Prezentace aplikace PowerPoint

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INNATE IMMUNITY BASIC MECHANISMS
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determines context for specific immunity
fylogenetically conserved
relationship to other systems
INNATE IMMUNITY
identification of danger patterns
immediate reactivity
ontogenically conserved
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natural cytotoxicity
interferons
complement system
INNATE IMMUNITY
phagocytosis
macrophages dendritic cells
granulocytes
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identification of danger patterns
processing and presentation of antigens
exogenous
endogenous
dendritic cells
macrophages
context for specific recognition
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IDENTIFICATION OF PATHOGEN ASSOCIATED MOLECULAR
PATERNS (PAMPS)
lipoteichoic acide
peptidoglycan, lipoprotein
sacharide
polyanions
pathogenicity island
phosphoryl cholin
TLR2
LPS
TLR4
CpG
TLR9
pentraxins (CRP)
LPS
LBP
LECTIN
SCAVENGER RECEPTOR
cell activation
IL-1R
CD14
IL-1R
LPS
IL-1R
MyD88
DD
DD
TRAF6
NIK
CR
C3b
IRAK
I-?B
I-?B
NF-?B
ubiquitination degradation
NF-?B
cell activation
Y
activation of complement by lectin
TRANSCRIPTION
NF-?B
NF-?B
IL-1
IL-6
IL-8
IL-12
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immunopathology
tumor
infection
dendritic cells macrophages
killing of intracellular microbes
ACTIVATION
CYTOKINES
TH1 TH2
polarisation
stimulation of hematopoiesis
pluripotent proinflammatory
chemokines
INFLAMMATION
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ROLE OF DENDRITIC CELL IN INNATE IMMUNITY
capture and processing of antigens in tissues
presentation of antigens to T cells
DENDRITIC CELL
migration into lymphatic nodes
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ROLE OF GRANULOCYTES IN INNATE IMMUNITY
GRANULOCYTES
stimuli
exo-
endo-
hematopoiesis
activation
professional phagocytes
cytokines
adhesion to endothelia
inflammation
diapedesis
killing and destroying of microbes
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ROLE OF INTERFERONS IN INNATE IMMUNITY

most important humoral factors of innate
immunity inducible induced by viral
(microbial) agents, nucleic acids active
after binding to cell receptors protect against
viral infections immunomodulatory activity
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II nd class INF ? (TH1)
I st class INF ?,?,?
immunomodulatory activities
antiviral activity
proinflammatory activities
INTERFERONS
antimicrobial activity
?cytotoxicity
?expression HLA II
T ly
NK
antiproliferative activity
anticancer activity
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ANTIVIRAL ACTION OF INTERFERONS
infected cell
interferons
Jak STAT
uninfected cell
interference with viral proteosynthesis
cleveage of viral nucleic acid
VIRAL UNRESPONSIVNESS
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ANTIVIRAL ACTION OF INTERFERONS
inhibition of viral proteosyntesis
degradation of mRNA
RIBOSOM
mRNA
A
U
A U
U A
G
ElF4
ElF3
ElF2
C
UA
P
PKR active
P
ElF4
ElF2
RNAáza L aktivní
P
GTP
ElF2
Met
dsRNA ATP
Met
ElF3
PKR inactive
RNAáza L inaktivní
induction of protein kinasis (PKR)
IFN receptor
IFN
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COMPLEMENT SYSTEM
humoral factor of innate immunity
COMPLEMENT SYSTEM  
synthesis
hepatocytes
30 plasma and membrane proteins
macrophages
amplification cascade
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FUNCTION OF COMPLEMENT SYSTEM  
anafylactic
cytolytic
elimination of immune complexes
opsoniziing
proinflammatory
chemotactic
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NOMENCLATURE OF COMPLEMENT SYSTEM
components of complement system C1 C9 factors
of complement system
designed by capital letters (P, B, D,
H) enzymatically active complex
(C4b2a) fragments of complement system
small letters (a, b)
fragment b enzymatically active (C3b)
fragment a anafylactically active (C3a)
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ACTIVATION OF COMPLEMENT SYSTEM
enhanced activation cascade principle
- proactivation conditions
- active enzyme (serine protease)
- cleveage of the next component
- active enzyme formation tight
regulation of activation on several levels C3, C5
convertases formation are crucial steps of
activation
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AMPLIFICATION CASCADE
stimuli (microbial, contact activation,
coagulation)
resting component (factor) of complement system
proteolytically active
activation (proteolytic cleveage)
proinflammatory anafylactic, chemoattractive acti
vities
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CLASSICAL PATHWAY OF ACTIVATION OF COMPLEMENT
SYSTEME
starts on complex AgAb (IgM, IgG1, IgG3)
aggregates of immunoglobulins C3
convertase C4b2a C5 convertase
C4b2a3b
LECTIN PATHWAY OF ACTIVATION OF COMPLEMENT
SYSTEME
specific manose sugar residues are identified by
MBP (manose binding protein - lectin) MASP
serine protease is consequently activated
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ALTERNATIVE PATHWAY OF ACTIVATION OF COMPLEMENT
SYSTEME
spontaneous C3 component activation in the
presence of H2O activated C3b is rapidly
deactivated in the absence of proactivation
conditions C3b is not deactivated in the
presence of proactivation molecules.
proactivation molecules of either microbial
origin (surfaces, LPS, teichoic acid) or
agregates of immunoglobulins or arteficial
surfaces C3 convertases PC3bBb
C5 convertases PC3bBbC3b
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TERMINAL STEPS OF ACTIVATION OF COMPLEMENT
SYSTEME
alternative and classical pathways of complement
activation are separated C5 activation
level solid phase is necessary for C3 and C5
convertases formation small fragments (C5a,
C4a) with anafylactic and chemotactic activity
are formed
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ACTIVATION OF COMPLEMENT
lectine pathway
alternative pathway
classical pathway
C1q, r, s
MBP
MASP
C3 convertases of either classical or
alternative pathway
C5 convertases of either classical or
alternative pathway
complex MAC
lysis
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TERMINAL PHASE OF COMPLEMENT ACTIVATION
unified for both pathways nonenzymatic, starts
from membrane bound C5b component conformational
changes of complement components membrane attack
complex (MAC) formation cell membrane perforation
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MEMBRANE REGULATION OF COMPLEMENT ACTIVATION
the expression of membrane regulatory proteins
which prevent MAC complex formation protectin
(CD59) decay accelerating factor (DAF. CD55)
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RECEPTORS FOR COMPONENTS OF COMPLEMENT
expressed on T and B cells (regulation of their
functions) expressed on phagocytes
(opsonisation) expressed on erythrocytes
(immune complexes elimination) CD classified
(CD 35, CD21, CD11)
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COMPLEMENT SYSTEM - CLINICAL REMARKS
INHERITED DEFECTS are very rare early components
deficiency prone to immunopathological
diseases (SLE) C1 esterase deficiency
hereditary angioedema late components
deficiency susceptibility to
meningoccocal infections
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COMPLEMENT SYSTEM - CLINICAL REMARKS
ACQUIRED DEFECTS frequent in systemic tissue
disorders (SLE) enhanced complement activation
in dialysis, extracorporal
circuits deregulated activation of complement
in patients with systemic inflammatory
response syndrome (SIRS)
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COMPLEMENT SYSTEM - LABORATORY REMARKS
all components, factors and activation fragments
of complement could be determined
immunochemically C3, C4 components are acute
phase proteins evaluation of activation of
complement in vitro (CH50 level)
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PHAGOCYTOSIS
cell factor of innate immunity

