Immunology

Question 1

What two molecules does inflammation involve?

Answer 1

Macrophages and neutrophils

Question 2

Describe a macrophage

Answer 2

They have two life cycles. Immature in blood and mature in tissue.
They scout roaming tissue
Involved in acquired immune response
Induce fever

Question 3

Describe neutrophils

Answer 3

Bacterial specialist
Called by the macrophages
Leave bloodstream and enter tissue
They chase bacteria and secrete nets that trap bacteria. Emzymes destroy bacteria.

Question 4

Describe phagocytes that targeting bacteria

Answer 4

Macrophages and neutrophils have receptors that bind bacteria. (TLRS)
Bind components of bacterial cell walls
Bacteria can resist by covering their walls with polysaccharide capsules not

Question 5

Describe systemic inflammation

Answer 5

Sepsis: microbes in the blood
Leaky. Look vessels throughout the body, too much fluid leaves the vessels, drop in blood pressure.
Activation of clotting factors
O2 starvation occurs in both cases. Can lead to lung and kidney failure.

Question 6

What are the three levels of defense?

Answer 6

Barrier defense: physical, chemical and mechanical: skin, stomach pH
Innate defense: rapid generic response. Does not distinguish pathogens.
Acquired response: slow, tailored for a particular pathogen.

Question 7

What are the two phagocytic cells involved in inflammation?

Answer 7

Defense proteins called Macrophages and neutrophils

Question 8

How do phagocytes target bacteria. What can bacteria do to get out if?

Answer 8

They have receptors that target bacteria called TLRS that bind components of bacterial cell walls.
Bacteria can resist by covering their walls with polysaccharide capsule that prevents the binding of the TLRS.

Question 9

What are the characteristics of acquired/adaptive response

Answer 9

Tailored to an individual foreign substance
Provedes immunity against reoccurrence
Distinguishes self from non self

Question 10

What are the targets of specific immune reposes?

Answer 10

Extracellular invader: humoral response - release of antibodies
Intracellular invader: cell mediated response- direct attack by immune system cells

Question 11

What cells are involved in an acquired immune response?

Answer 11

They are all cells that recognize a specific antigen:
T lymphocytes: helper T cells (TH), cytotoxic T cells (TC) and regulatory T cells (Treg)
B lymphocytes– secrete antibodies

Question 12

Describe antigen presenting cells

Answer 12

Macrophages– Mostly present in phagocytosis
Participate in both innate and acquired response
Dendritic cells– mostly used for antigen presentation. Immature dendritic cells roam tissue and collect antigen by phagocytosis. Mature dendritic cells display antigen for lymphocytes

Question 13

What are some advantages of immune response

Answer 13

Additional line of defense

Immunity from disease reoccurrence

Question 14

What are some disadvantages of immune response

Answer 14

Lacquered immune system cd,la are specialized for particular,ar pathogen (only one in 10,000 T cells will respond to a particular antigen) SLOW

Question 15

How do immune cells communicate

Answer 15

Chemical signal= cytokines and lymphokines– interleukins (IL1)
Cell surface protein major histocompatibility cells (MHC)– HLA is the human version.

Question 16

What are the two types of MHC proteins and Describe MHC1

Answer 16

MHC1 and MHC2
MHC1 us present on all uncleared cells, works in the disposal of antigen fragments for TC In the cytoplasm of infected cells.
MHC 2 is used in antigen presentation

Question 17

Describe MHC 2

Answer 17

Is used in antigen presentation and requires processing and display by APC’s
The structure is 2 non identical subunits.
Antigen binds via non-covalent interaction, antigen fragments 13-20 aas long
( MHC cannot bind an Extracellular antigen)

Question 18

What TH detect?

Answer 18

Short denatured piece of antigen and surroundingMHC

Conformation of MHC groove and binding properties determined by genetics

Question 19

Describe the steps of antigen processing by APC

Answer 19

AG binding and phagocytosis 
Fusion with lysosomes 
Digestion of antigen
AG fragment binds MHC-2 in vehicle 
AG display on cell surface (TH)

Question 20

What is a limitation of MHC

Answer 20

Can’t bind all ranges of antigen

Certain pathogen may not bind certain MHC– greater susceptibility of individual to a disease

Question 21

Describe helper t-cells(TH)

Answer 21

They are produced in the bone marrow and mature in the thymus
Used in antigen recognition using a TCR
CD4 co receptor is an addition protein associated with helper T cells that binds MHC 2

Question 22

Describe TCRs. What cell are they associated with?

Answer 22

TH Cells
Made of 2 non-identical polypeptide
Each individual T cell has 1 type of TCR
TVR recognizes antigen fragment bound in MHC2

Question 23

Describe B CELLS

Answer 23

Produced in bone marrow
They generate antibodies– immunoglobulin
Immunoglobulin most common antibody in immune response
5 different constant regions each with their own roles

Question 24

What area the two regions of an antibody?

Answer 24

The top is the variable region: antigen binding fragment

The bottom is the constant region.

Question 25

Describe antigen antibody binding.

Answer 25

Antibody recognizes and binds 5 to 6 sugars of amino acids–epitope antigenic determinant
A single protein coups have many antigenic determinants

Question 26

Describe epitopes

Answer 26

Could be generated by primary through quart nary structure.

Question 27

Describe native B cells

Answer 27

In G0
Has a transmembrane antibody on surface
Each B cell produces antibody that recognizes only one epitope
Exposure to AG activates only B cells with matching ab– colonial selection
B cell detects Extracellular “free floating” whole antigen.

Question 28

Describe memory B cells

Answer 28

Ilona lived in G0
Resemble native B cells but there’s more of the,
Activated more easily than native B cells

Question 29

Describe plasma B cells

Answer 29

They are an antibody secreting factor
They are short lived- only about 4 weeks
Macrophages neutrophils and dendritic cells have Fc receptor

Question 30

What’s the difference between response time in primary and secondary antibodies

Answer 30

secondary response is much quicker and stronger

Question 31

What are the two strategies for vaccines?

Answer 31

Active: harmless form of antigen: whole thing killed or weaker
Passive: pre made antibodies

Question 32

Describe cytotoxic T cells

Answer 32

Function: detect and destroy infected cells
AG recognition: TCR and CD8 co receptor
AG fragment the displayed by MHC1: 2 polypeptides one transmembrane and 1 Extracellular
Ag fragment is 8-19 aa
MHC 1 displays AV from cytoplasm of cells

Question 33

What is the life cycle of a TC cells

Answer 33

Native and activated

Question 34

Describe a native TC cells I

Answer 34

Ag mhc1 complex recognizes TCR and CD8
Co stimulation
Cytokines from TH or licensed dendritic cells– TH activates dendritic cell to produce TC activating signals( TH doesn’t need to be present)

Question 35

Describe activated TC cells

Answer 35

Ieffecotr TC cells are activated

Memory TC cells activated

Question 36

What area the two killing strategies of TC cells

Answer 36

1– express FAS ligand on membrane
2– secrete cytotoxic so upon contact with infected cells
- perforin assembles unites in membrane to create price for 2nd cytotoxin
- granzyme a protease that directly cleaves procaspase 3