IM 3

Question 1

Lymphocyte receptor ( immunoglobulin)

Answer 1

2 types: b cell ( attached) , antibody: free floating

5 class : GAMED
IgG,M,E,D,A

structure: 4 chain, 2 heavy 2 light
stem binding site: same IG class (heavy chain)
variable end : millions of different (light chain)

Question 2

Lymphocyte receptor T cell

Answer 2

antigen must be combined and presented
No two individual has same MHC protein

MHC class 1 ( most cell ) cytotoxic T cell

MHC Class 2: only on Macrophages, dendritic cells, and B cell
Helper T

NK cell dont neeed MHC class

Question 3

antigen presentation (exogenenous)

Answer 3

antigen outside the cell
Ingestion of antigen by phagocytosis:
antigen broken down, combine with class 2
vesicle moves to surface
exocytosis and insertion on cell membrane surface

can now bind to helper T cell with correct receptor

Macrophages, b cell, dendritic cells can do exogeneous presentation

Question 4

Endogenous antigen

Answer 4

antigen is already inside the cell
viral protein as antigen
broken down and piece complex with MHC class 1
vesicle move to surface
exocytosis and insertion on cell membrane

Cytotix T cell can bind and activate
most body cells can do antigen presnetation

Question 5

Helper T cell activation

Answer 5

antigen presented and bind
costimulus: non antigen binding
secretion of cytokines ( IL - 1 tNF - alpha

after 3 three steps, it activates
clonal expansion some effector some memory
release more IL-2 and cytokine

release IL - 2 and interferon gamma type 2

trigger macrophages and NK cell to become activated and increase in number

activated version can release cytotix chemical that destroy target cell
not part of binding

Question 6

cytotoxic T cell activation

Answer 6

bind to antigen presented
form effector and memory cytotoxic cell
minimal without helper T cell involvment
need it to get maximal activation
activated cytotoxic t cell circulate and bind virus infected cell
release perforin: punch a hole in cell
Release granzymes into cell through the hole
cell self distruct
virus released into extracellular

Question 7

B cell activation

Answer 7

direct binding of pathogen to B cell receptor
helper t cell needed for maximal B cell activation
crease effector and memory B cell
Some effect B cell specialize into plasama cell to secrete antibodies for specific antigen

Direct antibody effect
Neutralization : blocks pathogen attachment to healthy cell: ( no longer atttack healthy cell)

agglutination : form big clump so its easier to phagocytosis

precipitation: make it easier to spot

Enhanced phagocytosis :
variable end bind to antigen
stem end bind to phagocytes
forms a bridge

NK cell with correct receptor can also attach to stem end
NK cell release cell killing chemical

Question 8

Other antibody effect

Answer 8

Classic complement pathway :
antibody bind to pathogen
C1 protein inactive ,
C1 protein bind to binding site on step end of antibody
trigger a complement protein activation
c 3 classic complement pathway

Question 9

Immunity active and passive

Answer 9

active :
natural : antigen by chance
artifical : vaccine: deliberate exposure to antigen
small quantities of living or dead pathogen, toxic or harmless antigenic molecules

passive: direct transfer of preformed antibody
natural: mother to fetus : igG
breast feeding IgA
Passive artificial: injection of another person’s antibody into yours need for rapid dangerous or fatal conditions
limited lifespan

Question 10

stress and immunity and exercise

Answer 10

stress :
depress immune response
less likely to eat well, exercise regularly.
adequate sleep, outlook, good relationship with people

J shape curve
Moderate exercise : enhance immune response but
exhaustive exercise: depress immune response