Islet Amyloid Polypeptide Is a Target Antigen for Diabetogenic CD4+ T Cells
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Transcript of Islet Amyloid Polypeptide Is a Target Antigen for Diabetogenic CD4+ T Cells
Islet Amyloid Polypeptide Is a Target Antigen forDiabetogenic CD4+ T Cells
Thomas Delong, …Kathryn Haskins Diabetes 2011
Register 3 mimotope
12-14 wk vaccination
3-4 wkvaccination
Prevention of type 1 diabetes in mice by tolerogenic vaccination with a strongagonist insulin mimetope
Carolin Daniel,1,4 Benno Weigmann,3 Roderick Bronson,4and Harald von Boehmer1,2
JEM 2011
Stadinski et al Diabetogenic T cells recognize insulin bound to IAg7 inan unexpected, weakly binding registerPNAS 107:10978, 2010
All anti-B:9-23 only reacted with peptide in Register 3 with arginine in pocket 3
FIXING IN REGISTER 3 WITH DISULFIDE BONDS
Stadinski et al PNAS 2010
By mutating the MHC binding groove of NOD’s I-Ag7 insulin peptide B:9-23 is fixed in specific register 3, and this is low affinity register diabetogenic
T cell receptors “see” the peptide.
I-Ag7Peptide
Peptide Presentation Model
AA Peptide Side Chains
ARG(22)
GLU
GLY
CYS
VAL
LEU
TYR
LEU
ALA(14)
Crystal Structure of I-Ag7
INSULIN PEPTIDE B:9-23 IN TWO REGISTERS (arrow 3)
Unique autoreactive T cells recognize insulin peptides generated within the islets of Langerhans in autoimmune diabetes James F Mohan,…& Emil R Unanue Nature Immunology March 2010
Rag-/- isletsOnly islets + type B
CD11c islets
InsulinomaType A
Insulin granules
Type B
TEETH
GROOVE
“TEETH”
T Cell Receptor Analogy
Conserved T Cell Receptor Alpha Chain Induces Insulin Autoantibodies
Kobayashi et al PNAS 105:10090-94 2008
Anti-B:9-23 TCR alpha Transgene No Transgene
Leader 1: MAL LVHFLPLLALLALWEPKPTQALeader 2: MALWMRFLPLLALLFLWESHPTQAHuman : MALWMRLLPLLALLALWGPDPAAA 10 20 B Chain 1: FVKQHLCGPHLVEALYLVCGERGFFYTPKSB Chain 2: FVKQHLCGSHLVEALYLVCGERGFFYTPMSHuman : FVNQHLCGSHLVEALYLVCGERGFFYTPKT 25 30 40 50C-Peptide 1: RREVEDPQVEQLELGGSPG…..DLQTLALEVARQC-Peptide 2: RREVEDPQVAQLELGGGPGAGDLQTLALEVAQQHuman : RREAEDLQVGQVELGGGPGAGSLQPLALEGSLQ 55 60 70 80A Chain 1: KR GIVDQCCTSICSLYQLENYCNA Chain 2: KR GIVDQCCTSICSLYQLENYCNHuman : KR GIVEQCCTSICSLYQLENYCN 88 100
Amino Acid Sequence of Mouse 1 and 2 and Human Insulin
B:9-23
0 10 20 30 40 50 600
20
40
60
80
100
ins1-, ins2-, Tg+ (n=25, P<0.01)ins1+, ins2-, Tg+ (n=25)
Weeks of age
% D
iabe
tes
Free
Lack of progression to diabetes of NOD mice lacking both insulin native genes.
Ins1-, ins2-: n=Ins1+, ins2-: n=
2525
1014
2123
11
24 Life table update 5/19/05
Nakayama Nature 435:220,2005
Insulin is the primary antigen and precedes IGRP in hierarchy of autoantigens
Epitope and antigen spreading,expansion
Diabetes
Insulin specific T cells
Insultis
Krishnamurthy et al JCI:116:3258, 2006
Is there a primary antigen or immune response to multiple antigens required for autoimmunity?
