reproductive + neuroendocrine immunology Flashcards
Which mechanisms operate to enable the conceptus to survive within a woman with a competent immune system
1) The placenta is a physical barrier through which lymphocytes cannot normally pass
2) There is immunosuppression at the conceptus-uterine interface
3) trophoblasts do not express classical MHC Class 1 Ag
what happens in the cervix after coitus?
A cervical leukocytosis consisting of neutrophils and macrophages is generated soon after coitus.
The prime function of the inflammatory response is to remove excess sperm and any microorganisms although there is experimental evidence from work in mice that cytokines secreted from the leukocytes may have other physiological functions, particularly within the uterus, to assist the development of embryo and establishment of pregnancy
Name two mechanisms that believed to operate to prevent immunological recognition of sperm within the epididymis.
1) epithelial cells form tight junctions which prevents sperm Ag leakage into the surrounding tissues and circulation (would generate immune response)
2) in epididymis there are substantial numbers of intraepithelial lymphocytes (suppressor lymphocytes) that suppress any possible immune recognition of sperm antigen
in a woman suspected to be infertile due to the presence of anti-sperm antibodies, what part of the reproductive tract could be sampled to detect the present of anti-sperm antibodies
cervical mucous
what are some brain-endocrine-immune system interactions?
1) immune cells in resting/ activated states express cell surface receptors for hormones + neuropeptides
2) nervous and endocrine cells express cytokine and chemokine + GF receptors
(HPA axis activated in inflammation/ infection mediated by IL1, IL6 and TNF alpha)
3) physical and psychological stress results in organs to release mediators and cross talk (controls cytokine prod, immune activation, cytotoxicity, haematopoiesis etc.)
which hormones are immunosuppressive vs immunostimulatory? and what happens when you’re exposed to stress?
immunosuppressive
- NE + CORTISOL
- glucocorticoids
(depress immune cell function i.e. cortisol decreases inflammation, depressed immune system and slows healing)
when exposed to stress
there is a higher incidence of disease + poorer Ag response
immunostimulatory
- PROLACTIN + GROWTH HORMONE
how is the CNS protected and what happens when these protective measures fail?
- protected from cell + mediator infiltration by BBB
- when breached results in infection, neuroinflammation/ immune mediated neurological disease
- immune responses against CNS Ag trigger diseases (eg. MS)
what are the effects of the ovarian hormones on inflammation?
- oestrogen
- increase the capacity to eliminate microorganisms. This is correlated with a rapid influx of neutrophils - progesterone
- inhibits the capacity of phagocytes to eliminate microorganisms
how + when do endometrial leucocyte populations differ?
- how: NK cells in endometrium peaks in secretory phase
- when: vary with menstrual phase
how many NK cells in circulating leucocytes vs leucocytes in endometrium?
- NK cells make up 10% of circulating leucocytes
- NK cells make up 70% of leucocytes in endometrium
explain how sperm is highly immunogenic but exerts inhibitory effects on NK cells, lymphocytes and complement function
- seminal fluid contains spermicide, TGF beta, PGs which inhibits NK cells, lymphocytes and complement function
which anti sperm Ab are present in infertile women and where can they be found?
- IgA and IgG
- found in cervical mucous
how do anti sperm Ab affect sperm?
- Antibodies bind to sperm and influence:
1) motility,
2) complement-mediated lysis,
3) opsonisation,
4) ADCC,
+ block sperm-ovum fusion.
how does sperm avoid immune system in males?
- blood testis barrier which creates immune privileged site
- as sperm is only prod at onset of puberty ->would be seen as foreign, but blood testis barrier prevents immune response
which Ag do sperm express?
- sperm specific Ag
