Rôle de récepteur Toll-like 8 dans le développement d'autoimmunité spontanée chez la souris, Role of Toll-like receptor 8 in the development of spontaneous autoimmunity in mice

Olivier Demaria

Description

Sous la direction de Lena Alexopoulou
Thèse soutenue le 10 novembre 2010: Aix Marseille 2
Les récepteurs Toll-like (TLRs) détectent des structures conservées exprimées par différentes classes de microorganismes, jouant ainsi un rôle majeur dans la réponse immunitaire. Les TLRs localisés dans les endosomes (TLR3, 7, 8 et 9) reconnaissent principalement des acides nucléiques dérivés de microbes. Cependant, ils peuvent également être responsables de la reconnaissance d’acides nucléiques endogènes et contribuer au développement d’auto immunité. A la différence du TLR8humain, le TLR8 murin n’induit pas de réponse à l’ARN simple brin et a ainsi été considéré comme non fonctionnel. Le but de cette étude est d’étudier le rôle du TLR8 murin dans l’immunité. Nous avons montré que les cellules dendritiques déficientes en TLR8 surexpriment le TLR7 et présentent une réponse accrue à une stimulation de TLR7. Chez la souris, la déficience en TLR8 entraine une augmentation des taux d’anticorps circulant (IgM, IgG, IgG2a), des autoanticorps, et au niveau rénal la présence de dépôts de complexes immuns. A l’inverse des souris TLR8-/-, les souris TLR7/8-/- sont protégées de tout symptôme. Nos résultats indiquent donc que chez la souris le TLR8 joue un rôle primordial dans la modulation de l’expression de TLR7, et cette régulation est cruciale dans le contrôle du développement d’autoimmunité spontanée.
-Récepteur Toll-like
-Autoimmunité
-Cellules dendritiques
-Lupus érythémateux systémique
Toll-like receptors (TLRs) detect conserved molecular products of microorganisms and play anessential role in the induction of immune responses. Endosomal TLRs (TLR3, 7, 8 and 9) sensenucleic acids derived from microbes. However they can also recognize self nucleic acids and thus beinvolved in the development of autoimmunity. Unlike human TLR8, murin TLR8 does not respond tosingle-stranded RNA suggesting that it could be not functional. In the current study, we investigatedthe role of murine TLR8 signaling in immunity. We found that TLR8-/- dendritic cells overexpressTLR7 and are hyperesponsive to various TLR7 ligands. In mice, TLR8 deficiency leads to increasedlevels of IgM, IgG, IgG2a circulating antibodies, autoantibodies and in the kidney to higher depositionof immunocomplexes while double TLR7/8-/- mice are protected from autoimmune features. Thesedata provide evidence for a pivotal role of murine TLR8 in the regulation of murine TLR7 expressionand this control is critical for the prevention of spontaneous autoimmunity development.
-Autoimmunity
-Toll-like receptors
-Dendritic cells
-Systemic lupus erythematosus
Source: http://www.theses.fr/2010AIX22102/document

Informations

• Publié par: Thesee
• Nombre de lectures: 45
• Langue: English
• Poids de l'ouvrage: 30 Mo

