Cytokines etc for Immunology Flashcards
TNF-alpha [Function, source]
Function: pro-inflammatory
- enhance adaptive immunity
- active endothelial cells [inflammation, coagulation]
- activate neutrophils
- fever [systemic effects of acute phase response]
Source: macrophages, T cells
IL-1 [B] [Function, source]
Function: pro-inflammatory
- fuel acute inflammation
- fever [systemic effects of acute phase response]
- enhance adaptive immunity
- active endothelial [ inflammation/coagulation]
- in liver: synthesis acute phase proteins
- catabolism –> cachexia
Source: macrophages, endothelial cells
Nitric oxide [Function, source]
Function
- aid in killing of microbes
Source: macrophages
IFN-gamma [Function, source]
Function
1. NK cells release to activate macrophage to kill phagocytosed microbe
2. membrane attack complex activation
Source: NK cells, Th1 cells
C3a [Function]
Function
- activate inflammatory cells
- recruit phagocytosis by macrophages
- chemoattraction
- activate macrophages to make cytokines
C3b [Function]
Function
- opsonization of pathogens
- phagocytosis of immune complexes
C5a [Function]
Function
- mediator of Inflammation
- recruit phagocytosis by macrophages
- chemoattraction
- activate macrophages to make cytokines
IL-12 [Function, source]
Function
1. increase cytotoxic activity of NK and T cells
2. increase IFN-gamma production NK/T cells
3. Induce Th1 differentiation
4. membrane attack complex activation
5. involved in macrophage activation [indirecrly via IFN gamma]
Source: dendritic, macrophages
Type 1 IFNs [IFN-a, IFN-B] [Function, source]
Function = primary barrier to viral infection
1. increase class I MHC expression in all cells
2. activate NK cells
Source: a- dendritic, macrophages; b- fibroblasts
IL-10 [Function, source]
Function 1. inhibit IL-12 production 2. reduced expression costimulators 3. reduce expression MHC II molecules Source: macrophages, dendritic, T cells
IL-6 [Function, source]
Function: Pro-inflammatory
1. in liver: synthesis of acute phase proteins
2. activate B cell proliferation
3. induces Th17 differentiation [along with TGFB]
Source: macrophages, endothelial cells, T cells
IL-15 [Function, source]
Function
1. activate NK cell proliferation
2. activate T cell proliferation
Source: macrophages
Il-18 [Function, source]
Function
1. activate NK and T cells to produce IFN-gamma
Source: macrophages
Membrane attack complex [what makes it up, function]
C5b - C9
- lysis of pathogens and cells
C1q inhibitor [C1qINH] [function/mech]
regulate complement by:
- blocking classical pathway initiation
Factor H [Function/mech]
regulate complement by:
- inactivating C3 and C4 convertases
- works with factor I and membrane cofactor protein
- protects from complement activation in exposed basement membrane [kidney, eye]
CD55 (Decay Accelerating Factor) [Function/mech]
regulate complement by:
- accelerating decay of C3 convertase on cell surface
CD59 (Protectin) [Function/mech]
regulate complement by:
- Blocking membrane attack complex formation by blocking C9
What is mech of factor B and D?
- bind C3b on cell surface
- amplify downstream complement
What 3 cofactors work together to degrade C3B? Into what?
- Factor I, membrane cofactor protein, factor H
- don’t get amplification of C3b signal instead get iC3b that is an opsinin
what is function of membrane cofactor protein?
inhibits C3 convertase
What is DM? What type of MHC? T cell? Function?
- intracellular protein involved in peptide presentation
- MHC Class II
- CD4
- promotes dissociation CLIP [placeholder peptide] rom MHC II to allow to bind antigen
What is TAP? What type of MHC? T Cell? Which path of antigen processing?
- transporter protein associated with antigen processing
- MHC class I
- CD8 T Cell
- endogenous pathway
What main cytokine does NK cell secrete? What other cytokine released by macrophages activates this secretion?
- NK makes IFN-gamma
- in response to IL-12 released by macrophages
What complement pathways involve C4?
- classical
- mannose-binding lectin
How is complement a bridge to adaptive immunity? [2 mech]
- C3b binds Cr1/2 on B cell and lowers activation threshold and enhances Ab production
- upregulations co-stimulation molecules
What is function RAG1 and 2?
- VDJ recombinase enzymes
- generate diversity in b/t cell development
What is CD3? Function? Where expressed?
- expressed on T cells
- stabilized TCR and leads to signalling downstream of activated TCR
Th1 [What induces it, what cytokines it expresses, function]
- induced by IL-2, IL-12
- secretes IFN-g –> activates macrophages to promote degradation ingested pathogens
- work against bacteria
- helps B cells make complement fixing antibodies, respiratory burst, macrophages
Th2 [What induces it, what cytokines it expresses, function]
- induced by Il-4, Il-5, Il-9, IL-3
- secretes IL-4 and IL-5, Il-10
- promotes B cell production antibodies [IgE]
- work in allergy/against helminth, anti-parasitic
Th17 [What induces it, what cytokines it expresses, function]
- induced by IL-6 and TGF-B
- secretes IL-17
- activates/recruits neutrophils + macrophages
- may play role in autoimmune
T regs [2 types, what cytokines it expresses, function]
- FoxP3 cells and TRs that secrete IL-10, TGF-B
- suppresses surrounding immune response
- may play role in suppressing autoimmunity [IBD]
TGF-B [function, source]
- Induces Th17 differentation along with IL-6
- regulatory cytokine secreted by T regs
source: T regs
IL-4 [function, source]
function
- induce class switching to IgE
source: TH2 CD4 cells
Il-5 [function, source]
function
- recruit/activate eosinophils [which bring histamine
source: TH2 CD4 cells
IL-17 [function, source]
function source: TH17 CD4 cells
Two costimulatory signals [which molec on T cell vs pAPC, activated vs naive T cell]
- CD28 on naive T cell binds B7 on APC
- CD40L on activated T cell binds CD40 on APC
IgG [major function, what cytokine induces]
- most abundant, fixes complement
- class switching induced by IFN-gamma [TH1]
IgA [major function, what cytokine induces]
- mucosal immunity [gut, lung]
- class switching induced by TGFB
IgE [major function, what cytokine induces]
- anti-helminth, allergy
- class switching induced by IL-4
What is ITIM?
- downregulates/shuts down B cell antibody production
What part of Ig changed in class switching?
constant region
Activation Induced Deaminase [AID] [function]
- somatic hypermutaton/affinity maturation in secondary response of B cell
Do CTLs need costimulation?
Once activated they don’t!
What two things to CTL release
- perforin and granzymes
2 Mech of ADCC
- IgG bound to pathogen-infected cell binds NK cell, Nk cell releases cytokines like IFN-gamma and kills cell
- IgE bound to parasite binds eosinophil, eosinophil degranulates to kill cell
Il-13
secreted in type I hypersensitiviy
