Ch.2 Acute Inflammation pt.2 Flashcards
Derived from monocytes circulating in the blood
Macrophages
Macrophages injest organims via ____?
Phagocytosis
Phagocytosis in macrophages is faciliateted by what?
Opsinins
What helps destroy phagocytosed materials in macrophages?
Lysosyme & 2nd granuales
Macrophges can either 1. or 2.
- Promote resolution & healing if balance restored
- Recruit more help
Secretion of anti-inflmmatroy cytokines IL-10 and TGF-Beta by macrophages signales what?
Balance restored, promoting healing
What cytokiene is secreted by macrophages if there is continued inflamation and persistant pus formation
IL-8
What may follow acute inflammation if the issue is not resolved?
Abcess formation
Macrophages, active antigen presenters and activate + regulate what?
Chronic inflmation
CD4+ Helper T cells
Activation of what kind of cell via antigen prensentation from macrophages secrete cytokienes that promote chronic inflammation?
CD4+ Helper T cells
Macrophages are the link bewteen what?
Innate & adaptive immunity
_____ have the principle ligan Sialyl-Lewis X
Selectins
L-selectin, E-selectin, P-selectin
____ have the principle ligand ICAM-1 expressed
Integrings
LFA-1, MAC-1, VLA-4, a4b7
___ are important causes of injury to normal cells and tissues
Occures during normal defesne agaisnt microbs **esp those resistant*
Ex. Mycobacteria
Leukocytes
leukocyte-mediated tissue injury is release of the contents of ___ and ____
Lysozymes and Granules
Cells that secrete cytokienes like IL-17 that recruit neutrophils and stimulate production of antimicrobial peptides that directly kill microbes.
Th17 cells
Kind of T-cell
Cells that are mportant in reactions to helminthic parasites and in some allergic disorders
Eosinophills
(can cause cell damage)
critical cells of allergic reactions.
mast cells and basophils
What kind of inflmmatory mediator ?
Released from intracellular granules (e.g.,amines) or are synthesized de novo (e.g., prostaglandins and leukotrienes, cytokines) in response to a stimulus.
Cell-derived mediators
Produced locally by cells at site inflam. or derived from ciruclating
What are the three major cell types that produce mediators of acute inflammation?
- Tissue macrophages
- Dendritic cells
- Mast cells
What kind of inflmmatory mediator?
Complement protiens
Plasma-derived mediator
produced mainly in the liver and circulate as inactive precursors.
produced only in response to various stimuli, including microbial products and substances released from necrotic cells, which ensures that inflammation is triggered only when and where it is needed.
Acitve Mediators
Receptors found in innate immune system effectors (mac & dend) that detect foreign molecular patterns
Toll like receptors
Antigen presentors, cotrol what to process and send out necessary signals
Just the umbrella term
Regulators
They respond to stimulus
Just umbrella term
Effector
ex. Macrophages & Dendritic cells
Commo structural patterns found on many foreign microbs
Pathogen Associated Molecular patterns (PAMPS)
Ex. Cell membrane, dsRNA ssDNA, Proteins (flagella, techoic acid).
This is an example of what?
CD14 (a co-receptro fro TLR4) can identify a specific PAMP fond in LPS of gram (-) bacteria.
Toll Like receptors
TLR actiavtion results in upregulation of what?
Nuclear transcription Factor
NF-kB, activates immune response + promote inflmation
What gives TLR a link in mediation of both acute & chronic inflamation?
They are housed on lymphocytes
Which are adaptive immunity effector & regulators
What are the 2
lipid mediators produced from arachidonic acid (AA) present in membrane phospholipids that stimulate vascular and cellular reactions in acute inflammation
Prostaglandins & Leukotrienes
20-carbon polyunsaturated fatty acid that is released from membrane phospholipidsthrough the action of cellular phospholipases, mainly phospholipase A2
Arachindroic Acid
AA mediator is produced by what?
Generate prostaglandins
Cyclooxygenases
AA mediator is produced by what?
Produce leukotrienes and lipoxins
5- Lipooxgenanses
produced by mast cells, macrophages, endothelial cells, and many other cell types and are involved in the vascular and systemic reactions of inflammation.
Prostaglandins
What Cyclooxygenase?
produced in response to inflammatory stimuli and is also constitutively expressed in most tissues, where it may have homeostatic functions
COX-1
Cyclooxygenase
fluid and electrolyte balance in the kidneys, cytoprotection in the GI tract
Homeostatic function of tissues where ___ is found
COX-1
induced by **inflammatory stimuli **and thus generates prostaglandins in inflammatory reactions but is low or absent in most healthy tissues.
