Fungal Immunity Flashcards Preview

Y2 MCD - Microbiology - Laz DC > Fungal Immunity > Flashcards

Flashcards in Fungal Immunity Deck (23)
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1

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

Ascomycota – MAIN ONE
Basidiomycota
Chytridiomycota
Zygomycota

2

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

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

3

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

TLR

4

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

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

5

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

TLR4 S4 – loss of function
Dectin 1
Plasminogen alleles

6

Which PRR is actively recruited to Aspergillus fumigatusphagolysosomes?

TLR9

7

What can plasminogen directly bind to?

Aspergillus fumigatus conidia

8

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

Neutrophils

9

What do neutrophils release that enable them to trap Aspergillus?

NETs

10

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

Hyphal forms = Th2 response
Conidium = Th1 response

11

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

IFN-gamma

12

Describe the principles of adoptive immunotherapy for fungal infection.

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

13

Give an example of gene therapy for chronic granulomatous disorder.

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

14

What types of hypersensitivity reaction are associated with fungal allergies?

Type 1, 3 and 4

15

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

Asthma
Cystic fibrosis

16

What is the obligatory criteria for ABPA?

Total baseline serum IgE > 1000 IU/ml
Positive immediate hypersensitivity skin test or Aspergillus-specific IgE

17

List some supportive criteria for ABPA.

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

18

List some radiological features of ABPA.

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

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

Hyper dense mucous sign

20

Describe the main treatment options for ABPA.

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

21

List three other examples of fungal allergies, including associated features of each.

Aspergillus rhinosinusitis
 May be allergic or invasive
 Obliterated sinuses
 Treated with oral corticosteroids
Severe asthma with fungal sensitisation
 Fungal sensitisation as a potential cause of severe asthma
 Requires exclusion of ABPA
 Treatment with anti-fungal unclear
Hypersensitivity pneumonitis (extrinsic allergic alveolitis)
 Allergy requires long-term exposure to allergen (often occupational)

22

What test is used to diagnose fungal allergies?

Skin prick testing

23

Which type of hypersensitivity is each of the previously mentioned fungal allergies?

ABPA – type 1 or 4
Asthma – type 1
Rhinitis – type 1
Hypersensitivity pneumonitis – type 4