Inflammation and Repair Flashcards
Acute inflammation
Onset:
Cellular filtrate:
Tissue injury, fibrosis:
Local and systemic signs:
Onset: fast - minutes to hours
Cellular filtrate: mainly neutrophils
Tissue injury, fibrosis: mild, self-limiting
Local and systemic signs: prominent
Chronic inflammation
Onset:
Cellular filtrate:
Tissue injury, fibrosis:
Local and systemic signs:
Onset: slow - days
Cellular filtrate: monocytes/Mo, lymphocytes
Tissue injury, fibrosis: severe, progressive
Local and systemic signs: less
Autoinflammatory syndromes are caused by:
What is used to treat them?
Gain-of-function mutations in the sensor.
IL-1 antagonists
What gets impacted by reactions to urate crystals, lipids, cholesterol crystals (atherosclerosis), and AD?
The inflammasome
3 major components of acute inflammation
- Dilation of small vessels leading to an increase in blood flow.
- Increased permeability of microvasculature allowing proteins and WBCs to leave circulation.
- Migration of WBCs from circulation to the site of injury.
Exudate vs. transudate
Exudate: high protein content and WBCs. Pus-like.
Transudate: low protein content w/ few cells.
Histamine
Source:
Action:
Source: mast cells, basophils, platelets.
Action: vaodilation, vascular permeability, endothelial activation.
PGs
Source:
Action:
Source: mast cells, leukocytes.
Action: vasodilation, pain, fever.
Leukotrienes
Source:
Action:
Source: mast cells, leukocytes.
Action: vascular permeability, chemotaxis, leukocyte adhesion, activation.
Cytokines (TNF, IL-1, IL-6)
Source:
Action:
Source: Mo, endothelial cells, mast cells.
Action: upregulation of expression of adhesion molecules (locally) and fever, metabolic abnormalities, hypotension, shock (systemically).
Platelet-activating factor (PAF)
Source:
Action:
Source: leukocytes, mast cells.
Action: vasodilation, vascular permeability, leukocyte adhesion, chemotaxis, degranulation, oxidative burst.
Complement
Source:
Action:
Source: plasma.
Action: leukocyte chemotaxis and activation, MAC, vasodilation.
Kinins
Source:
Action:
Source: plasma.
Action: vascular permeability, SM contraction, vasodilation, pain.
What 2 molecules induce the coordinated expression of adhesion molecules during WBC migration?
TNF
IL-1
Explain the process of getting a WBC from circulation to the target site
TNF and IL-1 upregulate the expression of P and E-selectins on the endothelium which allows WBC to begin rolling.
ICAM-1 firmly grabs the WBC.
PECAM-1 pulls the WBC into the CT.
WBC engulfs the microbe and produces chemokines.
The chemokines stimulates other WBCs to continue producing TNF, IL-1.
What endogenous and exogenous agents help the WBCs find their target?
Exogenous agents like N-formylmethionine terminal on some AAs and lipids.
Endogenous chemoattractants like cytokines, complement, and arachidonic acid metabolites (mainly LTB4)
What do integrins connect? What can they trigger?
They link the intracellular cytoskeleton w/ the “outside world”. They can trigger signaling cascades within the cell that influences locomotion, proliferation, shape, etc.
What is leukocyte activation?
The recognition of microbes or dead cells by a receptor.
How does a microbe get engulfed by a Mo?
The mannose receptor on a macrophage binds a terminal mannose on a microbe. The microbe gets placed in a vesicle where it is degraded.
What are opsonins?
What are some main ones?
They are molecules that enhance the microbes’ ability to be phagocytosed.
IgG, C3b, MBL - all which can bind receptors on WBCs.
Once phagocytosed, what do Mo use to degrade the microbe? (3)
ROS
Reactive nitrogen species (from NO)
Lysosomal enzymes
What do smaller specific (secondary) granules contain?
What do azurophil (primary) granules contain?
Lysozyme, collagenase, gelatinase, lactoferrin, etc.
Myeloperoxidase, bacterial factors, etc.
Toxic granulation
What cells are most effected?
Changes in granulocytes on blood film in patients with inflammatory conditions (often in sepsis)
Mostly seen in neutrophils.
Neutrophil extracellular traps (NETs)
EC traps that provide a high concentration of antimicrobial substances at sites of infection and prevent the spread of microbes by trapping them in fibrils.
Extrinsic defects (phagocytic disorders)
What can it lead to?
Abnormalities in opsonization secondary to deficiencies of Ab and complement factors.
Neutropenia by suppression of granulocytes, or increased autoAbs or isoAbs directed against neutrophil Ags.
Intrinsic defects (phagocytic disorders)
Defects in granulocyte development or exit into circulation, granulocyte killing ability or chemotaxis (movement).
TTM for dermographism urticaria
How does it develop?
Anti-histamines.
Thought that trauma releases Ag that binds IgE (membrane-bound) of MCs that causes release of His.
What are 2 lipid mediators?
What do they do?
PGs and leukotrienes produced from arachidonic acid.
Stimulate vascular and cellular reactions in acute inflammation.
What are COX-1 and COX-2?
They catalyze the production of PGs from cyclooxygenase (from AAcid).
What do montelukast and zafirlukast inhibit?
Inhibit leukotriene receptors
What do Lipoxin A4 and Lipoxin B4 do? (LXA4, LXB4)
Inhibit inflammation
Thromboxane A2 does:
Vasoconstriction and promotes platelet aggregation.
PGD2 and PGE2 does:
Vasodilation and increased vascular permeability