innate immune system

Question 1

specifity of the innate IS

Answer 1

non-speciifc, recognizes DAMP and PAMP so one receptor could bind multiple microbes

Question 2

receptors of the innate diversity?

Answer 2

non-diverse like the apdaptive

encoded in the germline=limited receptor diversity (100)

Question 3

distribiution of innate receptors

Answer 3

non-clonal, identical receptors in cells of the same lineage

Question 4

is the innate non-reative to self?

Answer 4

yes, self cells may display factors to prevent an innate response against them

Question 5

The two principal types of reaction of the innate immune

system are:

Answer 5

stimulate acute inflamm and innate anti-viral defenses

Question 6

acute Inflammation.

Answer 6

— which is the accumulation of leukocytes, phagocytic cells, plasma proteins, and fluid derived from the blood at an extravascular tissue site of infection or injury.

Question 7

Anti-viral defenses mediated by:

Answer 7

• – NK cell-mediated killing of virus-infected cells.
• – Interferon α/β (Type I interferons), which are secreted by virus-infected cells, bind to receptors on surrounding cells, and inducean anti-viral state in those cells.

Question 8

Prominent cell-associated Pattern Recognition Receptors and

Sensors of Innate Immunity

Answer 8

Toll-Like Receptors (TLRs).
NOD-like Receptors (NLRs).
RIG-like Receptors (RLRs).

Question 9

where can the innate receptors be located

Answer 9

extracelluar (membrane)
cytosolic
endosome

Question 10

extracellular innate receptors

Answer 10

lecitin

TLR

Question 11

cytosolic innate receptors

Answer 11

nod-like receptors
rig-like receptors (scans for viral RNA)
cytosolic dna sensors (should be no DNA here)

Question 12

endosomal innate receptor

Answer 12

TLR

Question 13

Toll-Like Receptors (TLRs)
where?
what can they recognize?

Answer 13

located at membrane and endomsome
can recognize bacterial lipoproteins, LPS, peptidoglycan, saccharides and flagellin
can recognize foreign RNA/DNA (ss or ds) within the endosome

Question 14

Toll-Like Receptors (TLRs) signaling

Answer 14

Question 15

NOD-like Receptors (NLRs).

Answer 15

NLRs are a family of more than 20 different cytosolic proteins that recognize
PAMPs and DAMPs in the cytoplasm and recruit other proteins to form signaling complexes (such as inflammasomes) that promote inflammation via the production/activation of interleukins

Question 16

RIG-like Receptors (RLRs).
recognize?
response?

Answer 16

RLRs are cytosolic sensors of viral RNA that respond to viral nucleic acids by inducing production of the antiviral type I interferons.

Question 17

epithelial barrier of the innate

Answer 17

physical barrier to infection
possess cells that can produce antibiotics to kill microbes
intraepithelial lymphocytes present as well: can kill microbes/infected cells

Question 18

Phagocytes of the innate

Answer 18

Neutrophils.
…Circulating phagocytic cells; Most abundant leukocytes blood.
…First cell type to respond to most infections.
…Live only a few hours in tissues.

Monocytes/Macrophages.
…Blood monocytes differentiate into tissue macrophages
after entering tissues.

Question 19

Macrophages:
products/function?
lifespan?

Answer 19

Secrete cytokines that induce inflammation, and ingest and destroy microbes.

Survive for long time periods in tissues

Question 20

Activation of macrophages

Answer 20

TLR responding to microbe, cytokine receptors and complement receptors can all stimulate the macrophage

Question 21

TLR activation result at macrohages

Answer 21

cytokine production: stimulate inflamm/ signal to adaptive
phagocyte oxidase activation: kill microbes (via reactive O2 species)
iNOS: kill microbes (via nitric oxide)

Question 22

Phagocytosis and intracellular killing of microbes within macrophages

Answer 22

microbes binds receptors=endocytosis/ phagosome formed
phagosome fuses with lysosome
microbe killed with ROS, nitric oxide, and lysosomal enzymes

Question 23

Dendritic cells (sentinel cells) functions

Answer 23

…Secrete cytokines.

