Fungal Immunity Flashcards

1
Q

What are the four main phyla of fungi and which most commonly causes human fungal infection?

A

Ascomycota – MAIN ONE
Basidiomycota
Chytridiomycota
Zygomycota

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2
Q

Give examples of how the morphogesis of fungi contributes to its ability to cause disease in the host.

A

Candida albicans exist as single spores which normally affect mucosal tissues but they can become hyphae, which allows tissue invasion
Cryptococcus neoformans forms a capsule to evade phagocytosis
Aspergillus sp. are inhaled as conidia and invade tissues as hyphae

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3
Q

Which pattern recognition receptors are important in detection of fungal pathogens?

A

TLR- toll like receptor

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4
Q

Name 2 deficiencies that are associated with an increased risk of chronic mucocutaneous candidiasis.

A
Dectin 1 (involved in activation of an inflammatory cytokine response) 
CARD 9 (downstream of Dectin 1)
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5
Q

Name 3 factors that are associated with increased risk of Aspergillosis in transplantation.

A

TLR4 S4 – loss of function
Dectin 1
Plasminogen alleles

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6
Q

Which PRR is actively recruited to Aspergillus fumigatusphagolysosomes?

A

TLR9

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7
Q

What can plasminogen directly bind to?

A

Aspergillus fumigatus conidia

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8
Q

Which cells are the most important in defence against fungal infection?

A

Neutrophils- especially aspergillus

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9
Q

What do neutrophils release that enable them to trap Aspergillus?

A

NETs

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10
Q

Describe how fungal morphogenesis governs the dendritic cell modulation of adaptive immunity.

A

Hyphal forms = Th2 response

Conidium = Th1 response

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11
Q

What cytokine therapy has been shown to enhance clearance ofinvasive fungal infection?

A

IFN-gamma

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12
Q

Describe the principles of adoptive immunotherapy for fungal infection.

A

If a patient is receiving a stem cell transplant, you can generate anti-fungal T cells, which can be cultured in large numbers and administered to the patient

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13
Q

Give an example of gene therapy for chronic granulomatous disorder.

A

Restoration of gp91 function
This is involved in the generation of NADPH oxidase – this generates reactive oxygen species, which is required to kill microbes
NOTE: another type of gene therapy = restoration of neutrophil NET formation

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14
Q

What types of hypersensitivity reaction are associated with fungal allergies?

A

Type 1, 3 and 4

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15
Q

What are two predisposing conditions for allergic bronchopulmonary aspergillosis (ABPA)?

A

Asthma

Cystic fibrosis

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16
Q

What is the obligatory criteria for ABPA?

A

Total baseline serum IgE > 1000 IU/ml

Positive immediate hypersensitivity skin test or Aspergillus-specific IgE

17
Q

List some supportive criteria for ABPA.

A

Eosinophilia > 500 cells/ul
Serum precipitating or IgG antibodies to Aspergillus fumigatus
Consistent radiographic abnormalities

18
Q

List some radiological features of ABPA.

A
Dilated bronchi with thick walls  
Proximal bronchiectasis  
Ring or linear opacities  
Upper or central region predilection  
Lobar collapse due to mucous impaction  
Fibrotic scarring
19
Q

What might be seen in a CT scan of a patient with ABPA?

A

Hyper dense mucous sign

20
Q

Describe the main treatment options for ABPA.

A

Corticosteroids
Itraconazole may be used as a steroid-sparing agent
Recombinant anti-IgE antibodies (omalizumab) may be useful

21
Q

What test is used to diagnose fungal allergies?

A

Skin prick testing

IgE and IgM

22
Q

Overview of immunity to fungal infections

A

Opsonisation occurs
Phagocytes important first line defense
NK cells produce interferon gamma
Dendritic cells produce cytokines to affect t-cell differentiation
TH1 and Th17 play a role
MUCOSAL IMMUNITY TENDS TO DETERMINE RESPONSE AND IS MOST IMPORTANT

23
Q

What do fungae normally exist as

A

Unicellular oragnisms

24
Q

What is name given to when when become multicellular

A

Hypha

25
Q

How do dectin 1 and card 9 deficiencies lead to increased risk of fungal infections

A

These are found on phagocytes- their pathway activation leads to inflammatory response and cytokine production

26
Q

Do we inhale may fungal spores daily

A

yes

27
Q

What happens when host response to fungal inhalation is inadequate

A

Invasive fungal disease

28
Q

What happens when fungal inhalation response is exaggerated

A

Allergy- asthma or rhinitis

29
Q

Main driver between fungal allergy and disease

A

Aspergillis