Immunology Flashcards
Which type of immunity forms immunological memory?
Adaptive
When is the immediate innate immune response begun in response to a pathogen?
0-4 hours
When is the early innate immune response begun in response to a pathogen?
4-96 hours
When is the late adaptive immune response begun in response to a pathogen?
> 96 hours
What aspects of innate immunity does the skin not have? What aspects does it have?
No physical barrier or commensal bacteria. There are chemical agents and immunological cells present.
What enzyme is found in tears which is an important chemical barrier?
Lysozyme
What 3 cells are found in tears which are important in the immune response?
Neutrophils, macrophages and conjunctival mast cells
What is the function of conjunctival mast cells?
Vasoactive mediators
What 3 things does the adaptive immune system require?
Antigen presenting cells, lymphatic drainage, variety of effector cells
What are 3 examples of antigen presenting cells?
Dendritic cells, B cells, macrophages
What are the principle antigen presenting cells in the eyes?
Langerhans cells
Langerhans cells are rich in what type of MHC molecule?
Class II
Where are Langerhans cells most abundant? Where are they absent?
Most abundant at the cornel-scleral limbus, absent from the central 1/3rd of the cornea
What is the only part of the eye with lymphatic drainage?
Conjunctiva
What three cell types of always present in MALT? What 2 cell types are present only if they are recruited?
Always present are macrophages, mast cells and Langerhans cells. Neutrophils and eosinophils are present only if they are recruited.
What part of the eye has commensal bacteria?
Conjunctiva
What parts of the eye make a tough collagen coat, are avascular and have a relative lack of APCs?
Cornea and sclera
What does immune privilege mean?
Ability to tolerate the induction of antigens without eliciting a systemic inflammatory immune response
Name 5 sites in the eye which are immune privileged?
Cornea, anterior chamber, lens, vitreous cavity, sub-retinal space
In ACAID, primed CD4+ cells and B cells produce what?
Non-complement fixing antibodies
Describe the relative amounts of MHC I and MHC II found in the cornea?
Decreased expression of MHC I and no MHC II
What is sympathetic ophthalmia?
Rare, bilateral, granulomatous uveitis due to trauma or surgery
What is the primary mediator of sympathetic ophthalmia?
T cells
In sympathetic ophthalmia, which comes first- CD4+ cells or CD8+ cells?
Primary wave is composed of CD4+ cells
In sympathetic ophthalmia, what are the affected and non-affected eyes known as?
Affected- exciting eye, non-affected- sympathising eye
Acute allergic conjunctivitis is an example of what type of hypersensitivity?
Type I
What can cells be killed by in type II hypersensitivity?
Macrophages/NKCs or complement (MAC)
What is ocular cicatricial pemphigoid?
A blistering condition affecting the surface of the eye and eyelid resulting in scarring- treat with steroids
What type of hypersensitivity reaction is ocular cicatricial pemphigoid?
Type II
An autoimmune corneal melt is an example of what type of hypersensitivity reaction?
Type III
A corneal graft rejection is an example of what type of hypersensitivity reaction? When does this occur?
Type IV- occurs once there is vascularisation