macrophages
presentation of antigens
dendritic cells
granulocytes
PHAGOCYTOSIS
is the ability of specialised cells to
engulf to kill to destroy microbes and
foreign particules
source of cytokines
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MONOCYTE - MACROPHAGES

• long-living tissue cells
• principal source of pluripotent
• proinflammatory cytokines
• processing and presentation of antigens to T
  cells
• immunoregulatory functions- killing
• of intracellular microbes (M. tuberculosis)

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GRANULOCYTES
professional phagocytes short-lived blood
cells rapid turnover (G-CSF) highly glycosylated
surface molecule CD15 cytoplasmic granules
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PHAGOCYTOSIS
activation adhesion chemotaxis
ingestion killing and destruction
ACTIVATION RESULTS IN
increased genes transcription increased
metabolic activity changes in cell shape
changes in cytoskeleton changes in surface
molecules
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ACTIVATION OF PHAGOCYTES
EXOGENOUS
ENDOGENOUS
proinflammatory cytokines
C3a C5a PAF LT
bacterial components LPS, CpG, danger
patterns (PAMP)
chemokines
CSF
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ACTIVATION OF PHAGOCYTES
changes in membrane molecules expression
changes in cytoskelet
changes in metabolism
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ADHESION
activated granulocytes
activated endotelial cells
DIAPEDESIS
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A D H E S I O N

• firm adherence of activated neutrophils
• to activated endothelial cells
• is prerequisited for diapedesis
• mediated through the specific interactions
• between adhesion molecules and their ligands
• expression of adhesion molecules is inducibile
• (under cytokine control)
• selective adhesion together with chemokine
  signalling
• is responsible for selective migration
• of different leukocyte populations

