Zusammenfassung der Ressource
MIIM20001 - immunity
- Innate
Anmerkungen:
- -molecule recognised by immune system
- dendritic cells
Anmerkungen:
- - antigen presenting cells
> recognise PAMPs via TLR.
- MHC I & II expressed
- immature forms phagocytic
- macrophages
Anmerkungen:
- - present antigen to T cells
- highly motile
- remove apoptotic/ dead cells/ waste
- secrete TNF-a
> helps regulate inflammatory response
- Phagocytosis
Anmerkungen:
- - receptors that recognise opsinins which increases adherence of pathogen to phagocytic cell surface
- ingested material to lysosome
- Danger
Anmerkungen:
- - NK cells respond to changes in expression of self proteins.
- MHC I good recognition
- Stranger
Anmerkungen:
- - recognition of novel microbial structure (PAMPs)
- via pattern recognition molecules
> mannose receptors
> RNA helicases (notice viral RNA structures)
- Tol like receptors (TLRs)
> TLR4 (LPS - gram negative bacteria)
>TLR2 (peptidoglycan - gram positive)
>TLR5 (Flagellin)
- NK cells
Anmerkungen:
- - important in anti-viral response
- directly lyse cells
- secrete anti-viral cytokines
- activation by peptides
- mast cells
Anmerkungen:
- - found only in tissues
- 2 types
> mucosal
> connective tissue
- important in response to helminthes
- cytokines
- Interferons (IFN)
Anmerkungen:
- - blockage of transcription & translation in viral cells
- upregulate MHC molecules
> impact on adaptive immunity
- Chemokines
Anmerkungen:
- Interleukens (IL)
Anmerkungen:
- - change permeability of blood vessels
- Tumour necrosis factor (TNF)
Anmerkungen:
- - IL12
- favours strong cell mediated response (CTL & macrophage)
- transforming growth factor B
Anmerkungen:
- - promotes IgA production
- IL4 --> igE (helminth immunity)
- acquired
- non self and self differentiation
- naive T cells
Anmerkungen:
- - never recognise antigen
- need 2 signals for activation
>TCR/MHC interaction
> co-stimulation (CD28/CD80)
- most bodily cells do not express CD80
- no costimulation = death
- engagement of TLRs will induce CD80 expression of cell.
- derived from bone marrow
- Primary lymphoid
- 2 types
- humoral
Anmerkungen:
- antibody mediated
- B cells
Anmerkungen:
- - Surface Ig recognition
- bind directly to antigen
- Bone marrow
- memory B cells
- plasma cells
Anmerkungen:
- - mature activated B cell
- secrete antibodies
- antigen binding
- epitopes
Anmerkungen:
- - denaturation results in loss of epitopes
- conformational
- linear
- antibodies
- neutralization
Anmerkungen:
- - blocks binding of pathogen to cell surface
- causes disruption to conformational changes --> opsinization
> changes to cell surface of pathogen increasing phagocytation
- complement lysis
Anmerkungen:
- - cells coated with antibody and c3b protein
> increases binding and phagocytosis
- antibody binds through multiple Fc regions.
- C1 binds antibody --> produce inflammatory mediators and pore forming mediators
- cellular toxicity (ADCC)
Anmerkungen:
- - NK cells kill cells coated by antibody
- do NOT remove free antigen
- naive B cells
- Ig secretion
- IgM
Anmerkungen:
- - Pentamer
- J chain linkage
- activate complement
- high valency
- IgG
Anmerkungen:
- - Major component of serum
- major class in secondary response
- bind to Fc receptors expressed by macrophages & monocytes & NK cells.
- cross placental activation of compliment ability
-
- IgA
Anmerkungen:
- - monomer = surface
- dimer = secreted
> J chain
- mucosal sites
- transported across epithelial sites when it has secretory component
- IgE
Anmerkungen:
- - lowest component of serum
- actively secreted monomer
- important in parasitic response
- allergic reaction
- IgD
Anmerkungen:
- - low amounts in serum
- monomer
- structurally similar to IgG
- doesn't cross placenta
- no gene coding for secretion
- secreted via cleavage from cell surface
- receptor function
- no activation of compliment
- cellular
- T cell mediated
- cell-cell interaction
- T cell
Anmerkungen:
- -T - cell to T cell surface interaction
- don't bind directly to antigen
- Thymus
- CD8+/CD4+
- recognise antigen via TCR
> unique receptor/ T cell
> receptors bind to short linear peptides made via proteolysis
> recognised by MHC
- MHC
- Class I
Anmerkungen:
- - expressed on all nucleated cells
- once expressed they are killed by CTL
- Bind peptides bound in cytoplasm and in ER lumen
- Class II
Anmerkungen:
- - expressed only on B cells or dendritic cells & macrophages
- can stimulate T(H) cells.
- peptides displayed generated in endosomal network.
- education
Anmerkungen:
- - T cells that survive process express TCR and have low affinity for self MHC molecules
- TCR first expressed in thymus
- two types of selection
- positive
Anmerkungen:
- - TCR has no capacity to bind any self MHC molecule = death
- negative
Anmerkungen:
- - TCR binds self MHC too tightly = cell death
- Effector
- Helper T cells
Anmerkungen:
- - CD4+
- help CTL B cells & macrophages
- good motility e.g. survey skin
- Th1
Anmerkungen:
- Th2
Anmerkungen:
- Th17
Anmerkungen:
- - inflamation/ autoimmunity
- Treg
Anmerkungen:
- Cytotoxic T Lymphocytes (CTL)
Anmerkungen:
- - CD8+
- kill in response to effected cells
- restricted to tissue with initial infection
- NK cells (NKT)
Anmerkungen:
- - don't recognise antigens
- activation by glycolipids
- memory
- type of response
- viral
Anmerkungen:
- - never Th2
- IFNg and IL12 and IL18 = Th1 (IL2 & IFNg --> strong cell mediated response)
- virons
Anmerkungen:
- - attack via innate factors and antibodies
- infected cells
Anmerkungen:
- - attack via interferons
> affect replication life cycle- attack via NK/T cells
> lyse infected cells (CD8 secrete cytokines IFNg)
- activate macrophages (CD4 IFNg)
> helps CD8 cells
> helps B cells (class switching)
- Virus specific antibodies
Anmerkungen:
- - neautralise virus
- fix complement
- enhance phagocytosis via opsinisation
- facilitate ADCC
- bacterial
- innate
Anmerkungen:
- - activation of complement
- phagocytosis
- activation of phagocytic cells
> these secrete cytokines and inflammatory mediators
- kill microbes and normal tissue
- adaptive
Anmerkungen:
- - CD4 T cell releases IFNg = Th1 (IL2 & IFNg)
- innate cells with IFNg --> cell mediated
- innate cells with IL4 = Th2 which is antibody mediated
- helminthes
Anmerkungen:
- - never Th1
- release of IL4 by innate cells = Th2 which releases IL4, IL5, and IL6 = class switching to IgE which is a strong antibody mediated response