immunity to viruses and fungi Flashcards
virus infects epithelial cells and ____ amongst them
infected cells respond by producing ____ (which acts in an autocrine/paracrine manner (which helps to slow spread of virus)
replicates
type I interferons (e.g. IFN-alpha)
local effects of IFN-alpha (Type I interferons):
inhibition of ____ ____ replication
up-regulation of MHC ____ molecules
viral gene
MHC I
DC response to virus:
- 1Tissue DCs recognize viral particles and release dhemokines to attract other immune cells, primarily ____
- cytokine ____ for neutrophils
- ____/____ for monocytes
- ____ activation occurs to allow circulating cells into the tissue
- Ag carrying DCs will migrate to ____ where they will activate T cells
- APCs
- IL-8
- MIP-1/MCP-1
- endothelial
- LNs
some locally released cytokines from cells such as tissue macrophages (e.g. ____ , and ____ ) enter bloodstream and have systemic effects of fever, acute phase response, and arthralgia/myalgia)
IL-1 and TNF-alpha
DCs travel to LNs to T cell zone presenting viral peptides:
- naive T cells that recognize peptides become ____ cells
- naive B cells that acquire viral particles through attachment to surface IgM or IgD process and present viral peptides to Th cells, and in turn receive positive growth and differentiation signals. ____ antiviral Ab is produced as a result (some B cells differentiate and class switch leading later to production of high affinity antiviral ____ ) (this is conisdered a secondary Ab response)
- T helper
- IgM IgG
Th1 cells produce ____ taht activate strong proliferation of virus-specific CTLs
____ and ____ increase the resistant of CTLs to apoptosis
IL-2
IL-2 and IFN-gamma
Th and CTLs leave the LN via the ____ towards other lymph nodes and ultimately enter the ____
lymphatics
blood
NK cells can be recruited at 2 points during the virus infection:
- early innate antiviral role following activation by epithelium-derived cytokines and macrophage-derived ____
- later stage wehre they are activated by ____ producing Th1 cells specific the the virus
- IL-12
- IL-2
NK cells target cells that don’t constitiutively express MHC ____ . these are typically very stressed cells, normally by ____ of mutations
MHC I
viruses
macrophage resopnse to virus:
- clear ____ particles
- clear ____ debris
- cytokine production ( ____ and ____ )
- viral
- cellular
- IL-1 and TNF
virus-infected cells secrete and excrete viral proteins. these may be neutralized of removed by ____ in the form of immune complexes which are cleared, or Ab may be used to guide Fc receptor-expressing NK cells activating ____
Ab
ADCC (antibody dependent cell-mediated cytotoxicity)
after resolution of the infection, virus-specific memory T and B cells reside long term in the ____ , ____ , and ____ ____
LNs, spleen, bone marrow
CTLs:
- activated by ____ via cross-presentation on ____ with cytokines (____ and ____ ) from T helper cells
- klling of virus infected cells with ____ presentation
- DCs MHC I
IFN-gamma and IL-2
- MHC I
primary immune responses to viral infection:
innate immunity is mediated by ____ which prevent infection, and ____ cells which eliminate infected cells
adaptive immunity is mediated by ____ which block infection, and ____ which kill infected cells
Type I IFN (e.g. IFN-alpha) NK
antibodies CTLs
fungi are recognized by ____ binding the PAMPs
dectin-1 is a recently decovered PRR that binds ____
PRRs (present on macrophages and DCs)
beta-glucan (cell wall)