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ADHESION MOLECULES
families are subdivided according to their
structural characteristics
FAMILY OF IMMUNOGLOBULINS
immunoglobuline domain ICAM-1, 2, 3 VCAM-1 many
others
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FAMILY OF INTEGRINS
heterodimers (?, ? chains) common type of ? chain
determinates subfamily of integrins ?1 (CD29)
integrins - VLA molecules - ligands
are molecules of ECM (collagen) ?2 (CD18)
integrins - leukocyte integrins -
LFA-1 (CD11a/CD18) - ligand
is ICAM-1 (CD54) ?3 integrins -
cytoadhesins - platelets
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FAMILY OF SELECTINS
terminal part of molecule is lectin-like ligands
are sugars absent on resting cells rapidly
mobilized from intracellular stores
E-selectin (CD62E) - activated endothelia -
ligand is a sugar on CD15 molecule P-selectin
(CD62P) - activated platelets - activated
endothelia - ligands are various glycosylated
molecules
(PSGL-1, CD 162) L-selectin (CD62L) -
leukocytes - ligand is CD34 molecule
on endothelium
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CADHERINS
IMMUNOGLOBULINS ICAM-1, 2, 3, VCAM-1
SELECTINS E, P, L - selectins sugar ligands
ADHESION MOLECULES
INTEGRINS heterodimers
?7 homing
?1 integrins (VLA) ECM binding
?3 integrins cytoadhesins
?2 integrins leukocytic (LFA-1)
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ADHESION MOLECULES
proinflammatory cytokines, chemokines
inducibile
macrophages dendritic cells
immuno- pathology
infection
tumor
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1ST STEP OF ADHESION
rapid upregulation (minutes) of selectin
molecules on endothelial cells by the action
of proinflammatory cytokines interaction
between E-selectin and CD15 weak interaction
(tethering) rolling of leukocytes on
activated endothelia
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IST STEP OF ADHESION, SELECTINE MEDIATED
collagens
IMMUNOPATHOLOGY
a1 b1
fibronectin
a1 b1
INFECTION
proinflammatory proadhesive signals
a3 b1
MALIGNANCY
MACROPHAGE
CD62E
IL-1 TNF?
CD34
CD62P
E-CADHERIN
CHEMOATTRACTANTS
CD15
CD62L
PECAM-1
PSGL-1
ENDOTHEL
GRANULOCYTE
rolling
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2ND STEP OF ADHESION
firm adhesion interaction between LFA-1 and
ICAM-1 signaling outside-in

inside-out cell
spreading
3RD STEP OF ADHESION
diapedesis into tissues
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II ND STEP OF ADHESION
A C T I V A TION
C-X-C CHEMOKINES
ENDOTHELIA
MACROPHAGES
C-C CHEMOKINES
ICAM-1
VCAM-1
VLA-4
LFA-1
ICAM-1
DIAPEDESIS
EOSINOPHIL
LFA-1
? b2
NEUTROPHIL
?3CYTOADHESINS
FIBRINOGEN vWF
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non-random movement of granulocytes in the
gradient of chemoattractants
endogennous chemoattractants
complement C5a, C3a
CHEMOTAXIS
chemokines
exogennous chemoattractants
CXC
CC
ELR
ELR-
microbial products
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CHEMOTAXIS
serpentin receptors for chemoattractants
diapedesis
binding of chemokines on proteoglykans and
erythrocytes, neutralisation of biological
activity of chemokines
ECM degradation MMP, TIMP
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INGESTION
close contact with microbe is prerequisited opsoni
ns specific antibodies
complement components
CRP surface receptors for
Fc fragment of immunoglobulins
C3b component of complement
lectins ?
sugars interactions phagosome is fused with
cytoplasmic granules
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INGESTION
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INTRACELLULAR KILLING AND
DEGRADATION
O2 independent
O2 dependent
defensins
NADPH oxidase
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NEUTROPHIL GRANULOCYTE - GRANULE CONTENT
primary granule
? defensins ? MPO ? lysosyme ? BPI ? lactoferin ?
cathepsin-G ? elastase ? proteinase-3
secondary granule
? cytochrome b558 ? integrins ? lysosyme
? lactoferin ? collagenase
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N A D P H OXIDASE
Rap1A
gp 91
gp91
p22
p 22
Rap1A
rac2
P
rac2
p47
P
OH
P
p67
p47
OH
p67
OH

Rac 1
p40
ACTIVATED
RESTING
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OXYGEN INTERMEDIATES GENERATION
H2O2 H2O
HOCl
1O2
Cl-

singlet oxygen
MYELOPER- OXIDASE
FENTONS REACTION
O2- O2
Fe2 Fe3
e
H
H2O
H2O2
OH
O2-
O2
H2O
superoxide anion
hydroxyl radical
SUPEROXIDE DISMUTASE
NADPH OXIDASE
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DEFECTS OF PHAGOCYTOSIS
PRIMARY
inherited defects of granulocyte
production deficiency of adhesion molecules
LAD-2 syndrome (deficit of sugars on
CD15) LAD-1 syndrome (absence of
? chain of LFA1) defect of chemotaxis (lazy
leukocytes) deficiency of defensins deficiency
of myeloperoxidase defect in NADPH complex
(CGD, chronic granulomatous disease)
SECONDARY
idiopathic,
caused by infection or by
therapy granulocytopenias low level of
opsonins