Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI Exam 3 > GI Immunity > Flashcards

GI Immunity Flashcards

1
Q

Entry into body for pathogens?

A

mucosal lining of GI tract is GREAT ENTRY POINT

- immune system puts forth a great effort into defending that area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Central Immune System

A

Th1 response

- IgG is most common AB (75%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Surface Immune System

A

Th2 response

  • IgA 1 and 2 are most common AB
  • they are secreted into extracellular space to find and neutralize the pathogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Tolerance?

A

mucosal immune system is more tolerant than central because we need to get nutrients into our system!!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The changing ecosystem of GI tract

A

different areas of GI tract have differing pH to help protect us from pathogens
- nutrients spend most time in colon –> plenty of time for the bacteria to replicate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

GALT

A

primary site for antigen entry!!!

- GI and resp tracts harbor largest reservoirs of lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Layers of Defense

A
  1. Intraepithelial Barrier
  2. Lamina propria
  3. Peyer’s Patch
  4. Mesenteric Lymph Nodes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Intraepithelial lymphocytes

A

contains effector cells –> don’t need an antigen to be presented to them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lamina propria

A

immune cells need to have antigen presentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Peyer’s Patches

A
  • found in distal ileum
  • allows antigens to cross so immune system can recognize them and build immunity
  • M cells is specialized cell responsible for allowing antigens in which come in contact with numerous follicles enriched by B and T cells
  • germinal centers are absent at birth -> develop once antigens are present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

of lymphocytes as you travel down GI tract?

A

they increase!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lymphocyte migration

A

itinerate –> constantly on the move

  • Selectins and Integrins direct movement
  • beta-7 integrin is common on mucosal lymphocytes
  • extravasation controlled by chemokines, adhesions, integrins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Role of vitamins?

A

Vitamins and metabolites can provide homing cues

  • Vit D specifically for skin
  • Vit A specifically for gut
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Inductor and Effector Sites

A

Inductor –> in mucosa of GI tract -> M-cells allow antigens to enter and begin selecting and activating B/T cells -> immune cells then travel to lymph nodes and get further educated -> enter blood -> travel to effector site
Effector Site –> B/T cells enter through endothelium and perform immune functions on antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Isolated Lymphoid Follicles

A
  • collection of lymphocytes in lamina propria

- density increases distally in GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

GI defense strategies

A
  1. Block entry into organism -> most pathogens
  2. Block entry into cell -> bacteria/virus
  3. Prohibit spreading -> most
  4. Direct killing -> most
  5. Kill infected cell -> virus, intracellular bacteria, protozoa
  6. Expulsion -> multicellular parasites
  7. Nutrient deprivation -> bacteria, protozoa
17
Q
  1. Block entry into organism
A
  • epithelial and mechanical barriers –> tight junctions, trefoil factors (rapid repair or perforations
  • cilia-mediate expulsion -> mucins from goblet cells
  • Neutralizing antibodies -> natural (IgM, IgG) or sIgA
  • Antimicrobial peptide -> perforates bacterial cell walls
  • Enzymes -> lysozyme and PLA2
18
Q

Penetration into host cell

A

some bacteria and viruses cross epithelium via M-cells through transcytosis

  • macrophages on basolateral side engulf microbes
  • strong route for vaccination
19
Q

Molecular Harbingers

A

PAMPs -> recognized by TLRs
TLR -> drive production of cytokines that cause inflammation (NFkB)
TF -> transcription factors cause nausea, fever, aches (inflammation)

20
Q

Intraepithelial Barrier

A 
intraepithelial lymphocytes promote barrier repair and are rapidly recruited
- express CD8 and recognize MHC class I
2 types of TCR
1. alpha-beta (thymus derived)
2. gamma-delta (non-thymic derived)
21
Q

Lamina propria

A

Reservoir to 70-80% of total lymphocytes, predominantly CD4 recognized by MHC II

22
Q
  1. Block entry into cell
A

Neutralizing Antibodies –> sterically block the pathogen adherence to host cells precluding invasion
- bacteria agglutinate

23
Q

IgA Synthesis

A
  1. Normal/regular way we already learned (APCCD4 T-cellIgM –> secretes AB
  2. isolated lymphoid follicles (DC presents to B-cell with BAFF)
  3. Stromal cell presents to B-cell (T-cell independent)
24
Q
  1. Prohibit Spreading
A

Coagulation, vaso-constriction –> vascular responses
Neutralizing ABs
Interferons Type 1 –> increase MHC I –> Cell-mediated cytotoxicity

25
Q
  1. Direct Killing
A 
Antimicrobial Peptides --> punch holes
Bacterial permeability proteins --> similar to AMP
Lysosomes and Stomach Environment
Complement
ROS, RNS --> neutrophils and macrophages
26
Q

Defensins

A

alpha -> neutrophils, NK cells, Paneth cells

beta -> leukocytes and epithelial cells

27
Q
  1. Kill infected host cell
A

Type 1 Interferons -> induce MHC I expression

-> NK cells, NKT cells, CTL, Antibody dependent cytotoxicity

28
Q
  1. Expulsion
A 
IgE -> drives secretion of mast cells and eosinophils -> lots of mucous
Vasoactive substances - LKT, PGE, Hist
Mucous
Smooth muscle contraction
Cilia-mediated expulsion
29
Q
  1. Nutrient Deprivation
A

Take away any of these -> shut down metabolism of pathogen

  • Lactoferrin –> takes away iron
  • Natural resistance-associated macrophage protein -> manganese
  • ZIP/ZnT -> Zinc
  • Calprotectin -> broad spectrum scavenger of divalent cations
  • Lipocalin -> lipids
  • Indoleamine 2,3-dioxygenase -> tryptophan
30
Q

Acute Inflammation mediators

A 
Th1 Lymphocytes
IFN-gamma
M-1 macrophages
IgG and sIgA
CTL cells
NK cells
31
Q

Chronic Inflammation mediators

A 
Th2/Th17 lymphocytes
IL-4 and IL-17
M-2 macrophages
IgE
Eosinophils
Basophils
32
Q

Salmonella infection

A
  1. Contacts cells with Type II secretion system (delivers toxins for step 2)
  2. Subverts host cell cycle
  3. Restructures cytoskeleton
  4. Pronounced ruffling –> entry
  5. Recovers

GI Exam 3 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions