Lecture 18

Question 1

what are the different kinds of MALTs (mucosa-associated lymphoid tissues)? (3)

Answer 1

1. NALT (nasal associated)
2. BALF (brachial associated)
3. GALT (gastrointestinal associated)

Question 2

what are the three kinds of GALTs mentioned in the slides.

Answer 2

1. peyer’s patch
2. isolated lymphoid follicles (ILFs)
3. appendix

Question 3

MALTs are ____ sites, meaning…

Answer 3

indution sites; location of mucosal immune response initiation

Question 4

maturation of GALT is driven by…

Answer 4

commensal bacteria

Question 5

at birth, peyer’s patch is…

Answer 5

present, but grows after birth

Question 6

at birth, cryptopatch is…

Answer 6

present

Question 7

at birth, isolated lymphoid follicles (ILFs) are…

Answer 7

not present, and develop after birth.

Question 8

muscoal immune system is triggered by…

Answer 8

ILC3 (IL22, IL17)

Question 9

M cells are specialized for…

Answer 9

transcytosis

Question 10

Components of peyer’s patch (4)

Answer 10

1. follicle-associated epithelium (FAE)
2. subepithelial dome
3. M cell
4. germinal center (big and many)

Question 11

Components of Isolated lymphoid follicles (ILFs) (

Answer 11

1. mucus
2. M cells
3. follicle-associated epithilium (FAE)
4. subepithelial dome
5. germinal center (small and few)

Question 12

The intestines are ____ , meaning…

Answer 12

effector cites; they are regions where mucosal immune functions are actively carried out

Question 13

the small intestine is lined with…

Answer 13

intestinal epithelium

Question 14

the large intestine is lined with…

Answer 14

lamina propria

Question 15

the small intestine contains… (3)

Answer 15

1. IELs
2. ILCs
3. T cells (no B cells)

Question 16

the large intestine contains… (3)

Answer 16

1. T cells
2. B cells
3. ILCs

Question 17

Traits of the intestines include…

Answer 17

1. viscous
2. negatively charged – for commensal bacteria
3. mucins (MUC2)

Question 18

what are the two types of IELs? How do they work?

Answer 18

1. Type A IEL: function like cytotoxic T cells
2. Type B IEL: function like NK cells

Question 19

What are the absorbitive subsets the the intestines? (2)

Answer 19

1. enterocytes
2. m cells

Question 20

What are the secretory subsets of the intestines?

Answer 20

1. globlet cells (mucus)
2. paneth cells (AMPs)
3. enteroendocrine cells (hormones / NTS)
4. Tuft cells (cytokines / lipid mediators)

Question 21

what are the means of antigen uptake into the intestines? (6)

Answer 21

1. transport across m cells
2. FcRn-dependent transport
3. globlet cell uptake
4. paracellular transport through tight junctions
5. apoptosis-dependent transfer
6. antigen capture via transepithelial dendrites.

Question 22

Intestinal macrophages induce… (4)

Answer 22

1. phagocytosis
2. Th17 and Tregs
3. IL-10
4. PGE2 (intestinal repair)

Question 23

gut dendritic cels induce production of…

Answer 23

IgA and Tregs

Question 24

what do Tregs do?

Answer 24

• promote clearance of infection
• limit immune-mediated damage and responses to self
• maintain homeostasis

Question 25

Desrcibe the process of IgA secretion from the intestine.

Answer 25

1. IgA is secreted (dimer) and interacts w plgR via its J chain. 2. the complex undergoes transcytosis across the epithlilum 3. it is released on the other side of the membrane w part of plgR still attatched (secretory component)

Question 26

the subepithelial dome is rich in ____ and ____.

Answer 26

dendritic cells and lymphocytes