Fungal Immunity

Question 1

Which phylum is the most common in causing human disease?

Answer 1

ascomyota

Question 2

What is the appearance of aspergillus?

Answer 2

flowering- stalk with spores which germinate and form hyphae

Question 3

Where does the cryptococcus neoformans that we breathe in all the time from?

Answer 3

trees and pigeons

Question 4

Who gets cryptococcus neoformans?

Answer 4

people with defects in T cells e.g HIV/AIDs

Question 5

How does cryptococcus avoid phagocytosis?

Answer 5

forms a capsule

Question 6

Why does candida cause endophthalmitis?

Answer 6

gets stuck in microcapillaries

Question 7

What are the opsonins in fungal infections?

Answer 7

pentraxin 3 and MBL

Question 8

What type of T cells are protective in fungal infection?

Answer 8

Th1 and Th17

Question 9

What are the 2 forms of candida?

Answer 9

yeast (circular cell form) and hyphal forms

Question 10

Why does transitions between different forms of fungus cause problems in the host?

Answer 10

causes switching between protective (Th1/Th17) and non-protective (Th2) responses

Question 11

What is aspergillus species inhaled as?

Answer 11

conidia

Question 12

What form does aspergillus invade tissues as?

Answer 12

hyphae

Question 13

What is the classic DAMP signalling in fungal recognition?

Answer 13

S100B-RAGE

Question 14

What receptors are involved in the phagocytosis of fungi?

Answer 14

CTLRs, not TLRs

Question 15

What 2 pathways are downstream of dectin-1 signalling?

Answer 15

inflammasome and NFkB

Question 16

What does dectin-1 deficiency result in?

Answer 16

reduced IL-6 production and binding to candida–mucocutaneous fungal infections

Question 17

What is required for NFkB activation by dectin-1?

Answer 17

CARD9

Question 18

What does homozygous CARD9 mutation result in?

Answer 18

chronic mucocutaneous candidiasis

Question 19

What cytokine is CARD9 required for production in response to beta-glucans?

Answer 19

TNFa

Question 20

How is CARD9 invovled in T cell differentiation?

Answer 20

required for T cell Th17 differentiation

Question 21

Deficiency in what TLR results in greater susceptibility to aspergillosis?

Answer 21

TLR4

Question 22

What effect does plasminogen have aspergillosis defense?

Answer 22

directly binds to aspergillus conidia and decreases susceptibility

Question 23

How are macrophage depleted mice affected with aspergillus fumigatus?

Answer 23

not any more susceptible

Question 24

Which cells are most important in defense against invasive aspergillosis?

Answer 24

neutrophils - as without have no ability to clear the infection

Question 25

What effect does NET production have on aspergillus?

Answer 25

traps fungus and stops from germinating

Question 26

How does the fungal morphogenesis affect T cell differentation?

Answer 26

different morphotypes are phagocytsed through different modalities by DCs which results in different mautration states

Question 27

What is the effect of coiling phagocytosis vs zipper-type on DC maturation?

Answer 27

coiling results in increased IL-12 production whereas zipper-type results in increased IL-4 and IL10 production

Question 28

What type of phagocytosis is used for single cell fungal morphology?

Answer 28

coiling

Question 29

What type of phagocytosis is used for hyphase forms of fungi?

Answer 29

zipper-type

Question 30

How does IFNy therapy aggect invasive fungal infection?

Answer 30

enhances clearance by down-regulating IL-10 and causing a burst of inflammatory cytokine expression

Question 31

What is required for NET formation?

Answer 31

ROS production

Question 32

What are the emerging possibilities in the treatment of fungal infections?

Answer 32

IFN-y injections and adoptive T cells therapy (generation of antifungal T cells from stem cells and then injected in patients)

Question 33

What are the main infections in patietns with CGD?

Answer 33

staph. and fungal infections

Question 34

What are the common aspergillus species in the environment?

Answer 34

aspergillus niger and aspergillus fumigatus

Question 35

What does the damage response framework describe?

Answer 35

that too weak or strong host responses to microbes can result in disease and death

Question 36

What patients have a much higher incidence of mould allergy?

Answer 36

asthmatics

Question 37

What are the 2 types of hypersensitivty reactions inovlved in ABPA?

Answer 37

type I and IV

Question 38

What type of hypersensitivty reaction is hypersensitivity pneumonitis?

Answer 38

type III and IV

Question 39

What is the main fungus invovled in allergy?

Answer 39

aspergillus

Question 40

Why is there a suggestion that some of the damage in allergic disease to aspergillosis is autoimmune?

Answer 40

there is cross-reactiivity of one of hte main aspergillus allergens with human cyclophylin

Question 41

What does ABPA stand for?

Answer 41

allergic bronchopulmonary aspergillosis

Question 42

What diseases predispose to ABPA?

Answer 42

CF and asthma

Question 43

What does hyphae formation allow the fungus to do?

Answer 43

germinate and proliferate

Question 44

What are the obligatory criteria for ABPA?

Answer 44

IgE >1000; positive skin prick or aspergillus specific IgE

Question 45

What are the radiological features of ABPA?

Answer 45

dilated bronchi with thick walls; ring/linear opacities; upper/central region prediliction; proximal bronchiectasis; lobar colllapse due to mucous impaction; fibrotic scarring

Question 46

What sign is seen on CT with ABPA?

Answer 46

hyper dense mucus sign

Question 47

What is the mainstya of treatment for ABPA?

Answer 47

steroids

Question 48

What can be used as a steroid sparing agent in ABPA?

Answer 48

itraconazole

Question 49

What is aspergillus rhinosinusitis associated with?

Answer 49

atopy and nasal polyposis

Question 50

What is seen on imaging with aspergillus rhinosinusitis?

Answer 50

obliterated sinuses with hypo-attenuated mucosa and enhancing material

Question 51

What are the 3 main cell wall components of funal species?

Answer 51

beta-glucans; chitin; mannans

Question 52

What is the function of galectin 3 in fungal infection?

Answer 52

allows aphgocytes to discriminate between pathogenic and non-pathogenic yeats through recognition of beta-mannosides

Question 53

What is the function of dectin-2 in fungal immunity?

Answer 53

high mannose structures that are common to many fungi and binds hyphal forms with higher affinity than yeast forms

Question 54

What type of fungus infection are dectin-2 deficient mice susceptible to?

Answer 54

C.albicans but not C.neoformans

Question 55

What other receptor does dectin-2 pair with to induce pro-inflammatory cytokines?

Answer 55

Fc receptor y chain

Question 56

What is the function of DC-SIGN?

Answer 56

recognises N-linked mannans, and directs mannosylated fungal antigens into the DC endocytic pathway promoting antigen processing and presentation to T cells

Question 57

What effect on fungal immunity does a polymorphism in TLR4 have ?

Answer 57

increased susceptibility to pulmonary aspergillosis and bloodstream candidiasis

Question 58

What fungal disease is a polymorphism in the promoter region of TLR9 associated with?

Answer 58

ABPA

Question 59

What allows fungal escape of C.albicans by dectin-1?

Answer 59

beta glucans are exposed in the bud scar of C.albicans yeasts but masked on hyphae

Question 60

How does P.jireveci evade immunosurveillance?

Answer 60

changes the expression of major surface glycoproteins

Question 61

What is the function of hte capsule of C.neoformans?

Answer 61

completely covers the fungal cell wall and prevetns recognition by PRRs and the induction of inflammation

Question 62

What might explain how c.neoformans establishes latency and spreads in the host wtihout triggering inflammation?

Answer 62

are able to escape from macrophages through an expulsive mechanism that does not kill the host cell and avoids inflammation