Epitope and antigen spreading, expansion
Diabetes
T cells specific for one antigen
Diabetes
Expansion of T cells
T cells specific for multiple antigens
Insulitis Insulitis
OR
Krishnamurthy et al JCI:116:3258, 2006
Multiple Antigens are Targeted in Type 1 Diabetes
CPE
Hsp70
IGRP
Jun-B
SOX13
DNA TopII
S100
GAD67
Hsp90
Peripherin
GLUT2
GAD65
Glima38
HIP/PAP
Insulin
IAPP
Sulphatide
IA-2
Hsp60
Imogen38
IA-2
ICA69
GM2-1GT3
DMK
Nucleus
Synaptic-likeMicrovesicles
EndoplasmicReticulum
Cytosol
GolgiNetwork
SecretoryGranules
Mitochondria
GD3
CD38
ZnT8
Chg A
Hsp10
RegRegII
Importin
PDX1
Ab AbT TH M
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Figure modified from Tissue Antigens 2003, 62:359Information from Expert Rev Clin Immunol 2010, 6:939
HUMAN MOUSE
Reported Antibody or T Cell
Dilorenzo
The Generation of Retrogenic Mice
Insertion: TCR alpha only oralpha_P2A_beta
Phoenix cells(293T cells transfected with pCL-Eco)
pMIG
pMIG
pMIG
SCID orCa-KOBM cells
SCID
3’LTR
5’LTR
IRE
S
GFP
Ψ
pMIG
MIG
CMV-env (Mo-MuLV)RSV-gag-pol (Mo-MuLV)
Anti-GAD TCR + or – B Lymphocytes TCR Retrogenic Induction High Levels GAD65 Autoantibodies
T Cell Islet Accumulation in Type 1 Diabetes is a Tightly Regulated, Cell-Autonomous Event Lennon et al
Immunity 31, 643-653, 2009
Nat Immunol. 2010 Mar;11(3):225-31. Epub 2010 Feb 7.Chromogranin A is an autoantigen in type 1 diabetes.
Stadinski, …Kappler, Haskins
Peptide WE14 bound to the NOD mouse major histocompatibility complex class II molecule I-A(g7) in an atypical manner, occupying only the carboxy-terminal half of the I-A(g7) peptide-binding groove.
T Cell Receptor Gene Segments
Chr. 14
Chr. 6
Va
Ja
V
D J
HLA Molecule Peptide
Antigen Presenting Cell
Antigen Recognition by CD8+ T Cells
T cellreceptor
V Va
Tcell
class IMHC
2m
cellT. DiLorenzo
V(D)J Rearrangement
1011 -1016 different possible
combinations.
Kuby Immunology
Child with IPEX syndromeAwaiting Bone Marrow Transplant
9 Months of Age
IPEX: Immune Dysfunction, Polyendocrinopathy, Enteropathy, X-linked
• Scurfin gene (Foxp3/JM2)- Controls Regulatory T Cells!
• Approximately 80% of children with syndrome develop diabetes!
• Bone marrow transplant can reverse
“Typical” Insulitis of man differs from peri-insulitis NOD mouse: Bottazzo
In’t Veld and Atkinson, Diabetes (Submitted)
Pipeleers and Ling, Diabetes/Metabolism Reviews 8:209, 1992.Gepts et al, 1965, 1978; ,Doniach et al, 1973; Klöppel et al, 1984; Bottazzo et al, 1985; Foulis et al, 1986; Hänninen et al, 1992; Somoza et al, 1994; Lernmark et al, 1995; Shimada et al, 1999; Dotta et al, 2007; Uno et al, 2007; Butler et al, 2007, Gianani and Atkinson, 2010.
