BGDA Practical Placenta - Implantation and Early Placentation: Difference between revisions
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===Decidual Macrophages=== | |||
:''Specialised immune cells.'' | |||
* regulatory role at the fetal-maternal interface. | * regulatory role at the fetal-maternal interface. | ||
* M2 phenotype involved in tissue remodeling and inhibit inflammation | * M2 phenotype involved in tissue remodeling and inhibit inflammation |
Revision as of 10:23, 12 June 2013
Practical 14: Implantation and Early Placentation | Villi Development | Maternal Decidua | Cord Development | Placental Functions | Diagnostic Techniques | Abnormalities |
Early Placenta
Human Embryo Day 8 to 9 | Human Embryo - early implantation (stage 5) |
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Practical 14: Implantation and Early Placentation | Villi Development | Maternal Decidua | Cord Development | Placental Functions | Diagnostic Techniques | Abnormalities |
Additional Information
Additional Information - Content shown under this heading is not part of the material covered in this class. It is provided for those students who would like to know about some concepts or current research in topics related to the current class page. |
Maternal Immune
How does the implanting conceptus avoid immune rejection by the maternal immune system? There are a number of maternal and embryonic mechanisms that are thought to act to prevent immune rejection of the implanting conceptus, though the complete mechanism(s) are unknown. This is particularly relevant to Assisted Reproductive Technologies involving donor eggs.
Below are some examples of research on this topic.
Decidual Macrophages
- Specialised immune cells.
- regulatory role at the fetal-maternal interface.
- M2 phenotype involved in tissue remodeling and inhibit inflammation
Chemokine Gene Silencing
- Remove the attraction of maternal immune cells.
A mouse study[1] has shown that the normal immune response to inflammation, accumulation of effector T cells in response to chemokine secretion does not occur during implantation. This is prevented locally by epigenetic silencing of chemokine expression in the decidual stromal cells.
Corticotropin-Releasing Hormone
- Kill the maternal immune cells.
Both maternal and implanting conceptus release CRH at the embryo implantation site. This hormone then binds to receptors on the surface of trophoblast (extravillous trophoblast) cells leading to expression of a protein (Fas ligand, FasL) that activates the extrinsic cell death pathway on any local maternal immune cells ( T and B lymphocytes, natural killer cells, monocytes and macrophages).[2] (Note - This cannot be the only mechanism, as mice with dysfunctional FasL proteins are still fertile).