COX-2
Cyclooxygenase
Major Prostiglandins made by mast cells, cause vasilodation + increased membrane permability of post-cap venules.
(potentiant exduatio resulting in edema)
PGD2 and PGE2
PGDis a chemoattractant for neutrophuls.
Platelets contain the enzyme thromboxane synthase, which produces _____ the major eicosanoid (AA mediator) in these cells.
TxA2
Potent platelet-aggregating agent and **vasoconstrictor.
vascular endothelium lacks thromboxane synthase. Instead, it contains this enzyme____, which produces ____
prostacyclin synthase; produces Prostacyclin PGL2
*vasolidator, inhibitor of paltlet agregation, prevent thrombosis
Prostoglandins are in invloved in the pathogenesis of ___ and ____
Pain & Fever
Derived from Prostoglanding G2/H2
- Induce platlet agregation
- Potent vasoconstrictor
- Induce vascular smooth muscle proliferation
- Proatherogenic
Thromboxone A2
TXA2
Derived from Prostoglanding G2/H2
- Inhibit platlet agregation
- Induce vasolidation
- inhibit vascular smooth muscle proliferation
- ANTI-athrerogenic
- Gut protection
- Renal blood flow regulation
Endothelial Prostacyclin
PGL2
produced by leukocytes and mast cells by the action of lipoxygenase and are involved in vascular and smooth muscle reactions and leukocyte recruitment.
Leukotrienes
Activation of ___ examples
- Prevent closure of ductus arteriosis in newborns with cyanoic heart defects
- Tx of NSAID induced gastric ulcers
- Reduction of pulmonary hypertension
- Induction of childbirth
- Vasodilation of digits for treatment of severe Raynaud disese or critical limb ischemia
- Management of glaucoma
- Tx of erectile dysfunction
Activation of Prostiglandins
The ____ pathway yields hydroperoxyeicosatetraenoic acid (HPETE) and its derivatives
5-lipoxygenase pathway
What does this do?
Zileuton
Used for tx of chronic asthma
Inhibit leukotriene synthesis
LTC4, LTD4, LTE4
These leukotrienes do what?
Increase broncial tone
*intense vasoconstriction
* bronchospasm (important in asthma)
* increased permeability of venules.
What does medicatio do?
Monetlukast & Zafirlukast
For allergic asthma & alergic rhinitis
Prevent action of leukotrienes responsible for increase in bronchial tone
LTC4, LTD4, LTE4
What leukotriene?
produced by neutrophil and some macrophages and is a potent chemotactic agent and activator of neutrophils
LTB4
neutrophils arrive B4 others remember!
In leukotriene synthesis
____ gives rise to leukotrienes
5-HPETE
Also generated by AA through lypoxygenase pathway.
supress inflamation; inhibit neutrophil chemotaxis, no recruitment of leukocytes
Lipoxins
Principle action of Arachidonic Acid Metabolites in Inflammation
Prostaglandins PGI2 (prostacyclin), PGE1, PGE2, PGD2
Vasodilation
Big blood vessles
Principle action of Arachidonic Acid Metabolites in Inflammation
Thromboxane A2 (COO pathway) , leukotrienes C4, D4, E4
Vasoconsriction
Small vessels
Principle action of Arachidonic Acid Metabolites in Inflammation
Leukotrienes C4, D4, E4
Increased vascular permeability
(exxudation & dev of edema in PG) ( Bronchospasm in leukotrienes)
Principle action of Arachidonic Acid Metabolites in Inflammation
Leukotriene B4
Chemotaxis, leukocyte adhesion
Activate neutrophil, chemotaxis bring inmore.
Aspirn & NSAIDs ex. Ibuprofen.
Inhibit COX-1 & COX-2
Cyclooxygenase inhibitors
= prostaglandin synthesis blocked
Why are asprin and NSAIDs good at treating pain and fever?
They block COX-1 and COX-2 which prevents prostaglandin syntheis.
Aspringirreverisbly inactiavted COO
What kind of inhibitiors:
may increase the risk of cardiovascular and cerebrovascular events:
Impairs PGL2 (antitrhombotic)
while ignoring COX-1 mediated production of TxA2 which promotes plate aggregation
*only used to treat arthritis & pre-op pain in pt. with zero cardio. ris
Selective COX-2 inhibitors
Anti-inflammatory agents like glucocorticoids and corticosteroids are what?
Lipoxygenase inhibitors
Broad spectrunm antiinflamatory drugs.
Reduce transcription of genes encoding COX-2, Phospholipase A2..
