Test 2: lecture 2 immune provilege

Question 1

immunologic ingnorance

Answer 1

can transplant eyes with little immune response

There is a profound antigen-specific suppression of cell- mediated immunity, especially T-cell–mediated inflammation, such as delayed hypersensitivity and a concomitant induction of antibody responses.

Question 2

Injection of antigens in the anterior chamber of the eye, vitreous or subretinal space induce ____________.

Answer 2

tolerance → will not have a big response (will not attack self)

Question 3

The prolonged survival of incompatible ocular grafts is what defines immune privilege. This is achieved through ___ to alloantigens and local suppression of inflammatory responses.

Answer 3

induction of systemic tolerance

Question 4

These mechanisms establish a strong blockade in activating graft ___ immune responses.

Answer 4

destructive

Question 5

-Immune responses are not completely suppressed, and the mechanisms behind such suppression are in large part due to the regulation of ___ to activate Treg function.

Answer 5

APC activity

Question 6

No lymphatic vessels drain the ____, vitreous cavity or subretinal space, although lymph drainage for the conjunctiva, ___ and choriocapillaris exists

Answer 6

anterior chamber

sclera

Question 7

Aqueous humor from the anterior chamber drains through the ____ to enter directly into the ___circulation that serves the conjunctiva, iris, ciliary body, sclera and choriocapillaris

Answer 7

trabecular meshwork

venous

Question 8

what are some cell surface molecules that promote ocular immune privilege

Answer 8

Question 9

in the eye what are some soluble factors that promote immune privilege

Answer 9

IL-10, TGF beta

Question 10

T-cell effector functions are neutralized when crossing the pigment epithelium layer of the eye as this process induces a ___phenotype.

Answer 10

Treg

Question 11

T cells entering the aqueous humor encounter transforming ____ and neuropeptides such as___- which also favor conversion of T effector into Tregs.

Answer 11

growth factor-β (TGF-β)

α-melanocyte stimulating hormone (α-MSH)

Question 12

Antigenic material placed in the anterior chamber elicits induces ___ to the antigen (initial experiments using MHC-mismatched skin). Same response in vitreous and sub-retinal space.

Answer 12

systemic tolerance

Question 13

Antigens released into the aqueous humor are recognized by dendritic cells of the iris and ciliary body. These APCs can then enter the ___ circulation and induce regulatory T cells in the spleen, bypassing the ___ system.

Answer 13

venous

lymphatic

Question 14

ACAID

Answer 14

anterior chamber–associated immune deviation (ACAID).

ACAID is a down-regulation of delayed-type cellular immunity.

the body will have a decreases immune response (tolerance) to antigens presented in the anterior chamber

Question 15

The tolerance induced in ACAID is ___ mediated by tolerogenic T cells. It is ___ specific, and it suppresses the activation of ____ responding to the same source of antigen.

Answer 15

efferent suppression

antigen

effector T cells

Question 16

explain how ACAID works in the eye

Answer 16

antigen from the anterior chamber gets eaten by APC, these go right into venous circulation (skip lymphatics) and go to the spleen

the APC will be seen by NKT cells that produce anti immune cytokines (TGFB, IL-10 and CCL5 that recruits T cells)

The antigen on the APC is seen by T cells, but those cells are tuned into tolerant cells by the cytokines produced by the NKT cell

these suppression cells will then travel back to the eye and decrease immune response

→ tolerance

Question 17

• The ___ is vulnerable to damage by inflammation and neovascularization.

Answer 17

visual axis

Question 18

The corneal endothelium and the neuronal retina have limited ___properties.

Answer 18

regenerative

Question 19

Innate (NK cells, neutrophils, macrophages) and adaptive immune effector cells (Th and Tc cells) and molecules threaten vision by triggering ___ inflammation and angiogenesis, and by destroying irreplaceable cells.

Answer 19

intraocular

Question 20

-Immune elements posing a major threat to eye health are the main targets of immunoregulatory and___ mechanisms in the eye.

Answer 20

anti-inflammatory

Question 21

what happens to the efferent and afferent arm of the immune response in the brain

Answer 21

decreases, mildly in the efferent arm

greatly decreases in the afferent arm (cellular route DCs)

Question 22

drainage of the CNS through the ___ is required to preserve proper nervous function and tissue homeostasis

Answer 22

cribriform plate to the nasal mucosa lymphatics

Question 23

blood vessels in the parenchyma of the brain have more or less CAMs than blood vessels in the meninges meaning?

Answer 23

less CAMs in the parenchyma → less adhesion and pulling of immune cells into parenchyma then when in the meninges

Question 24

CNS endothelial cells (___) represent a heterogeneous cell population able to interact and modulate the function of immune cells.

Answer 24

BBB/BMB

Question 25

GME

Answer 25

similar to MS

lesions in meningeal areas that eat away at cells

(there are a lot of B cells and T cells that attack the brain cells)

Question 26

astrocytes produce ___ that trigger endothelial cells ___

Answer 26

Shh

immune tolerance→ increase barrier integrity, decrease CAM expression, decrease cytokine release

Question 27

Astrocytes enhance endothelial barrier properties through the maintenance of ____.

Answer 27

junctional proteins

Question 28

___ derived factors (e.g: Shh) promotes immune privilege by decreasing the expression of CAMs, chemokines as well as by reducing the adhesion and migration of CD4 T cells across the BBB.

Answer 28

Astrocyte

Question 29

Astrocyte-derived factors provide a ___ effect and an endogenous anti-inflammatory balance to CNS-directed immune attack.

Answer 29

barrier-promoting