Protein Protein Interactions: The Inflammasome Mark D. Wewers, M.D. Davis Heart and Lung Research...
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Transcript of Protein Protein Interactions: The Inflammasome Mark D. Wewers, M.D. Davis Heart and Lung Research...
Protein Protein Interactions:The Inflammasome
Mark D. Wewers, M.D.
Davis Heart and Lung Research Institute
Outline of Presentation
• Innate vs. Adaptive Immunity
• Focus on TLR and NLRs
• Pyrogens (endogenous and exogenous)
• Intracellular sensors/inflammasomes– Example of intracellular pathogen– Example of population differences in
pathogen responses (caspase-12)
Lewis Thomas: The Lives of a Cell 1974
“Our arsenals for fighting off bacteria are so powerful andinvolve so many different defense mechanisms that we are more indanger from them than from the invaders.
We live in the midst of explosive devices, we are mined….When we sense lipopolysaccharide, we are likely to turn on everydefense at our disposal…”
How can our defense repertoire cover the enormous diversity in pathogen
challenges?• Innate host response:
– Static defense system– Focus on immutable components of pathogens (e.g.,
cell wall component)
• Acquired host response:– Creative ability to change with pathogen– Depends upon the acquisition of recombinase gene
(RAG)
News from the Genome Project that has expanded our understanding of the innate host response repertoire.
NATURE | VOL 411 | 14 JUNE 2001
Guard Hypothesis
Dangl, J. et al.
NB-LRR protein dissociates due to pathogen
NB-LRR protein binds target complex due to pathogen binding to complex
CATERPILLER: A Large Family of Mammalian Genes Containing CARD, Pyrin, Nucleotide-binding, and Leucine-Rich Repeat Domains
Harton JA et al. J. Immunol. 169:4088, 2002.
CARD/PYD NBDLRR
Toll like receptors and the Signalosome
signalosome
gene expression
proteasome
NFBNFBIB
IKK complex
TLR
*
NFBNFB
100’ s of genesincluding IL-1 and TNF
CARD NBDLRR
CARD NBDLRRCARD
NBDLRRpyrin
CARD NBDLRR
pyrin CARD
NBDLRRpyrin CARD
ASC
NALP1
IPAF
NOD1
NOD2
NALP3
IL-1
proIL-1
Caspase-5
NALP-1
NOD-2
TLR
ASC
CARD domain
pyrin domain
inflammasome
CASPASE-1
Martinon, F et al. Mol.Cell 10:417-426, 2002.
A B
DC
Francisella as Model of Inflammasome Activation
Gavrilin MA, PNAS 103:141, 2006.
F. novicida
E. coli
F. n. heat-killed
F. n. + cytochalasin D
-1-1
-1-1
-1-1
-1-1
-1-1
-1-1
-1-1
-1
-1-1
-1 -1-1-1-1
-1-1-1-1
-1-1
-1-1-1-1
-1-1
Phagosome Escape Induces Inflammasome Assembly
IL-1
proIL-1
phagosome
F.novicida
Mo LVS F.nov E.coli LVS F.nov E.coli LVS F.nov E.coli
live killed endotoxin
31 kDa
17 kDa
A. IL-1 mRNA B. IL-1 in media C. IL-1 in cell extract
0
1000
2000
3000
4000
Un
stim
ula
ted
LV
S
F.n
ov
E.c
oli
LV
S
F.n
ov
E.c
oli
LV
S
F.n
ov
E.c
oli
RC
N
live killed endotoxin
0
20
40
60
80
100
Uns
timul
ated
LVS
F.n
ov
E.c
oli
LVS
F.n
ov
E.c
oli
LVS
F.n
ov
E.c
oli
ng
/ml
live killed endotoxin
D. IL-8 mRNA E. IL-8 in media F. Protein/RNA Ratio
F. novicida induces both mRNA and processing and release of IL-1
Gavrilin MA, PNAS 103:141, 2006.
Toll like receptors and the Signalosome
gene expression
proteasome
NFBNFBIB
IKK complex
TLR
*
NFBNFB
100’s of genesincluding IL-1 and TNF
signalosome
proIL-1
Caspase-12L (active) versus Caspase-12S (inactive) Allelic
DistributionThe American Journal of Human Genetics Volume 78 April 2006
Source Total (n)
Genotype Frequency (%) Allele Frequency (%)
T/T T/C C/C T C
Sepsis 38 60.5 29 10.5 75 25
Control 148 81.1 17.6 1.3 89.9 10.1
Caspase-12L Linked to Sepsis
Saleh M. Nature 429:75, 2004.