…Present antigenic peptides to T cells.

Question 24

Mast cells 
granules? 
where found?
contain?
cause?

Answer 24

…Abundant cytoplasmic granules.
…Present in skin and mucosal epithelium.
…contain vasoactive amines (e.g. histamine).
…cause vasodilation and capillary permeability

Question 25

Innate lymphoid cells function

Answer 25

…lymphocyte-like cells.

…produce cytokines but lack T cells antigen receptors (TCRs).

Question 26

• Complement functions

Answer 26

…Induce inflammation, opsonize microbes enhancing their phagocytosis, cause osmotic lysis of microbes.

Question 27

complement paths/ activation mech

Answer 27

alternative: microbe binds the receptor
classical: ab binds microbe
lecithin: mannose bonds lecitihin

Question 28

early complement steps/ function

Answer 28

all paths converege to cleave c3 to a and b fragments

a: inflammation
b: opsinitzation/ phago

Question 29

late complement steps/ fucntion

Answer 29

c5 cleaved to a and b

a: inflammation and recruitment of c6-9 to form the MAC for osmotic lysis of microbe

Question 30

what is inflammation/ how does it occur

Answer 30

Delivery of neutrophils, macrophages, T lymphocytes, complement proteins, antibodies, and acute-phase reactants to the site of inflammation is due to reversible changes in blood vessels in the infected or damaged tissue:

• • increased blood flow into tissue due to arteriolar dilation
• • increased adhesiveness of circulating leukocytes to the endothelial lining of venules
• • increased permeability of capillaries and venules to plasma proteins and fluid

Question 31

changes associated with inflammation due to?

Answer 31

All these changes are induced by cytokines and small molecule mediator initially derived from sentinel cells (resident phagocytic cells) in the tissue, as well as endothelial cells, in response to stimulation of PAMPs or DAMPs

Question 32

Sequence of events in migration of blood leukocytes to sites of infection

Answer 32

The sequence of selectin-mediated rolling, chemokine-dependent integrin-mediated firm adhesion, and chemokine-mediated motility leads to the migration of blood leukocytes to the extravascular site of infection.

Rolling> binds selectin> integrin activation via chemokines> stable adhesion> migration thru endothelium

Question 33

Natural Killer (NK) cells function/secretion?

Answer 33

..Kill virus-infected cells presenting nonself peptides at MHC or no MHC
…Secrete interferon γwhich activates macrophages to kill phagocytosed microbe

Question 34

Activating and inhibitory receptors of natural killer (NK) cells

Answer 34

prevent destruction: activating receptor of NK binds activating ligand but the inactivation receptor binds MHC I with self peptide present
cell destruction: only activating receptor binds ligand, no MHC present

Question 35

• IFN α/β (Type I Interferons)

Answer 35

…Secreted by virus infected cells, induce anti-viral state in surrounding cells.

Question 36

Antiviral actions of type I interferons

Answer 36

Question 37

Cytokines of innate immunity

Answer 37

many different proteins: TNF, IL, INF, etc.
made by many different cells
multiple effects possible from these

Question 38

Role of Innate Immunity in Stimulating Adaptive Immune Response.

Answer 38

innate occur first and can produce molecules to simulate the adaptive response
two signal requirement for lymphocyte activation: microbial Ag must bind Ag receptor and molecule induced form innat response will bond a receptor as well, both these lead to lymphocyte prolif and dif

Question 39

how Extracellular bacteria and fungi are combated by the innate

Answer 39

mainly by an acute inflammatory response, in which neutrophils and monocytes are recruited to the site of infection, and by the complement system.

Question 40

how Intracellular bacteria is combated by the innate

Answer 40

Intracellular bacteria, which can survive inside phagocytes, are eliminated when the microbial killing functions of phagocytes are activated by Toll-like receptors and other sensors, as well as by cytokines.

Question 41

innate viral defense

Answer 41

Defense against viruses is provided by type I interferons (interferons α and β) and by natural killer (NK) cells.