GI Mucosal Immunology Flashcards Preview

07. Year 2: Alimentary System > GI Mucosal Immunology > Flashcards

Flashcards in GI Mucosal Immunology Deck (63)
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1

What does the upper GI tract consist of?

Oesophagus

Stomach

2

What does the lower GI tract consist of?

Small intestine

Large intestine

3

In basic terms, what are the 2 kinds of bacteria found in the GI tract?

Commensal bacteria

Pathogenic bacteria

4

What are some examples of challenges of antigen processing in the GI tract?

Develop self-tolerance

Develop exogenous tolerance

Develop an effective immune response

5

What is self-tolerance?

Non-responsiveness of the immune system to self-antigens

6

What is exogenous tolerance?

Non-responsiveness of the immune systemto newly encountered environmental antigens that are harmless

7

What are examples of different facets to normal antigen processing in the GI tract?

Epithelial layer

Mucus layer

Innate immune response

Antigen presenting cells

Tolerance versus activated of adaptive immune response (T cell)

Soluble mediators of immunity

8

How does the epithelial layer provide protection?

Specialised tight junctions that regulate permeability

9

How does the mucus layer provide protection?

Physical barrier keeping microbes from host cells

10

What are examples of antigen presenting cels?

Dendritic cells

Macrophages

11

What are examples of soluble mediators of immunity?

Chemokines and cytokines

12

What are the 2 different parts of the immune system?

Innate immune system

Adaptive immune system

13

What kind of immune cells are innate?

Granulocyte (neutrophil, eosinophil, basophil)

Mast cell

Monocyte

Dendritic cell

Macrophage

Natural killer cell

14

What kind of immune cells are adaptive?

CD4+ T cell (memory)

CD8+ T cell (memory)

B cell (memory), which become plasma cells that produce antibodies

 

15

Where do all cells of the immune system originate from?

Haematopoitic stem cell which comes from bone marrow

16

What are the 2 things that a haematopoietic stem cell can differentiate into?

Myeloid progenitor cell

Lymphoid progenitor cell

17

What does myeloid progenitor cell differentiate into?

RBC

Platelet

All cells of innate immune system (except natural killer cells)

18

What do lymphoid progenitor cells differentiate into?

All adaptive immune system cells

Natural killer cells

19

Which immune system causes inflammation?

Innate immune system

20

What is a key determinant of T cell differentiation?

The cytokine milieu

21

How do cytokines vary in terms of inflammation?

Some are pro-inflammatory and some are anti-inflammatory

22

What is a T cell called before it has differentiated into its subtype?

Naive T cell

23

What are peyer's patches?

Small masses of lymphatic tissue found throughout the ileum region of the small intestine

24

What do peyer's patches allow?

Sufficient sampling of particulate antigens and delivery to antigen presenting cells

25

What is a macrophage?

Type of phagocyte which is responsible for detecting, engulfing and destroying pathogens and apoptotic cells

26

What is the first line of defence system in the gut?

Macrophages

27

What are functions of macrophages?

Sampling of particulate antigens

Phagocytic (ingests harmful pathogens or dying/dead cells)

Secrete cytokines (such as IL-10 required for the survival of FoxP3 and Treg cells)

Antigen presenting cells to modulate adaptive immune response

28

Where are dendritic cells found in the GI tract?

Lamina propria and peyer's patches

29

Why are dendritic cells important for mucosal immune responses?

Efficient sampling of antigen

Different dendritic cell subsets give rise to distinct T cell responses (such as tolerance vs immunity)

Different subsets distinguished by cell markers)

Present antigen to naive T cell

30

What to dendritic cells do after they have sampled gut bacteria and gut antigens?

Migrate to major lymph nodes