Defence against specific Fungi Flashcards
phagocytosis of candida albicans is activated by
complement
phagocytosis of candida triggers
production of ROS
Interaction of cell wall component such as mannoproteins and b-glucan with phagocyte receptors such as TLR2 an lectin 1 stimulates release of
IL-1, IL-6 and TNF
how can cytokines promote activation of the adaptive immune system
production of cytokines by activated neutrophils, together with direct interactions of neutrophils with dendritic cells within inflammatory sites promotes maturation of dendritic cells, such that the adaptive immunity becomes activates
where does the commensal fungus candida albicans colonise
the normal human oral gastrointestinal and urogenital mucosa - disruption of mucosal barriers leads to persistent superficial infections
thursh
a superficial infection of the oral mucosa
Candida esophagitis are
common opportunistic infections in patients with HIV
in the setting o compromised immunity
infections can disseminate to cause life-threatening infections of virtually any organ
which is the most common infection in humans
Candida
how common are candida infection in the US
4th most common nosocomial blood stream infections
- costs $1 billion per year
how to candida rpeorduce
asexually via budding
when does candida switch from yeast form to filamentous
when changes occur in microenvironment
- changes in pH, cell density, exposure to serum and iron deprivation
the ability of candida to switch morphologies has been linked to
pathogencitity
yeast form more easily
disseminated through bloodstream
filamentous form facilitates
invasion and evasion of phagocytosis
candida mutants unable to make the
dimorphic switch are commonly non-pathogenic in animal models
Chromoblastomycosis and Fonsecaea pedrosoi
are non-fatal disease of skin and subcutaneous tissues
where does Chromoblastomycosis and Fonsecaea pedrosoi frequently occur
in tropical and sub tropical regions of America, asia and africa
when do infections causes by Chromoblastomycosis and Fonsecaea pedrosoi occur
following transcutaneous trauma
- chronic disease that can take decades to develop (polymorphic skin lesion)
- difficult to treament
why is F. pedrosoi so pathogenic
F.pedrosoi does not stimulate TLR2- meaning not enough of an inflammatory response (TNF production0 occurs
-if an artificial agonist like Pam is introduced which stimulates TLr2, then an appropriate inflammatory response can be mounted
F. pedrosoi binds to
MINCLE
