BPH/5 Pre-eclamptic Mice Have Increased Uterine IL-15 & This Is

Associated with Decidual Natural Killer (dNK) Cell Loss At The Maternal-Fetal

Interface Early In Pregnancy

Jenny L. Sones, Heinrich E. Lob, Catherine E. Isroff, Jiunn Song, Emilie Williamson, Robin L. Davisson

Cornell UniversityCollege of Veterinary Medicine

Ithaca, NY

No disclosures

Preeclampsia (PE)

• Sudden onset of maternal hypertension & proteinuria (>20wks in gestation)

• Affects 2-6% of pregnancies in the US*

– Up to 18% in developing countries*

– Contributes to 42% maternal deaths/year†

• Maternal syndrome resolves upon delivery of fetus and placenta

*Lim et al. 2011; †Hund et al. 2014

BPH/5 mice spontaneously exhibit the cardinal signs of preeclampsia

Hypertension Proteinuria

Davisson et al. Hypertension 2002

75

100

125

150

175

MA

P(m

mH

g)

0 4 8 12 16 20 24 28

***

*

**

** **

* * **

**

##

##

# #

BPH/5

C57

Days of Gestation & Postpartum

#*

Non-pregnant

Mid-Gestation

LateGestation

Tota

l Urin

ary

Pro

tein

(m

g/g

Bod

y W

eigh

t/24h

)

30

15

0

C57BPH/5

BPH/5 mice develop in utero fetal demise & fetal growth restriction

Reduced litter size Lower birth weight pups

Davisson et al. Hypertension 2002

Litte

r Siz

e(n

o. li

ve p

ups

born

/litte

r)

6

0

12

BPH/5 C57

*

Pup

Wei

ght (

g)

2

0

4

BPH/5 C57

*

BPH/5 placental defects mimic those of patients with preeclampsia

Inadequate spiral artery remodeling

Dokras et al. Biol Reprod. 2006

C57 BPH/5

Shallow trophoblast invasion

C57 BPH/5

Reduced uteroplacental perfusion & placental hypoxia

The placenta is implicated as the cause of preeclampsia

• Preeclampsia is described as a two-stage disorder– Stage 1

• Abnormal implantation & vascular remodeling reduced uteroplacental & fetoplacental perfusion

– Stage 2• Maternal syndrome: hypertension & proteinuria• Preterm and/or growth restricted baby

Adapted from Cross Clin Genet 2003

Pregnancy success requires synchronous maternal-fetal interactions

0.5 3.5 5.5 7.5 10.5 20.5

Fertilization Placenta formed

Delivery

DecidualizationImplantation

Increased inflammation at the maternal-fetal interface in BPH/5

0

0.2

0.4

0.6

Rel

ativ

e m

RN

A

Ptgs2 expression

C57 BPH/5

*

0

1

2

3

Rel

ativ

e m

RN

A

Ptgs2 expression

C57 BPH/5

*

e5.5e7.5

actinCox2

C57 BPH/5

0

0.5

1

Rel

ativ

e pr

otei

n

Cox2 expression*

C57 BPH/5

Ptgs

2

C57 BPH/5 C57 BPH/5

Ptgs

2

0

5

10

15

20

25

30

IL-6 IL-15 IL-17 TGFβ TNFα

Rel

ativ

e m

RN

A

e5.5 implantation sites

C57BPH/5

IL-15 is increased early in BPH/5 implantation sites at e5.5

Pre-dNKs

Mature dNKs

VEGFPlGF IFN-γ

IL-15

apoptosis

Angiogenic factors necessary for establishing

placental perfusion

IL-15 plays a crucial role in decidual NK cell activation & maturation

*

BPH/5 implantation sites have significant increases in IL-15 at

implantation & peak decidualization

C57 BPH/5 C57 BPH/5C57 BPH/5

IL-15actin

e4.5 e5.5 e7.5

0

0.01

0.02

0.03

0.04

0.05

e4.5 e5.5 e7.5

Rel

ativ

e m

RN

A

IL-15 expression

C57BPH/5

*

*

*

0.5 3.5 5.5 7.5 10.5 20.5

Fertilization Placenta formed

Delivery

DecidualizationImplantationDay of pregnancy

BPH/5 implantation sites show dramatic decreases in mature decidual

NK cells early in pregnancy

C57

BPH/5

e5.5 implantation sites e5.5 developing deciduaDBA= Dolichos biflorus agglutinin

02,0004,0006,0008,000

10,00012,00014,000

CD

122+

/DB

A+

cells

Impl

anta

tion

site

C57 BPH/5

*

0

0.02

0.04

0.06

0.08

0.1

e4.5 e5.5 e7.5

Rel

ativ

e m

RN

A

NKp46 expression

C57BPH/5

Day of pregnancy

**

†

IFN-γ is reduced in BPH/5 implantation sites at the time of maximal NKp46

expression

Pre-dNKs

Mature dNKs

VEGFPlGF IFN-γ

IL-15

apoptosis

0

1

2

3

4

e5.5 e7.5

Rel

ativ

e m

RN

A

IFN-γ expression

C57BPH/5

Day of pregnancy

*

†

n.s.

IL-15 in utero decreases dNK cell mRNA & numbers in C57 e5.5

implantation sites

0

2000

4000

6000

8000

10000

12000

CD

122+

/DB

A+

cells

impl

anta

tion

site

veh rIL-15/IL-15Rα

0

2

4

6

8

10

Impl

anta

tion

site

s/lit

ter

veh rIL-15/IL-15Rα

*

0

0.5

1

1.5

Rel

ativ

e m

RN

A

NKp46 expression

veh rIL-15/IL-15Rα

*

0.5 3.5 5.5 7.5 10.5 20.5

rIL-15/IL-15Rα

Placenta formed

DecidualizationImplantation

dNKcells?

n.s.

Adapted from Croy et al. 2002

dNK cell division & maturation

Ovarian hormones

Decidual induction Mobilize splenic pre-dNK cells

Activated dNK cell

IL-15

Decidual maintenance & spiral artery modification

IFN-γ

IFN-γ = dNK cell apoptosis

VEGF, PlGF

Cox2

?

Summary

• BPH/5 have inflammation at the maternal-fetal interface in early pregnancy– Increased Ptgs2/Cox2 & IL-15

• BPH/5 implantation sites have a dramatic reduction in mature dNK cells– Associated with lower IFN-γ at peak

decidualization• Recombinant IL-15 given in utero to C57

pregnant mice at e2.5 mimics BPH/5 dNKcell loss at e5.5

Future directions

• Determine the source of the dNK cell loss• Does blunting IL-15 in BPH/5 prevent dNK

cell loss?• Assess pregnancy outcomes after

restoration of dNK cell populations at the maternal-fetal interface

Acknowledgements Davisson LabRobin Davisson, mentorScott ButlerHeinrich LobColin YoungChrista Heyward

Catherine IsroffCasey PhlegarJulie HorwathStephanie Shapiro

Past membersAshley WoodsYi Zhou

Collaborators

Jeeyeon Cha S.K. Dey