Adaptive immunity

Question 1

adaptive (acquired, specific) immune response

Answer 1

• acts against a specific intruder
• acquired when a pathogen is encountered for the first time
• has memory:
• responds more vigorously the second time a particular pathogen is encountered

Question 2

adaptive is divided into two branches

Answer 2

• humoral (antibody mediated) immunity

- cellular (cell mediated) immunity

Question 3

antibodies are also called (Ab)

Answer 3

immunoglobulins (Ig)

Question 4

glycoproteins are composed of 4 subunits

Answer 4

• 2 identical heavy chains

- 2 identical light chains

Question 5

each antibody has..

Answer 5

• 2 identical antigen binding sites (Fab)

- one Fc site- can interact with other components o the immune system

Question 6

5 classes of antibodies

Answer 6

• IgG
• IgM
• IgA
• IgD
• IgE

Question 7

Immunoglobulin G (IgG)

Answer 7

• monomer
• most abundant antibody in blood and tissues
• most important for combating a pathogen

Question 8

IgM

Answer 8

• a pentamer
• first antibody made when a new antigen is encountered
• excellent at agglutination
• does not leave blood and enter tissues

Question 9

IgA

Answer 9

• a dimer
• secreted into saliva, tears, mucous
• helps to protect mucosal surfaces

Question 10

IgD

Answer 10

• monomer
• found on the surface of B cells
• plays a role in activating B cells to respond against an antigen
• diamond antigens instead of triangle

Question 11

IgE

Answer 11

• monomer
• found on the surface of mast cells and basophils
• causes them to release granules of histamine
• trigers allergic response
• extra long light chains

Question 12

five major functions of antibodies

Answer 12

1. neutralization
2. opsonization
3. agglutination
4. antibody mediated cytotoxicity
5. complement activation

Question 13

neutralization

Answer 13

• Ab stick to antigens on a foreign particle and block attachment sites
• stops bacteria, viruses and toxins from entering host cells

Question 14

Opsonization

Answer 14

• Ab stick to a pathogen’s surface and flag down phagocytes
• phagocyte interacts with the Fc region and engulfs the pathogen
• greatly increases rate of phagocytosis

Question 15

Agglutination

Answer 15

• Ab can stick to two identical antigens
• bridges particles together in clumps
• can be phagocytized more easily

Question 16

antibody mediated cytotoxicity

Answer 16

• Ab binds to antigen on the surface of a parasite
• Fc can interact with eosinophils
• eosinophils release enzymes and reactive oxygen intermediates to attack the parasite

Question 17

Complement activation

Answer 17

• Ab found to a bacterial cell can activate complement
• A set of proteins in the blood that assist other components of the immune system
• classical pathways of complement activation
• results in the membrane attack complex (MAC)
• insert into bacterial membranes
• forms a pore
• cell leaks and dies

Question 18

adaptive response properties

Answer 18

• acquired
• specific
• memory
• tolerance

Question 19

acquired

Answer 19

-a pathogen must be encountered before the adaptive immune response is mounted

Question 20

specific

Answer 20

can mount a directed attack against a specific pathogen

-immunity to one pathogen does not confer immunity to another

Question 21

memory

Answer 21

once a specific pathogen has ben encountered immune system cells multiply and produces long living memory cells
-if the pathogen is encountered again, the memory cells will mount a faster, stronger response

Question 22

tolerance

Answer 22

• inability to mount an adaptive immune response against self antigens
• immune system cells that recognize self-antigens are destroyed during development

Question 23

primary response

Answer 23

• the first time a new pathogen is encountered, the adaptive immune response is weak
• the major result is the production of immunologic memory

Question 24

secondary respond

Answer 24

the next time that pathogen is encountered memory cells are ready to respond

• response can be so quick that the pathogen is unable to cause disease
  ie. immunity

Question 25

immunogen

Answer 25

any foreign particle that can induce an adaptive immune response -normally large molecules- proteins, polysaccharides, some lipids

Question 26

antigen

Answer 26

any substance that can react with antibodies or receptors on adaptive immune system cells

Question 27

antibody

Answer 27

protein made by the immune system that can bind to, and inactivate foreign antigens

Question 28

epitiope

Answer 28

(or antigenic determinant) - the actual part of the antigen that can bind to an antibody - the more epitopes on an antigen, the more immunogenic it will be - and the more diverse population of antibodies can be generated against it

Question 29

hapten

Answer 29

low molecular weight compound too small to be immunogenic on its own, but can be highly antigenic

Question 30

hapten example

Answer 30

penicillin is small and non-immunogenic on tis own - can bind to proteins in the blood forming a strong immunogen - antibodies are formed against it-leading to an allergic response

Question 31

cells of the adaptive immune system

Answer 31

- b lymphocytes (B cells) | - T lymphocytes (T cells)

Question 32

B cells

Answer 32

- antibody producing cells | - involved in the humoral immune response

Question 33

T cells

Answer 33

- T-cytotoxic cells (Tc cells) | - T-helper cells (Th cells)

Question 34

Tc cells

Answer 34

- destroy abnormal body cells (ex. cells infected by viruses) - involved in cel mediated response

Question 35

Th cells

Answer 35

Help B and Tc cells prepare for an immune response | -humoral and cell mediated