Lecture 30 - Pregnancy

Question 1

What does the placenta do

Answer 1

it forms a relatively efficient barrier preventing the access of activated T cells to the fetus and preventing fetal cells from entering the maternal circulation
- oxygen and nutrient exchange
- removal of wastes
- barrier against maternal immune response and infections

Question 2

What is the syncytiotrophoblast

Answer 2

a single cell layer separating the fetal blood and maternal blood

Question 3

What is the ST barrier effective against

Answer 3

Toxoplasmosis
Other - syphilis, varicella, parvovirus, zika
Rubella
Cytomegalovirus
Herpes infections

Question 4

What is microchimerism

Answer 4

• bi-directional trafficking of fetal and maternal cells
• low levels
• cells are detected decades after delivery and likely persist for a lifetime
• highly conserved across species

Question 5

What are the positive maternal effects of microchimerism

Answer 5

• existing Tregs may enhance fetal protection in the next pregnancy
• pluripotent fetal microchimeric cells may differentiate into and replace diseased cells in maternal tissues

Question 6

What are positive offspring effects of microchimerism

Answer 6

• protection against fetal wastage in next generation pregnancies under conditions that interrupt fetal tolerance mechanisms
• may contribute to maturity of immune response in fetus/newborn
• increased Tegs may dampen inflammation from microbial colonization, training the neonatal immune response
• reduced rejection of transplants

Question 7

What is the placental villous trophoblast

Answer 7

it does not express classical MHC Class I or Class II which means no killing by maternal T cells

Question 8

What does the ST do

Answer 8

expresses FAS ligand which can kill a maternal immune cell attacking the placenta

Question 9

What does IDO do

Answer 9

depletes tryptophan and inhibits T cell proliferation

Question 10

What is protection of the immunologically foreign fetus

Answer 10

• physiology of the immune privileged placenta
• transient reduction of systemic type 1 immunity
• system-wide transient tolerance to paternal antigens
• local environment of the uterus

Question 11

What are immune-based pregnancy complications

Answer 11

• preeclampsia
• autoimmune diseases
• viral infections in pregnancy