wk1: AED - Immunopath Flashcards
Are lymphatic vessels present intraocularly?
No. However, they are present on the edge of the limbus and on the conjunctiva, among some other places
Where in the eye and orbit does the lymphatic system exist?
Conjunctiva Limbus Lacrimal Gland Optic Nerve (dural sheath) Eyelid EOMs (connective tissue) Choroid?? (controversy!)
What does MALT stand for?
Mucosa Associated Lymphoid Tissue
What is the function of MALT?
MALT inductive sites are secondary immune tissues where antigen sampling occurs and immune responses are initiated
Describe the cellular makeup of MALTs in the lacrimal gland
Mainly IgA-positive plasma cells, associated with grouped and individually patrolling T cells
Describe the cellular makeup of MALTs found in canaliculae and lacrimal mucosa
Predominantly T cells; Macrophages plentiful
Name 3 locations where MALTs can be found
Lacrimal Gland
Canaliculae
Lacrimal Mucosa
Define Intraocular Immune privilege
Sites in the body where foreign tissue grafts can survive for extended or indefinite periods of time (whereas similar grafts placed in other regions get rejected)
Name an example of a location where intraocular immune privilege takes place
Cornea
From an immune standpoint, what differs between the eye and other tissues of the body that provides intraocular immune privilege
TGF-B2 levels are high in the eye (whereas not high in other tissues)
Where in the eye is TGF-B2 expressed?
expressed by pigmented cells of the eye (RPE, PE of ciliary body and iris)
Name 8 cells or proteins involved in innate immunity
complement proteins, granulocytes (basophils, eosinophils, neutrophils), mast cells, macrophages, dendritic cells, natural killer cells
What is the role of TGF-B2 expression in the eye?
inhibit immune response
What is the role of a-MSH expression in the eye? [2]
Inhibits macrophage activation and promotes production of anti-inflammatory factors
Name the 3 mechanisms behind intraocular immune privilege
Physical barrier
Inhibitory microenvironment
Active regulation of the immune response