Exam 1 10/2 Kingsley Immuno Flashcards
Anatomic physical barrier that keeps pathogens out of tissues and bloodstream
Tight junctions (zona occludens)
Mucosal epithelium examples
Saliva, mucins, ciliary escalator
Major proteins of zona occludens
claudins, occludins
What is the mucociliary escalator?
self clearing mechanism of bronchi; removes debris (pathogens) in a sweeping motion for you to swallow them so they die in gastric juices
How fast does mucociliary escalator beat?
700-1000 beats per minute
What does lysozyme do?
Cleaves Beta-1,4 bond between NAG and NAM in peptidoglycan
Where is lysozyme found?
saliva, PMN granules (red)
tears, breast milk, urine (black)
What do defensins do?
Permeabilize cell membranes of bacteria by creating pores or openings
What are defensins made of?
small cysteine rich proteins
What cells are defensins found in?
- neutrophil (in cytoplasmic granules)
- epithelial cells (skin, mucus secretions)
Lactoferrin is a globular _____
glycoprotein
Where is lactoferrin found?
saliva, tears, nasal secretions, breast milk
What does lactoferrin do?
Chelates iron - takes iron away from bacteria, considered antibacterial
What cells is lactoferrin found in?
Glandular epithelial cells; neutrophils
2 types of inflammation
- acute
- chronic
Acute inflammation is characterized as:
- short duration
- fluid and plasma exudate (edema)
- neutrophilic infiltrate
What cell is associated with acute inflammation?
Neutrophils
Chronic inflammation is characterized as:
- longer duration (months, years)
- influx of lymphocytes and macrophages (more cell recruitment)
- fibrosis (scarring)
TLR4 binds to
LPS
LPS is an:
exogenous pyrogen
Normal body temp range
99.5-100.9 (above that is fever)
Pyrexia
febrile response
Pyrogen
biochemical substance that induce fever
Endogenous pyrogens (localized)
IL-1, IL-6
Endogenous pyrogens (hypothalamus)
Prostaglandin E2
What endogenous pyrogen is transcriptionally mediated?
Interleukins (IL-1)
True or false: interleukins participate in paracrine signalling
False - Both paracrine and autocrine; prostaglandin E2 as well does both
Eicosanoids
Arachidonic acid metabolites
Which endogenous pyrogen is an eicosanoid?
Prostaglandin E2
Prostaglandin E2 influences:
hypothalamic set-point inducing generalized fever as an endocrine
True or false: eicosanoids are stored in PMN granules
False - they are synthesized as needed
Three major eicosanoids participate in innate immune responses, which are:
- leukotrienes
- prostaglandins
- lipoxins
Classical eicosanoinds
leukotrienes, prostaglandins
Non-classical eicosanoids
lipoxins
_____ is inhibited by aspirin/Advil
Cyclooxygenase
PLA2
enzyme that converts phospholipid into arachidonic acid
What cells are leukotrienes found in?
neutrophils, mast cells/basophils, monocytes, eosinophils
_____ recruits neutrophils and is a chemoattractant
Leukotriene B4
What enzyme allows the formation of leukotrienes?
5-lipoxygenase
Prostaglandins are derived from what kinds of signals?
ENDOCRINE (red)
autocrine, paracrine
What cells are prostaglandins associated with?
neutrophils, mast cells/basophils, monocytes, eosinophils
Function of Prostaglandin E2
increases vasodilation, fever; hypothalamus
What enzyme allows formation of prostaglandin from arachidonic acid?
Cyclooxygenase
What cells are lipoxins associated with?
neutrophils, mast cells/basophils, monocytes, eosinophils
______ inhibits chemotaxis/inflammation
Lipoxin A4 LXA4
What enzyme allows formation of lipoxins from arachidonic acid?
1,2-lipoxygenase
Interferon I is produced by:
leukocytes (WBC, PMN)
IFN-alpha and IFN-beta are:
Interferon type I
Interferon I is a ____ factor to ____ neurons
pyrogenic; thermosensitive hypothalamic neurons
Interferon Type I functions to:
down-regulate RNA production (anti-viral)
Interferon gamma is associated with
Interferon Type II
Interferon type II is produced by _____ and inhibits ____
Th1 cells; Th2 cytokines
____ is a potent activator of Class II MHC
Interferon Type II
Complement system promotes ______
Inflammation and phagocytosis
C3a and C5a
chemoattractants
C3b is a:
opsonin
Complement mediated lysis occurs through formation of the:
MAC attack (membrane attack complex)
Complement is a part of (adaptive/innate) immunity
Innate
Classical complement pathway is activated by:
antibody-antigen complex (IgM or IgG bound to antigen)
C1q activation occurs in:
classical complement pathway; binds to antigen/antibody complex
Alternate complement pathway is activated by:
bacteria products (LPS, teichoic acid)
What happens during alternate complement pathway?
