Immunity to microbial infection

Question 1

what antimicrobial factors are present in the oral cavity

Answer 1

lysozyme
antibodies
antimicrobial peptides

Question 2

what do lysozymes do

Answer 2

cleaving the bonds between the peptidoglycan in the bacterial cell wall

Question 3

which antibodies are most abundant in saliva

Answer 3

IgA

Question 4

which antibodies are most abundant in GCF

Answer 4

IgM

IgG

Question 5

give examples of antimicrobial peptides

Answer 5

defensins
histastins
LL37

Question 6

give examples of the innate immune system cells

Answer 6

macrophages

neutrophils

Question 7

describe host defence peptides

Answer 7

they are Short cationic peptides- meaning overall +ve charge

Question 8

where are host defence peptides

Answer 8

Present in saliva and GCF
Production from
salivary glands, leukocytes and epithelial cells

Question 9

what do host defence peptides

Answer 9

→ Bactericidal activity
→ Antiviral activity
→ Immune cell recruitment
Immune cell activation

Question 10

describe defensins

Answer 10

alpha and beta defensins
widely expressed in the body
short peptides
○ Conserved pattern of 6 paired cysteine residues and 3 disulphide bonds
○ Conserved structure of beta sheets
They are produced as a proforma and then proteolytically cleaved to be activated

Question 11

describe a defensins

Answer 11

produced by neutrophils

aka human neutrophil peptide

Question 12

how many human neutrophil peptides are expressed in the oral cavity

Answer 12

4

Question 13

where do HNP1 and 3 differ

Answer 13

in the n terminal amino acid

Question 14

which HNP is high in abundance in saliva and GCF

Answer 14

HNP 1, 2 , 3

Question 15

how long are the a Defensins genes

Answer 15

25-35AA

Question 16

where are alpha defensins stored

Answer 16

in primary granules

Question 17

what happens to alpha defensins in disease

Answer 17

→ Increased levels found in aggressive periodontitis

Less found in edentulous pts and Morbus Kostmann disease

Question 18

what are the immune activities of a defensins

Answer 18

1) HNP1,2,3 are directly chemotactic for monocytes
2) They can increase neutrophil recruitment by
→ Increasing IL-8 production
→ Regulate cytokines expression increasing pro inflammatory cytokine expression whilst inhibiting anti inflammatory IL-10
→ Induce mast cell degranulation histamine release and vasodilation
Promote the induction of adaptive immune through the activity od dendritic cells

Question 19

describe beta defensins

Answer 19

four types of beta defensins

Question 20

what are the four types of beta defensins

Answer 20

→ hBD-1 constitutively expressed
→ hBD-2 inducible except in the oral cavity expression is constitutive
→ hBD-3 inducible
hBD1-4 expressed at low levels

Question 21

what is the length of beta defensins

Answer 21

They are all 36-45 AA in length

Question 22

which bacteria can alpha defensins be against

Answer 22

→ Such as S mutans
→ P gingivalis
→ A Actinomycetesomitans
C albicans

Question 23

where are beta defensins expressed in the oral cavity

Answer 23

cells of the gingiva, salivary glands, tongue mucosa and mainly epithelial cells

Question 24

which epithelial cells express HBD1 + HBD2

Answer 24

Stratum spinosum and granulosum

Question 25

which epithelial cells express HBD3

Answer 25

stratified basal layer

Question 26

give examples of bacteria that HBD3 defensins act against

Answer 26

``` Including P gingivalis S mutans F nucleatum T denticola A actinomycetescomitans ```

Question 27

give examples of bacteria that HBD2 defensins act against

Answer 27

Active against gram -ve + candida sp

Question 28

give examples of bacteria that HBD1 defensins act against

Answer 28

``` Least potent Active against P gingivalis AA F Nucleatum ```

Question 29

describe the anti viral activity of defensins

Answer 29

``` 1) Targeting lipid envelope Changes the shape of the envelope and therefore makes it harder to infect the host 2) Extracellular aggression 3) Receptor blocking 4) Inhibition of fusion 5) Blocking uncoating Cellular changes ```

Question 30

describe LL37

Answer 30

a helical structure present in the salivary glands and GCF the only human membrane of cathlecidin

Question 31

what is LL37 produced by

Answer 31

epithelial cells and leukocytes

Question 32

what is the length of LL37 in the active form

Answer 32

37AA

Question 33

what is ll37 stored by

Answer 33

as a HCAP-18 proforma in secondary granules

Question 34

what is the names of some gram -ve bacteria that antimicrobials are against

Answer 34

p intermedia p gingivalis f nucleateum AA

Question 35

what is the names of some gram +ve bacteria that antimicrobials are against

Answer 35

s gordonii | s sanguinis

Question 36

what is the actions of LL37

Answer 36

reduces candida binding to the epithelium promotion of healing auto aggregation of candida albicans inhibits inflammatory response to gram -ve LPS stimulates pro inflammatory responses direct chemoattractant

Question 37

what models can we use to see antimicrobial peptide insertion into lipid layer

Answer 37

barrel stave model toroidal model carpet method

Question 38

what is the barrel stave method used for

Answer 38

perforin

Question 39

what is the toroidal method

Answer 39

generates a pore and lined with AMP(antimicrobial peptides) and the lipid head of the bacterial cell membrane

Question 40

what is the carpet method

Answer 40

little micelles being ripped off the membrane

Question 41

describe histatins

Answer 41

histadine rich mildly amphipathic produced by the major salivary glands

Question 42

what are the prominent human histatins

Answer 42

1,3 ,5

Question 43

what is the length of a histatins

Answer 43

7-38AA

Question 44

which species is histatin have the greatest potency for

Answer 44

candida- they disrupt the mitochondrial respiration

Question 45

what is the definition for a hypersensitivity reaction

Answer 45

An abnormal or exaggerated reaction to the ingestion, inhalation or contact with a substance that does not provoke a reaction in most people

Question 46

what are the types of hypersensitivity reaction

Answer 46

I II III IV

Question 47

how are reactions grouped

Answer 47

according to the immune effector mechanisms that mediate the response and type of antigens that stimulates them

Question 48

describe Type I HS reaction

Answer 48

immune reactant IgE antigen is soluble EFFECTOR MECHANISM IS mast cell activation example- allergic asthma

Question 49

describe type 2 HS reactions

Answer 49

IR- igG antigen- cell surface receptor or cell/matrix associated antigen effector mechanism- antibody altering for cell surface receptor and complement for cell/matrix assoc antigen example- drug allergies eg penicillin

Question 50

describe type III HS reactions

Answer 50

IR- IgG antigen is soluble effector mechanism- complement example- serum sickness

Question 51

describe type IV HS reactions

Answer 51

``` 1. IR- tH1 cell soluble antigen effector mechanism- macrophage activation example- dermatitis 2. IR-TH2 cells soluble antigen effector mechanism- IgE production, eosinophil activation example- chronic asthma 3. IR- ctl cell assoc antigen effector mechanism- cytotoxicity example- graft rejection, allergic contact ```

Question 52

what are some dental allergies we can see

Answer 52

latex allergy- immediate antibiotics- penicillin nickel titanium allergies