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APECED:
monogenic autoimmune disease
Pärt Peterson
University of Tampere, Finland
University of Tartu, Estonia
APS1 or APECED
• APS1 (autoimmune polyendocrine syndrome type 1)
or APECED (autoimmune polyendocrinopathy
candidiasis ectodermal dystrophy)
• Autosomal recessive inheritance
• More prevalent in some populations such as Finns
(1:25000), Iranian Jews (1:9000) and Sardinians
(1:14400). Very high incidence (1/4400) reported in a
small town Bassa del Grappa, in Northern Italy
• No HLA association
Autoimmune regulator (AIRE) is a gene mutated
in APECED
Clinical Features
• Endocrinopathies
• Chronic mucocutaneous
candidiasis
– Hypoparathyreoidism
• Ectodermal dystrophies
– Addison’s disease
– dental enamel
– Gonadal dysfunction
– nails
– Type 1 diabetes mellitus
– alopecia
– Autoimmune thyroiditis
– vitiligo
– Autoimmune gastritis
• Autoimmune hepatitis
• Keratopathy
Candida infection and vitiligo of APS1 patient
From Prof. Olle Kämpe, Uppsala University
APS1/APECED
and APS2
are two different
syndromes
Disease components
APS1
APS2
Addison’s disease
60-100
70-100
Hypoparathyroidism
77-100
absent
Chronic candidiasis
73-100
absent
Ectodermal dysplasia
10-77
absent
Autoimmune thyroid
disease
8-18
69-83
Type 1 diabetes
4-23
28-52
Hypogonadism
31-60
9
Alopecia
27-72
2-5
Vitiligo
4-26
4-11
Keratopathy
12-35
absent
Autoimmune hepatitis
10-19
4
Pernicious anemia
12-15
2-25
6
11
Chronic gastritis
Autoantigens in Addison’s
disease
• Steroid 17a-hydroxylase, P450c17
• Steroid 21-hydroxylase, P450c21
• Side-chain cleavage enzyme, P450scc
Thomas Addison
All three P450 enzymes are
active in steroidogenesis in
adrenal cortex. P450c21 is
expressed only in adrenal
cortex, P450c17 and P450scc
are also expressed in gonads
Krohn et al. Lancet 339: 770, 1992
Uibo et al. JCEM 78: 323, 1994
APS1/APECED autoantigens
Autoantigen
Prevalence %
Steroid 21 hydroxylase (P450c21)
66
Side-chain cleavage enzyme (P450scc)
52
Steroid 17 alpha hydroxylase (P450c17)
44
Aromatic L-amino acid decarboxylase (AADC)
51
Glutamic acid decarboxylase (GAD65)
37
Histidine decarboxylase (HDC)
37
Cysteine sulfinic acid decarboxylase (CSAD)
3.6
Tryptophan hydroxylase (TPH)
45
Tyrosine hydroxylase (TH)
44
Thyroglobulin (TG)
36
Thyroid peroxidase (TPO)
36
Transcription factor SOX10
22
Cytochrome P4501A2 (P4501A2)
8
Tyrosine phosphatase-like protein IA-2 (IA-2)
7
AIRE protein
•N-terminal HSR domain: homodimerisation
•SAND domain: putative DNA binding
•PHD finger: transcriptional regulation
•Proline rich region
•LXXLL motif: binding to nuclear receptors
Nagamine et al. Nat Genetics 17: 393, 1997
The Finnish-German Consortium. Nat Genetics 17: 399, 1997
Similarity to Nuclear Proteins
Mi-2:
helicase, involved in chromatin remodelling,
autoantigen in dermatomyositis
TIF1:
transcriptional coactivator
Sp100: interferon responsive, transcription activator,
autoantigen in PBC, lymphoid restricted
Sp140: homologous protein to Sp100,
autoantigen in PBC
Expression in the Thymus
•The major AIRE expressing tissue is the thymus
•Lower levels of expression are seen in the fetal liver, spleen
