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


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


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


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



Mast cellbasophil

TGF-b


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



Mast cellbasophil

TGF-b


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


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



Mast cellbasophil

TGF-b



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


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



Mast cellbasophil

TGF-b


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



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


DESENSITIZATION

Th2 CD4+Plasma

cell

Mast cell

basophil

TGF-b

15

Take-home messages


EPIT-induced Langerhans cells prime more TREG andless TEFF .

Lymphnode

FoxP3+ Treg

epidermis

dermis

LC

cDC1cDC2


DESENSITIZATION

Th2 CD4+Plasma

cell

Mast cell

basophil

TGF-b

16

Take-home messages



Langerhans cells, but not cDC1, are required for theefficacy of desensitization by EPIT. (data not shown)

Lymphnode

FoxP3+ Treg

epidermis

dermis

LC

cDC1cDC2


DESENSITIZATION

Th2 CD4+Plasma

cell

Mast cell

basophil

TGF-b

17

Perspectives



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


DESENSITIZATION

Th2 CD4+Plasma

cell

Mast cell

basophil

TGF-b

?

Centre

International

de Recherche

en Infectiologie

Thank you for

your attention

contribution of skin dendritic cells to epicutaneous immunotherapy (epit) in food … · 2020. 6....

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