Duration of disease
≤1 week >1 week - ≤1 year
>1 year total
Onset childhood (0-14 yrs)
22/23 37/42 3/32 62/97
Onset young adult(15-39 yrs)
8/14 17/26 1/23 26/63
Meta-Analysis of Insulitis – T1D Patients Stratified to Age at Onset and Duration of Disease
Atkinson
-cells
PancreaticLymph Node
T cells
ISLET
A MODEL
Ag
APC
t
tt
Mathis/Benoist
TRAV5D-04+TRAJ53 Restriction?Insulin B:9-23: SHLVEALYLVCGERG?
Natural T Regulatory Cells Antigen Specific T Reg
IPEX Syndrome MAN:
foxP3 mutant DM in days of birth!NOD anti-B9-23insulin TCR:
foxP3 mutant DM
?
MAN NOD MOUSE
IAg7DR3/DR4
Homann 2006,JCI
ENVIRONMENTAL FACTORS Incidence type 1 DM Increasing 3%/year > 30 years!
Protective Factor Decreasing
-Hygiene Hypothesis – Bach NEJM 347:911, 2002
Triggering Factors
-Congenital Rubella-Rubenstein Diabetes 31:1088, 1982
-Kilham Rat Virus (BB-DR rat)-Zipris J. Immunol 174:131, 2005
-Poly-IC Induction Interferon Alpha-Devendra Diabetes 54 2005
-Dietary Factors-Scott Ann Rev Nutr 26:175, 2006
T Cell Receptor
Natural T Regulatory Cells
Antigen Specific T Reg
Natural peptides selected by diabetogenic DQ8 and murine I-Ag7 molecules show common sequence
homology Suri et al JCI 115:2268, 2005Structure of Human insulin peptide DQ8, Lee et al
Nature Immunology 6:501, 2001Crystal DQ8;B:9-23: S H L V E A L Y L V C G E R G
P1 P4 P9
I-Ag7 v,e,q I,L A,s D,E
12% 20% 30,11% 45%
P6
DQ8 E,d A,S A,V,s E,D
27,17% 19% 20% 60,25%
Preferred AA in Bound Peptides
Wiley Nat Immunol
% amino acid at position
Clone CD4/CD8 Source Antigen TCRα/β Tetramer Transgenic Retrogenic Comment AuthorBDC2.5 CD4 Spleen Chromagranin 7D-6/2 yes yes yes 10.1 same mimotope HaskinsBDC10.1 CD4 Islet Chromagranin 17/20 yes yes DM+++ retrogenic HaskinsBDC5.10.3 CD4 Islet Chromagranin /2BDC5.2.9 CD4 Amyloid(IAPP 1-20) 2/19BDC6.9 CD4 Islet ? IAPP 5D-4*01/2 yes yes Strain specific, chr 6 HaskinsNY4.1 CD4 Islet 5D-4*04/16 yes yes DM transgenic Santamaria
Phogrin-13 CD4 Immun LN IA2β 640-659 13-2/3 yes insulitis retrogenic HuttonPhogrin-18 CD4 Immun LN IA2β 755-777 10/16 yes insulitis retrogenic Hutton10.23 CD4 Immun LN IA2 676-688 13-4/4 yes Hutton
