Lecture 14

Question 1

Innate immunity

Answer 1

First line of defense, resistance to microbe or foreign material, NO MEMORY (skin, mucus)

Question 2

Adaptive immune response

Answer 2

activated by cells and chemicals of innate immunity, tailored to particular foreign agent, MEMORY

Question 3

Characteristics of adaptive immunity (4)

Answer 3

1. discrimination between self and non-self
2. specificity
3. Diversity
4. memory

Question 4

Naturally acquired active immunity

Answer 4

specific immunity a host develops after exposure to foreign substance

Question 5

Naturally acquired passive immunity

Answer 5

Transfer of antibodies (mother to infant - breast milk)

Question 6

artificially acquired active immunity (vaccine)

Answer 6

intentional exposure to foreign material (antigen)

Question 7

Artificially acquired passive immunity

Answer 7

preformed antibodies or lymphocytes produced by one host are introduced into another host

Question 8

Antigens

Answer 8

self and non-self substances that illicit an immune response, large complex molecules

Question 9

Antigenic determinant sites (epitopes)

Answer 9

site on antigen that is recognized by specific antibody, valence = # of epitopes on antigen

Question 10

T cell development

Answer 10

multiple subsets of t cells, initiate, orchestrate, an adaptive immune response, originate from CLP cells from bone marrow

Question 11

Thymic selection

Answer 11

Determines what kind of T cell any given immature cell will become
Pos - Sorted into 2 types based on t cell receptor
neg - t cells that recognize self antigen destroyed

Question 12

T helper cells

Answer 12

CD4+ cells, activated by antigen presentation, role is to help other immune cells by releasing signals

Question 13

Different T helper cells (most important)

Answer 13

TH0 (mature, not activated), TH1 (help activate macrophages), TH2 (help B cells produce antibodies), TH17 (assist in antibacterial responses), Treg (control lymphocyte responses)

Question 14

Cytotoxic t cells (2 types of cell they can kill)

Answer 14

CD8+ cells activated by antigen presented by dendritic cells
1. virus infected
2. cancer neoantigens
Kills by perforin which activates apoptosis

Question 15

B cells

Answer 15

mature in bone marrow, has to be activated by specific antigen

Question 16

B cell receptors

Answer 16

made of membrane bound antibodies, major naive b cells attach an antibody to their cell membrane antibody faces antigen

Question 17

T dependent antigen activation (require 2 signal), (what they differentiate to)

Answer 17

1.antigen b cell receptor specific interaction
2. Activated t helper binds b cell presented antigen and secretes b cell growth factors
1. Plasma cell 2. Memory cell

Question 18

antibody (found where, what does it recognize)

Answer 18

found in blood serum, tissue fluids, mucosal surfaces, antibody can recognize and bind antigen that caused its production

Question 19

Antibody (made out of)

Answer 19

immunoglobulin, glycoprotein made by activated b cells, serves as antigen receptor on b cell surface

Question 20

Antibody (chains)

Answer 20

Fc (crystallizable fragment), 2 Fab (antigen binding fragment), light chain

Question 21

Antibody structure (and regions)

Answer 21

four polypeptide chains (2 heavy, 2 light), connected by disulfide bridges
1. constant regions - does not vary
2. variable regions - sequence varies

Question 22

Immunoglobulin function (Fab)

Answer 22

binds antigen specifically, marks antigen for immunological attach, activates non specific defence mechanisms that destroy antigen

Question 23

Immunoglobulin function (Fc)

Answer 23

mediates binding to host tissue, receptor on various immune cells, first component of complement system

Question 24

Primary antibody response

Answer 24

relatively slow antibody response when antigen is encountered for first time

Question 25

Secondary antibody response

Answer 25

occurs upon subsequent exposure to same antigen, rapid, prevents illness, MEMORY

Question 26

Consequences of antigen-antibody binding

Answer 26

toxin neutralization (prevent toxic action), precipitation + agglutination (aids phagocytosis), opsonization (foreign microbe coated with antibodies cells destroyed)