Induced Immunity: Cellular Responses and Cytokines Flashcards
What are the two innate immunity effector pathways?
- Immediate
2. Induced
What are the effector functions of Immediate innate immunity?
- Barriers
- Antimicirobial peptides
- Opsonization
- Inflammation
- Cellular recruitment
What are the 3 aspects of Opsonization?
- Isolation
- Pore Formation
- Targeting
What are the induced effector functions?
- Phagocytosis
- Targeted killing
- Antimicrobial Peptides
- Cytokine Release
- Inflammation
- Cellular recruitment
- B and T cell activation
List the local tissue resident immune cells
- Macrophages
- Dendritic cells
- Mast cells
- Specialized T cells
What are the pro-inflammatory signaling molecules?
- Cytokines
- Eicosanoids
- Acute phase response
Under what circumstances would you see an interferon response?
Infected, damaged, or diseased tissues
Under what conditions would you get altered MHC expression?
Infected, damaged, or diseased tissues
What are the steps of the inflammatory response?
- Healthy skin is not inflamed
- Surface wound introduces bacteria, which activates resident effector cells to secrete cytokines
- Vasodilation and increased vascular permeability allow fluid, protein, and inflammatory cells to leave blood and enter tissue
- The infected tissue becomes inflamed, causing redness, heat, swelling, and pain
What are the general factors involved in the initiation of the induced immunity?
- Local, tissue resident immune cells
- Complement system
- Pro-inflammatory signaling
- Infected, damaged, or diseased tissues
Macrophages are derived from ______
Monocytes
What do you call resident macrophages in the brain?
Microglia
What do you call resident macrophages in bone?
Osteoclasts
What do you call resident macrophages in the liver?
Kupffer cells
What do you call resident macrophages in the skin?
Langerhans cells
What do Macrophages do?
- Induce and direct inflammation
- Activate adaptive immune system (T cells)
- Initiation of immune responses
What are the effector mechanisms used by machrophages?
- Phagocytosis
- Cytokine release
- Degranulation
- Antigen presentation
What is an example of Innate immune cells recognizing extracellular patterns?
Macrhophage receptors recognize the cell-surface carbohydrates of bacterial cells but not those of human cells
What is an example of innate immune cells recognizing intracellular patterns?
NK cell receptors recognize changes at the surface of human cells that are caused by viral infection
T/F Pattern Recognition Receptors are present on most innate cells
TRUE
Pattern recognition receptors have both local and direct activation T/F
TRUE
List the common pattern recognition receptors that are macrophage receptors
- Mannose receptor
- Complement Receptors 3 and 4
- Dectin-1
- Macrophage receptor with collagenous structure
- Scavenger Receptor A
- Scavenger receptor B
- Lipopolysaccharide receptor
What would you associate CD206 with?
Mannose receptor
What would you associate Mac-1, CD11b or CD18 with?
Complement receptors 3 and 4
What is MARCO?
Macrophage receptor with collagenous structure
What is CD36?
Scavenger receptor B
What is CD14?
Lipopolysaccharide receptor
What is Phagocytosis?
Pathogen Internalization and Destruction
What are the innate phagocytic cells?
- Macrophages
- Dendritic cells
- Neutrophils
What are the steps of Phagocytosis?
- Bacterium becomes attached to membrane evaginations called Pseudopodia
- Bacterium is Ingested, forming phagosome
- Phagosome fuses with lysosome
- Bacterium is killed and then digested by lysosomal enzymes
- Digestion products are released from the cell
Which of the macrophage receptors is a Beta-glucan receptor?
Dectin-1
What does MHC stand for?
Major histocompatibility complex
Toll-like receptors activate _______
Macrophages
T/F Toll like receptors are expressed widely throughout the immune system
TRUE
What is required for Toll like receptor (TLR) Activation?
Dimerization
What are the two types of Dimerization?
- Heterodimerization
2. Homodimerization
How would Heteodimerization occur?
Binding of 2 TLRs to the same lipopeptide induces dimerization, bringing their cytoplasmic TIR domains into close proximity
TLR signaling intitiates _________ through _______
- Cytokine prouction
2. NF-kB
What do NOD receptors detect?
Degraded Antigens
What does NOD stand for?
Nucleotide-binding Oligomerization Domain
T/F Inflammosomes are formed by NOD receptors
TRUE
NOD receptors induce ________
Cytokine expression and release
NOD receptors recognize intracellular ________
PAMPs and DAMPs
What are some examples of intracellular PAMPs or DAMPs recognized by NOD receptors?
- Microbial Toxins
- Viruses
- Cell stress proteins
T/F NOD receptors cooperate with TLRs
TRUE
What does NOD receptor recognition of bacterial cell wall components lead to?
Activation of NFkB
Inflammasomes activate and promote __________
Cytokine release
T/F Inflammasomes function as somewhat of a checkpoint
TRUE
What type of activity do Inflammasomes have?
Proteolytic
What effect do inflammsomes have on other pro-inflammatory activity?
They enhance it
Inflammasomes drive ________
Cytokine release
What are cytokines?
Signaling molecules of the immune system
Are cytokines soluble or insoluble?
Mostly soluble
What type of signaling do cytokines predominantly use?
