Term
| What cytokine causes APPs to be released? What are some examples of APPs? |
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Definition
IL-6 induces the liver to produced acute phase proteins (APPs).
1) CRP (C-Reactive Peptide) - binds to C protein/phosphorylcholine on bacterial surfaces, i.e. Pneumococci
- acts as opsonin and activates complement system
2) Mannin-binding lectin - opsonin and activates complement
3) Alpha-2 macroglobulin
4) Serum amyloid protein
5) Fibrinogen |
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Term
| What are some examples of PRRs? |
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Definition
Pattern Recognition Receptors:
1) C-type lectin receptors - binds carbs
2) Toll-like receptors |
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Term
| Describe the function of TLR-2, -3, -4, and -9. |
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Definition
Toll-like receptors
TLR-2: recognizes variety of bacterial components
TLR-3: recognizes double-stranded RNA
TLR-4: receptor for bacterial lipopolysaccharide (LPS)
TLR-9: receptor for bacterial and viral non-methylated DNA sequences (CpG)
TLR-3, 7, 8, 9 are expressed in endosomes; others on cell surfaces |
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Term
| True or false. Macrophages and neutrophils engulf bacteria and present the antigens to CD4 T cells. |
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Definition
| False. Neutrophils do not usually present antigens. |
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Term
| What happens when the mannose receptor is bound? |
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Definition
Production of cytokines and reactive oxygen species.
Also, phagocytosis of microbes. |
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Term
| Which phagocyte membrane receptor associates with CD14, the receptor for bacterial lipopolysaccharide (LPS)? What will binding of this receptor do? |
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Definition
TLR4 - kills gram + bacteria
Activation will increased production of cytokines and reactive oxygen species |
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Term
| Which phagocyte membrane receptor senses chemokines, N-formlymethionyl peptides, lipid mediators (antigens given off by bacteria)? What will activation of this receptor do? |
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Definition
Seven alpha-helical transmembrane receptors
Activation will lead to changes in the cytoskeleton and migration of phagocyte to the tissues. |
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Term
| What are the characteristics of a phagocyte undergoing metabolic burst? |
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Definition
1) Increase oxygen consumption
2) Activation of hexose-monophosphate shunt
3) Activation of NADP system
4) Increase glycolysis |
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Term
| When macrophages recognize CpG sequences, what cytokines are produced? |
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Definition
IFN-alpha, IFN- beta, IL-12
CpG sequences are bacterial DNA that are present intracellularly |
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Term
| Describe the oxygen-dependent system of lysosomal discharge and respiratory burst. How is this system upregulated? |
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Definition
Phagocyte oxidase system --> generates free radicals
Upregulated by IFN-gamma, and TLR signaling |
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Term
| Describe the oxygen-independent system of lysosomes. |
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Definition
1) Lactic acid (from glycolysis)
2) Lysozyme (cleaves beta-1,4 linkages in carbs)
3) Lactoferrin - competes with microbes for iron
4) "Defensins" - phagocytin and leukin - detergent-like (pH 7) |
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Term
| What cytokines/molecules induce macrophages to secrete nitrogen oxide? |
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Definition
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Term
| What cytokines are secreted by NK cells? What kind of receptor is on its surface which allows it to be part of ADCC? |
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Definition
Cytokines: IFN-gamma (activate macs), GM-CSF, TNF
Receptor: CD16 - FcR (Fc region receptor) for IgG |
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Term
| What is the "missing self" paradigm of NK cells? How do they lyse the target cells? |
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Definition
MHC I engage killer inhibitory receptors (KIR). If target cell does not have MHC I, killer activating receptors (KAR) will no longer be inhibited by KIR and NK cells will kill.
They kill via perforins, proteases --> apoptosis of other cell (like CTL) |
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Term
| What cells produce IFN-alpha and beta? What cells produce IFN-gamma? |
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Definition
IFN-alpha, beta: made by leukocytes, dendritic cells (plasmacytoid dendritic cell, PDC), monocytes and fibroblasts
IFN-gamma: CD4 T cells, NK cells |
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Term
| What cells secrete TNF-alpha? What is its function? |
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Definition
Activated macrophages and NJ cells.
Endotoxic shock, inflammation, immunoregualtion, antiviral responses. |
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Term
| What cells secrete IL-12? What does it do? |
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Definition
Produced by monocytes and other APCs (esp. Type I dendritic cells)
Stimulates cytotoxic cell activity and proliferation of T and NK cells.
NOTE: Major link between innate and adaptive immune systems --> develops TH1 response |
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Term
| What cells secrete IL-6? What does it do? |
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Definition
Produced by macrophages, T cells, endothelial cells
Increases bone marrow production of neutrophils and stimulations production of fibrinogen, CRP. |
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