and lymph nodes
•In the thymus, AIRE is seen in a distinct subset of cells
in situ hybridisation
Anti-AIRE ab
Heino et al. BBRC 257: 821, 1999
Subcellular localization
Aire localizes to nuclear dots in thymus medulla
and in transfected Cos cells
Human and Mouse AIRE proteins are 77% identical
545
516
520
475
430
434
340
350
299
280
189
100
63
67
7
11
aa
AIRE
L HSR/ASS L
NLS
SAND
PHD
PRR
L
(23.5%)
PHD
L
552
520
524
475
430
434
342
352
301
279
188
99
64
68
8
12
aa
Aire
L HSR/ASS L
NLS
SAND
PHD
PRR
(16%)
L
PHD
L
mouse : MAGGDGMLRRLLRLHRTEIAVAIDSAFPLLHALADHDVVPEDKFQETLRLKEKEGCPQAFHALLSWLLTRDSGAILDFWRILFKDYNLERYSRLHSILDGFPKDVDLNQSR : 111
human : MA-TDAALRRLLRLHRTEIAVAVDSAFPLLHALADHDVVPEDKFQETLHLKEKEGCPQAFHALLSWLLTQDSTAILDFWRVLFKDYNLERYGRLQPILDSFPKDVDLSQPR : 110
ASS
L
L
mouse : KGRKPLAGPKAAVLPPRPPTKRKALEEPRATPPATLASKSVSSPGSHLKTKPPKKPDGNLESQHLPLGNGIQTMAASVQRAVTVASGDVPGTRGAVEGILIQQVFESGRSK : 222
human : KGRKPPAVPKALVPPPRLPTKRKASEEARAAAPAALTPRGTASPGSQLKAKPPKKPESSAEQQRLPLGNGIQTMSASVQRAVAMSSGDVPGARGAVEGILIQQVFESGGSK : 221
NLS
mouse : KCIQVGGEFYTPNKFEDPSGNLKNKARSGSSLKPVVRAKGAQVTIPGRDEQKVGQQCGVPPLPSLPSEPQVNQKNEDECAVCHDGGELICCDGCPRAFHLACLSPPLQEIP : 333
human : KCIQVGGEFYTPSKFED-SGSGKNKARSSSGPKPLVRAKGAQGAAPGGGEARLGQQGSVPAPLALPSDPQLHQKNEDECAVCRDGGELICCDGCPRAFHLACLSPPLREIP : 331
SAND
PHD
mouse : SGLWRCSCCLQGRVQQNLSQPEVSRPPELPAETPILVGLRSASEKTRGPSRELKASSDAAVTYVNLLAPHPAAPL--LEPSALCPLLSAGNEGRPGPAPSARCSVCGDGTE : 442
human : SGTWRCSSCLQATVQEVQPRAEEPRPQEPPVETPLPPGLRSAGEEVRGPPGEPLAGMDTTLVYKHLPAPPSAAPLPGLDSSALHPLLCVGPEGQQNLAPGARCGVCGDGTD : 442
L
mouse : VLRCAHCAAAFHWRCHFPTAAARPGTNLRCKSCSADSTPTPGTPGEAVPTSGPRPAPGLAKVGDDSASHDPVLHRDDLESLLNEHSFDGILQWAIQSMSRPLAETPPFSS : 552
human : VLRCTHCAAAFHWRCHFPAGTSRPGTGLRCRSCSGDVTPAP-VEGVLAPSP-ARLAPGPAK--DDTASHEPALHRDDLESLLSEHTFDGILQWAIQSMARPAA---PFPS : 545
PHD
L
Mittaz et al. BBRC, 255: 483, 1999
Aire co-localizes with epithelial
cell markers in thymus medulla
MTS5
MTS10
Spl macroph.
Thymocytes
Spl CD4-8+DC
Spl CD4-8-DC
Spl CD4+8-DC
Thy CD8lo/-DC
Thy CD8+ DC
AIRE is
expressed in
Dendritic cells
Aire
b-actin
AIRE mRNA is
upregulated
in vitro stimulated
human DCs
Several subclasses of
mouse dendritic cells
express Aire
Cortex
Thymocyte differentiation
Double negative
CD4- CD8No T-cell receptor
Medulla
Double positive
CD4+ CD8+
T-cell receptor
Single positive
CD4+ CD8or
CD4- CD8+
T-cell receptor
Thymocytes are selected differentially according to their reactivity
TCR reactive to non-self antigens
Cells survive and
when meeting
pathogen will
proliferate
T-cell
precursor
TCR reactive to self antigens
Cell death
Autoimmune diseases and autoantigens
Addison’s disease
Autoimmune gastritis
Pernicious anemia
Hashimoto thyroiditis
Graves disease
Myasthenia gravis
Type 1 diabetes
Vitiligo
Rheumatoid arthritis
Multiple sclerosis
steroid P450 cytochromes
H+/K+ ATPase
intrinsic factor
thyroid peroxidase, thyroglobulin
thyroid receptor
Acetylcholine receptor
insulin, GAD65
tyrosinase, MART
type 2 collagen
myelin basic protein
Ectopic (promiscuous) expression of
self antigens in thymus
Many tissue specific
autoantigens are expressed
in thymus.