- direct activation of complement on bacterial cell surface
What does Factor H do?
deactivates alternate pathway on host cells so complement doesn’t poke holes through our own cells
Lectin pathway is activated by:
mannose binding protein (can be an opsonin)
What bacteria/fungi are associated with lectin pathway?
- salmonella
- listeria
- neisseria
- fungal candida
- cryptococcus
C1q binds what part of the antibody?
CH2 Fc
Order of C proteins in classical pathway
1, 4, 2, 3, 5, 6, 7, 8, 9
C5 to C9
MAC
C3a and C5a characteristics
- chemoattractants
- pro-inflammatory
- anaphylatoxins
Alternate complement pathway is activated by
spontaneous hydrolysis of C3
Most abundant complement protein in blood plasma
C3
Lectin pathway occurs in presence/absence of antigen-antibody complex
Absence
Mannose binding lectin binds to:
mannose on microbe surface
Ficolin binds to:
NAG on bacterial cell wall
True or false: all complement pathways converge with C3
True - thus can proceed to MAC
What does MAC do?
forms transmembrane channels –> cell lysis; death
Complement “a” fragment function
biologically active, remains in liquid phase
Complement “b” fragment function
“binds” to a surface (opsonin)
Opsonins are molecules that enhance _____
phagocytosis
What do acute phase proteins (APP) do?
increase or decrease in response to inflammation; include many cytokines and interleukins (IL-1, IL-6, IL-8)
C-reactive protein (CRP) function
opsonin, proinflammatory
In acute inflammation, we see ____ and ____ which leads to capillary dilation, fluid exudate, and ______
vasodilation; vascular leakage; transmigration of PMN
Selectins are used for
rolling adhesion
Tight binding uses what proteins
integrins
Another name for leukocyte extravasation
Diapedesis
What is diapedesis?
movement through intact capillary wall due to inflammation
Chemotaxis
moving along a concentration gradient
Diapedesis is ______ mediated
Receptor (C3a, C5a, leukotriene B4, IL-1 and 6)
Another name for chemokine
cytokine
Which cytokine binds GPCR on PMN?
IL-8
Acute inflammation is primarily which cell
neutrophil
Neutropenia is associated with:
periodontitis
Agranulocytosis
less than 200/uL means 100% of infection - 100% risk of death
For neutropenia, under _____, there is an increased risk of infection
1000/uL
Phagolysosome
Fusion of phagosome and lysosome
Primary PMN granule
Released during phagocytosis; stored in active form
What proteins are stored in primary PMN granule
cathepsin B, defensins; also lysosome
Secondary PMN granule
stored in inactive form, released after phagocytosis
What happens during respiratory burst?
reactive oxygen species:
1. superoxide (O2-)
2. hydrogen peroxide
3. hydroxyl radical
What are neutrophil NETs?
release web like structure as last resort; all granules and respiratory burst vesicles released
Types of acute inflammation
- serous
- fibrinous
- suppurative (purulent)
Serous inflammation - describe
watery, protein poor fluid (ex blister)
Fibrinous inflammation describe
more serious injury/infection, fibrinogen gets into the area due to greater vascular permeability
Suppurative/purulent inflammation describe
Lot of pus, exudate containing PMN, fluid, necrotic cells
Dental abscess example
Causes of chronic inflammation
- mycobacteria in macrophages (don’t get broken down due to cell wall)
- hypersensitivity, autoimmune responses
Why do mycobacteria continue to live in macrophages?
waxy lipid coat can’t be broken down, inhibits phagolysosome, thus can replicate in macrophages
Why does a granuloma form?
failure of acute inflammation resolution; protective immune response to infection
What cells form granuloma?
epithelioid cells (end stage macrophages)
What bacteria causes the formation of granulomas?
mycobacterium tuberculosis
Sjogren’s syndrome
dry mouth, dry eyes
Xerostomia
dry mouth
Keratoconjunctivitis sicca (KCS)
dry eyes
Sjogren’s syndrome increases risk of:
caries
In Sjogren’s syndrome ____ forms in salivary glands
secondary follicles
Type II autoimmune diseases are associated with:
lymphocytic infiltrates