Innate Immunity 1

Question 1

what is innate immunity?

Answer 1

non-specific, no lasting memory, first line of defence against the oral microbiota

Question 2

what are the stages of innate immunity immediately after infection?

Answer 2

recognition by performed, non-specific and broadly specific effectors - removal of infectious agent

Question 3

what are the stages of early induced innate response after infection?

Answer 3

recruitment of effector cells - recognition of PAMPs, activation of effector cells and inflammation - removal of infectious agent

Question 4

what are the 5 groups of disease causing agents?

Answer 4

bacteria, viruses, fungi, protozoa, helminths

Question 5

what do disease symptoms depend on?

Answer 5

where the pathogen replicates and the damage it causes

Question 6

when is the innate immune response effective?

Answer 6

with regular contact with potential pathogens which are destroyed within minutes or hours, only rarely causing disease

Question 7

what cells contribute to innate immune response?

Answer 7

epithelial/endothelial cells + fibroblasts

Question 8

how does epithelium contribute to innate immunity?

Answer 8

it is a physical barrier and produces antimicrobial peptides, cytokines and chemokines

Question 9

what are the innate cell subsets and complement?

Answer 9

phagocytic cells (macrophages and neutrophils) and antigen-presenting cells (dendritic cells)

Question 10

what is the function of chemokines?

Answer 10

cell recruitment

Question 11

what is the function of cytokines?

Answer 11

cell activation/proliferation

Question 12

what are the different main components of innate immunity?

Answer 12

epithelium, innate cell subsets and complement, chemokines/cytokines

Question 13

what is produced by the epithelium in the oral cavity?

Answer 13

antimicrobial peptides, immunoglobulins (secretory IgA), lactoferrin, lysozyme and cystatins

Question 14

what do antimicrobial peptides do?

Answer 14

attach and disrupt membranes

Question 15

when are antimicrobial peptides effective?

Answer 15

in low concentrations

Question 16

what are the major families of the antimicrobial peptides?

Answer 16

beta-defensins, human neutrophil peptides, cathelicidins, psoriasin proteins

Question 17

what are the two different functions of antimicrobial peptides?

Answer 17

directly kill microbes and modulate host immunity

Question 18

how do antimicrobial peptides directly kill microbes?

Answer 18

there is an electrostatic interaction between the two cells, the AMP ruptures the membrane OR inhibits intracellular function both causing bacterial lysis

Question 19

what are the different ways in which AMPs modulate host immunity?

Answer 19

recruit or activate immunocytes, neutralise bacterial products to suppress inflammation, enhance nucleic acid recognition to promote auto-inflammation

Question 20

where is secretory IgA produced?

Answer 20

at mucosal surfaces

Question 21

what does secretory IgA do when binded to a flagella?

Answer 21

prevents motility

Question 22

what does secretory IgA do when it is binded to a bacterial toxin?

Answer 22

it neutralises it

Question 23

how does secretory IgA prevent effects of microbes on mucosa?

Answer 23

it cross links target macromolecules and bacteria and prevents attachment of bacteria to mucosal surfaces

Question 24

what is lactoferrin and what does it do?

Answer 24

glycoprotein that transports iron ions but has antimicrobial activity

Question 25

where is lactoferrin present and what is it produced by?

Answer 25

present in saliva and produced by neutrophils

Question 26

where are lysozymes present and what are they produced by?

Answer 26

present in saliva and produced by macrophages/neutrophils

Question 27

what do lysozymes target?

Answer 27

cell walls of bacteria

Question 28

what is the function of cystatins?

Answer 28

they have anti-protease activity and support re-mineralisation of the teeth

Question 29

what are the salivary components that have antimicrobial activity?

Answer 29

AMPs, secretory IgA, lactoferrin and antimicrobial activity

Question 30

what do cell surface TLRs recognise?

Answer 30

different compounds of bacterial or fungal cell wall/membrane

Question 31

what do intracellular TLRs recognise?

