Lec 2: Arms of the Immune System Flashcards
Innate Immunity
Recognition of molecular motifs with invariant non-rearranging receptors
similar or same response each time
fast (within minutes or hours)
all cells mount innate responses to varying degrees, epigenetic changes to increase the robustness of the initial respose can act as a “memory” sort of
Adaptive immunity
recognition of antigens with receptors that rearrange for enhanced specificity
improved response to repeat exposure
SLow (5-6 days)
has memory and is mediated by B and T cells
Adaptive immunity may be divided into what two catagories
Humoral immunity = B cells, and the production of antibodies
Cellular Immunity = T cells, these kill cells and direct the adaptive immune response
Why does the magnitude and speed of the immune respose increase with repeated exposure
Adoption and increase of specificity of an antibody to a specific antigen
Tolerance
The B and T cells which are selected for are non-responsive// weakly respoinsive to the cells// antigens of the host
Plasma proteins are also known as
reactive proteins
serum is
the non clotting and a cellular component of the blood
Intrinsic immunity
Sub-catagory of the innate immune system
innate immunity can be activated, but intrinsic immunity is always present
consituitvely passive immunity in most cells of the body, but expression is enhanced by innate immunit signalling
basal expression is independent of IRF3, STAT1 and IFN signalling
restriction factors
cellular proteiins that directy restrict pathogen replication and assembly
clotting factors and bacteria for example
intrinsic immunity
Antimicrobial peptides
part of intrinsic immunity
these are built into mast cells and exhibit antimicrobial activity towards bacteria, viruses and fungi
What does it mean when you say that the innate immunity is non-specific
It means that innate immunity only recognizes components of a given pathogen
ex// the cell wall of S. aureus, not the microbe it’self
What PRRs are the innate immune system mediated by
Toll like receptors (TLRs) RIG like receptors (RLRs) Nod like recep[tors (NLRs) C-type lectin receptors (CLRs) Orphan receptors
Which cell is the important link between the innate immune system and the adaptive immune system
Dendridic cell
Which transcription factors activate the innate immune system
Interferon response factors (IRFs)
Nuclear factor kappa B (NF-kB)
PAMPs
Pathogen associated molecular patterns
Bacterial or viral proteins Bacterial or viral DNA Viral RNA Foreign glycans Toxins
DAMPs
Damage associated molecular patterns
Location is super important, not just the signal
Damaged cells
Intracellualr host proteins
Host RNA, DNA and purine metabolites in the wrong compartment
Which TLR does peptidoglycan bind to
TLR2
Gram positives
Which TLR does Lipoteichoic acid bind to
TLR2
TLR6
Gram Postives
Which TLR does Lipopolysaccharide bind to
TLR4
Gram negatives
Why might TLRs be on cell surfaces
TLRs might be on a cell surface because it allows recognition before a cell is infected, or allows for the identification of microorganisms that only infect or colonize surfaces of cells
How do TLRs detect cololonization on the outside of the cell
leusine rich repeats
TIR Domain
Dimer formed by TLR and PAMP on the initial protein adapter on the cytoplasmic domain
WHy might TLRs be in endosomes
For engulfment of bacteria or when infected with a virus
What is triggered by PRR activation
IFNs
ISGs
Proinflammatory cytokines