Post on 29-Jan-2018
IMMUNOLOGY OF THE MATERNAL – FETAL INTERFACE
Asha Ann Philip
MVSc Scholar
Division of Pathology (VPL)
IVRI,Izatnagar, UP-243122
OVERVIEW
INTRODUCTION
HISTORICAL PERSPECTIVE AND SIGNIFICANCE
PREGNANCY –MOUSE Vs HUMAN
MATERNAL FETAL INTERFACE
IMMUNE CELLS (d NK cells, Macrophages, DC, T
cells )
ANTIGEN SPECIFICITY AND TRAFFICKING
INFECTIOUS DISEASE CONTROL
PERSPECTIVE VIEW
CONCLUSION
pregnancy complications
preeclampsia
congenital infections
IUGR
abortion,
Interface :-
Composition and functions vary locally- Uterine decidua
(NK cells, Dendritic cells, Macrophages, T cells)
Immune cells play a role in pregnancy /failure
Mouse and human studies
Pathogenesis of pregnancy complications
INTRODUCTIONd NK cells,
Dendritic cells
Macrophages,
T cells
? Paternal histocompatibility by fetus should provoke tissue rejection response (Medawar ,1953)
? Unusual kind of decidual NK ( d NK ) cells perform key developmental role in human and mice .
? Immunological lesions underlying pregnancy complication.
Uterine vasculature remodeling in gestation
Preeclampsia (5-7%)
(Impaired activation of d NK cells)
Reproductive
success in placental
(eutherian)
mammals
Placenta Uterus
HISTORICAL PERSPECTIVE AND SIGNIFICANCE
PREGNANCY –MOUSE VS HUMAN
•20 days
•Placental trophoblast do not
invade deep in decidual
arteriole.
•Preeclampsia and IUGR rare
•Decidualisation only at
implantation
• 9 months
• Trophoblast temporarily replace
maternal endothelial cells
• Common
• Decidualisation at
Secretory phase and implantation
•Haemochorial placentation
•Decidual accumilation of NK cells (Moffett,2006) and (Maltepe et al,
2010)
MATERNAL FETAL INTERFACE
Flow cytometry and
Immuno staining
(Bulmer et al, 2010)
NK Cells- 70%
Macrophages- 20%
T cells - 10-20%
DC & B cells- rare
Cellular constituents in first trimester of human decidua
MATERNAL IMMUNE CELLS
d NK cells,
Dendritic cells
Macrophages,
T cells
Placental Development and
function
Minimise chance of placenta
being attacked.
To combat infection
Trophoblast
(PLACENTA)Uterine MucosaDecidualization
NATURAL KILLER CELLS (D NK CELLS)
1.Transforming spiral arteriole in decidua
Replacing endothelium by trophoblast
Incomplete spiral transformation and failure of trophoblast
Preeclampsia & IUGR (Khong et al, 1986)
Role of IFN γ in Remodelling of spiral arteriole (Apps et al, 2011)
Preeclampsia: KIR lack Tel-B for HLA-C.
Inhibitory signal to d NK Cell RSA & IUGR (Hiby et al, 2010)
No mice shows gestational hypertension
Trophoblast endovascular migration
FUNCTIONS
Second phase
First phase
d NK cell
Hypoxia
2. Role in I/U inflammation & Abortion
d NK cell Cytotoxic granules (perforin and granzyme) (Manaster, 2010)
Why d NK cell do not threaten fetal survival?
d NK cell cytolytic action is low at base line
Non classical MHC I molecule interaction (HLA-E, HLA-G)
on trophoblast cell (App et al, 2008) ( Chazara et al, 2011)
D NK cell is embryotoxic at certain circumstances
IL-10 TNF- α , IL-6: Embryo resorption
Appear in secretory endometrium prior to implantation.( CD 56 bright,
CD16-) (Koopman et al, 2003)
Pregnancy specific functions :TGF-β, IL-15 (Keskin et al, 2007)
MACROPHAGES
2nd most abundant : 20% ( 50-100 cells/mm² in first trimester)
Marker : CD 14 , CD 209 (IL-10 level)
Remodelling: (fibronectin, collagen components, matrix metalloproteinase-9, C1q)
d macrophage in 3rd trimester: Preeclampsia
Role in parturition:Pro inflammatory mediators (IL-6, TNF- α )
PAMPs Acute chorio amnionitis preterm birth
Remodelling
Pathogen sensors
Immune effector cell
macrophage
CD 14
Monocytes
CSF
IL-10
d Macrophage
D stromal cells
dNK cell
glandular epithelial cells
F4/80+MHCII hi (CD 209-)
F4/80+ MHCII lo (CD 209 +)
Growing myometrium
CSF
dNK cell
DENDRITIC CELLS
Adaptive immune responses
D C are scarce at Interface (1-5 cells) (Tagliani,2011)
Decidualisation : fall of DC cells 9/mm²to 2/mm²
DC ENTRAPMENT Mouse endometrium lack lymphatic vessel (Collins et al, 2009)
Inflammation
pathogen
DENDRITIC CELLS
Lymphatic vessel
Lymph node
FUNCTIONS
Dendritic cell as decidua
Tissue remodelling
Uterine mucosa to
survey pathogen
T cell immunostimulation
T CELLS
10-20% of leucocytes in first trimester is CD3 TCR
10-20% T cell
CD4
(30-45 %)
50% Memory
5% Regul
CD8
(45-75%)
40% Memory
Th2
Th 17
Th1
•5%
•2 %
•Spontaneous Abortion
•5-30%
•RSA
Spontaneous Abortion
Preeclampsia
T Reg
Th 17
Activated T cell accumilate at
inflammatory site: chronic
deciduitis, chronic
chorioamnionitis and VUE.