Answer 31

internalised viruses

Question 32

what are the two main TLRs to remember?

Answer 32

TLR2 and TLR4

Question 33

what are the main type of microbial receptors?

Answer 33

toll-like receptors

Question 34

what is the function of toll-like receptors?

Answer 34

primarily for bacterial and viral recognition

Question 35

apart from TLRs what other receptors are there?

Answer 35

dectin and glucan receptors, NOD-like receptors, protease-activated receptors

Question 36

what do dectin and glucan receptors recognise?

Answer 36

fungus

Question 37

what do NOD-like receptors recognise?

Answer 37

bacteria

Question 38

what do protease-activated receptors recognise?

Answer 38

microbial and allergen recognition

Question 39

what are the main roles for receptors?

Answer 39

promote phagocytosis of microbes and activation of immune cells

Question 40

overall what are microbial receptors?

Answer 40

pattern recognition receptors (PRRs) that recognise pathogen associated molecular patterns (PAMPs)

Question 41

what do cellular mechanisms include?

Answer 41

both the epithelium as well as the innate immune cells that patrol the epithelium

Question 42

what can cytokines do?

Answer 42

instruct all immune cells what to do

Question 43

what are cytokines?

Answer 43

small proteins which are signalling molecules which co-ordinate immune responses

Question 44

what are the different cytokine families?

Answer 44

interleukins, TNFs, interferons and unassigned

Question 45

what are interleukins?

Answer 45

a class of cytokines

Question 46

how are interleukins divided up into group?

Answer 46

it depends on the functions of each family member as some are pro-inflammatory and some anti-inflammatory

Question 47

what are the 3 main functions of cytokines?

Answer 47

autocrine, paracrine and endocrine

Question 48

what is the autocrine function of cytokines?

Answer 48

alter behaviour of cell from which they were secreted from

Question 49

what is the paracrine function of cytokines?

Answer 49

alter behaviour of neighbouring cells

Question 50

what is the endocrine function of cytokines?

Answer 50

enter circulation and alter behaviour of distant cells

Question 51

where are the cytokine receptors?

Answer 51

on the target cells

Question 52

what does cytokine binding induce?

Answer 52

a conformational change in a majority of receptors intracellularly

Question 53

what does signal transduction lead to?

Answer 53

the activation of transcription factors that leads to control of gene regulation

Question 54

overall what do cytokines and chemokines do?

Answer 54

shapes type of immune response

Question 55

overall what do antimicrobials do

Answer 55

protection against invading organisms

Question 56

overall what do growth factors do?

Answer 56

tissue remodelling and repair

Question 57

overall what are receptors responsible for?

Answer 57

differentiation and proliferation

Question 58

what are chemokines?

Answer 58

small signalling proteins

Question 59

what is chemotaxis?

Answer 59

the movement of a cell in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance

Question 60

what are chemokines involved in?

Answer 60

recruitment (directing)

Question 61

what is the difference between chemokines and cytokines?

Answer 61

chemokines tell cells where to go and cytokines tell cells what to do

Question 62

what are the 4 classes of chemokines?

Answer 62

C (2 members), CC (31 members), CXC (18 members) , CX3C (1 member)

Question 63

what are the 4 classes of chemokines dependent on?

Answer 63

their first 2 cysteine residues

Question 64

where are chemokine receptors?

Answer 64

on a range of innate and adaptive immune cells

Question 65

what is the main chemokine to play a role at the oral mucosa?

Answer 65

CXCL8

Question 66

what are pathological features of a certain disease dependent on?

Answer 66

over or under reaction of the immune system

Question 67

what compounds does the oral mucosa produce to prevent infection?

Answer 67

AMPs, Secretory IgA, lactoferrin, lysozyme and cystatins

Question 68

overall what are Pattern Recognition Receptors?

Answer 68

a variety of receptors that recognise unique features of microbes