Inflammation Flashcards
Characteristics of the Immediate transient response of inflammation
- Cause
- Inducers
- Vessels most affected
A. Endothelial Contraction
B. Inducers:
- Histamine
- Serotonin
- Bradykinin
- Leukotrienes
C. Venules
Characteristics of the Immediate Sustained Response of inflammation
- Cause
- Vessels most affected
A. Damage (necrotizing injury, burns, microbes)
B. All vessels
Characteristics of the Delayed Prolonged Leakage of inflammation
- Cause
- Vessels most affected
- UV or thermal injury
- venules and capillaries
Characteristics of Neutrophil-mediated endothelial injury
- Cause
- Vessels most affected
A. Released enzymes or ROIs by neutrophils
B.
- Venules
- Pulmonary Capillaries
- Glomerular Capillaries
Which receptors/molecules are involved with leukocyte rolling in the inflammatory response?
“Speed-bump selectins”
- E and P selectins (Endothelium) – sialyl Lewis X glycoprotein (leukocytes)
- CD34 (Endothelium) – L selectin (leukocytes)
Which molecules are involved with activation of integrin affinity to leukocytes in the inflammatory response?
Cytokines:
- IL-1
- TNF
Chemokines:
- IL-8
- C5a
- LTB4
Which receptors/molecules are involved with leukocyte binding to endothelium in the inflammatory response?
ICAM-1 (endothelium) – CR3 and LFA-1
ICAM-2 (endothelium) – LFA-1
VCAM-1 (E) – VLA-4
Difference in fuction of VLA-4 vs VLA-2, -3, -6 in the inflammatory response
VLA-4: lymphocyte-endothelial interactions
VLA-2, -3, -6: lymphocyte – ECM interaction
Which receptors/molecules are involved with leukocyte emigration in the inflammatory response?
In which type of vessel does diapedesis occur?
- PECAM-1
- JAMs (junctional adhesion molecules) – Integrins
Diapedesis occurs in the venules
Timeline of Acute Inflammation
Order of infiltration
- Edema
- Neutrophils
- Macrophages
Exception: viral infection has only mononuclear infiltrate.
Activation of neutrophils occurs via which receptors?
- TLR binding to PAMPS (LPS)
- Mannose reeptor
- Fc or complement receptor
Function of NADPH oxidase in microbial killing
respiratory/oxidative burst
converts O2 to superoxide (O2-)
Function of Myeloperoxidase in Microbial killing
Convert H2O2 to Hypoclorite (HOCl radical)
Defect in Leukocyte Adhesion Deficiency 1
No expression of LFA-1
(No attachment to endothelium to prepare for transmigration)
Defect in Leukocyte Adhesion Deficiency 2
No sialyl-Lewis X (no selectin receptor)
(No rolling)
Defect in Chronic Granulomatous Disease?
No NADPH oxidase (no superoxide formation)
Defect in Chediak-Higashi syndrome
No fusion of lysosomes with phagosomes
Differences in initiation of:
Alternative pathway
Classical pathway
Lectin pathway
- C5 convertase: C3bBbC3b (spontaneous breakdown of C3b)
- Crosslinking leading to C5 convertase: C4b2a3b
- MBL binds mannose-containing structures of microbes, which initiates C4 hydrolysis; C5 convertase: C4b2a3b
Stimulus and Results of Kinin cascade
Stimulus: Hageman Factor (XIIa)
Results:
- Bradykinin synthesis (Pain, Increased vascular permeability, Vasodilation)
- Complement Cascade
- Fibrinolytic cascade (plasmin formation)
Stimulus and Results of Clotting Cascade
Stimulus: Hageman Factor (XIIa)
Result: Thrombin formation
- Acute inflammation
- Clotting (fibrin formation)
Function of Decay Accelerating Factor (DAF)
*Regulate complement*
- Block C2 binding to C4b
- Dissociation of C2a and C4b
- Block CD59 (inhibit C9 polymeration and MAC formation)
Effects of C3a
Leukocyte activation
Mast cell degranulation
Effects of C5a
Neutrophil chemotaxis
Leukocyte activation
Mast cell degranulation
Effect of C3b
Opsonization and phagocytosis
Effects of Histamine
Dilation of arterioles and Capillaries
Contraction of endothelial cells (increased permeability of venules/caps)
Effects of Serotonin
Produced by platelets
Dilation
Endothelial contraction causeing increased vasc. perm.