2H6 CD4 Panc LN insulin B:12-25 21/31 yes TGFβ protection Zekzer12-4.1 CD4 Islet insulin B:12-22 5D-4*04/1 yes yes DM retrogenic Wegmann12-4.4 CD4 Islet insulin B:12-22 5D-4*04/5 yes DM retrogenic Wegmann 8-1.1 CD4 Immun LN insulin B:12-22 5D-4*04/15 yes yes DM retrogenic Wegmann12-1.19 CD4 Islet insulin B:9-23 13-1/19 yes DM retrogenic Wegmann12-2.35 CD4 Islet insulin B:9-18 7-4/13-1 yes DM retrogenic Wegmann6-4.3 CD4 Islet insulin B:9-23 5D-4*04/1 Wegmann12-2.4 CD4 Islet insulin B:9-16 WegmannPCR1-10 CD4 anti 8-1.1 isletinsulin B:9-23 5D-4*04/16 yes Same alpha 8-1.1 NakayamaAS91 CD4 Islet insulin B12-20 5-1/ yes UnanueAS150 CD4 Islet insulin B13-21 UnanueI.29 CD4 Islet insulin 10/1 yes Unanue
6C5 CD4 islet 9D-4/19 young NOD Fathman
5A CD4 Immun Spl GAD ZekzerB16.3 CD4 spleen GAD65 pp286–300 6-2/5 yes suppress DM McDevittBW5147 CD4 spleen GAD65 pp206–220 3/13-2 suppress DM McDevittPA15.14B CD4 spleen GAD pp206–220 6D-6/13-3 yes no DM retrogenic VignalliIA4 CD4 GAD pp217–236 6-6/2 yes no DM retrogenic Tisch
PA18.10F10CD4 GAD pp510–524 7-4/4 yes no DM retrogenic VignalliPA18.9H7 CD4 GAD pp524–538 21/15 yes no DM retrogenic Vignalli530.45.19 CD4 GAD pp530–543 (5D-4/2) yes no DM retrogenic SercarzPA17.9G7 CD4 Immun GAD pp284–300 4.5/10 yes no DM, encephalitis Vignalli4B5 CD4 GAD pp217-236:290-309 2.4/6 no DM, encephalitis TischPA19.9G11 CD4 Immun GAD pp221-237:284-300 17.1/5.2 no DM, encephalitis Vignalli
G9C8 CD8 Islet insulin B:15-23 yes Wong
8.3 CD8(Kd) Islet IGRP 206-214 17/ yes yes Perforin independent, Fas SantamariaAI4 CD8(D6) DMK 138-146 DMK Widespread DiLorenzo
Clone CD4/CD8 Source Antigen TCRα/β Tetramer Transgenic Retrogenic Comment AuthorBDC2.5 CD4 Spleen Chromagranin 7D-6/2 yes yes yes 10.1 same mimotope HaskinsBDC10.1 CD4 Islet Chromagranin 17/20 yes yes DM+++ retrogenic HaskinsBDC5.10.3 CD4 Islet Chromagranin /2 HaskinsBDC5.2.9 CD4 Amyloid(IAPP 1-20) 2/19 HaskinsBDC6.9 CD4 Islet ? IAPP 5D-4*01/2 yes yes Strain specific, chr 6 HaskinsNY4.1 CD4 Islet 5D-4*04/16 yes yes DM transgenic Santamaria
Phogrin-13 CD4 Immun LN IA2β 640-659 13-2/3 yes insulitis retrogenic HuttonPhogrin-18 CD4 Immun LN IA2β 755-777 10/16 yes insulitis retrogenic Hutton10.23 CD4 Immun LN IA2 676-688 13-4/4 yes Hutton
2H6 CD4 Panc LN insulin B:12-25 21/31 yes TGFβ protection Zekzer12-4.1 CD4 Islet insulin B:12-22 5D-4*04/1 yes yes DM retrogenic Wegmann12-4.4 CD4 Islet insulin B:12-22 5D-4*04/5 yes DM retrogenic Wegmann 8-1.1 CD4 Immun LN insulin B:12-22 5D-4*04/15 yes yes DM retrogenic Wegmann12-1.19 CD4 Islet insulin B:9-23 13-1/19 yes DM retrogenic Wegmann12-2.35 CD4 Islet insulin B:9-18 7-4/13-1 yes DM retrogenic Wegmann6-4.3 CD4 Islet insulin B:9-23 5D-4*04/1 Wegmann12-2.4 CD4 Islet insulin B:9-16 WegmannPCR1-10 CD4 anti 8-1.1 isletinsulin B:9-23 5D-4*04/16 yes Same alpha 8-1.1 NakayamaAS91 CD4 Islet insulin B12-20 5-1/ yes UnanueAS150 CD4 Islet insulin B13-21 UnanueI.29 CD4 Islet insulin 10/1 yes Unanue