Paracrine and autocrine
Give some examples of the nomenclature of Cytokines
- Interleukins
- Chemokines
- etc
Name the 6 families of cytokines
- Class I
- Class II
- Interleukin 1
- Interleukin 17
- TNF
- Chemokines
What is the classification of the 6 families of interleukins based on?
Receptor Morphology
T/F Cytokines only effect immune tissues
FALSE, the effect immune and non-immune tissues
What are the common intracellular signaling pathways associated with Cytokines?
- JAK-STAT
- MAPK
- NF-kB
T/F Macrophages can release Inflammatory cytokines
TRUE
Give 5 examples of Pro-inflammatory Cytokines
- IL-12
- CXCL8
- IL-6
- TNF-alpha
- IL-1Beta
IL-1B, IL-6, and TNF-a have systemic effects in which areas of the body?
- Liver
- Bone Marrow Endothelium
- Hypothalamus
- Fat, muscle
- Dendritic cells
What do inflammatory cytokines stimulate in the liver?
Liver Acute Phase response
Cytokines can also intitiate leukocyte recruitment T/F
TRUE
What are the steps of cytokines Initiating leukocyte recruitment?
- Cytokines produced by macrophages cause dilation of local small blood vessels
- Leukocytes move to periphery of blood vessel as a result of increased expression of adhesion molecules by endothelium
- Leukocytes extravasate at site of infection
- Blood clotting occurs in the microvessels
What are the 3 things that Extravasation depends on?
- Chemokines
- Adhesion Molecules
- Proteases
What are chemoattractants?
Chemokines
What would you consider Tether leukocytes to be?
Adhesion molecules
What would consider molecules that open the ebasement membranes like MMPs and Elastases?
Proteases
What do chemokine gradients do?
recruit cells to tissues
Leukocytes Extravasate to where?
The site of inflammation
How do Leukocytes such as Neutrophils exit the blood and enter the tissue at the sit of inflammation?
- Chemokine receptor activation leads to binding
- Binding Triggers protease release
- Basement membrane degradation and chemokines induce diapedesis and tissue entry
What does excessive plasma TNF-a cause?
Septic shock syndrome
Describe Toxic Shock syndrome from excessive TNF-a in plasma
- Often initiated by blood-borne infection
- Systemic extravasation
- Systemic Neutrophil infiltration
- Vascular Collapse
- Rapid Multi-organ failure
What is the primary cell of the induced response?
Neutrophils
What are the effector mechanisms of neutrophils?
- Phagocytosis
- Degranulation
- Extracellular Traps
- Cytokine Release
What is the relative size of neutrophils?
They are small but numerous
What are the 4 neutrophil granule types?
- Azurophil Granules
- Specific Granules
- Gelatinase Granules
- Secretory Granules
What two purposes are served by Granules?
- Phagocytosis
2. Degranulation
Which innate immune cell is associated with an oxidative burst?
Neutrohpils
Dendritic cells intitiate _________
Adaptive immunity
Are Dendritic cells resident in tissue?
Yes
Dendritic cells are derived from _______
Monocytes
Describe the range of PRRs of dendritic cells
- They have an enormous range of PRRs
- Different PRRs induce different responses
T/F Dendritic cells are phagocytes
TRUE
How are Dendritic cells associated with antigens?
- Process pathogens into antigens
- Present antigens to lymphocytes
T/F Dendritic cells perform cytokine regulation
TRUE
What targets infected, diseased, and stressed cells?
Natural Killer Cells
Which cells would you describe as Large, cytotoxic lymphocytes?
NK cells
NK cells have diverse combinations of ___________ and ___________ receptors
- Activating
2. Inhibitory
NK cells target and kill _________
Diseased self cells
Which cells respond to interferons, MHC class I and Unique stress ligands?
NK cells
NK cells regulate the shift from _______ to _______
- Induced innate
2. Adaptive immune
Bone marrow education selects __
Functional receptor patterns
What causes the interferon response?
Viral infections
What is RLR?
Retinoic-acid-inducible gene (RIG)-I-like receptor
What is MAV?
Mitochondrial antiviral signaling protein
What are interferons?
They are cytokines
When acting as cytokines, what do interferons do?
- Reduce viral replication
- Prevent cell division
- Induce Apoptosis
- Activate NK cells, T cells, Macrophages
What releases Interferons?
Diseased or stressed cells
**Intracellular infection or cancer
Aside from diseased or distressed cells, what else can release interferons?
Leukocytes
How many types of Interferons are there?
3
What are the type I interferons?
- IFN-alpha
- IFN-Beta
- IFN-E
- IFN-K
- IFN-w
What are the type II interferons?
IFN-y
What are the Type III interferons?
IFN-upside down y
Interferons activate ________
NK cells
DC cells locally activate _________
NK cells
During a large NK response what happens to the DC presentation?
It is inhibited
During a small NK response what happens to DC cells?
They are activated
Granulocytes protect _______
Local tissues
Where do you find Granulocytes?
Predominant in tissues, rare in the blood
What do granulocytes respond to?
Parasitic organisms
Granulocytes are responsible for intitiating _________
Type I hypersensitivity (allergic reactions)
What do Granulocytes do when activated?
Degranulate
*Cell-type specific granule components
Granulocytes express PRRs which are _______
Often primed by prior adaptive responses