Corticosteroids
Contain Cortisol
A major vasoactve amine that stored as a preformed molecule in the granules of mast cells, blood basophils, and platelets
Vasoacivte= affect diameter of blood vessles
Histamine
Rapidly released when cells are aitvated
What kind of cell has the richest source of histamine?
Mast cells
normally found in connective tisssue next ot blood vessels
What 5 things can activate Histamines?
- Trauma
- Complement C3a & C3b
- Cell surface IgE cross-linking by hapten/antigen (allergy)
- Cytokiene IL-1
- Neuropeptides
What happnes when histamines are activated?
Degranulation of mast cell
histamine was already fromed
What occurs if there is a mass degranulation of mast cells?
Anaphylactic SHOCK! Mass release of histamine; high vasodialation= hypotension
What is the immeidte response of histamine?
Vasodialation of arterioles+ increased vascular permeability.
What are the complement fragments C3a and C5a called?
They actiavte degranulation of mast cell; release histamine
Anaphylatoxins
What kind of drug?
drugs that treat inflammatory reactions, such as allergies, bind to and block the H1 receptor
Antihistamines
Vasodialation & increased vascular permeability causes what symptoms of inflmation?
What are their key-mediators?
- Redness (rubor)
- warmth (calor)
Both caused by histamines, prostaglandins & bradykinins
What symptom of inflmmation?
When fluids escape from post-capillary venules into interisital space
Swelling (tumor)
What key mediator of inflmation will act on the integrity of the Blood vessel, which causes endothelial cell contraction and tissue damage, resulting in endothelial cell dissruption
Histamines
Is congestive heart faliure inflmmatory?
Stagnation fo blood in heart
NO. b/c **permeability of vessels is not affected **. It is a transudate, fluid escaping due to pressure diffrences.
How do prostogladinds like PGE2 affect pain?
What is a major player?
They** dont cause pain, **they lower threshold of pain i.e you feel more pain.
Bradykinin is major player in making action potential
Pain is peripheral!
Lower concentrations of Bradykinn & histamine results in what?
Activation of nociception= more painful stimuli
Substances that induce fever
Pyrogens
ex. Bacterial products like LPS
Pyrogens stimulate leukocytes to release cytokienes ___ and ___
IL-1 & TNF
Acute Phase Response
Following pyrogen stimulaton of leukocytes (macrophages 3-4 days post intial infection) to release IL1 & TNF the production of _____ is upregulated via increased cyclooxygenease acitvity.
Occurs in perivascular cells of hypothalamus
Prostaglandins, specifcally PGE2
PGE2 does what to the body?
Fever!
Lowers threshold.
WHere does temperature control occur?
Perivascular cells of the hypothalamus
Fever is CNS
NSAIDS including aspring reduce fever how?
Inhbit cyclooxygense COX-1 and COX-2 therefor no prostoglandin syntheiss (no PGE2)
proteins produced by many cell types (principally activated lymphocytes, macrophages, and dendritic cells, but also endothelial, epithelial, and connective tissue cells) that **mediate and regulate immune and inflammatory reactions
Cytokines
What cytokienes?
serve critical roles in leukocyte recruitment by promoting adhesion of leukocytes to endothelium and their migration through vessels.
Mainly acitvated by macrophages & dendritic cells
TNF & IL-1
Systemic effect of TNF & IL-1
Induce fever and Leukocytosis (send out lots of mature leukocytes, high leveles)
sustained production of ____ contributes to cachexia, a pathologic state characterized by weight loss and anorexia that accompanies some chronic infections and cancers.
TNF
What kinds of drugs? What is downside?
effective in the treatment of chronic inflammatory diseases, particularly rheumatoid arthritis, psoriasis, and some types of IBD
TNF antagonist.
Pt. more suseptible to mycobacterial infection b/c of reduced ability of macrophages to kill intracellular microbes
Synthesis of acute pase protiens, induced by TNF & IL-1in the liver.
Hepatic Syntheis
TNF & IL-1increase the expression of ____ molecules in the endothelium of blood vessels
Adhesion moleules
IL-1 and TNF reduce the thromboresistant properties of endothelium, thus promoting ______
Vasodialation + increased permeability
Thrombosis
This cytokinene raises hear rate, lower blood pressure due to vasodialation b/c of increased circulation of Neutrophils
TNF
family of small (8 to 10 kD) proteins that act primarily as chemoattractants for specific types of leukocytes
Chemokines
Chemokines bind to proteoglycans and are thus displayed at high concentrations on the ____ of endothelial cells and in the extracellular matrix
Surface
What are 2 main function of Chemokines?
- Inflamtion; bind leukocyte receptors & stimulate inegrin dependent attachement to endothelium or migration (chemotaxis) of leukocyte to damaged tissue
- Maintain tissue architecture