Core Ii, Lec 2, 3 Innate Immunity

Front 1

What are some examples of infectious agents (microbes)

Back 1

bacteria, fungi, viruses

Front 2

T/F. All multicellular organisms have innate immunity.

Back 2

T

Front 3

Innate Immunity can...

it stimulates...

Back 3

control and eradice infections before adaptive immunity is activated

Adaptive immunity.

Front 4

How are microbes recognized by the innate immune system?

Back 4

Cellular components of innate immunity contain receptors
capable of recognizing structural features also called
molecular patterns that are present on or in the infectious agents
(bacteria, viruses, and fungi), but are absent on the host cells.

Front 5

Examples of structures unique to infectious agents that are
recognized by the innate immune system:

Back 5

1. Bacterial lipopoly sacchardie (LPS)
2. Terminal mannose of glycoproteins
3. Double stranded RNA found in viruses

Front 6

how does innate immune system
recognize and respond to almost all kind of infectious agents?

Back 6

A limited number of cellular receptors of the innate immunity
can recognize molecular patterns shared by different types of
infectious agents.

Front 7

How does innate immunity make it difficult for microbes to evade it?

Back 7

the innate immunity recognizes structures of microbes that are essential for survival. Therefore, microbes cannot simply mutate the structures recognized by innate immunity as an evasion mechanism.

Front 8

What is one great advantage of innate immunity vs adaptive immunity?

Back 8

microbes frequently mutate their recognition motifs for adaptive immunity to evade it. They cant readily evade innate immunity since those are the essential parts of their survival

Front 9

How does innate immunity differ with adaptive immunity in terms of repeated encounters with a microbe?

Back 9

The innate immune system responds in the same way to repeated
encounters with a microbe, whereas the adaptive immune system
responds better each successive encounter with a microbe.

Note:
Adaptive immune system has “Memory”

Innate immune system does not have “Memory”

Front 10

What are two reasons that innate immunity does not attack the host?

Back 10

Two reasons for it:

1.Inherent specificity of innate immunity for microbial structures

2. Regulatory proteins on mammalian cells prevent innate immune
reactions

Front 11

What are six components of innate immunity?

Back 11

1.Epithelial barriers,
2. phagocytes: Neutrophils and monocytes/macrophages
3. Natural Killer Cells
4. Complement System
5. Cytokine of innate immunity
6. Other plasma proteins

Front 12

Common portal entry of microbes include:

Back 12

gi TRACT, respiratory tract, skin

Front 13

What are the three mechanisms against microbes for epithelial barriers?

Back 13

1. Physical barrier
2.Killing of microbes by locally produced antibiotics
3. Killing of microbes by intra-epithelial lymphocytes

Front 14

What are the two types of phagocytes?

Back 14

Neutrophills and monocytes/macrophages

Front 15

what are phagocytes?

Back 15

These are circulating blood cells that are recruited to sites of
infection, where they recognize and ingest microbes for
intra-cellular killing.

Front 16

What are the most abundant leukocytes in the blood?

Back 16

neutrophills

Front 17

What leukocyte usually responds first to bacteria or fungi?

Back 17

neutrophils.

Front 18

In response to infection, the neutrophil count jumps from 4-10,000 to 20,000. How?

Back 18

The production of cytokines by neutrophils stimulates production in bone marrow

Front 19

When a neutrophil ingests a microbe, what happens to the neutrophil?

Back 19

it dies

Front 20

monocytes are more/less? abundant than neutrophils?
They ingest microbes in the ___ and the -__.

Back 20

Less abundant.

blood and tissue

Front 21

How are monocytes different from neutrophils?

Back 21

They enter the extra vascular tissue, like the neutrophils, but they survive much longer and differentiate into macrophages.

Front 22

When an infectious microbe breaches the epithelium and enters the
sub-epithelial tissue, the leukocytes migrate to the site of infection.
Why?

Back 22

Once activated, the macrophage starts to produce Cytokines (TNF, IL-1). Production of this cytokine acts on the endothelial cell by activating receptors to stimulate leukocytes swimming by. The leukocytes swimming by start to get attached because of the increase of receptors. As the leukocytes start rolling, more receptors are formed. Eventually, the leukocyte can enter through the endothelium

Front 23

Inflammation:

Back 23

The accumulation of leukocytes at the site of infection,with attendant vascular dilation and increased vascularpermeability

Front 24

Inherited deficiencies in integrins and selectins lead to :
what are integrins and selectins?