ANTIGEN SPECIFICITY AND TRAFFICKING
How many T cells have fetal/ placental specificity?
Human: CD 25 ( activated/ memory) CD4+ T cell in pregnancy is elevated (10%) if mismatch in fetal-matetnal HLA-C allele (Tilburgs et al,
2009)
Differentiating decidual stromal cells silences expression of the key Th1/CTL-attracting chemokines (CXCL9 ,CXCL10 ,CXCL11 and CCL5)
Loss of chemokine silencing: Late pregnancy complications.
Naive maternal CD8+ T cells fail to
encounter Ag and differentiation into
Th1 cells and CTLs (Reinchart et al, 2003)
INFECTIOUS DISEASE CONTROL
Organisms infect placenta and amniotic membrane.
Preterm birth
IUGR
Still birth
Congenital Abnormalities
P.falciparumMaternal
bloodVillous
tree
Other organisms
Decidua Placenta
Decidua is GROUND
ZERO for avoiding
immunological assault
& infection
CYTOMEGALO VIRUS
Haemopoiticprogenitor
Mononuclear phagocytes
Stromalcells
(MICE)
RESERVOIRHumoral immunity is the only defense.
Placental infection -vely corelated by Maternal IgG Titres
( Mc Donagh eta l, 2004)
CMV DNA detected in 89% of first trimester
Elective termination : +ve for i/c Staining Decidual biopsy
Immunocompetant host: Controlled by Memory T cells
organ transplant patients HIV patients
Latent infection: 30-70% population (Gandhi & Khanna, 2004)
LISTERIA MONOCYTOGENES
EXTRAVILLOUS TROPHOBLAST anchoring villi
PLACENTA
Organism carried by extravasating Leucocytes
Immunoprivilaged environment (T cells):
Survival
Decidua not at mercy of pathogen
Controlled by T cells
MACROPHAGESNEUTROPHILS
TROPHOBLAST
ACUTE CHORIOAMNIONITIS
IL-8TLR
d stromal cell
Trophoblasts
Amniotic epithelial cells
Neutrophils
IL-17 (T Cell)
IL-22 ( lymphoid cell)
G-CSF
Ascending bacterial infection from cervix.
Cause Pre term birth
Neutrophils are recruited
Decidua
IL-15 NK CELL
CSF Macrophage
Chemokine silencing Th1/ CTL
Decidua resisted homing of Th1and CTLs
Artificial decidual reaction
Restrict immune cells (T cell, DC, B cell )
Specialisation of leucocytes (NK, macrophage)
dNK cell accumulation
T cell exclusion as true decidua
loss of macrophage and DCdensity
PERSPECTIVE VIEW
Trophoblast - d NK cell interaction is essential for success of pregnancy
Threat in reproductive success is due to pro inflammatory molecules of macrophages (IL-6, TNF- α )
Decidual macrophage exposure to CSF-1 is a major
mechanism for local monocyte recruitment & constant at gestation.
Paucity of DCs limit adaptive T cell responses & minimizing immunogenic responses to fetal/placental antigens
Impaired activation of Immune cells lead to pregnancy complications ( Preeclampsia, IUGR, Abortion)
Decidua is GROUND ZERO for avoiding immunological assault & during infection.
CONCLUSION
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Manaster I, Mandelboim O. 2010. The unique properties of uterine NK cells. Am. J. Reprod. Immunol.63:434–44
Medawar PB. 1953. Some immunological and endocrinologicalproblems raised by the evolution of viviparity in vertebrates. Symp. Soc. Exp. Biol. 7:320–38
Moffett A, Loke C. 2006. Immunology of placentation in eutherian mammals. Nat. Rev. Immunol. 6:584–94
Romero R, Espinoza J, Kusanovic JP, Gotsch F, Hassan S, et al. 2006. The preterm parturition syndrome.Br. J. Obstet. Gynaecol. 113(Suppl. 3):17–42
Stewart IJ, Mitchell BS. 1991. The distribution of uterine macrophages in virgin and early pregnantmice. J. Anat. 179:183–96
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REFERENCES