JMacSharry lecture II Flashcards
name and describe three components of the inflammatory response to fungal respiratory infection
- recognition: PRR, TLRs, NLRs on epithelia and phagocytes (macrophages, neutrophils, DCs, mast cells)
- recruitment: cytokine secretion to attract leukocytes and plasma components, neutrophils
- resolution: successful acute response eliminates infection, resolution and repair by tissue resident macrophages
what does neutrophil degranulation release
defensins, AMPs, histamine, prostaglandins, ROS, proteinase, cathepsin, elastase.
name virulence factors of cyrcryptococcus spp.
capsid and melanin
by what age do humans normally develop Abs to C. neoformans
normally develop Ab to this by school age
what can cryptococcus spp cause in IC patients>
it can cause pneumonia
what can cryptococcus spp cause in non-immunocompromised patients
an asymptomatic latent infection
what is C. neoformans typically abundant in?
avian excreta
how do naturally acquired cases of cryptococcosis occur?
by inhalation of fungal cells from the environment.
what can happen after development of latent infection
dissemination of latent infection, most notably to the CNS.
What happens when cryptococcosis reaches the CNS?
overwhelming infection of the meninges and brain tissue, often accompanied by increase in intracranial pressure if there is no treatment.
cryptococci tend to be _ _. driving much lower levels of _-inflammatory cytokines
immunologically inert, pro.
name the complex carbohydrates which form the cryptococcal capsule?
glucuronoxylomannan (GXM) and galactoxylomannan (GalXM)
when GalXM and GXM are shed, what TF is inhibited and causes what?
inhibition of NF-kB to dampen levels of pro-inflammatory cytokines
cryptococcus spp block DC maturation, how?
by reducing both MHC class II-dependent antigen presentation and inhibiting the production of proinflammatory cytokines IL-12 and IL-23
mainly _ mycoses in immunocompromised
opportunistic
yeast example
candida albicans/candida spp yeast-like
cryptococcus neoformans yeast-like, bird faeces
mould example
aspergillus fumigatus
cryptococcus neoformans is found commonly from?
pigeon droppings
where does cryptococcus neoformans usually infect?
respiratory tract
how does cryptococcus neoformans typically present, esp. in immunocompromised
usually presents as Meningitis in IC (T cell deficient like HIV-AIDS)
how is cryptococcus neoformas typically diagnoses
lung wash or lung biopsy
describe the pathogenesis of cryptococcus neoformans?
alter M1 and Th1 pathways from their typical inflammtory pathway to something more typcial of the allergy pathway of Th2 and M2
why are cryptococcus neoformans so good at avoiding macrophages
this is because they grow among amoeba which macrophages have descended from
aspergillus fumigatus, describe
spore-forming mould, ubiquitous, opportunistic
how does aspergillus fumigatus infect?
inhaled spores
pulmonary aspergillosis
allergic form, allergic bronchopulmonary aspergillosis (ABPA) causing wheeze, cough, eosinophilia.
aspergilloma
inhaled spores enter pre-existing cavity (from previous TB infection), can be asymptomatic, cough, haeoptysis, dyspnoea, weight loss, fatigue, can also involve sinuses and ear canal
