Recap 3 Flashcards
LPS binding receptors
TLR4 = NLR inflammasome and produce ILB
CD14 = activate endocytosis
What are some secreted PRR
Collagenous lectin = mannan-binding lectins A et C
Ficolins
Surfactant proteins A (SP-A) et D
Conglutin (cattle)
What can NFkB and p38 induce (exception)?
Phagocytosis, DC activation, release inflamm cytokines, active innate immune system
TLR4 signaling = doesn’t engage MyD88 = form IFNy
TLR3 et 4 independent of MyD88
Through what do TLR and C-type lectin regulate innate and adaptive responses?
NFkB, TFAP-1, IRF
Mechanisms of NLR
Binding of NLR -> activate RIPK2 -> induce NFkB (facteur de transcription) = secretion of antimicrobial peptides, inflamm mediators, MAPK active for gene transcription and regulation of autophagy
Composition of NALP3 inflammasome
Release of
Multimeric protein units consits of NLR sensing molecule, ASC adaptor protein, caspase 1
Release of IL1B, IL18, IL33
What are alarmins?
Sulfate, hyaluronan, heat schock protein (HSP60), Gp96 (endoplasmic reticulum), fibronectin, fibrinogen, SP-A
Generate inflammation against neoplastic cells, toxins, mechanical injury
Can induce NLRP3
TNF and IL1 induce endothelial expression of integrin ligand :
1. VCAM-1
2. ICAM-1
3. PECAM-1
4. JAM A-B-C
- VCAM-1 - ligand for B1 integrin VLA4
- ICAM = LFA-1, MAC-1
- PECAM = on endothelial cell membrane
- JAM = mediate adherence activity
Where does leucocytes migration happen?
Mainly in postcapillary venules
Organisation of filopodia of leucocytes for migration
Polymerization of actin at the leading edge (VLA3 binds fibronectin) and localization of myosine at the back (tail anchored by LFA1)
Molecules causing mast cells degranulation
Fce-R to IgE
Substance P (released from C-reactive nerve fibers)
Granules of eosinophils
Small = arylsulphatase, acid phosphatase, MMP, gelatinase
Primary
Large Sp secondary = Major basic protein (MBP = inhibe heparin), cationic protein, eosinophil-derived neurotoxin, eosinophil peroxydase, histamine, lysosomal enzyme
Eosinophils produce which cytokine
IL1 à 6, 8-10-12-16, GM-CSF, TGFa et B, chemokines
Chemoattractants of eosinophils
Histamine
Eosinophil chemotactic factor A (from mast cells)
C5a
IL4-5-13
Chemokines (CCL5/RANTES, CCL11/eotaxin)
NK cells (sentinel) receptors and products
CD161 not CD3
Type I = 95% express CD56 produce IFNy
Type II = lack CD56 produce IL4, IL5, IL13 (Th2 response)
Regulation of active and inactive NK (sentinel)
IL21 regulates differenciation
Inactive stimulated by Flt-3 ligand, IL4, IL12, IL15, IL21
Activated leads to upregulation of CD16 and IFNy
R for NK-LT
CD3+
Recognize CD1d = induce release of IFNy, IL4, GM-CSF
Subtypes of IgG y Fc-R
ITAM domain = macro activation
ITIM domain = inhibe activation
How are ROS produced ? Damage cell?
Rapid assembly and activation of a multicomponent oxidase called NADPH oxidase = réduit NADPH en O2-
Damage through lipids peroxydation, cross-link of proteins, oxide thiol groups on methionine and cysteine, cleave glycoconjugates, directly damage DNA
Microbicide action of neutrophils
Azurophilic granules contain MPO = converts H2O2 to HOCl (hypochlorite = bleach)
Destroy microbes by halogenation or peroxidation
Antioxidant
1. Enzymatic
2. Non enzymatic endogene
3. Non enzymatic dietary
- SOD, catalase, thioredoxin, peroxiredoxin, glutathione peroxidase
- Ceruloplasmin, transferrin, metallothionein, uric acid, melatonin
- VitA, C, E, lycopenes, flavonoids, resveratol, genistein, anthocyanin, naringenin, reserpines
Action of NO
VasoD, inhibe platelets aggregat, inhibe mast cell induced inflammation, oxidizes lipids, regulates chemotaxis
In macrophages interacts with superoxide to generate ONOO-
What do neutral proteases of neutrophils do?
Cleave C3 and C5 complement and release kinin-like peptide from kininogen
What do macrophages contain?q
Acid hydrolase, collagenase, elastase, phospholipase, plasminogen activator
What does lyzozyme do?
Hydrolyzes the muramic acid-N-acetylglucosamine bond found in the glycopeptide coat of all bacteria
Action of defensin, cathelicidin
Forms pores in microbial membrane
Affects chemotaxis and activation of adaptive response
Action of elastase, inhibition
Hydrolyzes bacterial cell wall and tissue elastin
A1-antitrypsin = major inhibitor of neutrophil elastas e
What does the release of deoxyadenosine by Staph aureus do?
Enzymes that degrade NET