26/03 Flashcards
Differences between DAMPs and PAMPs
DAMPs: damage associated molecular patterns, series of molecules released by dying cells
PAMPs: pathogen associated molecular patterns, unspecific molecules present on the surface of pathogens
Which mediators can we find inside the granules of basophils and mast cells? (according to the timing of the production)
- Pre-formed mediators constitutively present: histamine, serotonin, proteases, TNF-α… They’re immediately released after the recognition of alarm signals
- Synthesized after few minutes after the degranulation of the first granules: thromboxane, prostaglandins, leukotrienes. They have to recruit neutrophils in the area
- Synthetized hours after activation: cytokines and chemokines. They recruit the proper cells needed to fight against the pathogen. They’re called “latter mediators” because they need the transcription of new genes
Which receptor recognize DAMPs and PAMPs? On which cells it’s present
PRM: pattern recognition molecules.
Soluble or expressed by innate leukocytes, macrophages or dendritic cells
Which are the components of the innate response?
anatomical barriers
physiological barriers: pH, enzymes
PRM
Complement
Inflammation
Phagocytosis and target cell lysis: mediated by innate cells
Which are the characteristic molecules with anti-bacterial activity (chemical barriers)?
- peptides: lysozymes, beta defensin, cathelicidin, , pentraxin
- alarmins
- cytokines
- chemokines
What’s the role of lysozyme? Where can we find it?
It can break the 1-4 glycosidic bond connecting N-acetylmuramic acid and N-acetylglucosamine. It destroy expecially GRAM+ walls.
It’s produced by salivary glands, paneth cells, granulocytes
Structure and role of cathelicidin
small anti-microbial peptide always present as precursor. When cleaved they can destroy the lipoproteic membrane of bacteria
Pentraxin: structure and role
cyclic pentameric molecule that binds to the surface of microbes. They’re considered PRM
Which different kind of mucosae we can have?
mucosa of the lips and the mouth
bronchial
digestive
rectal
immune cells: percentages of presence in the blood
basophils: 0-1,5
neutrophils: 40-74
eosinophils: 0-7
monocytes: 3,4-9
lymphocytes: 19-48
Examples of DAMPs and PAMPs
DAMPs: heat-shock proteins, altered membrane phospholipids, complement products
PAMPs: nucleic acids, surface glycoproteins, membrane components
Which are the function of neutrophils?
Sentinel activity
Phagocytosis
Spiderman effect: DNA net to capture the bacteria
Kamikaze effect
Which are the most important functions of eosinophils?
anti-helminthic activity, anti-tumor activity, phagocytosis
What are monocytes and in what can they differentiate?
They’re small cells with a V-shaped nucleus and no granules.
They can differentiate in tissues’ macrophages or dendritic cells
Which type of dendric cells can we have?
- Conventional dendritic cells (immature): they’re able to phagocyte
o Conventional (es: resident cells like Langerhans)
o Plasmacytoid: produces interferon - Mature dendritic cells: they’re the professional antigen presenting cells
Which ligands can activate a NK cell?
Hemagglutinin
Stress ligand (MICA, MICB)
HLA or MHC molecules
Which cytokines are released by NK cells?
- IL2: increase lytic activity and degranulation of NK cells
- IL4: decrease lytic activity of NK cells
- IL15: important for maintenance and proliferation of NK cells
- GM-CSF: induce the bone marrow to produce neutrophils, eosinophils and monocytes
- INF-γ: it’s active on T cells and macrophages
How did we get the information on hematopoies and the cell that are formed?
All the information about these cells and progenitors were made thanks to single cell transcriptomic analysis. We discovered that they mature differently because of different patterns of transcription in the nucleus or in the cytosol (epigenetic memory).