Back 24

lead to defective
leukocyte recruitment to site of infection and increased susceptibility
to infections.
They are a family of adhesion receptors on leukocytes

These deficiencies are called Leukocyte Adhesion Deficiencies.

Front 25

The recognition of microbes
by neutrophils and macrophages
leads to

Back 25

phagocytosis of the
microbes and activation of the
phagocytes to kill the
ingested microbes.

Front 26

What are natural killer cells?

Back 26

a group of lymphocytes that respond to intra-cellular microbes by attacking and killing them; they also produce macrophage activating cytokine, interferon-gamma

Front 27

Do natural killer cells express immunoglobins or T cell receptors? Yes or No?

Back 27

No

Front 28

Aside from microbes, what else can NK cells respond to?

Back 28

Host cells that have been altered by microbes

Front 29

NK cells make up about X % of lymphocytes in the blood and peripheral lymph organs?

Back 29

10

Front 30

How are Natural Killer (NK) Cells activated?

Back 30

Macrophages that have encountered microbes release cytokines. Important one is Interleukin 12.

Front 31

How do Natural Killer (NK) Cells respond once activated?

Back 31

1. They discharge proteins contained in their cytoplasmic granules
toward infected cells. Some of these proteins create holes in
the plasma membrane of infected cells; other molecules enter
apoptosis (programmed cell death)
2. They synthesize INF-g, which activates macrophages to become
more effective in killing microbes.

Front 32

If a normal host cell is infected, how does a NK cell know specifically to attack it?

Back 32

Well a NK cell makes two connections with any cell it wants to attack. If both connections are made, there will be no attack. If The MHC class 1 self complex is present, this makes the second connection, and the NK cell doesnt attack. If a virus has invaded a cell, than the cell is class 1 MHC negative, and the NK cell will attack it.

Front 33

What is the complement system?

Back 33

a collection of circulating and membrane associated proteins that play a role in host defense against microbes and also play a role in antibody mediated response

Front 34

The term "compliment" in compliment system refers to what?

Back 34

The ability of these proteins to complement/assist the antimicrobial activity of antibodies.

Front 35

How is the complement system involved in (1) innate and (2) adaptive immune system.

Back 35

Innate: The complement system may be activated by microbes in the
absence of antibodies, as part of innate immune response to
infection
Adaptive: Complement can be activated by antibodies attached to microbes
as part of adaptive immune response.

Front 36

What are the two pathways that lead to the initiation of the complement system?

Back 36

classical: antibody binds the microbe and this activates the complement system

Alternative; the microbe is recognized by the complement system

Front 37

During innate immunity, In response to microbes, macrophages and other cells secrete...
This is a protein/carb/lipid?

Back 37

Cytokines
Protein

Front 38

What is the principal source of cytokines in innate immunity

Back 38

Macrophages that are activated by microbes

Front 39

Cytokines are produced in response to...

Back 39

external stimulus

Front 40

Name two proteins also involved in innate immunity

Back 40

1.PLasma mannose binding protein(MLB). binds to bacterical carbohydrate to target it for phagocytosis;or activate complement system through the lectin pathway
2.C-reactive protein. Binds to phosphocholine on bacteria and targets them for phagocytosis

Front 41

How does innate immunity respond to different classes of microbes.
1. extracellular
2. intracellular

Back 41

1. Extra-cellular bacteria and fungi are combated by phagocytes
and the complement system, and acute phase proteins.
2.Intra-cellular bacteria and viruses are defended by phagocytes and NK cells, with cytokines providing the communications between the phagocytes and NK cells.

Front 42

Two primary functions of the innate immune system?

Back 42

1.Provide first line of attack against an intruder. It recognizes microbe to mount the first attack
2. Stimulate the adaptive immune system

Front 43

Why isnt adaptive immune system always working?

Back 43

This is to ensure that lymphocytes respond to pathogenic infectious
microbes and not to harmless substances.

Front 44

How many signals does the adaptive immune system need to initiate?
What are they?

Back 44

2 signals.
1. Antigen, a component of microbe
2. A costimulatory molecule produced or induced by microbes

Front 45

What is an adjuvent?

Back 45

a substance that elicits the same innate immune reactions
as microbes do.

Front 46

Cytokines of innate immunity function to do what...

Back 46

function to stimulate inflammation (TNF, IL-1, chemokines), activate NK cells (IL-12), activate macrophages (IFN-g), and prevent viral infections (type I IFN).