Furthermore, in situ hybridization and immunohistochemistry of placental tissue showed that placental LEP in humans is expressed in
syncytiotrophoblast cells (facing maternal circulation) and villous vascular endothelial cells (facing fetal circulation) (Lea et al.
Antibody-dependent enhancement of HIV-1 infection in human term
syncytiotrophoblast cells cultured in vitro.
It is possible that
syncytiotrophoblast is a direct source of sFlt-1.
The trophoblast with maternal origin differentiates into cytotrophoblast and
syncytiotrophoblast. The embryoblast with fetal origin also differentiates into the hypoblast and the epiblast.
Strong homogeneous staining mainly in the cytoplasm is detected in the
syncytiotrophoblast cells on the outermost layer of the placental villi, with some scattered expression in cytotrophoblast cells (Figure 2(a)).
The critical cell type in this context is the villous cytotrophoblast (VCT) which constantly forms new
syncytiotrophoblast (SCT) throughout pregnancy.
Placental villosities, composed of the cytotrophoblast and covered by
syncytiotrophoblast, are immersed in the circulating maternal blood that comes into contact with its constituent immune cells.
Bick, "The PLAC1 protein localizes to membranous compartments in the apical region of the
syncytiotrophoblast," Molecular Reproduction andDevelopment,vol.
recently showed that human
syncytiotrophoblast tissue is refractory to chikungunya infection (23).