Ch. 1 Inflammatory Response Flashcards
What are the macroscopic signs of acute infllamtion
rubor
calor
dolor
tumor
What induces vasoconstriction immediately upon injury
catecholamines
serotonin
bradykinin
prostaglandins
all released from local tissues
what induces vasodilation
what induces vasodilation
vascular smooth muscle changes that are mediated by nitric oxide, histamine, leukotrienes, prostaglandins, and complement factors
how is permeability of vasodilation mediated?
histamine and serotonin mediate an increase in the number and size of intracellular endothelial gaps in the venules called transcytoplasmic channels or vesiculovacuolar organelles
Interendothelial gaps also form
Why does edema occur in early inflammation
increased permeability = serum protein loss = decreased intravascular osmotic pressure and increased blood viscosity –> inreases in hydrostatic pressure means edema fluid accumulation
Edema is advantageous because it facilitates delivery of antibodies and acute phase proteins to the site of inflammation
What is Sialyl Lewis X complex
weak transient interactions between selectins (glycoprotein cell adhesion molecules on endothelial cells) and ligands their leukocytes occur
Sialyl Lewis X is one with a carbohydrate ligand
What are the three most commonly described endothelial selectins?
E, P, and L selectins
What are integrins
proteins on the leukocytes that have alpha (CD11a, CD11b, CD11c) and beta (CD18) subunits that bind to corresponding proteins on the endothelium
What does Integrin ligand ICAM-1 interact with
interacts with integrins called lymphocyte associated antigen 1 (LFA-1 which is also CD11a/CD18) and macrophage antigen 1 (Mac 1 which is also known as CD11b/CD18)
How does diapedesis occur
- adhesion molecules like ICAM 1 is expressed more near interendothelial junctions and facilitate migration
- platelet endothelial cell adhesion molecules like PECAM 1 also facilitate leukocyte transendothelial migration and transmigration through the basement membrane
What are the four processes of acute vascular response
vasodilation
increased permeability
stasis
leukocyte extravasation
How do neutrophils kill bacteria
phagocytosis
release of superoxide radicals
formation of neutrophil extracellular traps
what are neutrophil extracellular traps
cell free DNA and other antimicrobial peptides including histones ensure a local high concentration of granule enzymes
WHat is azurophil
this is the primary neutrophil granule
contains microbicidal polypeptides such as myeloperoxidase, defensins, lysosome hydrolases, neutral proteases
what are examples of secondary neutrophil granules
metalloproteases
what are examples of tertiary neutrophil granules
gelatinase
what are the primary cytokines released by neutrophils
Interleukin 1 alpha - IL-1a
Interleukin 1 beta - IL-1b
interleukin 6 - IL-6
tumor necrosis factor alpha - TNF a
How do neutrophils go from a resting state to primed
two stage process
within minutes of stimulation by bacterial products or cyto/chemokines, mobilization of tertiary granules and secretory vesicles increase neutrophil cell surface receptors
At the same time, new expression of receptors and cytokines are induced
This allows primed neutrophils to release reactive oxygen species and other inflammatory mediators as well as increase their life span
What chemical signals will macrophages respond to to cause extravasation
fibronectin elastin complment factors C3a and C5a thrombin PDGF TGF beta (transforming growth factor)
What is the main macrophage type in inflammatory conditions
monocyte derived macrophages (remember, macrophages either come from monocytes or they start as tissue resident marophages)
What is macrophage polarization
macrophages will assume two functional phenotypes: M1 or M2
Describe the characteristics of M1 macrophages
activated by infectious agents or proinflammatory cytokines like interferon gamma (IFN-y) or TNF alpha
Debride the affected site by phagocytosis
Secrete IL-1b, IL-6, TNF alpha, prostaglandins
secrete collagenases and elastases
Describe the characteristics of M2 macrophages
activated in response to ANTI inflammatory cytokines like IL4, IL13, IL10
aid in wound repair and healing by releasing PDGF and TGF beta
secrete collagenases and elastases
Toll like receptors, scavenger receptors, mannose receptors, c type lectin like domain containing receptors, peptidoglycan recognition receptors and nucleotide binding site leucine rich repeat receptors are all part of what group
pattern recognition receptors, many will bind to more than one alarm signal molecule