Unit 4- Specific Resistance (Adaptive Immunity)

Question 1

where do B-cells mature?

Answer 1

in the bone marrow

Question 2

where do T-cells mature?

Answer 2

thymus

Question 3

what are APCs?

Answer 3

antigen presenting cells

Question 4

what cells are professional APCs?

Answer 4

neutrophils, macrophages, T-cells and B-cells

Question 5

how do APCs display antigens?

Answer 5

using the protein complex MHC-II, they display Ags of phagocytized pathogens on their surface

Question 6

how do B-cells contact an antigen

Answer 6

either directly, or on the surface of an APC, then they make antibodies in response

Question 7

what do helper T-cells do?

Answer 7

they activate B_cells and T-cells (act as managers/match-makers)

Question 8

2 types of B-cells?

Answer 8

memory B cells, plasma B cells (the effector cells, making antibodies)

Question 9

2 types of T cells?

Answer 9

memory T cells and cytotoxic T cells (Tc)- teh effector T cells attacking pathogen directly

Question 10

effector cell of B cells are called…

Answer 10

plasma B-cells

Question 11

effector cell of T cells are called.

Answer 11

cytotoxic T cells (Tc)

Question 12

what do Abs do?

Answer 12

ANOC out punch!!

1) Agglutination
2) Neutralization
3) Opsonization
4) Complement Activation

Question 13

aggultination?

Answer 13

some Abs stick together, clumping the target

Question 14

neutralization

Answer 14

Abs bind the surface of a pathogen, toxin and prevent its function (prevents pathogen from moving fwd by piling on top)

Question 15

opsonization

Answer 15

Ab-bound cells are more often phagocytized

Question 16

complement activation

Answer 16

complement factors poke holes (MACs) to lyse membrane

Question 17

MHC stands for…?

Answer 17

multihistocompatibility complex; it takes proteins from digested bacteria and presents on surface of a neutrophil

Question 18

2 classes of MHC

Answer 18

MHC Class 1- foudn on all human nucleated cells
MHC class II- found on some types of WBCs (the antigen presenting cells)

Question 19

what are MHC genes known as?

Answer 19

HLA genes

Question 20

antigen

Answer 20

substances, specific molecules usually proteins, that bind to lymphocyte receptors (B/Tcell)

Question 21

epitope

Answer 21

the segment of the antigen that is recognized by lymphocyte receptors (shape is recognizable)

Question 22

immunogens

Answer 22

agents that can provoke an immune response and react with the prodcts of that response

Question 23

what antigens are not immunogens?

Answer 23

1) haptens (when they’re too small)
2) when they’re too similar to normal cellular proteins
3) when they either don’t have a static structure, or have a highly repeating structure

Question 24

haptens

Answer 24

are too small, and cannot elicit an immunological response, although bound to T/B cells. HOwever, they can bind to larger molecules (carriers)

Question 25

example of an antigen that isn't immunogenic because of similarity to normal cell proteins?

Answer 25

streptococcus pyogenes- molecular mimickry

Question 26

what antigens have a changing structure?

Answer 26

lipids and globular proteins with slimay, dynamic structures... they're poorly immunogenic

Question 27

what antigens have a repeating structure?

Answer 27

starch, glycogen and other polysaccharides. they're poorly immunogenic

Question 28

what 6 factors determine immunogenicity of an Ag?

Answer 28

chemical composition, size, complexity, genetic disparity, and processing by APCs

Question 29

proteins, carbohydrates, pure lipids--- rate on immunogenicity

Answer 29

proteins are highly immunogenic, carbs are weakly and pure lipids are non-immunogenic

Question 30

pattern of size and immunogenicity of Ag?

Answer 30

larger the size, greater the immunogenicity

Question 31

structural complexity and immunogenicity of Ag?

Answer 31

greater the complexity, greater the immunogenicity

Question 32

what structure of Ag molecules are almost most immunogenic?

