lecture 9 exam 2

Question 1

aquired immunity can be conferred/induced from

Answer 1

passive or active ways

active can come through natural infection or artifical immunization
artificial immunizaiton can come from living and nonliving organisms

Question 2

passive immunity

Answer 2

antigen or antibody from immune individual can be administered to uninfected individual causing mini infection which then the person recovers

specific but no memory
decreases in antibody amount as days go on

Question 3

active immunity

Answer 3

microbial agent in body (vaccine or infection) then has immune response over days to challenge the infection and recovers

specific and memory
continue increasing in antibody count as days go on and more antigen encounters administered

Question 4

homologous vs heterologous passive immunizaiton

Answer 4

use horse antibody in horse then antibodies last longer (homo)
use horse antibody in dog then antibodies last shorter (hetero)

Question 5

ideal vaccination

Answer 5

correlate of protection

1. mimic natural infection without actual pathogen
2. prolonged & enhanced immunity: efficient antigen presentation, activation of T and B cells to several epitopes of pathogen to enhance immunity in individuals of an outbred population
3. safe w few or no side effects
4. stable and easy to administer

Question 6

herd immunity

Answer 6

more population immunized then the spread of disesae is contained

Question 7

types of available vaccines

Answer 7

1. killed vaccines/purified subunit
2. modified-live vaccines (infections)
3. recombinant vaccines

Question 8

killed/purified subunit vaccines

Answer 8

processing of noninfectious vaccine induces B cell and Th2 responses

1. DC take up extracellular antigen, inactivated bacteria/virus or inactivated toxin
2. no CD8 activation (kill kill kill)
3. IL1 or IL4 w MHC2 presentation to activate Th2+
4. IL4, IL5, IL10 released to stimulate antibody production (w Th2 bias) - IgE and some IgG subclasses

adv: stable on storage (lyophilization), killed by heat, chemical or irradiation, noninfectious and cannot cause dz
disadv: does not elicit strong Th1 response or cytotoxic T cells, elicits principally antibody responses (th2), strain specific, requires adjuvants, increase risk of adverse reactions

Question 9

adjuvant

Answer 9

immune response enhancer: potentiates killed/subunit antigens by causing inflammation to increase cytokines and costim molecules

three types: depot adjuvants, particulate adjuvants, immunostimulatory adjuvants

Question 10

depot adjuvants

Answer 10

stimulate inflammation and delays antigen decay
aluminum salts (alum)
-produces strong Th2 responses
-associated w sarcomas in cats
water in oil (freunds incomplete adjuvant)
-induces Th1
-mineral oil is very irritating and causes tissue damage in food animals such that hide can be condemned

Question 11

particulate adjuvants

Answer 11

enhance antigen-presentation and costim of T cells
liposomes
-lipid based microparticles containing antigens
-readily trapped and processed in endosomes (MHC2)
carrier proteins linked to carbohydrates antigens:
-hapten carrier principle improve immunogenicity by activating T cells
-ex: toxoids + haemophilius influenza b polysaccharides

Question 12

immunostimulatory adjuvants

Answer 12

CpG motifs of bacteria
saponins
BCG or muramyl dipeptide of mycobacterium tuberculosis

Question 13

CpG motifs of bacteria for immunostimulatory adjuvants

Answer 13

• propionobacterium acnes in Eqstim stimulate TLR9
• added to bordetella pertussis vaccine to enhance Th1 becuase B pertussis killed vaccine stimulates Th2 and IgE production

Question 14

saponins for immunostimulatory adjuvants

Answer 14

• extract from bark of tree Quillaja saponaria (Quil A)
• creates pores in cell membrane and directs antigens into cytosol for MHC1 processing and presenting
• activates cytotoxic t lymphocytes

Question 15

BCG/muramyl dipeptide of mycobacterium tuberculosis for immunostimulatory adjuvants

Answer 15

enhances Th1 immune responses by stimulation IL12 secretion

Question 16

adverse reactions caused by adjuvatns

Answer 16

respiratory syncytial virus (RSV)
-leading cause of respiratory dz in infants
-similar to bovine resp syncytial virus (BRSV)
-formalin inactivated vaccine was give ID in 1960
-vaccine-enhanced dz in children exposed to the virus
example of inappropriate immune response (Th2)
-stimulated systemic IgE antibody to glycoprotein epitopes, but not neutralizing antibody to viral epitopes
-killed BRSV: IL4 and IgE produced in mice and cattle

Question 17

modified live vaccines (attenuated)

Answer 17

infectious
made by reducing virulence of a pathogen
ex: (viral) polio, measles, chicken pox & yellow fever (bacterial) BCG, typhoid, brucellosis

pathogenic organism with gene for virulence factor - virulence gene removed - avirulent organism lacking gene for virulence factor -> virulence

Question 18

MLV vaccine: nonreplication

Answer 18

develop strain of organism that lacks ability to cause dz:

• modify genes of virulence
• pseudorabies (mad itch) vaccine for pigs

Question 19

pseudorabies vaccine for pigs details

Answer 19

remove thymidine kinase and gE
-virus cannot replicate and spread via nerves
serologic testing for Ab to gE is negative
antibody positive means exposed to field virus
considered marker vaccines or DIVA (differnetiating infected from vaccination animals)

Question 20

MLV advantages and disadvantages

Answer 20

adv:

1. replicates - exposes immune system to numerous epitopes and persists longer than killed
2. less virulence than field strain - grown in nontarget cells (attenuated)
3. no adjuvant needed (good costim) - activates cytotoxic T cells, good for herd immunity
   dis:
4. can cause illness or mild dz
5. immunocompromised hosts are at risk
6. can revert to virulence