Immunology

Front 1

Pathogen Assosciated Molecular Patterns (PAMPs) was a term dubbed by which scientist?

Back 1

Charlie Janeway

Front 2

Does necrosis result in innate immune response?

Back 2

Yes

Hint 2

It's because it is a non-physiological tissue damage that result in direct exposure of self DAMPs to blood

Front 3

Where are DAMPs normally found?

Back 3

DAMPs are normally sequestered within the cell, never exposed to ECF

Hint 3

DAMPs are only released when necrosis happens

Front 4

Which scientist first identified such self-molecules and named them "danger signals"

Back 4

Polly Matzinger

Front 5

What type of injuries lead to necrosis?

Back 5

Tissue trauma, burns, toxins and other non-physiological stimuli

Front 6

What physical observations can be made to a cell experiencing necrosis?

Back 6

Plasma membrane rupture, Rapid swelling, Burst, Cellular compartments out.

Front 7

What are DAMPs also known as?

Back 7

Alarmins

Front 8

Which molecules are good candidates as being identified as a DAMP?

Back 8

HMGB1 (chromatin binding protein), IL-1alpha, IL-33

Front 9

Why should we use DAMPs?

Back 9

Because the events leading to necrosis are usually accompanied or followed by infection. If pathogen escapes detection but makes cell necrosis, it can now be identified

Front 10

Are DAMPs released by apoptosis?

Back 10

No because there is no direct release of cell components. Cell breaks into apoptotic bodies which are phagocytosed

Hint 10

Cells place Phosphatidylserine to the outer leaflet of cell membrane which tags them for removal via phagocytosis (macrophage,monocytes). DAMPs remain hidden.

Front 11

What do PRRs recognize?

Back 11

Conserved (not prone to mutation) specific 3D structures called PAMPs not represented by body's own cells.

Front 12

Give example to molecules which are regarded as PAMPs to PRRs

Back 12

Carbohydrates (on outer leaflet) such as lipopolysaccharide or mannose, Proteins such as flagellin and ax21, Double stranded RNA, Peptidoglycans and teichoic acid of Gram +ve walls

Front 13

Can PRRs also recognize DAMPs?

Back 13

Yes.

Front 14

What happens after PRR---PAMP/DAMP engagement?

Back 14

Either secretion and then binding of bactericidal humoral pattern recognition molecules to destroy cell wall and cause bacterial osmotic lysis, OR phagocytosis (if PRRs are found on membrane of phagocytes) OR Humoral Pattern Recognition molecules binding and coating the microorganism to increase phagocytotic uptake efficiency OR Activation of signal transduction pathway to release cytokine or chemokine

Hint 14

Humoral Pattern Recognition molecules are Lysozyme, Complement molecules, Mannose Binding Lectin and C-reactive protein

Front 15

Upon encounter with a pathogen, cells of immune system communicate with each other so as to amplify immune response. Which 2 classes of messenger proteins are the most effective in this role?

Back 15

Cytokines and Chemokines

Front 16

What are the properties of cytokines?

Back 16

Diverse group of proteins with pleiotropic effects.
Ability to activate other cells
Ability to differentiate cells
Enhance anti-microbial activity
Released in response to PAMPs and DAMPs and leads to alteration of activation state and behavior of cells

Front 17

What are the properties of chemokines?

Back 17

Released upon encountering PAMPs and DAMPs
Serve as chemotactic factors, laying a trail to guide the immune cells to the site of infection

Front 18

How many levels of defense is the vertebrate immune system made up of?

Back 18

1- Physical barrier to infection: Skin, Mucous secretions, commensals,
2-Innate Immune System:
Broad acting,Highly effective, Instantaneous, Alerts Adaptive Immune system Cells
3-Adaptive Immune Sys:
Attack is highly specific to nature of pathogen
Uses highly specific antibodies
Performs clonal selection (expansion + mass secretion of only the specific antibody)
Acts relatively delayed

Front 19

Upon entry of a pathogen, innate immune responses occur immediately. Do innate immune responses improve upon frequent encounter with pathogen?

Back 19

No, innate immune responses dont improve upon frequent encounter.

Front 20

Do PRRs of innate immune response recognize only a specific PAMP structure or is it a broad range?

Back 20

PRRs of innate immune sys recognize a broad range of PAMPs

Front 21

What two mechanisms does innate immune sys employ so as to mount an immediate attack on pathogen?

Back 21

Phagocytosis or destructive anti-microbial proteins, e.g. lysozyme, proteases, membrane attacking proteins

Front 22

What are the main components of innate immune response?

Back 22

Macrophages, Neutrophils, soluble bactericidal proteins such as lysozyme and complement molecules

Front 23

Is innate immune response sufficient in eliminating a highly specialized threat?

Back 23

No. Specific attack via adaptive immune response should follow

Front 24

Adaptive immune responses are usually delayed and take time to occur after infection starts, For a typical pathogen, how much time does it take for adaptive immune response to occur after innate response?

Back 24

Adaptive immune responses usually take 4-5 days after innate immune response

Front 25

Do adaptive immune responses improve upon frequent encounter?

Back 25

Yes. This is called immunological memory which forms the basis of vaccination.

Front 26

What are the key players of adaptive immune system?

Back 26

T- lymphocytes and B-lymphocytes. These display specific receptors (antibodies) on cell membrane tailored to recognize PAMPs

Front 27

Antigens are recognized by receptors on B- and T-cells. What happens next?

Back 27

Differentiation and proliferation of lymphocytes to increase the numbers of cells that can specifically recognize the antigen and in the case of B-cells, to produce large concentrations of antibodies against them

Front 28

What is the function of memory response?

Back 28

They are properties of adaptive immune system where, if the same antigen is encountered, a more effective and quicker responses take place which means destruction at a lesser time with a greater rate of antibody production.

Front 29

What kind of receptors (PRRs) do innate immune cells deploy?

Back 29

Hard-wired receptors (germ-line encoded which means the genes from a parent are passed down to an offspring in the identical form)

Front 30

Why are the innate immune responses similar between individuals of the same species?

Back 30

That's because the genes encoding the receptor structure are identical to one another which results in identical responses to PAMPs (identical signal transduction pathways)

Front 31

What kind of receptors do adaptive immune cells deploy?

Back 31

They deploy randomly generated receptors which are highly specific for the antigen.

Front 32

Why are the adaptive immune responses different between individuals of same species?

Back 32

The genes encoding the receptor structure are modified via mutations/rearrangements so as to give rise to a different molecular structure.

Front 33

How can we summarize the events that occur to eliminate a pathogen?

Back 33

Innate immune cell PRRs detect PAMPs--> apply an immediate,broad and non-specific attack on pathogen (phagocytosis/ anti-microbial proteins (lysozyme/complement))--> Cells are being destroyed--> This allows time for delayed specific adaptive response--> Adaptive immune cells differentiate and proliferate --> antibodies are formed-->