During negative selection, Tcells to these antigens are
deleted.
If antigen is not expressed in
thymus or is expressed in a
different way, this may cause
autoimmunity
From Gotter et al. 2004
Diverse genes expressed in thymic epithelial cells
Tissues specific antigens (pancreas, stomach, brain, eye, liver,
muscle, kidney specific genes)
Expression of genes expressed during fetal stages, pregnancyassociated genes
Expression of male specific genes in females and vice versa
Expression of cancer specific antigens
Conserved in mice and humans
Estimation of 3000 genes (5-10% of known genes) in addition
to basal expression of thymic epithelial cells
AIRE (autoimmune regulator) gene is central in
expressing tissue specific antigens
Aire deficient mice have autoantibodies
and lymphocytic infiltration in multiple tissues
Anderson et al. Science, 2002
Microarray analysis of gene
expression in wild-type and
Aire deficient mouse
The expression of tissue
specific genes is lower or
non-existing in Aire
deficient mouse
Anderson et al. Science, 2002
The PHD zinc fingers form the activation
domain of AIRE
HSR
NLS
SAND
PHD
PRR
PHD
AIRE Interacts with CBP
•AIRE binds CBP at its CH1 and CH3 domains by far
western and yeast two-hybrid assays
•CH1 also binds STAT2 and HIF-1a; CH3 binds E1A and
TFIIB
CBP: cAMP response element
binding (CREB) protein binding protein
CBP is implicated in various
transcriptional responses
regulating growth, differentiation or apoptosis
Belongs to the class of
transcription co-activators
possessing histone acetyltransferase activity (HAT)
and thus have the potential
to regulate the chromatin
structure
From Hottiger and Nabel, 2000
CBP/p300 interacts with many
transcription activators and coactivators
AIRE Colocalises with CBP
AIRE
CBP
merge
3D picture of AIRE dots
Nuclear Bodies
• Most prominent nuclear bodies are promyelocytic leukemia
(PML) nuclear body or POD (PML oncogenic domain)
• Approximately 0.3 to 1 micrometers in diameter
• Other proteins in nuclear dots are involved in transcription or
suspected in chromatin binding (Sp100, CBP, BLM, p53)
• Function unknown, activation or degradation site?
• Some of the proteins like CBP move in and out.
AIRE Function
AIRE induces the expression of autoantigens that lead to the
elimination of the autoreactive T cells
Thymus
T cell autoreactive to APECED
autoantigen
AIRE
Thymic epithelial cell
expressing autoantigens
Loss of Function
When AIRE is defective, autoreactive T cells escape
selection, and autoimmunity develops
Thymus
T cell autoreactive to APECED
autoantigen
No AIRE
Thymic epithelial cell
expressing autoantigens
University of Tampere
Jukka Pitkänen
Camelia Magureanu
Ulla Aapola
Niko Sillanpää
Astrid Murumägi
Maarit Heino
Pärt Peterson
Kai Krohn
WEHI, Melbourne
Hamish Scott
Li Wu
University of Tokushima
Mitsuru Matsumoto
Keio University, Tokyo
Jun Kudoh
Nobuyoshi Shimizu
University of Würzburg
Philipp Ströbel
Alex Marx
University of Geneva
Laureane Mittaz
Stylianos Antonarakis
University of Birmingham
Graham Anderson
Eric Jenkinson
University of Tartu
Ana Rebane
Vivian Kont
Kaidi Möll
Tõnis Org
Ingrid Liiv
Eneli Õis
Annika Reimets
Rainis Venta
Mario Saare