Extrait

Université de la Méditerranée Aix-Marseille II
Faculté des Sciences de Luminy
Ecole Doctorale des Sciences de la Vie et de la Santé
Thèse
Pour obtenir le grade de
Docteur de l’Université d’Aix-Marseille II
Discipline: Immunologie
Présentée et soutenue publiquement par
Olivier Demaria
Role of Toll-like receptor 8 in the development
of spontaneous autoimmunity in mice
Directrice de thèse: Dr. Lena Alexopoulou
Soutenue le 10 novembre 2010, devant le jury composé de :
Pr. Franck Galland Président
Dr. Bénédicte Manoury Rapporteur
Dr. Vassili Soumelis Rapporteur
Dr. Marc Dalod Examinateur
Dr. Lena Alexopoulou Directrice de thèseTABLE OF CONTENTS
LIST OF ABBREVIATIONS.................................................................................................. 1
RESUME EN FRANÇAIS....................................................................................................... 6
INTRODUCTION.................................................................................................................... 9
1 – PRRs and innate immunity ............................................................................................. 10
1-1 Secreted PRRs................................................................................................................ 12
1-2 Cytosolic PRRs .............................................................................................................. 12
1-3 Transmembrane PRRs ................................................................................................... 16
2-Toll-like receptors ............................................................................................................... 17
2-1 Plasma membrane TLRs ................................................................................................ 19
2-2 Intracellular TLRs.......................................................................... 22
2-3 Intracellular localization and trafficking of nucleic acid sensing TLRs ........................ 26
2-4 Distinct signaling pathways ........................................................................................... 28
2-4-1 MyD88.................................................................................................................... 29
2-4-2 TRIF........................................................................................................................ 30
2-4-3 NF-!B signaling ..................................................................................................... 31
2-5 TLR cooperation............................................................................ 33
3- Adaptive immune system .................................................................................................. 34
3-1 DCs orchestration of conventional lymphocytes ........................................................... 34
3-2 Innate B lymphocytes: MZ and B1 B cells.................................................................... 373-3 Specialization of DC subsets ......................................................................................... 38
4-Autoimmunity and nucleic acid sensing-TLRs ................................................................ 40
4-1 Autoimmunity and tolerance.......................................................................................... 40
4-2 Systemic lupus erythematosus (SLE) ............................................................................ 42
4-3 Autoantibodies ............................................................................................................... 43
4-4 Cell activation by endogenous ligands through endosomal TLRs................................. 45
4-4-1 TLR7 and TLR9 implication in SLE...................................................................... 45
4-4-2 How self-ligand can reach endosomal TLRs.......................................................... 49
4-5 SLE: a disease of TLR-driven amplification ................................................................. 51
4-5-1 TLR-driven B cell activation.................................................................................. 51
4-5-2 TLR-driven pDCs activation 52
4-5-3 TLR-driven cDCs activation 54
4-6 Treatments for SLE........................................................................................................ 54
RESULTS................................................................................................................................ 56
TLR8 deficiency leads to autoimmunity in mice ................................................................. 56
COMPLEMENTARY RESULTS ........................................................................................ 78
1-TLR8 inhibits TLR7 signaling........................................................... 78
-/-2-The reduced MZ B cell population in TLR8 mice is not B cell autonomous .............. 80
3-TLR9 is implicated in the control of TLR7 expression and signaling. .......................... 81
Experimental procedures: ..................................................................................................... 84
DISCUSSION & PERSPECTIVES...................................................................................... 85CONTRIBUTION TO OTHER PUBLICATIONS ............................................................ 95
REFERENCES....................................................................................................................... 98
ANNEXES............................................................. 125
1- Involvement of Toll-like receptor 5 in the recognition of flagellated bacteria
2- Brucella control of dendritic cell maturation is dependent on the TIR-containing
protein Btp1
3- Contribution of TLR7 and TLR9 signaling to the susceptibility of MyD88-deficient
mice to myocarditis
4- TLR3 and RIG-like receptor on myeloid dendritic cells and RIG-like receptor on
human NK cells are both mandatory for production of IFN-" in response to double-
stranded RNA
5- Gender bias in susceptibility differences to MCMV infection correlates with TLR9
expressionList of abbreviations
LIST OF ABBREVIATIONS
A
AIM2 absent in melanoma 2
ANA antinuclear antibody
AP1 activator protein 1
B
BAFF B cell-activating factor
BCR B cell receptor
BIR baculoviral inhibitor-of-apoptosis-protein repeat
BMDC bone marrow-derived dendritic cell
C
CARD caspase recruitment domain
CD cluster differentiation
cDC conventional DC
CLR C-type lectin receptor
CRD carbohydrate recognition domain
CRP C reactive protein
CTL cytotoxic T lymphocyte
D
DAI DNA-dependent activator of IRFs
DAMP danger associated molecular pattern
DC dendritic cell
DNA deoxyribonucleic acid
dsDNA double-stranded DNA
1List of abbreviations
E
EAE experimental autoimmune encephalomyelitis
EBV Epstein-Bar virus
EMCV encephalo-myocarditis virus
ER endoplasmic reticulum
ERK extracellular regulated kinase
F
FcR! Fc-gamma-receptor
G
CpG cytidine-phosphate-guanosine
H
HEK human embryonic kidney
HMGB high mobility group box
HIV immunodeficiency virus
HSV herpes simplex virus
I
IFN interferon
Ig immunoglobulin
I"B inhibitor of nuclear factor-"B
IL interleukin
iNOS nitric-oxide synthase
IPS-1 IFN# promoter stimulator-1
IRAK IL-1R associated kinase
IRF interferon regulatory factor
2List of abbreviations
J
JNK JUN N-terminal kinase
L
LPDC DC of the lamina propria
LPS lipopolysaccharide
LRR leucine rich repeat
M
MAL MyD88 adaptor like protein
MAPK mitogen activated kinases
MAVS mitochondria antiviral signaling
MBL mannan-binding lectin
MCMV mouse cytomegalovirus
MDA5 melanoma differentiation-associated gene 5
MD2 myeloid differentiation factor 2
MDP muramyl dipeptide
MHC major histocompatibility complex
MyD88 myeloid differentiation primary-response gene 88
MZ marginal zone
N
NAIP neuronal apoptosis inhibitory protein
NALP NACHT, LRR and Pyd containing protein
NF-kB nuclear factor-"B
NLR NOD-like receptor
NK natural killer
NOD nucleotide oligomerization domain
3List of abbreviations
O
ODN olidodeoxynucleotide
OmpA outer membrane protein A
P
pDC plasmacytoid DC
PAMP pathogen-associated molecular pattern
PGN peptidoglycan
Pol III polymerase III
PRAT4A protein associated with TLR4 A
PRR pattern recognition receptor
PTX3 pentraxin 3
PYD pyrin domain
R
RAG recombination-activating gene
RAGE receptor for advanced glycation end-products
REL reticuloendotheliosis viral oncogene homolog
RIG-I retinoic acid-inducible gene I
RIP1 receptor interacting protein-1
RIP2 receptor interacting protein-2
RLR (RIG-I)-like receptor
RNA ribonucleic acid
RNP ribonucleoprotein
RSV respiratory syncytial virus
S
SAP serum amyloid P
siRNA silencing RNA
SLE systemic lupus erythematosus
Sm Smith antigen
SnRNP small nuclear nucleoprotein
4List of abbreviations
ssRNA single-stranded RNA
T
TAK1 transforming-growth-factor-#-activated kinase
TCR T cell receptor
TBK1 TANK binding kinase-1
TGF-#$$ $ transforming growth factor#
tGPI Glycosylphosphatidylinositol-anchored mucin-like