Test Flashcards
Low affinity IgM is effective at eliminating microorganisms because (compared to IgG)
IgG has 2 binding sites. IgM has 10 binding sites. Therefor, even with low affinity, it can still have high avidity
B cell proliferation cytokines
IL-2, 4, 5
IFN-y effect on B cell
Become plasma cell secreting IgG
TGF-b effect on B cell
Become plasma cell secreting IgA
IL-4 effect on B cell
Become plasma cell secreting IgE or IgG
IL-2, 4, 5 effect on B cell
Become plasma cell secreting IgM for complement activation
Which Ig can transport across epithelium
IgA
Subclasses of different IgG have slightly different sequences where
In their H-Chains which results in the different functional activities
IgG provides the bulk of immunity for
Blood born pathogens
IgM and IgD- what happens when one binds an antigen while on B cell
B cell internalizes Ag, processes it and presents it to helper T cell. It then proliferates and differentiates into Ab secreting plasma cell
First antibody produced by Ag-activated B cell prior to contact with Th cell
IgM
Secretory component (SC) of IgA function
Involved in transepithelial transport of exocrine IgA and stabilizes IgA against degradation in the GI tract
Secretory IgA function
Binds to antigens and prevents or inhibits their attachment to/or invasion of epithelial cells
Hassals corpuscles are involved in
Generating T regulatory cells
White pulp is made up of
T and B cell zones
IFN a/b have potent
Antiviral activities
What triggers the expression of E and P selection on endothelial cells, and what synthesizes the molecules
E-Selectin- IL-1 and TNF, synthesized by mast cells and macrophages
P-Selectin- Histamine or thrombin trigger expression
MCP-1 chemokine does what
Mediates recruitment of monocytes
CD44 expressed where, binds what, and causes what
Expressed on T cells, binds E-selectin or HA on activated endothelial cells, causes increased integrin affinity (inside-out signaling)
IL-12 effect and what produces it
Produced by macrophages, stimulates IFN-y production by NK cells and T cells
IL-15 effect
Proliferation of NK cells
IL-12 and TGF-b effect
Control of inflammation
Which TLRs recognize extracellular pathogens
1, 2, 4, 5, 6
Which TLRs recognize intracellular pathogens
3, 7, 8, 9
What triggers inflammasome activation
Crystals, reduction in cytosolic K+, microbial products
SR-AI and SR-AII mediate
The uptake of oxidized lipoproteins which leads to atherosclerosis
SRs bind molecules based on
Negative charges
Eukaryotic cell carbohydrates vs microbial carbs
Eukaryotic carbs are terminated by galactose and sialic acid.
Bacterial carbs are have mannose, n-acetylglucosamine and B-glucans
DAMPs include
ATP, Lipid (oxLDL, saturated fatty acids) HSP, HMGB1
Monocytes/macrophages begin arriving at sites of inflammation after how long
16-48 hours
Defensins are produced by
Epithelial cells at mucosal surfaces, neutrophils, NK cells, CTLs
Cathelecidins produced by
Neutrophils
Cathelecidins function
Direct or indirect toxicity to microbes (can activate leukocytes)
Bind and neutralize LPS
Some can play anti-inflammatory role by binding DNA and blocking inflammasome activation
Effect when natural killer cell releases IFN-y vs IL-10
If IFN-y is released, macrophages and T cell responses are boosted
If IL-10 is released, they are dampened
Ligands MICA/MICB
Absent on healthy cells, expressed upon cellular stress associated with viral infection/malignant transformation
NK cells have NKG2D receptors that recognize MICA/MICB and activate them
IL-1 secreted by, causes
Secreted by macrophages, activates endothelial cells, causes fever, synthesis of APPs by liver
CRP and SAP
CRP- recognizes phosphorylcholine on bacteria
SAP- recognizes phosphatidylethanolamine on apoptotic cells
Both can activate complement system by binding C1q
