Lecture 4 Flashcards
why is microbial dna recognized in our immune systems but our host rna not usually
methylation: bacterial dna is methylated
what would happen if you take foreign rna and then you inject it into a mice
If you took rna and youin ject into a mice, it would develop a robust immuneresponse aka that’s problematic= compromises its ability to be transcribed into proteins that can be used for vaccination or vaccine candidate
How can we suppress the immune response to foreign RNA?
-use tnf-a in a cell line
-lipifectin : detergent, lipophilic, so that it can get into the cell: was the empty vector to carry the rna into the cell
-We need the rna to get into the cell so that it can then be translated
Mammalian RNA was pretty much the same as us except for…
Mammalian RNA was pretty much the same as us except for mitochondria rna because it is the closest to bacterial rna aka the powerhouse. If the mitochondria is in trouble, then the cells are in trouble
experiment with the immune response and foreign rna: results
-They had basically no baseline induction of TNF-a and when they gave PolyIC which is a agonist of different TLR like tlr 7and R-848 which is another agonist that activates TLR-7 and TLR-8 to mimic a viral sensing that induce a robust TNF-a response
-If they just generated naked RNA in vitro and then gave rnase to degrade that rna, they don’t get a response, it is a nice control
-When they looked at mammalian rna, they found very similar effect of the lack of a response to this, except for mitochondrial rna because we acquired mitochondria from bacteria
what happens if the mitochondrial membrane is compromised
got compromised and that the mitochondrial DNA got out of the mitochondria, we would get a strong immune response
true or false: rna modifications have different immunostimulatory capacities
true
rna can be modifies through…
- different processes like methylation and that this could then shape how it is able to become recognized by different TLRs
true or false: viruses can alsi modify their rna to be able to not be sensed by bacteria ex: bacteriophages
true
true or false: tlrs only respond to one thing
false they respond to different modifications
Different modifications to a greater extend lead to ….
Different modifications to a greater extend lead to certain TLR activation ( TLR 3,7 and 8)
what are the advantages of cell lines
-highly control systems: we know exactly what they are going to express
-primary cells are harder to get
-easier to to access
disadvantages to cell lines
-we don’t have the normal beig activated in cell lines
-We basically fuse them to a tumor cell which makes them proliferate but we don’t get the normal pathways because they are disturbed due to the tumor cell
-We dunno if these signaling pathways that are working in cells lines will be able to work in primary cell lines
-Primary cell like: use your blood or tissue
true or false: certain modifications to rna will completely eliminate responses
true
Certain modifications to RNA will completely eliminate response because some of the modifications: how did they come to that conclusion
-There was this particularly this modification where they combines the methylation of the arginine M6A and the pseudo uridine, when they put those 2 thing together on the same rna they completely eliminated the response
-But if they took rna that had the either of these modifications and then mixed these 2 cells: they still got a response
=There is an additional signal that is inhibited by the combination of the pseudo uridine and the methylated arginine on the same rna as opposed to individual because just mixing the 2 together still elicited the response too
=Whatever happened with the pseudo uridine was not sufficient to inhibit the response same with the methylated arginine
what are rlr able to recognize?
viral dsdna that has the M6A modification
true or false: there is only one type of DCs
false there are 2
true or false: different dc respond differently depending on the stimulus they receive
true
dc2 usually produce…
Dc2 will usually produce INF-a and not type one interferon
true or false: one modification will elicit one type of response in one dc but to in the other type
true
The capacity of RNA to induce DCs to mature and secrete cytokines depends ….
The capacity of RNA to induce DCs to mature and secrete cytokines depends on the DC subtype and the characteristics of nucleoside modifications present in RNA
The Rig like receptor activated a unique pathways independent of….
The Rig like receptor activated a unique pathways independent of MyD88 that acts through MABS which then stimulate mitochondrial activation to release factors from the mitochondrial membrane go to the nucleus and then stimulate type 1 interferon production, but this has no antiviral activity in and of itself, this is a 2 step process: fundamental to understand how we fight viral infections
what is a paracrine system
it is basically when one infected cell is like omg I am infected by secreting type 1 interferon so that the other cells can kill it
Type 1 interferons signals to other cells that
Type 1 interferons signals to other cells that secrete interferon stimulated genes, those genes have direct antiviral activity to kill the infected cells