ann Neurol, 2004)
EuroMG, Paris01.12.2009
Thymomas as an human model to study the relationship
between
AIRE expression and generation of FOXP3+ regulatory T
cells
00
200
400
600
800
1.000
Thymus Thymomas
AIRE-1AIRE-2p < 0.05
mol
ecul
es/
-act
in
Thymomas Thymus
MHC levelTreg
Exp
ress
ion
/ -
Act
in
0
2
4 FOXP3
NT MG(+) MG(-) -
* *
Ströbel et al. Ann N Y Acad Sci, 2008
EuroMG, Paris01.12.2009
Auswertung medulläre Areale in B1 Thymomen
H+A+ H-A+ H+A- H-A-
1
Var4
-10
0
10
20
30
40
50
AIRE+ AIRE-
Hassall + 343 222
Hassall --- 34 123
P<0.0001
AIRE & HC Status of Medullary Islands in B1 Thymomas
H+A+H--A+H+A--H--A--
AIRE Expression and Hassall‘s Corpuscles are correlated in B1 Thymoma
Hassall+ B1 Thymoma
Hassall--- B1 Thymoma
EuroMG, Paris01.12.2009
mean FOXP3 pro AIRE+ mean FOXP3 AIREneg
1 2 3 4 5 6 7
Fall No
-1
0
1
2
3
4
5
6
7
8
mean FOXP3 pro AIRE+ Ausreisser Extremewerte mean FOXP3 AIREneg Ausreisser Extremewerte
1
Var9
-2
0
2
4
6
8
10
In B1 Thymomas the number of FoxP3+ cells (likely Tregs)
is NOT correlated with the presence of Aire+ cells
FoxP3 per Aire+ cell
FoxP3 per Aire-- cell
Case #
AIRE is probably NOT involved in the generation of Tregs in humans
EuroMG, Paris01.12.2009
Why is AIRE Expression Reduced in Thymomas?
EuroMG, Paris01.12.2009
Factors known to be associated with thymic Aire deficiency
in thymic epithelial cells (TECs)
• Germ line mutation of Aire gene (APS I, APECED)
• Abnormal hyper-methylation of Aire promoter
• Lack of LTRANK/RANKL, TRAF, RelB / NFkB signalling
• Defective T-cell maturation in various SCIDs, Omen Syndrome,
chronic cyclosporine treatment (> secondary defects of TECs)
• Defective TEC maturation in thymoma ?
EuroMG, Paris01.12.2009
NO !
Phenotypic Markers of Thymic Epithelial Cell Subsets
MHC-IIlo
Aire -----MHC-IIhi Aire +/- Kyewski, 2007
Anderson, 2009
MHC-IIlo
DEC205+MHC-IIhi DEC205+
Medullary GenesCortical Genes
153
53
4606 Geneson OncoChip
443
„Compartment-specific“ gene expression profiling of thymomas compared to purified cortical and medullary normal TECs
162Gotter et al.
2004
Hypothetical „Developmental Concept“ of the WHO Thymoma
Classification
MHC-IIlo
Aire ----MHC-IIhi
Aire +
Mutation
B1 ThymomaOther MG+Thymoma Types
EuroMG, Paris01.12.2009
B1 Thymoma
Oversize of
Cortex
Summary
• AIRE deficiency in thymomas does not correlate with
• the MG Status of thymoma patients
• the efficiency of intrathymomatous CD4+ thymopoiesis
• the capacity to generate FoxP3+ Tregs
• AIRE deficiency in thymomas is an indicator of TEC immaturity
and likely of functional insufficiency of TECs in A, AB, B2
and B3 thymomas
• The massively increased cortex/medulla ratio in B1 thymomas might
be a structural basis for tolerance failure in AIRE+ B1 thymomas
Mannheim:Philipp Ströbel
Wen-Yu Chuang
Christian Sauer
Djeda Belharazem
Li Li
Norbert Gretz
Alexander Marx
Würzburg etc.
Bei Huang
Andreas Zettl
Andreas Rosenwald
Mannheim:Philipp Ströbel
Wen-Yu Chuang
Christian Sauer
Djeda Belharazem
Li Li
Norbert Gretz
Alexander Marx
Würzburg etc.
Bei Huang
Andreas Zettl
Andreas Rosenwald
Email: [email protected]
Acknowledgments