Immunity wrap up

Question 1

what are the 4 stages once bacteria has made it past our defenses

Answer 1

1. leukocytosis - neutrophils enter the blood from bone marrow
2. margination - neutrophils cling to capillary wall
3. diapedesis -neutrophils flatten and squeeze out of capillaries
4. chemotaxis - neutrophils follow chemical trail

Question 2

what happens to the capillaries once bacteria has made it past our defenses

Answer 2

inflammation makes capillaries leaky - neutrophils squeeze out of leaky capillaries and enter tissue

Question 3

what are neutrophils attracted to once bacteria has made it past our defenses

Answer 3

neutrophils are attracted to the site of infection by chemicals released from damaged/infected cells or associated leucocytes - especially macrophages

Question 4

how is bacteria killed once bacteria has made it past our defenses

Answer 4

bacteria are phagocytosed - lysosomal enzymes (eg acid hydrolyses) in the phagolysosome kill the bacteria

Question 5

what are the 2 types of responses by adaptive immunity

Answer 5

1. cellular immunity
2. humoral immunity

Question 6

what is cellular immunity

Answer 6

cell mediated immunity - an immune response that does not rely on antibodies but instead involves the direct action of immune cells, primarily T lymphocytes (T cells), to eliminate infected cells, pathogens, and cancer cells

Question 7

what is humoral immunity

Answer 7

antibody-mediated immunity - a type of adaptive immune response where antibodies, produced by B cells, circulate in the body’s fluids (blood and lymph) to neutralize pathogens and other foreign substances

Question 8

where can viral proteins enter the DC

Answer 8

• the phagolysosome
• the cytosol

Question 9

what is loaded onto MHC-II for CD4 T cell stimulation

Answer 9

phagosomal antigen

Question 10

what is loaded onto MHC-I for CD8 T cell stimulation

Answer 10

cytosolic antigen

Question 11

what does activated B cells divide and differentiate into

Answer 11

plasma cells that secrete antibody as well as forming a separate population of memory B cells

Question 12

why is the second encounter with antigen more efficiently delt with

Answer 12

memory b cells are more numerous and are rapidly stimulated by antigen to become plasma cells

Question 13

what is clonal selection

Answer 13

selective expansion of lymphocytes that interact with antigen

Question 14

what can B cells generally do during an immune response

Answer 14

B cells can genetically switch the heavy chains to change class - but this does not change the antibody specificity = doesn’t change the function of the antibody

Question 15

what is the main function of IgD

Answer 15

signaling function only

Question 16

what is the main function of IgM

Answer 16

classical activation of complement

Question 17

what is the main function of IgG

Answer 17

crosses placenta/neutralization

Question 18

what is the main function of IgA

Answer 18

mucosal protection

Question 19

what is the main function of IgE

Answer 19

targets parasites/allergic responses

Question 20

what antibody is present in primary immune response

Answer 20

IgM

Question 21

what antibodies are present in secondary immune response

Answer 21

IgG, IgA and IgE (class switching)

Question 22

what are adjuvants

Answer 22

immune stimulants added to vaccines that enhance the activation of antigen presenting cells (APC)

Question 23

what can RNA stimulate

Answer 23

toll like receptors

Question 24

what are adjuvants usually required for

Answer 24

subunit vaccines