Immunology 1

Question 1

Strong external barriers top infection…..

Answer 1

Nails, hair, skin, eyes

Question 2

Vulnerable mucosal membranes…..

Answer 2

Respiratory tract, urogenital tract, gastrointestinal, oral cavity

Question 3

Surface epithelium provides ……….., ………… and ……….. barriers to infection

Answer 3

mechanical, chemical and microbiological

Question 4

Skin
Mechanical:
Chemical:
Microbiological:

Answer 4

M: epithelium joined by tight junctions
longitudinal flow of air/fluid
C: Fatty acids, b-defensins lamellar bodies cathelicidin
M: Normal microbiota

Question 5

Gut
Mechanical:
Chemical:
Microbiological:

Answer 5

M: epithelium joined by tight junctions/longitudinal flow of air/fluid
C: Low PH/ enzymes (pepsin)/ alpha defensins (cryptdins) / Regll (lecticidins) cathelicidin
M: Normal microbiota

Question 6

Lungs
Mechanical:
Chemical:
Microbiological:

Answer 6

M: epithelium joined by tight junctions / Movement of mucus by cilia
C: Pulmonary Surfactant alpha defensins/ cathelicidin
M: Normal microbiota

Question 7

Eyes/Nose/Oral cavity
Mechanical:
Chemical:
Microbiological:

Answer 7

M: epithelium joined by tight junctions/ Tears/ nasal cilia
C:enzymes in tears and saliva lysozyme/ histatins , B-defensins
M: Normal microbiota

Question 8

Lysozyme is most active against gram…….. bacteria, e.g ……….. this is because the peptidoglycan layer is…………………..
Peptidoglycan is a polymer of sugars, Lysozyme cleaves the bonds linking theses 2 sugars…….

Answer 8

positive, streptococcus mutans (cariogenic). more easily accessible with gram negative which has an additional lipid bilayer
Exposes the lipid bilayer to other antimicrobial agents

Question 9

Zymogen

Why is it good to keep it inactive

Answer 9

inactive form of an enzyme, usually need proteolytic cleavage to become active
good to keep inactive form going round cutting everything

Question 10

(oral cavity) Defensins

Answer 10

are amphipathic Insertion into membranes generates pores, membranes become leaky

Question 11

(oral Cavity) Cathelicidins

Answer 11

LL-37, amphipathic, membrane disruption

Question 12

(oral Cavity) Histatins

Answer 12

produced by parotid, sublingual, submandibular glands. Histadine rich, active against fungal pathogens

Question 13

Innate Arm
Response-
Recognition-
Lasting protection/memory-

Answer 13

Mins, hrs. Always present
Limited range, unchanged during response, Genome encoded receptors (DNA in inherited form)
None

Question 14

Adaptive Arm
Response-
Recognition-
Lasting protection/memory-

Answer 14

Days, weeks usually silent, response needs to be raised
vast range, receptor recognition improves, receptors not genome encoded (DNA changes from inherited form)
Years (leave memory effector cells)

Question 15

Innate vs adaptive; Response speed

Answer 15

Innate: provides initial defence, limiting pathogen proliferation and speed. Can control less virulent pathogens. important role in inducing the adaptive immune response
Adaptive: more potent activity to control more virulent pathogens, takes time to raise population of cells specific for pathogens

Question 16

Innate vs adaptive; Diversity of recognition

Answer 16

locked in a arms race with our pathogens

Diversity: problem with germline encoded immune system

Question 17

Innate vs adaptive; Memory

Answer 17

Innate: none
Adaptive: Faster , Higher, Stronger Antibody is the product of the adaptive immune system, immunological memory gives more efficient and effective immune response to previously seen pathogens

Question 18

The complement system was discovered in 1890 by jules border he found that …………… complemented the killing of bacteria by phagocytes

Answer 18

Plasma

Question 19

Complement system functions:

Answer 19

1. facilitates the recognition of bacteria by phagocytes

2. can directly lyse bacteria