8. Acute Inflammation IV Flashcards
REVIEW: LAD
LAD1 - genetic mutation in which expression of one subunit of ___ is reduced, cannot adhere to EC, and the neutrophils cannot transmigrate > display susceptibility to infection; severe LAD1: expression of integrin by ___ > not survive past few months, delayed umbilical cord separation and infection will spreads; moderate LAD1: recurrent infection, manifests as gingivitis/periodont
LAD2 - defect in earlier molecule > if ligand for ___ is absent > neutrophil will not roll > cannot firmly adhere > similar manifestation
LAD3 - integrins expressed normally, but they must be activated by chemokines and then aggregate on surface and bind ICAM1 (surface of endo); cannot ___ them, cannot bind ___ > same phenotypes as LAD-I, but they also have ___ > mutation in gene is also present in ___ of bleeding
b-integrin
98%
selectin
activate
ICAM-1
bleeding disorders
homeostasis
Direct migration of leukocytes in response to a gradient of chemoattractants
Bc of tissue injury, the first cell activated is the ___ > release of histamine > firstly, causes ___ and increase in ___ (redness, heat, swelling are a result of this)
Initiates neutrophil recruitment/rolling: histamine also acts on vascular endothelial cells > ___ on endo cells > upon histamine binding: presynthesized selectin gets translocated from cytosol into membrane quickly
Macrophages produce ___ and ___ > major target: endo cells > increase ___ gene expression, and the expression of ___
Macrophages also produce ___ > activate integrin on surface of leukocytes, also induce chemotaxis
And then ___ is also an important chemoattractant
Concentration of cytokines is highest closest to the ___ > this gradient is important, no gradient = no ___
mast cells
vasodilation
vascular permeability
P-selectin
TNFalpha
IL1
E-selectin
ICAM1
chemokines
complement (C5a)
microbe
migration
Chemotaxis: Directed Cell Movement
Exogenous:
- ___ products;
- ___ peptide
Endogenous:
- complement pathway: ___ and ___
- lipid-derived mediators: ___
- cytokines, particularly those of the chemokine family (e.g., ___)
Exogenous:
Can be produced from microbes and host; from microbes (mostly) is exogenous (N-formyl-methionyl peptide), receptors for this is on surface of ___ > migration
Endogenous:
Activation of complement > C3a: more important for ___ activation thereby inducing ___
in early phase; and C5a: more important on ___ activation
Lipid derived mediator (LTB4) > important ___ chemoattractant; produced from ___ and ___
Cytokines (IL-8) is important for inducing ___
Defects in chemotaxis > increased risk of aggressive infection, and in oral cavity > ___
bacterial
n-formyl-methionyl
C3a
C5a
leukotriene B4
IL-8
neutrophil
mast cell
degranulation
neutrophi
neutrophil
macrophages
mast cells
chemotaxis
gingivitis/periodontitis
Recognition of microbes > receptors for chemoattractants (___ domain, GPCR) > upon activation > ___ changes and signal transduction > increased avidity > ___ of neutrophils on endothelium; followed by chemotaxis
TLR > amplify ___ signals
Release of ___ and ___ > result of phagocytic receptors (can also phagocytose microbe into phagosome), cytokine receptors and TLR
7 TM
cytoskeletal
adhesion
inflammatory
lysosomal enzyme
ROS
Why is this cell called neutrophil/PMN?
• Primary granules – Azurophilic – \_\_\_, BPO, LL-37, Elastase, Cathapsin • Secondary granules – \_\_\_ • Tertiary granules – \_\_\_ • All granules contain \_\_\_
- Small ___ apparatus
- Sparse ___ and ribosomes
- No ___
- ___ for energy production
- Phagocytosis/Respiratory burst /degranulation
Produced in ___, short-lived, only function is to phagocytosis
Do not require oxygen for ATP production, consumption occurs when activated > ___ (creation of free radicals)
the primary granules are the most important, can view them as lysosomes that digest ___ materials
MPO
lectoferrin
gelatinase
lysoszymes
golgi
mitochondria
rough ER
glycolysis
BM
respiratory burst
phagocytosed
Phagocytosis: 3 steps
___
___
___
Firstly, neutrophil must recognize the microbe, and then neutrophil must engulf (phagosome formation), and then contents of lysosome released into phagosome > phagolysosome, and then all mediators are released into the PL > degradation of microbe
recognition
engulfment
killing/degradation
Opsonization and Phagosome Formation • Phagocytosis – Opsonins; • IgG (\_\_\_) • C3b (Complement receptors 1 and 3 (\_\_\_) – Phagosome: • A cellular compartment in which a pathogenic microorganisms can be killed and digested. – Killing and degradation:
IgG and C3b > bind ___, and prepare them to be phagocytosed; there is a ___ receptor on neutrophil, and ___ for C3b thereby promoting binding and recognition
FcgammaR
CR1/CR3
microbes
FcgammaR
CR1/CR3
Killing and Degradation of Microbes
[LOOK AT SLIDE FOR DIAGRAM]
Respiratory burst:
NADPH oxidase > present on surface of ___ (membrane) > consists of 6 subunits > normally ___
Upon formation of phagolysosome it becomes ___ > transfers electron from ___ > conversion of oxygen into oxygen radicals > ___ dismutation > ___ (by itself this is not efficient) (oxygen ___)
Phagolysosome > primary granules > ___ > combine with H2O2 to produce ___ (___ acid, constitutive of bleach) > digests microbes (oxygen ___)
There are other important proteins: ___ released from granules (produced from neutrophils); ___ is an anti-micro peptide that punches hole in membrane (produced from neutrophils, ___ 37 ___ peptide); and ___ that degrades bacterial coat
phagosome inactive active NADPH spontaneous H2O2 dependent
MPO
HOCl
hypochlorous
independent
BPI LL37 leucine-leucine AA lysozyme
Chronic Granulomatous Disease
- Etiology/Pathogenesis:
- Mutations: Functional inactivation of ___ (phox) gene
- Inability to generate ___
- Clinical manifestation:
- Recurrent ___ infection
- Most susceptible to ___ bacteria.