6C5 CD4 islet 9D-4/19 young NOD Fathman
5A CD4 Immun Spl GAD ZekzerB16.3 CD4 spleen GAD65 pp286–300 6-2/5 yes suppress DM McDevittBW5147 CD4 spleen GAD65 pp206–220 3/13-2 suppress DM McDevittPA15.14B CD4 spleen GAD pp206–220 6D-6/13-3 yes no DM retrogenic VignalliIA4 CD4 GAD pp217–236 6-6/2 yes no DM retrogenic Tisch
PA18.10F10CD4 GAD pp510–524 7-4/4 yes no DM retrogenic VignalliPA18.9H7 CD4 GAD pp524–538 21/15 yes no DM retrogenic Vignalli530.45.19 CD4 GAD pp530–543 (5D-4/2) yes no DM retrogenic SercarzPA17.9G7 CD4 Immun GAD pp284–300 4.5/10 yes no DM, encephalitis Vignalli4B5 CD4 GAD pp217-236:290-309 2.4/6 no DM, encephalitis TischPA19.9G11 CD4 Immun GAD pp221-237:284-300 17.1/5.2 no DM, encephalitis Vignalli
G9C8 CD8 Islet insulin B:15-23 yes Wong
8.3 CD8(Kd) Islet IGRP 206-214 17/ yes yes Perforin independent, Fas SantamariaAI4 CD8(D6) DMK 138-146 DMK Widespread DiLorenzo
NOD T CELL CLONES
NOD Mouse anti-islet T Cell Clones/transgenics/retrogenics
Clone CD4/CD8 Source Antigen TCRα/β Tetramer TransgenicRetrogenicComment AuthorBDC2.5 CD4 Spleen 7D-6/2 yes yes yes 10.1 same mimotope HaskinsBDC10.1 CD4 Islet 17/20 yes yes DM+++ retrogenic HaskinsBDC6.9 CD4 Islet 5D-4*01/2 yes yes Strain specific, chr 6 HaskinsNY4.1 CD4 Islet 5D-4*04/ yes yes yes DM transgenic Santamaria
Phogrin-13 CD4 Immun LN IA2β 640-659 13-2/3 yes insulitis retrogenic HuttonPhogrin-18 CD4 Immun LN IA2β 755-777 10/16 yes insulitis retrogenic Hutton10.23 CD4 IA2 676-688 13-4/4 yes Hutton
2H6 CD4 Panc LN insulin B:12-25 21/31 yes TGFβ protection ZekzerBDC12-4.1 CD4 Islet insulin B:12-22 5D-4*04/1 yes yes DM retrogenic WegmannBDC12-4.4 CD4 Islet insulin B:12-22 5D-4*04/5 yes DM retrogenic WegmannBDC 8-.1.1 CD4 Immun LN insulin B:12-22 5D-4*04/15 yes DM retrogenic WegmannBDC12-1.19 CD4 Islet insulin B:9-23 13-1/19 DM retrogenic WegmannBDC12-2.35 CD4 Islet insulin B:9-18 7-4/13-1 DM retrogenic WegmannBDC6-4.3 CD4 Islet insulin B:9-23 5D-4*04/1 WegmannBDC12-2.4 CD4 Islet insulin B:9-16 Wegmann6C5 CD4 islet 9D-4 young NOD Fathman
