Natural killer cells and reproductive health 2016

Question 1

peripheral natural kill cells have which cell surface protein?

Answer 1

CD56 dim/CD16+ (few CD56 molecules with low intensity on staining / plentiful CD16 molecules)

Question 2

What is the key function of peripheral natural killer cells

Answer 2

Primary function of pNK is recognition of foreign antigens

CD16 is responsible for cell lysis

Question 3

What are the cell surface protein on uterine natural killer cells

Answer 3

uNK cells are CD56 bright (high intensity bright on staining)but lack CD16

express killer cell immunoglobulin-like receptors (KIRS)

Question 4

Role of uterine natural killer cells?

Answer 4

uNK play important role in decidualisation, implantation and embryo recognition

Binding of HLA-G by the KIR2DL4 receptor triggers inflammatory and angiogenic cytokines

Question 5

uNK cells are predominant in which part of menstrual cycle?

Answer 5

predominant leucocyte in late secretory phase of the menstrual cycle

Account for 30% of endometrial stroma during this time, found in spinal arteries.

Question 6

Role of uNK cells in pregnancy?

Answer 6

As the syncytiotrophoblast invades the endometrial stroma during implantation IFNG (via NO) promotes vasodilatation and inhibits smooth muscle proliferation

Control of synctiotrophoblast invasion is thought to occur due to interactions of the uNK cells. HLA-G binds to KIR2DL4 on uNK cells which blocks lytic activity whilst promoting angiogenesis. HLA-E binding to CD94/NKG receptors is also thought to inhibit synctiotrophoblast invasion