I&d The Mucosal Immune System

Front 1

Provides local host defence at mucosal surfaces throughout the body

Back 1

Mucosal immune system

Front 2

The mucosal system is based upon which tissue?

Back 2

Mucosa-associated lymphoid tissue (MALT)

Front 3

Where does the mucosal immune system provide defence?

Back 3

At mucosal surfaces throughout the body

Front 4

What is the main site for antigen entry into the body?

Back 4

Mucosal surfaces

Front 5

How much, in a percentage, does MALT account for of the lymphoid tissue?

Back 5

50%

Front 6

What is the 'mucocillary escalator'?

Back 6

The effect of the secreted mucus and beating cilia preventing microbes from reaching the lungs

Front 7

What are 'lymphoid aggregates'?

Back 7

Tonsils and bronchial nodules, where antigens are up to initiate an immune response

Front 8

Which tracts is MALT present in?

Back 8

Respiratory, gastrointestinal and genitourinary

Front 9

What is the GT tract?

Back 9

The genitourinary tract

Front 10

It comprises subepithelial accumulations of lymphoid cells which are not constrained by a connective tissue capsule

Back 10

MALT

Front 11

MALT accumulations constrained by CT capsules T/F

Back 11

F, they are not

Front 12

Where might MALT accumulations occur, and as what?

Back 12

Lymphocytes, plasma cells and phagocytes throughout the lung and in lamina propria of intestinal wall. Or as more clearly organised tissue with well-formed follicles

Front 13

Where are well formed follicles of MALT found?

Back 13

In tonsils and small intestinal Peyer's patches

Front 14

MALT forms a separate interconnected secretory system within which cells committed to IgA or IgG synthesis may circulate T/F

Back 14

F, it's IgA or IgE

Front 15

Antigens are largely excluded by the tight junctions and mucous layer of the mucosal epithelium T/F

Back 15

T

Front 16

What are 'M' cells?

Back 16

'Microfold' cells. They separate gut lymphoid tissue from the lumen.

They transport organisms and particles from the gut lumen to T and by lymphocytes of the Peyer's patches across the epithelial barrier, and thus are important in stimulating mucosal immunity.

Front 17

M cells are interspersed in a layer of columnar epithelium T/F

Back 17

T

Front 18

They transport organisms and particles from the gut lumen to T and by lymphocytes of the Peyer's patches across the epithelial barrier, and thus are important in stimulating mucosal immunity

Back 18

M cells

Front 19

They serve as a site for the induction of mucosal immune responses

Back 19

Peyer's patches

Front 20

When activated by the mucosal immune system, B lymphocytes mature into antibody-secreting cells T/F

Back 20

FALSE!

They migrate to the local MESENTERIC LYMPH NODES and undergo further division and differentiateion, and then home back to the lamina propria where they become IgA forming cells, which protect the intestine with antibody

Front 21

These cells migrate to the local mesenteric lymph nodes, undergo further division and differentiateion, and then home back to the lamina propria where they become IgA forming cells, which protect the intestine with antibody

Back 21

Activated B lymphocytes in the mucosal immune system

Front 22

What effect to IgA-forming cells have on the intestine?

Back 22

They protect the intestine with antibody

Front 23

Peyer's patches are referred to as _________ sites

Back 23

inductive

Front 24

The lamina propria are described as ________ sites

Back 24

effector

Front 25

What is the lamina propria?

Back 25

A constituent of the moist linings known as mucous membranes or mucosa, which line various tubes in the body (such as the respiratory tract, the gastrointestinal tract, and the urogenital tract).

Front 26

How do induced lymphocytes know where to go on different mucosal sites?

Back 26

They are guided by specific homing receptors they have, with appropriate vascular addressins on the relevant blood vessel endothelium

Front 27

What is 'addressin'?

Back 27

An extracellular protein of the endothelium of venules. Addressins are the ligands to the homing receptors of lymphocytes.[5] The task of these ligands and their receptors is to determine which tissue the lymphocyte will enter next. They carry carbohydrates in order to be recognized by L-selectin.

Front 28

An extracellular protein of the endothelium of venules. Addressins are the ligands to the homing receptors of lymphocytes.[5] The task of these ligands and their receptors is to determine which tissue the lymphocyte will enter next. They carry carbohydrates in order to be recognized by L-selectin.

Back 28

Addressin

Front 29

This area is home predominantly to αβ TCR population

Back 29

Lamina propria

Front 30

CD8+ T cells with NK cells act as cytotoxic cells in local sites of the lamina propria T/F

Back 30

T

Front 31

What are the main types of T cells that are intestinal intraepitheilial lymphocytes (IELs)?

Back 31

γδ T cells

Front 32

What are intraepithelial lymphocytes (IELs)?

Back 32

Lymphocytes found in the epithelial layer of mammalian mucosal linings, such as the gastrointestinal (GI) tract and reproductive tract. However, unlike other T cells, IELs do not need priming. Upon encountering antigens, they immediately release cytokines and cause killing of infected target cells. In the GI tract, they are components of gut-associated lymphoid tissue (GALT)

Front 33

Lymphocytes found in the epithelial layer of mammalian mucosal linings, such as the gastrointestinal (GI) tract and reproductive tract. However, unlike other T cells, IELs do not need priming. Upon encountering antigens, they immediately release cytokines and cause killing of infected target cells. In the GI tract, they are components of gut-associated lymphoid tissue (GALT)

Back 33

Intraepithelial lymphocytes (IELs)

Front 34

The lamina propria is rich in mast cells T/F

Back 34

F

Front 35

Why are mast cells important in the lamina propria?

Back 35

They are thought to protect against parasitic worm infections

Front 36

Since antibodies made against worms are IgE, cross-linking of the IgE on the surface of mucosal mast cells by worm antigens leads to mast cell degranulation, producing a powerful acute inflammatory response T/F

Back 36

T

Front 37

What Igs are mainly used against parasitic worms?

Back 37

IgE

Front 38

Where is dimeric secretory IgA present?

Back 38

Mucosal surfaces

Front 39

Where is dimeric secretory IgA produced? By what cell?

Back 39

Plasma cells in the lamina propria

Front 40

It transports dimeric secretory IgA across the epithelial cells into the lumen of the tract

Back 40

Poly Ig receptor

Front 41

What is the function of dimeric secretory IgA being in the tract?

Back 41

It protects the mucosal surfaces from microbial invasion

Front 42

What is the function of the secretory component, a cleavage product of the poly Ig receptor, attached to the dimeric IgA antibody?

Back 42

Thought to reduce proteolytic enzyme degradation of the secretory IgA in the harsh intestinal environment

Front 43

What is the function of 'poly Ig receptor'?

Back 43

It transports dimeric secretory IgA across the epithelial cells into the lumen of the tract