5A CD4 Immun Spl GAD ZekzerB16.3 CD4 spleen GAD65 pp286–300 6-2/5 yes suppress DM McDevittBW5147 CD4 spleen GAD65 pp206–220 3/13-2 suppress DM McDevittPA15.14B CD4 spleen GAD pp206–220 6D-6/13-3 yes no effect retrogenic VignalliIA4 CD4 GAD pp217–236 6-6/2 yes no effect retrogenic TischPA17.9G7 CD4 GAD pp284–300 6-2/4 yes no effect retrogenic VignalliPA18.10F10 CD4 GAD pp510–524 7-4/4 yes no effect retrogenic VignalliPA18.9H7 CD4 GAD pp524–538 21/15 yes no effect retrogenic Vignalli530.45.19 CD4 GAD pp530–543 (5D-4/2) yes no effect retrogenic Sercarz
G9C8 CD8 Islet insulin B:15-23 yes Wong
8.3 CD8 Islet IGRP 206-214 yes yes Perforin independent, Fas Santamaria
PeakmanA2 CD8 PPI:15-24
Durinovic-BelloDRB1*0401 CD4 73-90
GottliebB:9-23 DQ8
PeakmanDRB1*0401 C19-A3
HaflerDRB1*0401 A1-15
Expanded T cells from pancreatic lymph nodes of type 1 diabetic subjects recognize an insulin epitopeKent et al, Nature 435:224, 2005
• Pancreatic LN: Single cell cloning - PHA• 2/3 Patients Clonal expansion
duration diabetes 29 and 15 years• Vbeta29-1*03J2-3(50%)/Valpha8-3*02 J44*01(25%)
Vbeta5-1*01 J2-3(52%)/Valpha39*01 J33*01(26%)
• DRB1*0401 RestrictedInsulin A1-15
• Caveat: High concentration to stimulate 100uM
BDC
The insulin A-chain epitope recognized by human T cells is posttranslationally modified
Mannering et al, JEM 202:1191-1197, 2005• CD4 T cells cloned with CFSE method from peripheral
blood of one patient with diabetes and one child with insulin autoantibodies
• Subset of the clones reacted with insulin A-chain 1-13 epitope
• T Cells DR restricted and only reacted with peptide with vicinal disulfide bond between adjacent cysteines A6 and A7
• No reactivity with this peptide of clones from two normal controls with DR4
• Oral report by Sally Kent that their A1-15 peptide reactive T cells from pancreatic lymph node do not require vicinal disulfide cross-link
Ins2 deficiency augments spontaneous HLA-A*0201-restricted T cell responses to Insulin Jarchum and
DiLorenzo J Immunol 2010 vol 184
Ins B:10-18
Humanized HLA-A2 Mice lacking Insulin 2!
CD8 Elispot
Thymus-specific deletion of insulin induces autoimmune diabetes.
Fan et al EMBO Journal 28:2812-2824 2009• Ins1-/- mice (only) with cre mediated
thymic mTEC deletion of ins2 develop autoimmune diabetes by age 3 weeks.
• Diabetes develops in H-2b mice!• ELISPOT Responses to Insulin B:9-23
though mice do not have I-Ag7.• MYSTERIES: Need for Ins1-/-; Lack
protection H-2b; Presentation B:9-23 by H-2b.
