Immunology Flashcards
whatasinvolved in the innate immune response
anti microbial proteins, complement, mast cells, macrophages, inflammation
whatasinvolved in the innate immune response
anti microbial proteins, complement, mast cells, macrophages, inflammation
what are the physical barriers to protect the eye
tears (flushing, anti adhesive mucosal layer), blink reflex, eyelashes
what are the chemical protective properties of tears
lysozome, antibacterial lipis, secretory IgA, complement, IL-6,8 and MIP
what immune cells are in the eye
neutrophils (attracted by chemotaxis)
macrophages (phagotcytosis of damaged cells)
conjunctival mast cells (vasoactive mediators)
where do you get langerhan cells
specific to skin and eyes (corneo-scleral limbus)
what is the role of langerhans
principle antigen presenting cell in the external eye
what are the physical barriers to protect the eye
tears (flushing, anti adhesive mucosal layer), blink reflex, eyelashes
what are the chemical protective properties of tears
lysozome, antibacterial lipis, secretory IgA, complement, IL-6,8 and MIP
what immune cells are in the eye
neutrophils (attracted by chemotaxis)
macrophages (phagotcytosis of damaged cells)
conjunctival mast cells (vasoactive mediators)
where do you get langerhan cells
specific to skin and eyes (corneo-scleral limbus)
what is the role of langerhans
principle antigen presenting cell in the external eye
what is the only part of the eye with lymphatic drainage
conjunctiva
describe the lymphoid system of the conjunctiva
(lymphoid is a tissues that produces lymphocytes)
has specialised endothelial venules for regulated migration of lymphoid cells
diffuse lymphoid populations (CD4+ & CD8+, T cells, IgA secreting plasma cells
mucosa associated lymph tissue (MALT)
what cells work as antigen presenting cells in the conjunctiva
denditic cells
where are langerhans in the eye
peripheral cornea
what is the immune environment of the cornea and sclera
not much- avascular, no lymph, only langerhans
what is the immune system of the lacrimal gland and drainage system
gland has more plasma IgA and CD8+ cells than conjunctive
has T cells in small groups
in drainage system there is diffuse lymphoid tissue and follicles in MALT
how does anterior chamber associated immune deviation work
T and B cells that produce non complement fixing antibodies
inhibiting of B and T cells that produce complement fixing antibodies
decreased expression of MHC 1 molecules, dont express MGV 2
cornea lack blood vessels and lymph
the eye is an immune privilege site- what does this mean
able to tolerate the introduction of antigens without eliciting an inflammatory immune response
what are the other immune privilege sites
brain/CNS, testes, placenta/ foetus, eyes
where in the eye is immune privileged
cornea, anterior chamber, lens, vitreous cavity, subretinal space
how does the eye have immune privilege
has blood tissue barrier
has no lymphatic drainage
have molecules that inhibit the response of immune cells
anterior chamber has immune deviation (systemic form of tolerance of to a foreign antigen)
what is the purpose of anterior chamber associated immune deviation
protects eyes and visual axis from the collateral damage of an immune response by suppressing future response to infection
how does anterior chamber associated immune deviation work
T and B cells that produce non complement fixing antibodies
inhibiting of B and T cells that produce complement fixing antibodies
what is sympathetic opthalmia
Rare, bilateral, granulomatous uveitis due to trauma (more common) or surgery (less common- usually after multiple procedures) to one eye
thought to be caused by autoiimune immune reaction to ocular antigens exposed during the trauma/ surgery
downside of immune privilege
what cells mediate sympathetic ophthalmia
T cells
what are the types of hypersensitivity reactions
1- immediate
2- direct cell killing
3- immune complex mediated
4- delayed
what type of sensitivity are allergies- mediated by what cell
type 1- mast cells.
describe type 1 hypersensitivity reactions
B cells after meeting antigen release antigen specific IgE antibodies
allergen is cleared
if re-encountered allergen binds to IgE coated mast cells and there is immediate release of vasoactive mediators (histamine)
what is chemosis
oedema of the conjunctiva
what mediates type 2 hypersensitivity reactions
anti body mediated cytotoxicity
- macrohpages/ NK cells
- complement (membrane attack complex)
what is ocular cictricial pemphigoid
autoimmune conjunctivitis (type II reaction)- causes blistering and scarring of the conjunctiva
how do you treat ocular cicatricial pemphigoid
steroids
what type of hypersensitivity is autoimmune corneal melting
type 3 (immune complex mediated)
how is autoimmune corneal melting treated
sterorids
what cells mediate type 4 (delayed) hypersensitivity
T helper cells activated by pathgens
colonal expansion
re-exposure attracts macrophages
what causes corneal graft rejection
vascularisation of the host cornea reaching the donor tissue
name two eye side effects of steroids
cataracts, glaucoma
