Biology Reference
In-Depth Information
MOTHER
(Decidua)
FETUS
(Placenta)
DC
NK
PMN
NK
CC
Uterine BV
CTB
VC
BV
M
/DC
φ
M
φ
/DC
DC
Decidual
cells
Endometrial
gland
NK
ST
AV
NK
Invasion
FV
Fig. 1
Diagram of the placental (fetal)-decidual (maternal) interface near the end of the first tri-
mester of human pregnancy (10 weeks of gestational age). A longitudinal section includes floating
and anchoring chorionic villi. The floating villus (
FV
) is bathed by maternal blood. The anchoring
villus (
AV
) functions as a bridge between the fetal and maternal compartments. Cytotrophoblasts in
AV form cell columns that attach to the uterine wall. They invade the decidua and uterine vascu-
lature, anchoring the placenta and gaining access to the maternal circulation. Colors illustrate
different cell types: syncytiotrophoblasts (
ST
) (
beige
), cytotrophoblast (
CTB
) progenitors and inva-
sive cells (
light green
), decidual cells (
green
), endothelial cells (
yellow
), smooth muscle cells
(
brown
), glandular epithelial cells (
gray
), macrophage/dendritic cells (
Mf/DC
) (
light purple/pink
),
polymorphonuclear neutrophils (
PMN
) (
red
), and natural killer cells (
NK
) (
fuchsia
)
and proteinases that enable invasiveness - and immune-modulating factors for
maternal tolerance of the hemiallogeneic fetus (Cross et al. 1994; Damsky and
Fisher 1998; Norwitz et al. 2001). Villous cytotrophoblasts express certain integrin
subunits (Zhou et al. 1997), and interstitial invasive cells upregulate integrin α1β1
expression (Damsky et al. 1994). Endovascular cytotrophoblasts express αVβ3 and
vasculogenic factors and receptors that mimic the surface of vascular cells (Zhou
et al. 1997; Damsky and Fisher 1998). Invasive cytotrophoblasts also upregulate
matrix metalloproteinase 9 (MMP-9), which degrades the extracellular matrix of
the uterine stroma (Librach et al. 1991), and interleukin 10 (IL-10) for immune
tolerance and modulation of metalloproteinases and invasiveness (Roth et al. 1996;
Roth and Fisher 1999).
CMV is especially adapted to replicate in the immune tolerant microenvironment
at the maternal-fetal interface (Pereira et al. 2005). Examination of intrauterine CMV
infection in early gestation revealed patterns of virus replication in the decidua,
mirrored in the placenta, and dependent in part on maternal immune responses
(Fisher et al. 2000; Pereira et al. 2003; Maidji et al. 2006). With low neutralizing
antibody titers, areas of infection are found in the decidua and adjacent placenta.
With moderate neutralizing titers, cytotrophoblast infection is reduced in the
decidua, and occasional focal infection is found in floating villi. With high neutral-
izing titers, few cytotrophoblasts contain viral replication proteins in the decidua,