- ___ skin infections
- Abscesses
- ___
- Gingivitis
Mutation in one of six subunits that prevents the aggregation of all ___ for proper function
Chronic granulomatous disease > more susceptible to catalase-positive bacteria > breaks down H2O2 into H2O; if the individual cannot produce H2O2 and the bacteria is reducing further, then the patient is more ___
Similar to symptoms of ___ and ___
phagocyte NADPH oxidase
ROS
bacterial
catalase-positive
superficial
cellulitis
subunits
susceptible
LAD
neutropenia
Chronic Granulomatous Disease (CGD)
[CASE REPORT]
Unresponsive to antibiotic
___ > catalase-positive organism
High WBC
High PMN % (50-70%)
Normal sialyl lewis X on surface of leukocytes > not ___
Normal CD11b/CD18 > not ___, but can potentially have LAD3 (expression is normal, but activation is defective)
Normal chemotaxis > no problem with leukocyte rolling and diapedesis
Abnormal respiratory burst > ___
___ infiltrate > do not see presence of neutrophils (recruitment of monocytes); however, there are neutrophils located in the abscess
Take neutrophil from normal individual, and test to kill microbes > 100% death; but take from CGD > bacteria ___ (killing is diminished, but there is some killing observed)
Diagnose: test ___, or genetically test for the ___ of the gene
Treatment: antibiotics, but also the presence of ___ > antifungals, ___ > cytokine, produced by T cells and activates macrophages, ___ therapy
This mutation only occurs in leukocytes, side effects of gene therapy [???]
burkholderia
LAD2
LAD1
CGD
mononuclear
persists
respiratory burst
subunit
fungus
INFgamma
HCT/gene
Chediak-Higashi Syndrome
- Etiology/Pathogenesis:
- Mutation in ___.
- Abnormal ___ formation
- Melanocytes: large ___
- Neutrophils: giant ___ granules
- Clinical manifestation:
- Identified in ___
- Oculocutaneous Albinism
- ___
- Gray Hair color
- Recurrent ___ infection
- ___
- Oral Ulceration
- ___ diseases
• Diagnosis: ___ smear
Easy diagnosis: take a blood smear; normal > PMN and the neutral granular components; CHS > ___ is relatively normal, but the ___ become large
• Treatment: ___, ___ transplantation (HTC)
lysosomal trafficking modulator gene (CH51/LYST)
lysosome
granules
azurophilic
infancy/childhood photophobia bacterial gingivitis periodontal
blood
nucleus
granules
antibiotics
hematopoietic cell transplantation (HTC)
Papillon-Lefevre Syndrome • Mutation and loss of \_\_\_ gene (\_\_\_ protease) • \_\_\_ development and \_\_\_ function • \_\_\_ Keratoderma and Periodontitis • Antimicrobial peptide \_\_\_ in neutrophils • Treatment: – Skin lesions: \_\_\_ (acitretin) – Periodontisis -\_\_\_ + \_\_\_ and \_\_\_ control
LL37: synthesized as a precursor (pro-LL37) > in order to become activated, the serine protease must cleave it > LOF in this ___ > no production of LL37
Palmoplantar Keratoderma > palms/soles have abnormal ___ > can see at a very early age > main reason is because of lack of production of LL37
cathepsin C serine skin neutrophil palmoplantar LL37 retinoid antibiotics plaque calculus protease thickening
Beneficial Suicide (NETosis): Why neutrophils die to make NETs
All the above are intracellular mechanisms, there are also EC mechanisms
Red= nucleus, green = cytoplasm
Upon activation > NADPH > transfer of ___ > nucleus undergoes disintegration > ___ and ___ component mix together (nucleus = jelly-like, granular = ___, disorganized) > jelly-like component > as neutrophil dies it releases it EC > neutrophil extracellular trap
When neutrophil has performed function, it is dying, but it is releasing its ___ content thereby trapping other microbes
electrons nucleus granular phagolysosome IC
Bacterial Strategies to Avoid/Evade Neutrophils (Bacterial virulence Factors)
___
– (Aggregatibacter Actinomycetemcomitans, AA)
• Proteases that inactivate
___
– PG
• Factors that bind ___ of IgG
– Staph Aureus Protein A
• ___:
– Klebsiella pneumoniae
– Streptococcus pneumoniae
Bacterial virulence factors:
Leukotoxin released from AA, and is toxic to the ___ and can eliminate it
leukotoxin
antibodies/complement
Fc region
carbohydrate capsules
neutrophils
Acute Inflammation and Resolution
• PGD2, PGE2, PGI2, LTB4 (vasodilation, Permeability, PMN chemotaxis)
• Lipid mediator class switching from PGs and LTs to ___
—• ___ monocyte recruitment
—• Inhibition of ___ PMN influx
—• Anti-inflammatory ___
• PUFA (EPA; Resolvins) and (DHA: Protectins and Maresins)
- –• Increase ___ generation
- –• ___
• Resolution
—• Resolved exudate removed through ___ vessel
• Failed Resolution:
—• ___ Inflammation
lipoxins
non-phlogistic
LTB4-induced
cytokine
lipoxin
efferocytosis
lymphatic
chronic