COX 1 vs COX 2 function
COX 1: maintenance
COX 2: Proinflammatory
Both: Produce PGs and TXA2
Prostaglandins vs Leukotrienes
Synthesis
Function
Synthesis:
PGs: COX
LTs: Lipoxygenase
Function:
PGs: stimulate acute inflammation (vasodilation, (-) platelet aggregation)
LTs: Vasocontstriction, increased vasc. perm.
Production and Function of Lipoxins
Production: Leukocyte-Platelet interaction
Function: Resolution of acute inflammation
- (-) selectins: (-) neutrophil chemotaxis
- (+) monocyte chemotaxis
Functions of Platelet Activating Factor (PAF)
Low concentration:
- vasodilation
- increased vasc. perm.
High concentration:
- (+) platelet aggregation
- Vasoconstriction
- Bronchoconstriction
- (+) leukocytes
Major source of IL-1 and TNF-alpha
Macrophages
C-X-C chemokines
Function
Example
Function: neutrophil (leukocyte) chemotaxis
IL-8
Function of NO in acute inflammation
down-regulates acute inflammation through reduced leukocyte and platelet adherence
Steps of Complete Resolution of Acute Inflammation
What type of inflammation is pictured?
Serous Inflammation
Source: plasma or mesothelial cells lining body cavities
What type of inflammation is pictured?
Fibrinous inflammation
(with adhesions)
What type of inflammation is pictured?
Suppurative
What type of inflammation is pictured?
Suppurative
What type of inflammation is pictured?
Fibrinous
Pseudomembranous Inflammation is a combination of what two types of inflammation?
Purulent and fibrinous
Ex: Pseudomembranous entercolitis
What is pictured?
Ulcer
Silicosis
- Type of inflammation
- Cause
- Type of Granuloma pictured
- Chronic
- inhalation of silica
- Foreign body granuloma
(Results in fibrotic scarring)
Characteristics of Chronic Inflammation
- Infiltrate
- Cell types
- Morphology
- Location of infiltration compared to acute
- Mononuclear infiltrates
- Epithelioid macrophages, giant cells, plasma cells
- Granulomas, Signs of destruction, signs of healing (fibrosis) and angiogenesis
- Interstitial (in acute, it accumulates in cavities)
What type of inflammation is pictured? What is the cell type shown?
Chronic inflammation (see granuloma)
Langhans type giant cell
What type of inflammation is pictured? What is the cell type shown?
Chronic Inflammation
Foreign Body Giant Cell (forms near foreign material)
Chemotactic stimuli for macrophages
- MCP-1
- C5a
- PDGF
- TGF-alpha
- collagen
- Cytokine that stimulates resolution and repair following inflammation
- Cytokine that stimulates further inflammation and tissue injury
- IL-4 (followed by TGF-ß)
- IFN-gamma (from T cells)
What type of granuloma is pictured? What is the cause?
- Immune granuloma
- microbes that are poorly degraded (here, TB)
This shows a central area of caseous necrosis
What type of granuloma is pictured? What is the cause?
Foreign body granuloma
Silicosis
What is the function of C-reactive protein?
opsonize microbes
Used as a marker for increased risk of MI
Increased erythrocyte sedimentation rate signals what?
Increased fibrinogen which causes increased RBC stacking and increased sedimentation
**Signals inflammation**
Function of serum amyloid A protein
opsonization of microbes
Significance of elevated levels of band cells
Bacterial infections
(release of immature neutrophils (band cells) from bone marrow postmitotic reserve pool)
Significance of neutrophilia
bacterial infection
Septic shock triad and stimulating cytokines
Triad:
- DIC (expression of tissue factor, initiating coagulation)
- Hypoglycemia (Liver damage and reduced gluconeogenesis)
- Cardiovascular failure (overproduction of NO)
Cytokines: IL-1 and TNF