Quiz 4 - German - Induced Immunity - Cells And Cytokines Flashcards
Generally, what do macrophages do?
Phagocytosis
Present antigen to lymph
Activation of T cells
Initiation of immune responses
Monocytes are __________ in the bone marrow.
UNDIFFERENTIATED
Move into tissue and then differentiate
Monocytes differentiate into what?
Macrophage
Dendritic cells
What do dendritic cells do?
Activate T cells
Initiate adaptive immune responses
(Act like a vacuum)
- Drive ongoing inflammatory response to cease
- Collect antigen, go to lymph nodes, and initiate T cells
What do NK cells do?
Kill cells infected with certain viruses
Neutrophils. Tell me.
PHAGOCYTOSIS
-Then degranulate
*1st cell recruited in an immune response
**Billions of these sit in bone marrow and are waiting to be mobilized
***Also can extend a NET to catch and hold pathogen
Mast cells do what?
Expulsion of parasites from body thru release of granules containing histamine and other active agents
Presenters, too
What do eosinophils do?
Kill antibody-coated parasites thru degranulation
What do basophils do?
Control immune response to parasites via degranulation
What are 3 local, tissue resident immune cells?
Macrophage
Dendritic cells
Mast cells - Release histamine
*Adaptive - T cells
What initiates the induced immune response?
Local, tissue resident immune cells
Complement
Pro-inflammatory signaling
- Cytokines
- Eicosanoids
- Acute phase response
Infected, damaged, or diseased tissues
- Interferon response
- Altered MHC expression
What is the inflammatory response for a flesh wound?
Wound introduces bacteria
Resident effector cells secrete cytokines
Vasodilation and increased vascular permeability allow fluid, protein, and inflammatory cells to leave blood and enter tissue
Infected tissue becomes inflamed, causing redness, heat, swelling, and pain
Tell me about macrophages.
- Come from monocytes
- Most tissue have resident macrophages
- Induce and direct inflammation
- Pattern recognition receptors (PRRs)
- Activate adaptive immune system
-Effector mechanisms —Phagocytosis —Cytokine release —Degranulation —Antigen presentation
What tissue have resident macrophages?
Brain - Microglia
Bone - Osteoclasts
Liver - Kupffer cells
Skin - Langerhans cells
Bound material is internalized in a macrophage and then what happens?
Internalized in phagosomes and broken down in phagolysosomes
T/F - Macrophage receptors recognize the cell-surface carbohydrates of bacterial cells, but not those of human cells. (This is considered extracellular)
TRUE
T/F - NK cell receptors recognize change at the surface of human cells that are caused by viral infection. (This is considered intracellular)
TRUE
What are some common PRRs that result in phagocytosis?
Mannose
Complement
LPS
Dectin
MARCO (Macrophage receptor with collagenous structure)
Scavenger receptors A and B
What is a common PRR that does NOT result in phagocytosis?
Toll-like receptors
- These result in signaling
- These are mediated by a family of 10 receptors with variable specificity for a range of pathogens
Tell me the gross process of phagocytosis?
Bacterium become attached to membrane evaginations called pseudopodia
It is ingested, forming a phagosome
The phagosome fuses with the lysosome
Bacterium is killed and then digested by lysosomal enzymes (Proteases, lipases, granules)
Digestion products are released from the cell via exocytosis
What agents are in phagolysosomes?
Acid
Toxic O2-derived products - H2O2, OHCL
Toxic NO
Antimicrobial peptides
Enzymes
Competitors
What do Toll-Like Receptors do?
Activate macrophages
*These are expressed widely throughout the immune system
What TLRs bind lipid?
TLR1
TLR2
TLR4
TLR6
TLR10
What TLRs bind nucleic acid?
TLR3
TLR7
TLR8
TLR9
What TLR bind protein?
TLR5
What TLRs are heterodimers?
What TLRs are homodimers?
Hetero:
- TLR-1/TLR-2
- TLR-2/TLR-6
Homo:
- TLR-3
- TLR-4
- TLR-5
- TLR-7
- TLR-9
The heterodimers (TLR-1/TLR-2 and TLR-2/TLR-6) bind what?
Lipid
What homodimer binds protein?
What homodimers bind lipid?
What homodimers bind nucleic acid?
Protein - TLR-5
Lipid - TLR4, TLR10
Nucleic acid - TLR3, TLR7, TLR8, TLR9
What TLRs bind the plasma membrane? (Extracellular)
TLR1/TLR2
TLR2/TLR6
TLR5
TLR4
What TLRs bind the endosome? (Intracellular)
TLR3 - dsRNA
TLR7 - ssRNA
TLR9 - CpG-DNA
How does heterodimerization happen?
TLRs have binding sites for lipopeptides
Once the two TLRs bind the same lipopeptides, then dimerization is induced
Know this pathway
NF-kappaB
LOOK AT SLIDE 17 IF YOU NEED TO
Complex of TLR4, MD2, CD14, LPS is assembled at the macrophage surface
MyD88 binds TLR4 and activates IRAK4 to phosphorylation TRAF6 and that leads to phosphorylation and activation of IKK
IKK phosphorylates IkappaB, leading to its degradation and release of NFkappaB
NFkappaB enters the nucleus
NFkappaB activates transcription of genes for inflammatory cytokines which are synthesized in cytoplasm and secreted via the ER
What do NOD receptors do?
Detect degraded antigens
Recognize intracellular PAMPs and DAMPs
- Microbial toxins
- Viruses
- Cell stress proteins
Form inflammasome which cooperates with TLRs