Flashcards in Reproductive immunology Deck (20):
what part of the placenta NEVER expresses MHC class II antigens?
outer layer ( trophoblast)
what layer doesnt express MHC class I?
inner trophoblasts ( the part that is in contact with maternal blood)
what is expressed on the villous trophoblasts that stops NK cells from destroying them ( since they are MHC I negative)?
this induces activated T cells to under apoptosis
where is HLA-G expressed?
only in immune priveledged sites ( liek the thymus)
what are the functions of HLA-G?
apoptosis of NK cells
induces T-reg cells ( CD4)
apoptosis of CD8 cells ( Fas-FasL path)
immuno suppreses macrophages
suppreses B cells
induces tolerance of the dendritic cells
what is the general job of Indoleamine 2,3-dioxygenase ( IDO)?
causes a tryptophan deficiency--> leading to suppressing lymphocyte responses
this also causes a buildup of kineurins which help in immune homestasis
what does the placenta secrete?
immunosuppressors- IL-10, TGF-Beta, prostaglandin E2
what induces the secretion of Regeneration and tolerance factor (RTF) and progesterone induced blocking factor (PIBF)?
high doses of progesterone
what is the function of RTF?
get cleaved and up regulate the production of IL-10 and down regulate the production of IL-2
SHIFTING TOWARD A TH2 RESPONSE
what is the function of PIBF?
inhibits the release of perforin and degranulation of NK cells, INDUCTION OF TH2 RESPONSE, stimulates IL-3, 4, 10
what is the function of RU 486 (mifipristone)?
blocks PIBF, casues a massive shift to TH1, leading to abortion
what does the placenta use to prevent the activation of complement?
membrane cofactor protein (MCP)
Decay acelerating factor (DAF)
what does MCP and DAF do?
MCP- inactivates C3b and C4b
DAF- prevents the assembly of C3bBb complex
what is the function of the Fas and Fas ligand complex?
this is for the induction of apoptosis of CD8 T cells, when they attach to the FasL on the trophoblasts, the CD8 cells attach the Fas, and induces the apoptosis of the T cell
what are teh steps in fertilization of an egg?
1. binding of the sperm to the surface of the zona pellucida
2. acrosome reaction
3. binding of acrosome reacted sperm to the vitelline membrane of the oocyte
whaich sex can have anti sperm antibodies?
what are the types of antisperm antibodies?
IgA and IgG,
what type of IgG is the biggest problem?
IgG3, this leads to sperm damage
what is the role of anti-idiotypic antibodies?
they bind to the anti sperm antibodies, thus making a woman with antisperm antibodies able to have children