Immunological aspects of repro Flashcards
What is the definition of semi-allogeneic?
From the same species (allogeneic) but shares half of genetic material e.g a fetus.
Oestrogen is?
Pro-inflammatory and Th1 dominant
Progesterone is?
Anti-inflammatory and Th2 dominant
why women see remission of rheumatoid arthritis when pregnant
What are some of the negative effects of the anti-inflammatory dominance of progesterone during pregnancy?
Greater susceptibility to infections.
Why could an immune response be elicited by a fetus/foreign tissue graft?
Paternal antigens (e.g. MHC class I) are inherited and expressed on fetus and placenta within mother. MHC class I is just a foreign antigen in this case which could elicit an immune response.
What is the first barrier to a maternal immune response?
The trophoblast is first barrier to maternal immunity attack.
Why does the mother’s immune system not reject the
placenta & foetus?
Trophoblast is antigenetically unusual because in
general, it doesn’t express some of the main
paternal antigens that are easily recognised by
the maternal immune system.
— Examples are major histocomnatibilitv comnlex
antigens (MHC class I)
This makes the placenta resistant to recognition
and attack by maternal ¡mmune cells! (but there
are exceptions!)
The more invasive the degree of trophoblast invasion the …….?
Greater the immunological challenge.
How do species with decidua protect the fetus from the immunological challenge?
Natural killer cells (NK) found in deciduate species
account for 75% of decidual leucocytes
NK cells interact with placental antigens
— Normally results in the production of local factors
supportive of pregnancy
. E.g., immunosuppressive, placental growth.
How do species with endometrium protect the fetus from the immunological challenge?
Other specialised immune cells are present in the
uterus during pregnancy
— E.g., macrophages and specialisedTcells (sheep, horse)
Since placenta is less invasive, functions not as
clear but may involve:
— Immunosuppression (Intra-uterine factors identified)
- Growth enhancement
— Placental detachment at parturition
- Name three challenges to the uterus
which may provoke an immune response.
Sperm
Fetus
Trophooblasts
Commensal/pathogenic organisms
Define the fetal-placental allograft?
Maternal and paternal alleles mixed together.
Name two mechanisms which are thought
to be involved in survival of the feetal allograft
The trophoblast has a modified antigen expression and on maternal side population of immune cells interact with these antigens.
What is the chorionic girdle?
The chorionic girdle is band of fetal cells which migrate across tiny microdistance to attach to maternal epithelium and will invade maternal tissue to become binucleate and form cups that produce Ecg. They remain for 4 months from 35 days of gestation.
Does the equine trophoblast express MHC class I?
.
Yes at least on chorionic girdle