The frequency and immunodominance of Islet-specific CD8+ T-cell responses change after Type 1 Diabetes
Diagnosis and Treatment Martinuzzi et al Diabetes 57:1312-1320, 2008
7-16 months post onset most ELSIPOT (HLA-A2) responses decrease
New Responses
PROINSULIN
PREPROINSULIN
“Santamria” NRP(IGRP206-214): Class I (Kd)Recognized
Peptide• CD8 T cell from NOD islets (e.g. clone 8.3)
• Conserved Valpha/ nDn/ J alpha (Va17,Ja42)Vbeta not conserved but contributes
• Accelerated diabetes TCR Transgenic• Mimotope Defined-Kd Tetramer
ProducedNRP=KYNKANWFL; NRP-V7: KYNKANVFL
• Higher Avidity Peptide/Tetramer V7• 30% Intra-islet post 9 weeks
>.5% in Blood Predicts Diabetes NOD Mice
Female NOD Mice Peripheral Blood
Avidin
Kd
NRP-V7 Peptide (KYNKANVFL)
Kd
Kd
Kd
Tetramer Analysis
0
0.2
0.4
0.6
0.8
1
1.2
5 10 14 18 21 24 27 30
Age (weeks)% N
RP-
V7 te
tram
er+
CD
8+ c
ells
Diabetes
0
0.2
0.4
0.6
0.8
1
1.2
5 9 12 15 18 21 24 27 30
Age (weeks)% N
RP-
V7 te
tram
er+
CD
8+ c
ells
No Diabetes
Tan et al., JCI 1/2003
CTLs are targeted to kill β cells in patientswith type 1 diabetes through recognition ofa glucose-regulated preproinsulin epitope Ania Skowera,…. and Mark Peakman JCI 2008:118 3268-3271.
Interferon gamma HLA-A2 ELISPOT peripheral blood Patients+ (SI>3) DM vs Controls
CD8+ CTL
CTL
Screening of Peptide Fractions by 51Cr Release Cytotoxicity Assay Method Used to Discover IGRP
APC
T. DiLorenzo
GAD, glutamic acid decarboxylase; IAPP, islet amyloid polypeptide
Antigen Position MHC Why examinedGAD65 114-123 A2 MHC bindingIAPP 5-13 A2 MHC binding
Insulin B10-18 A2 Proteasome cleavageB14-22 A3, A11 Proteasome cleavageB15-23 A24 MHC bindingB15-24 A24 Proteasome cleavageB17-26 A1, A3, A11 Proteasome cleavageB18-27 A1, A2, B8, B18 Proteasome cleavageB20-27 A1, B8 Proteasome cleavageB21-29 A3 Proteasome cleavageB25-C1 B8 Proteasome cleavageB27-C5 B8 Proteasome cleavage
Antigens for CD8+ T Cells in Type 1 Diabetes Patients
DiLorenzo
Antigen Position MHC T cells How identified
DMK 138-146 H-2Db AI4; islet Positional scanning libraries
IGRP 206-214 H-2Kd 8.3; isletMHC purification andmass spectrometry
21-29 H-2Kd Islet MHC binding225-233 H-2Db Islet MHC binding241-249 H-2Db Islet MHC binding324-332 H-2Kd Islet MHC binding
Insulin 1/2 B15-23 H-2Kd G9C8; islet Expression cloning
DMK, dystrophia myotonica kinaseGAD, glutamic acid decarboxylaseIGRP, islet-specific glucose-6-phosphatase catalytic subunit-related protein
Antigens for Islet-infiltrating CD8+ T Cells in NOD Mice
DiLorenzo
Toma et al. Recognition of a subregion of human proinsulin by class I-restricted T cells in type 1
diabetic patients PNAS 102:10581, 2005• Selected 8-11mer peptides of proinsulin• PBMCs of 29/32 (90%) recent+long term
diabetics responded IFNgamma in ELISPOT assay versus minimal response of normals
• Significant Peptides often overlapped insulin B chain peptide B:9-23(=Proins 33-47); Proins 34-42(B10-18); Proins 41-50(B17-26);Proins 42-51;Prins44-51; but also B chain-C-peptide (49-57)
• Multiple class I alleles, including A1 and B8
Peptide 2: Amino acids 643-658Peptide 7: Amino acids 762-777
C terminus
PTP
GADPSADATEAYQEL (rat) GADPSADATEAYQEL (mouse) GGDPGADATAAYQEL (human)
KNRSLAVLTYDHSRI (rat)KNRSLAVLTYDHSRI (mouse)KNRSLAVLTYDHSRV (human)
TM
N terminus
T cell epitopes on the diabetes autoantigen Phogrin (IA-2beta) are conservedamong different species