GI Immunology

Question 1

antigen processing in the GI tract - define an effective immune response

Answer 1

elimination or control of infections, allergic and noxious agents

Question 2

epithelial layer of the gut tube

Answer 2

specialised tight junctions that regulate permeability

Question 3

mucus layer of the gut tube

Answer 3

physical barrier keeping microbes from host cells

Question 4

innate immune response in the gut tube. What does it do?

Answer 4

senses bacteria + anti-microbial peptides + IgA

Question 5

soluble mediators of immunity in the gut tube

Answer 5

chemokine and cytokines

Question 6

immune cell responses

innate cells

Answer 6

granulocyte (neutrophil, eosinophil, basophil)

mast cell

monocyte

dendritic cell

macrophage

natural killer cell

Question 7

immune cell responses

adaptive cells

Answer 7

CD4+ T cell (memory)

CD8+ T cell (memory)

B cell (memory)

Question 8

T cell subsets have an important role in

Answer 8

maintaining immune homeostasis

Question 9

what are payers patches?

Answer 9

a major organised lymphoid structure in the gut

large numbers of immune cells within

Question 10

payers patches are important for

Answer 10

immune response to commensal bacteria (tolerance) and pathogens (active immunity)

Question 11

what are macrophages

Answer 11

they are phagocytic and they ingest and kill foreign micro-organisms

Question 12

macrophages are the first line of defence in the

Answer 12

gut

Question 13

macrophages secrete

Answer 13

cytokines (eg IL-10)

Question 14

dendritic cells are important in

Answer 14

mucosal immune responses

Question 15

different dendritic cell subsets give rise to

Answer 15

distinct T cell responses

Question 16

different dendritic cell subsets are distinguished by

Answer 16

cell markers

Question 17

Lamina propria and dendritic cells are important for

Answer 17

directing the function of T cells

Question 18

APC

Answer 18

antigen presenting cells

Question 19

dendritic cells undergo maturation into potent what?

Answer 19

antigen presenting cells (APC)

Question 20

dendritic cell maturation involves:

Answer 20

altered antigen uptake and presentation

increases expression of co-stimulatoru molecules

production of cytokines

Question 21

Naive T cells functions as

Answer 21

effector cells and effector functions

Question 22

3 signals that determine T cell response

Answer 22

MHC/peptide TCR

CD80 - CD28

cytokine

Question 23

gut homeostasis is regulated by the balance between T ….. cells and T ….. cells

Answer 23

helper

regulatory

Question 24

innate immune system is induced upon

Answer 24

infection with microbes

Question 25

innate immune system is based on the recognition of

Answer 25

pathogen associated molecular patterns

Question 26

adaptive immune system is induced upon

Answer 26

infection by specialised pathogens

Question 27

the adaptive immune system is based on the recognition of

Answer 27

specific antigens presented by professional antigen presenting cells (eg dendritic cells)

Question 28

adaptive immune response is carried out mainly by

Answer 28

effector cells (mainly T and B cells)

Question 29

dendritic subsets and macrophages have an important role in

Answer 29

driving T cell differentiation (Th1 or Tregs)

Question 30

what happens what normal immune homeostasis goes wrong?

Answer 30

IBD coeliac disease

Question 31

In IBD there is a dysbiosis in

Answer 31

microbial communities

Question 32

dysbiosis of microbiota

Answer 32

leaky epithelial barrier disordered, perpetual innate and adaptive immune response

Question 33

Treatment strategies for IBD. What do we target?

Answer 33

lymphocytes directly single cytokines migration of immune cells to GI mucosa multiple cytokines cytokine intracellular signalling pathways modulation of microbiota

Question 34

A new drug therapy involves targeting the migration of immune cells to the GI mucosa. The aim is to block the migration of..... to the intestinal mucosal

Answer 34

leucocytes

Question 35

New 'biologics' the IBD arena include:

Answer 35

vedolizumab ustekinumab Tofactinib

Question 36

IBD involves what of the gut microbiota?

Answer 36

dysbiosis

Question 37

dysbiosis

Answer 37

microbial imbalance or maladaption of microbiota

Question 38

Coeliac disease is an inflammatory disorder of the

Answer 38

small bowel

Question 39

coeliac disease is an intolerance to what?

Answer 39

dietary gluten in wheat and similar proteins

Question 40

symptoms of coeliac disease

Answer 40

iron deficiency anaemia fatigue abdominal pain loose stool

Question 41

genetic susceptibility to ceoliac disease is linked to...

Answer 41

HLA-DQ2/8 on antigen presenting cells

Question 42

celiac disease (histology) results in changes to the

Answer 42

gut mucosa

Question 43

what changes occur in the gut mucosa due to celiac disease?

Answer 43

loss of villi (loss of absorptive capacity) increase in intra-epithelial lymphocytes