Answer 32

aromatic molecules (as compared to alipathic molecules)

Question 33

autograft

Answer 33

transplant from self

Question 34

isograft

Answer 34

transplant from twin

Question 35

allograft

Answer 35

transplant from unrelated person

Question 36

xenograft

Answer 36

trasnplant from animal (different species)

Question 37

autoantigens

Answer 37

when your own proteins becoem immunogenic and recognized as an antigen--> autoantibodies are produced

Question 38

alloantigens

Answer 38

antigens derived from other people (ie. blood transfusion or organ trasnplant)

Question 39

what are 2 ways of minimizing risk of genetic disparity?

Answer 39

1) umbilical cord blood biobanking-- cord blood rich in hematopoietic stem cells) 2) autologous blood transfusion- bank your own blood prior to surgery so you could receive your own blood for transfusion

Question 40

adjuvants

Answer 40

factors external to the substance that can make an Ag more immunogenic. Adjuvants are agents added to vaccines to enhance the vaccines' immunogenicty

Question 41

example of an adjuvant

Answer 41

alum and dead bacteria, as well as oil-in-water emulsion (clumps molecules together) while alum stimulates chemotaxis

Question 42

components of a vaccine:

Answer 42

1) Ag (primary 2) Adjuvant 3) Preservative

Question 43

epitope

Answer 43

immunogenic or antigenic determinants, they are part of immunogen/antigen that interact with the ag-binding site of the antibody/T-cell receptor, around 4-6 a.a. long

Question 44

what's the most important part of an epitope?

Answer 44

its 3D shape

Question 45

immunoglobulins

Answer 45

receptors on the surface of B-cells and T-cells

Question 46

lymphocyte immunoglobins mutate during when?

Answer 46

hematopoiesis

Question 47

what is the result of immunoglobulin mutation?

Answer 47

immunoglobulin Ag binding site changes shape.. final shape is random depending on mutation

Question 48

VDJ Recombination

Answer 48

genetic recombination that consists of 3 genes: Variable, Diverse, Joining.

Question 49

how many possible epitopes are there as a result of VDJ Recombination?

Answer 49

3 x 10^11 epitopes

Question 50

example of naturally acquired active immunity

Answer 50

exposure to pathogen

Question 51

example of articficially acquired active immunity

Answer 51

exposure to vaccine

Question 52

example of naturally acquired passive immunity

Answer 52

breast feeding/Abs from mother's placenta

Question 53

example of artificially acquired passive immunity

Answer 53

premade Abs from immune donor or purified IgGs

Question 54

what Abs do mother's pass to babies through breast feeding?

Answer 54

IgA, but it eventually runs out and baby needs to develop own immune system

Question 55

prophylaxis

Answer 55

administer an agent to prevent disease before exposure has occured

Question 56

source of antigens? 4

Answer 56

killed whole cell or inactivated virus, lived, attenuated cells/virus, proteins or other antigenic molecules purified from pathogen, genetically engineered antigen

Question 57

pros and cons of killed/inactivated pathogens?

Answer 57

pros: almost always dead/safe. cons: does not multiply, higher dose and booster shots needed

Question 58

pros and cons of attenuted pathogen

Answer 58

pros: multiples somewhat, long lasting protection. cons: small risk of reversion to active pathogen

Question 59

examples of attenuated pathogenvaccines

Answer 59

BCG (Tb), OPV (oral polio vaccine), toxoid (Td)

Question 60

pros and cons of purified molecules

Answer 60

pros: no living pathogen, cons: ag may change shape during purification

Question 61

examples of purified molecules

Answer 61

anthrax, hep B

Question 62

pros and cons of recombinant proteins

Answer 62

pros: cheap, safe; cons: clonal, pathogen can evolve resistance easily (it only represents one protein)

Question 63

herd immunity

Answer 63

when over 95% of people in the population are immune to the infectious agent