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41 Cards in this Set
- Front
- Back
most CAMs belong to four families of proteins:
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selectin family
mucin-like family integrin family immunoglobulin superfamily |
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has an extracellular lectin-like domain that enables these molecules to bind specific carbohydrate groups
responsible for the initial stickiness of leukocytes to vascular endothelium |
selectins
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most circulating leukocytes express this type of selectin
whereas these other two types are expressed on vascular endothelial walls during an inflammatory response |
L-selectin
E-, P-selectin |
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a group of serine- and threonine-rich proteins that are heavily glycosylated
extended structure allows them to present the sialyl-Lewis^x and other sulfated carbohydrate moieties as binding sites for selectins ex. L-selectin on leukocytes binds CD34 and GlyCAM-1 on endothelial cells |
mucins
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heterodimeric proteins consisting of an alpha and beta chain that are noncovalently associated at the cell surface
most bind extracellular matrix molecules and provide cell matrix interactions throughout the body |
integrins
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leukocytes express a specific subfamily of integrins known as the _________ (or _______ ____) as well as several integrins that are expressed on other cell types
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beta-2 integrins (or CD18-integrins)
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this group is expressed on vascular endothelial cells and bind to various integrin molecules
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Ig-superfamily CAMs (ICAMs)
include: ICAM-1 (CD54), ICAM-2 (CD102), ICAM-3 (CD50), and VCAM (CD106) |
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rolling is mediated by
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selectin - carbohydrate interaction
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arrest and adhesion is mediated by
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integrins binding to Ig-family membes
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during an inflammatory response, cytokines and other mediators act on the local endothelium, inducing expression of adhesion molecules of the _____ family
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selectin
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E- and P-selectin molecules bind to _____ _____ CAMs on the leukocyte membrane or w/ the sialyated lactosaminoglycan called sialyl Lewis
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mucin-like cell adhesion molecules
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slow rolling of the leukocytes allows for chemokine-chemokine receptor interaction
these interactions result in change of conformation and clustering of ________ on the leukocyte |
integrin
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the leukocyte squeezes in b/t two neighboring endothelial cells by homotypic binding of ____________
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platelet-endothelial-cell adhesion molecule-1 (PECAM-1; CD31)
located on both the leukocyte and the endothelium CD11a/CD18 also binds to JAM-1, another adhesion molecule located w/in the endothelial tight junction, to mediate egress from the bloodstream |
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complement split product C5a, bacterial peptides containing N-formyl peptides, and leukotrienes bind to specific receptors on the _______, contributing to the directed migration and activation of these cells
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neutrophils
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neutrophils express _________ and _________, which convert to their active, more adhesive conformation when the neutrophil is stimulated by chemokines
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CD11a/CD18 and CD11b/CD18
(LFA-1 and MAC-1) |
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resting endothelium expresses low levels of _________, which supports adhesion w/ activated CD11a/CD18 and CD11b/CD18 w/o the requirement of time-consuming synthesis of new Ig-family members
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ICAM-1 (CD54)
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monocytes from the peripheral blood take much longer to arrive at infection than neutrophils b/c of the time it takes for endothelial cells to increase expression of _______
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VCAM-1, the ligand for integrin alpha4beta1
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regions of of vascular endothelium in postcapillary venules of various lymphoid organs composed of specialized cells w/ a plump, cuboidal shape
lymphocytes extravasate at a very high rate through these areas which are contained in all secondary lymphoid organs excluding the spleen |
high-endothelial venules (HEVs)
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the development and maintenance of HEVs in lymphoid organs is influenced by cytokines produced in response to ______ ______
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antigen capture
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some adhesion molecules that are distributed in a tissue-specific manner have been called ____ _____, b/c they serve to direct the extravasation of different populations of recruiting lymphocytes to particular lymphoid organs
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vascular addressins (VAs)
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process of different subsets of lymphocytes migrating differently into different tissues
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homing or trafficking
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once naive lymphocytes encounter antigen trapped in a secondary lymphoid tissue, they become activated and enlarge into ________.
activation takes about 48 hours, and during this time the blast cells are retained in the _______ region of the secondary lymphoid tissue |
lymphoblasts
paracortical |
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the kinin system is an enzymatic cascade that begins when a plasma clotting factor, called ______ ______, is activated following tissue injury
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Hageman factor (factor XII)
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in the kinin system:
Hageman factor activates prekallikrein to for kallikrein, which cleaves kininogen to produce _______ |
bradykinin
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this potent peptide increases vascular permeability, causes vasodilation, induces pain, and triggers contraction of smooth muscle
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bradykinin
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thrombin acts on soluble fibrinogen in tissue fluid or plasma to produce insoluble strands of ______ and _________
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fibrin, fibrinopeptides
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insoluble fibrin strands crisscross one another to form a ____, which serves as a barrier to the spread of infection
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clot
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the integrin _____________ binds two components of the clotting system, factor X and fibrinogen
binding of factor X to __________ increases the activity of factor X, thereby promoting coagulation |
CD11b/CD18 (MAC-1)
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activated platelets secrete _____, which leads to increased production of proinflammatory cytokines, IL-6 and IL-8, and increased expression of adhesion molecules
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CD40L
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removal of the fibrin clot from the injured tissue is achieved by the fibrinolytic system
the end product of this pathway is the enzyme ______ this potent proteolytic enzyme breaks down fibrin clots into degradation products that are chemotactic for neutrophils also contributes to the inflammatory response by activating the classical complement pathway |
plasmin
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binding of the ________ to receptors of the membrane of tissue mast cells induces degranulation w/ release of histamine and other pharmacologically active mediators
these induce smooth muscle contraction and increase vascular permeability |
anaphylatoxins (C5a and C3a)
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metabolism of arachidonic acid by the cyclooxygenase pathway produces _______ and ________
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prostaglandins and thromboxanes
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have diverse physiological effects, including increased vascular permeability, increased vascular dilation, and induction of neutrophil chemotaxis
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prostaglandins
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cause platelet aggregation and constriction of blood vessels
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thromboxanes
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arachidonic acid is also metabolized by the lipoxygenase pathway to yield the four ________
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leukotrienes
LTB4, LTC4, LTD4, LTE4 |
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three of the leukotrienes produced through the metabolization of arachidonic acid (LTC4, LTD4, LTE4) together make up what was formerly known as _____ ______ ____ ______
these mediators induce smooth muscle contraction |
slow-reacting substance of anaphylaxis (SRS-A)
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activated tissue macrophages secrete...
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IL-1, IL-6, and TNF-alpha
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the local inflammatory response is accompanied by a systemic response known as the _____ ____ _____
this response is marked by the induction of fever, increased synthesis of hormones such as ACTH and hydrocortisone, increased production of WBCs, and production of a large number of ____ ____ ____ in the liver |
acute-phase response
acute-phase proteins |
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___ ____ ____ is a representative acute-phase protein whose serum level increases 1000-fold during an acute-phase response
binds to a variety of microorganisms and activates complement, resulting in deposition of the opsonin C3b on the surface of microorganisms |
C-reactive protein
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common transcription factor for acute-phase liver proteins
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NF-IL6
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constitutive transcription factor located in hepatocytes
high degree of sequence identity w/ NF-IL6 |
C/EBP
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