Chapter 2: Inflammation, Inflammatory Disorders, and Wound Healing Flashcards
tissue necrosis is always followed by?
acute inflammation – increase in neutrophils
What is the goal of acute inflammation?
eliminate pathogen or clear necrotic debris
How do macrophages deal with gram negative bacteria?
the CD14 receptor on macrophages recognize LPS on outer membrane of gram negs
Describe pathway of TLR’s
Pathogen Associated Molecular Patterns(PAMPs) activate TLR’s on macrophages/lymphocytes causing upregulation of NF-kB which is a nuclear transcription factor that activates immune response genes leading to production of multiple immune mediators
TLR on B-cells importance
They cross link enough receptors to NOT need a second signal!
Arachidonic Acid Metabolites
Arachidonic Acid released from cell membrane by phospholipase A2 and then acted upon by COX or 5-lipoxygenase creating prostoglandins, prostocyclines, thromboxanes(COX) and leukotrienes(5-lipoxygenase)
Mediates vasodilation and increases vascular permeability
PGI2, PGD2, PGE2
mediates pain and fever
PGE2
neutrophil chemoattractants
LTB4, IL-8, C5a
mediate vasoconstriction, bronchospasm, and increased vascular permeability
LTC4, LTD4, LTE4 leukotrienes cause smooth muscle contraction – bronchial muscles, smooth muscle in vessels and pericytes(edema)
Vasodilation occurs at the…
arteriole
increased vascular permeability occurs at…
venule
Mast cells activated by
tissue trauma, complement proteins C3a, C5a or cross linking by IgE
Mast cell immediate response
release histamine – vasodilation and increase permeability
Mast cell delayed response
release leukotrienes
Complement System
Classical Pathway – C1 binds IgG or IgM that’s bound to antigen Alternative pathway – microbial products directly activate Mannose binding lectin pathway - MBL binds to mannose on microorganisms and activates complement
What is important in DIC?
Hageman Factor(Factor XII)
Cardinal Signs of inflammation
Redness(rubor), warmth(calor) both caused by histamine mediated vasodilation Swelling(tumor) also caused by histamine mediated increase in vascular permeability Pain(dolor) mediated by bradykinin and PGE2 which sensitize nerve endings Fever is caused by the release of IL-1 and TNF which increase cyclooxygenase activity in perivascular cells of the hypothalamus which increases local PGE2 synthesis which raises temperature setpoint
Leukocyte margination occurs through?
postcapillary venules! Cells marginate from the center flow to the periphery due to the slow of blood flow from vasodilation
Leukocyte rolling occurs via?
selectin speed bumps upregulated in endothelial cells.Histamine causes release of P-selectin from Weibel-Palade bodies. E-selectin is induced by TNF and IL-1. Interaction of P-selectin and E-selectin causes leukocytes to roll along vessel wall
What does selectin on endothelial cells bind on leukocytes (neutrophils, macrophages, etc.)
Sialyl Lewis X
Leukocyte adhesion to endothelial cells occur via?
upregulation of adhesion molecules, ICAM and VCAM by TNF and IL-1 bind to integrins on leukocytes
What causes upregulation of adhesion molecules?
IL-1 and TNF
What causes upregulation of selectins?
Histamine for P-selectin from Weibel Palade bodies, TNF and IL-1 for E-selectin
What causes upregulation of integrins on leukocytes?
C5a and LTB4, the chemotactic factors!
What is the most common cause of leukocyte adhesion deficiency?
What is the clinical presentation?
Defective CD18 subunit.
NOTABLE CLINICAL SIGNS -
– failure of umbilical cord to detach,
– INCREASED circulating neutrophils because they can’t be stored by attaching to vascular walls.(marginated pool).
– Finally, recurrent bacterial infections that LACK pus formation
pus=dead neutrophils sitting in fluid
Opsonins…?
IgG and C3b
Chediak-Higashi syndrome
impaired phagolysosome formation.
Pathophys: Microtubule polymerization disorder means the “tracks” to get around the cell are broken, as such transport of phagosomes is deficient.
giant granules in leukocytes and defective primary hemostasis, albinism
Chediak-Higashi syndrome
abnormal dense granules in golgi apparatus leads to impaired primary hemostasis
giant granules in leukocytes arise from fusion of granules in golgi since they can’t move…
Generation of bleach
O2 –> O2- radical –> H2O2 –> HOCl NADPH Oxidase(oxidative burst), Superoxide Dismutase, MPO
NTB dye
O2–>O2- radical This reaction is marked, so if NADPH oxidase works, will stain blue
Chronic Granulomatous Disease
What organisms are you susceptible to?
poor O2 dependent killing due to NADPH oxidase defect. Particularly vulnerable to catalase positive organisms… Staph. Aureus, Pseudomonas Capacia, Serratia marcescens, Nocardia and Aspergillus. REMEMBER Pseudomonas Capacia
MPO Deficiency
defective conversion of H2O2 to HOCl increases risk for candida infections
Leukocyte O2 independent killing.
What does it bind to?
Reliant on lysozyme and major basic protein(binds heparin sulfate proteoglycans)
Anti inflammatory cytokines produced by macrophages?
Pro-inflammatory cytokines produced by macrophages?
Anti – IL-10 and TGF-ß
Pro – IL-8