Ingen lysbildetittel

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HLA and disease - learning from gluten sensitive
enteropathy Ludvig M. Sollid University of
Oslo Rikshospitalet University Hospital
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SOME HLA ASSOCIATED DISEASES
HLA
Frequencies ()
Patients
Healthy
Ank. spondylitis
B27
gt95
9
(Bechterews disease)
Narcolepsy
DQ6
100
33
Myasthenia gravis
DR3
50
27
Graves disease
DR3
65
27
DR4 (DRB10401/0404)
Rheumatoid arthritis
80
33
DQB102
Coeliac disease
DQA105,
99
28
Multiple sclerosis
DQ6
86
33
Diabetes (type I)
DQ8
81
23
DQ6
lt0.1
33
Pemphigus vulgaris
DR4 (DRB10402)
DQB10503
Stevens-Johnson synd. (carbamazepine induced)
9
B1502
100
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• HUMAN MHC (HLA)
• 224 gene loci
• 128 predicted
• to be expressed
• 40 immune
• related genes

MHC Sequencing Consortium Nature 1999
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CLASSICAL HLA MOLECULES
b
b2m
a
a
HLA cl. II
HLA cl. I
DP
DQ
DR
B
C
A
Series
B5
B3
B4
Loci
A
B
A
B
A
B1
A
A
A
11
36
223
23
2
339
78
169
Alleles
81
17
13
7
5
HLA ALLELES ASSOCIATED WITH DISEASE PROBLEM OF
LINKAGE DISEQUILIBRIUM
DP1
DQ2
B8
A1
DR3
DQ8
B62
A2
DR4
DP
DQ
DR
B
C
A
Class II
Class I
HLA gene complex
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HLA MOLECULES PRESENT PEPTIDE ANTIGENS TO T CELLS
CD8
CD4
TCR
HLA class II
HLA class I
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Reinherz et al, Science 1999
7
8
Stern et al, Nature 1994
8
9
Stern et al, Nature 1994
9
10
Nelson Fremont Rev Immunogenet 1999
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POCKET PROFILES OF SOME DR MOLECULES
Sturniolo et al., Nat. Biotech. 1999
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Sturniolo et al., Nat. Biotech. 1999
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BINDING SPECIFICITY AND CORRELATION WITH RA
SUSCEPTIBILITY
DRb residue at Anchors in
P4 HLA-DR 67 70 71 position
DRB10401 L Q K D, E DRB10404 L Q R D,
E DRB10402 I D E K, R
Hammer et al., JEM 1995
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SELECTIVITY OF PEPTIDE BINDING TO DR4 ANTIGENS
ASSOCIATED WITH DIFFERENT AUTOIMMUNE DISEASES
Wucherpfennig Strominger JEM 1995
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Wucherpfennig Strominger JEM 1995
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T CELL SELECTION
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HLA DISEASE

• For most diseases the involved HLA genes have not
  been unequivocally identified
• Classical, peptide-presenting, HLA molecules are
  likely to be involved
• For most diseases the antigens involved are
  unknown
• HLA molecules can predispose to or protect
  against disease development
• HLA molecules can predispose/protect
• at the level of thymic selection of TCR
  repertoire or
• by presentation of antigens in the periphery

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GENETIC AND ENVIRONMENTAL FACTORS INVOLVED IN
DEVELOPMENT OF CHRONIC INFLAMMATORY DISEASES
Genes
Environment
HLA
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GENETIC CONTROL OF THE T CELL IMMUNE RESPONSE
Protein antigen
T cell
"Peptide generating" genes
HLA
TCR
a
V
DP
DQ
DR
B
C
A
b
V
HLA genes
Peptide
TCR genes
Antigen Presenting Cell
"Immune modulating " genes cytokines, cytokine
receptors, accessory molecules
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CELIAC DISEASE

• ? Prevalence 1100. Clinical symptoms in 10-50.
• ? Precipitated by ingestion of wheat gluten
  proteins. Complete recovery on a gluten-exclusion
  diet.
• Villous atrophy in the small intestine ?
• malabsorption diarrhea.
• More often extraintestinal symptoms (fatigue,
  osteoporosis, anemia, infertility, depression,
  neurological diseases).
• ? Familial clustering (10 of 1st degree rel.
  affected).
• Very strong HLA association.

