Contribution of skin dendritic cells to epicutaneous immunotherapy (EPIT) in food … · 2020. 6....
Transcript of Contribution of skin dendritic cells to epicutaneous immunotherapy (EPIT) in food … · 2020. 6....
-
Contribution of skin dendritic cells to epicutaneous immunotherapy (EPIT)
in food allergy
EAACI 2020
Digital Congress
Léo Laoubi
CIRI – INSERM U1111
Thesis directors: M.VOCANSON - J.-F. NICOLAS
LYON - France
-
2
Disclosure
Type Company
Employment full time DBV Technologies
Research Grant (P.I., collaborator or consultant; pending and received grants)
DBV Technologies
Ownership interest (stock, stock-options, patent or intellectual property
DBV Technologies
In relation to this presentation, I declare the following, real or perceived conflicts of interest:
A conflict of interest is any situation in which a speaker or immediate family members have interests, and those may cause a conflict with the current presentation.Conflicts of interest do not preclude the delivery of the talk, but should be explicitly declared. These may include financial interests (eg. owning stocks of a related company, having received honoraria, consultancy fees), research interests (research support by grants or otherwise), organisational interests and gifts.
-
Skin or gut
3
Introduction: Pathophysiology of food allergy
Lymphnode
Sensitization phase Elicitation phase
Plasma cell
B cell
Th2 CD4+
IgE
DC maturation and migration
Anaphylaxis
Peripheral tissues
Mast cell
basophil
allergen
Inflammatory mediators(histamine, PAF, MCPT-7)
• IgE-dependent disease
• Th2 environment
• There is a need for efficacious and safedesensitization protocols
LC
cDC1 cDC2
-
4
Introduction: Mechanisms of epicutaneous immunotherapy (EPIT)
Clinical Aim: - To re-introduce tolerance to an allergen
Immunological Aim: - Induce tolerogenic skin DCs
Method: - Daily application of low dose allergen
Mechanisms: - Treg activation
- Immune deviation (Th2 vs Th1; IgE vs IgG)Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
- 1 patch per day- 1 to 3 years
-
5
Introduction: Mechanisms of epicutaneous immunotherapy (EPIT)
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
LCs
cDC1
XCR1+ CD103+/-langerin+IRF8+
cDC2
SIRPα+ CD11b+/-F4/80+IRF4+
Langerin+EpCAM+CD11b+SIRPα+
= CD141+
= LC
= CD1c+
Guilliams M, Ginhoux F. et al., Nat. Rev. Immunol., 2014
-
6
Thesis project : Objective
➢Aim of the study :➢Characterize the contribution of skin
DC subsets to the desensitizationprocess
➢ Perspectives :➢ Improve EPIT efficacy by targeting DC
subsets
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
-
7
Mouse model used in the study
Mice = C57BL/6JAllergen = Ovalbumin
2 s.c. OVA/Alum + i.n. OVA(21 days)
Epicutaneous immunotherapy (EPIT) :OVA-patch 48h per week
during 8 weeks
Sensitizedmice
Naïve mice
➢ Skin DC subsets:
❑ Uptake of the allergen❑ Migration to dLN❑ Activation status❑ Ability to activate Teff/Treg❑ Contribution to the efficacy of
desensitization
1 3 8 patches
To follow OVA+DC : last patch contains OVA-fluorochrome
Epidermis
Dermis
Allergen
(OVA-A488)
LangerinDioszeghy V. et al, JI, 2011
-
8
Result Ia: All DC subsets uptake the allergen in the skin
Skin collected 48h after the 1st, 3rd, 8th patchs
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
Analysis by Flow cytometry
*p
-
9
Result Ib: Activation status of DC is constant in the skin
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
Analysis by Flow cytometry
11 0 0 2
11 0 0 3
MF
I C
D8
6 o
n O
VA
+L
C,
cD
C2
or
cD
C1
pe
r
8m
m s
kin
1 patch
3 patchs
8 patchs
LC cDC2 cDC1
Data are representative of two experiments.
Skin collected 48h after the 1st, 3rd, 8th patchs
-
10
Result IIa: All DC subsets migrate constantly towards dLN
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
Analysis by Flow cytometry
11 0 0 1
11 0 0 2
11 0 0 3
11 0 0 4
#O
VA
+L
C,
cD
C2
or
cD
C1
pe
r b
LN
1 patch
3 patchs
8 patchs
LC cDC2 cDC1
Data are representative of two experiments.
dLN collected 48h after the 1st, 3rd, 8th patchs
-
11
Result IIb: Activation status of migratory DC is modulated with EPIT
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
dLN collected 48h after the 1st, 3rd, 8th patchs
Analysis by Flow cytometry
0
11 0 0 4
21 0 0 4
31 0 0 4
MF
I C
D8
6 o
n
OV
A+
LC
,
cD
C2
or
cD
C1
pe
r b
LN
* ,$* $
1 patch
3 patchs
8 patchs
LC cDC2 cDC1
Data are representative of two experiments.
-
Result IIIa: LC activated less Teff in vitro after EPIT treatment
12
ProliferationFoxP3- CD44+ OT-II T cells
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
dLN collected 48h after the 1st, 3rd, 8th patchs
4-days coculture with
OT-II CD4+ cells
OVA+DC sort
*p
-
Result IIIb: LC activated more Treg in vitro after EPIT treatment
13
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
Th2 CD4+ Plasma cell
Mast cellbasophil
TGF-b
ProliferationFoxP3+ OT-II T cells
*p
-
14
Take-home messages
EPIT profoundly modulates the activation status ofmigratory dendritic cell subsets.
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
-
15
Take-home messages
EPIT profoundly modulates the activation status ofmigratory dendritic cell subsets.
EPIT-induced Langerhans cells prime more TREG andless TEFF .
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
-
16
Take-home messages
EPIT profoundly modulates the activation status ofmigratory dendritic cell subsets.
EPIT-induced Langerhans cells prime more TREG andless TEFF .
Langerhans cells, but not cDC1, are required for theefficacy of desensitization by EPIT. (data not shown)
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
-
17
Perspectives
EPIT profoundly modulates the activation status ofmigratory dendritic cell subsets.
EPIT-induced Langerhans cells prime more TREG andless TEFF .
Langerhans cells, but not cDC1, are required for theefficacy of desensitization by EPIT. (data not shown)
What is the role of cDC2 in desensitization in vivo?
What are the key receptors or molecular pathwaysinvolved in tolerogenic properties of LCs ?
Lymphnode
FoxP3+ Treg
epidermis
dermis
LC
cDC1cDC2
Allergen-containing Patch
DESENSITIZATION
Th2 CD4+Plasma
cell
Mast cell
basophil
TGF-b
?
-
Centre
International
de Recherche
en Infectiologie
Thank you for
your attention