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CELIAC DISEASE MUCOSA
NORMAL MUCOSA
gluten - gluten
autoantibodies to tissue transglutaminase (TG2)
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GENETIC AND ENVIRONMENTAL FACTORS INVOLVED IN
DEVELOPMENT OF CELIAC DISEASE
Genes
Environment
HLA gt40
Gluten
5q32
19p13
2q33
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HLA ALLELES ASSOCIATED WITH CELIAC DISEASE THE
PROBLEM OF LINKAGE DISEQUILIBRIUM
DP1
DQ2
DR3 DR7
B8
A1
DP
DQ
DR
B
C
A
Class II
Class I
HLA gene complex
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Gut, 1983, 24, 534-537
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(No Transcript)
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THE CELIAC LESION
T-NK
T
TG2
TH1
IFN-?
APC
APC
TCR
TH1
CD4
T
T
HLA-DQ2 (or DQ8)
APC
T
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BINDING OF PEPTIDES TO HLA-DQ2
7
2
1
8
4
6
9
3
5
Peptides
E, D P
E, D
L, I, F Y, W, M, V
F, Y W, L I, V
E, D
Preferred
P6
P7
P4
P9
P1
DQ2
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GLUTEN PROTEINS
microheterogeneity
G L I A D I N S
Alcohol soluble
a
g
G L U T E N
?
G L U T E N I N S
LMW
Alcohol insoluble
HMW
? poor in negatively charged residues (E, D lt
2) ? rich in glutamine (Q gt 30) and proline (P
gt 10)
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Sollid Nat Rev Immuol 2002
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GENERATION OF T CELL EPITOPES IN THE GUT
a2-gliadin 1 MVRVPVPQLQ PQNPSQQQPQ EQVPLVQQQQ
FPGQQQPFPP QQPYPQPQPF PSQQPYLQLQ 61 PFPQPQLPYP
QPQLPYPQPQ LPYPQPQPFR PQQPYPQSQP QYSQPQQPIS
QQQQQQQQQQ 121 QQKQQQQQQQ QILQQILQQQ LIPCRDVVLQ
QHSIAYGSSQ VLQQSTYQLV QQLCCQQLWQ 181 IPEQSRCQAI
HNVVHAIILH QQQQQQQQQQ QQPLSQVSFQ QPQQQYPSGQ
GSFQPSQQNP 241 QAQGSVQPQQ LPQFEEIRNL ALETLPAMCN
VYIPPYCTIA PVGIFGTNYR

LQLQ 61 PFPQPQLPYP QPQLPYPQPQ
LPYPQPQPF
Transglutaminase (QXPY)
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T CELL RECOGNTION AND DQ2 BINDING OF DQ2-?-I
GLIADIN EPITOPE VARIANTS
IC50 (µM)
TG2
QXP(Y)
QLQPFPQPQLPY
103
--E---------
118
------E-----

--------E---
4
20
10
30
not tested
cpm (x103)
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HLA-DQ2 RESTRICTED GLIADIN T CELL EPITOPES
CLUSTER IN REGIONS RICH IN PROLINE RESIDUES
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SEVERAL GLUTEN T CELL EPITOPES proline spacing
and glutamine deamidation
Qiao et al. J Immunol 2005
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DEAMIDATED GLUTEN PEPTIDE CAUGHT IN THE ACT
X-ray crystal structure (2.2 Å resolution)
Kim et al. PNAS, 2004
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PEPTIDE INTERACTIONS AT THE P6 POCKET
Kim et al. PNAS, 2004
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DQ2-aI GLIADIN COMPLEX EXTENSIVE
HYDROGEN BONDING NETWORK TO MAIN CHAIN ATOMS
?-chain ?-chain
Kim et al. PNAS, 2004
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HYDROGEN BONDING NETWORK TO PEPTIDE MAIN CHAIN
INVOLVES AMIDE NITROGENS
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PROLINE RESIDUES UNABLE TO ESTABLISH THESE
HYDROGEN BONDS
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PROLINE RICH GLUTEN PEPTIDES CAN BIND TO MHC
CLASS II ONLY IN FEW REGISTERS
DQ2 ALLOWED REGISTER ALSO GIVES FAVORABLE SIDE
CHAIN INTERACTION ? HIGH AFFINITY BINDING
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(No Transcript)
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• ? WHY ONLY GLUTEN?
• - resistant to GI digestion (Pro).
• - good substrate for TG2 (Gln and Pro).
• - able to bind MHC class II (DQ2 and DQ8).
• - ? activates innate immune system.
• WHY ONLY DQ2?
• the many Pro impose constraints on MHC class II
  binding. DQ2 can match this and make favorable
  side chain interactions
• (TG2 formed Glu at P4, P6 or P7).

? WHY NOT ME? I am DQ2 positive without
Celiac Disease
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CONTRIBUTORS
Stanford Chu-Young Kim Lu Shan Jiang Xia Gary M.
Gray Chaitan Khosla
Oslo Hanne Quarsten Øyvind Molberg Helene
Arentz-Hansen Shuo-Wang Qiao Knut E.A.
Lundin Stephen McAdam Burkhard Fleckenstein Elin
Bergseng Melinda Raki Stig Tollefsen Erik Thorsby
Tübingen Günther Jung
EU project Leiden Frits Koning Aarhus/Oxford Lars
Fugger
Odense Peter Roepstorff
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(No Transcript)
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ANTI-ENDOMYSIAL ANTIBODIES A HALLMARK OF CELIAC
DISEASE

• ? Specific for tissue transglutaminase (TG2)
• (Dieterich Nat. Med 1997)
• Disease specific (IgA) - diagnostic tool
• ? Fluctuate with gluten exposure
• ? Involved in the pathogenesis???
• ? Since IgA/IgG Require T cell help for prod.

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TG2 AND GLUTEN PEPTIDES FORM COMPLEXES

• Incubation of TG2-GST (100kDa) with the
  biotinylated gliadin peptide aI QLQPFPQPQLPY

• Laemmli buffer / 1 b-ME, 2 SDS, 3 min 97C
• SDS-PAGE, Western blot specific detection of
  the biotin moiety

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MODEL FOR COGNATE T CELL HELP TO TG2 SPECIFIC B
CELLS
T-cell
APC
T-cell receptor
T- cell help
gluten peptide
HLA-DQ2
B-cell
anti-TG2
B cell
TG2
gluten
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GENETIC AND ENVIRONMENTAL FACTORS DISEASE
HETEROGENEITY
Patient A
Patient B
Genes
Environment
Genes
Environment
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GENETIC PATHWAYS OF TWO PATIENTS MAY BE DIFFERENT
NORMAL
LESION