Humoral Immune Response II

Question 1

describe the 3 main mechanisms of antibodies?

Answer 1

Question 2

describe the process of neutralization

Answer 2

Question 3

neutralization is the main function of which immunoglobulin?

Answer 3

IgA

Question 4

name the 2 most important Fc receptors

Answer 4

IgG contains the most Fc receptors, therefore, is the best at opsonization

Question 5

describe the process of opsonization (Fab/Fc region)

Answer 5

Question 6

describe antibody-dependent cellular cytotoxicity (ADCC)

Answer 6

Question 7

describe eosinophil-mediated killing

Answer 7

Question 8

describe complement mediated opsonization and cytolysis

Answer 8

Question 9

describe the functional activity and distribution of the different immunoglobulins

Answer 9

Question 10

name the major immunoglobulin involved in opsonization

Answer 10

IgG1

Question 11

name the major immunoglobulin involved in neutralization

Answer 11

IgG1,2,3,4 but mainly IgA

Question 12

name the major immunoglobulin involved in sensitization of mast cells

Answer 12

IgE (FcƐR1)

Question 13

name the major immunoglobulin involved in activation of the complement system

Answer 13

IgM

Question 14

name the major immunoglobulin involved in transport across epithelium

Answer 14

IgA

Question 15

name the major immunoglobulin involved in transport across placenta

Answer 15

IgG1

Question 16

summarize the effector function of the antibodies

Answer 16

Question 17

describe the process of mucosal immunity

Answer 17

• IgA is produced in mucosal lymphoid tissues
• transported across epithelia
• neutralizes microbes in lumen of mucosal organs

Question 18

describe the process of neonatal immunity

Answer 18

• maternal antibodies are actively transported across the placenta to the fetus
• also across the gut epithelium of neonates
• incomplete immune systems
• passive immunity from the mother
• acquire IgG by 2 routes that rely on neonatal Fc receptor (FcRn):
  
  • placenta while in uterus
  • gut after ingestion of mother’s colostrum

Question 19

describe the mechanism of immune evasion by pathogens

Answer 19

Question 20

describe whole vaccines: killed or inactivated

Answer 20

• in killed or inactivated vaccines the microbial agent is treated with heat, chemicals or radiation
  
  • usually don’t require refrigeration, easy to store and transport
  • stimulate a weaker immune response: humoral only
  • more likely to require multiple doses and boosters
• killed whole bacterial vacines:
  
  • cholera, plague
• inactivated whole viral vaccines:
  
  • polio (Salk), rabies, influenza hepatitis A

Question 21

describe whole vaccines: live attenuated

Answer 21

• attenuation: any porcess that substantially weakens or negates the virulence of a microbial agent (easier for viruses than bacteria)
• live attentuated vaccines:
  
  • stimulate a strong immune response: humoral + CMI
  • require fewer doses and booster shots
  • require refrigeration, more difficult to transport
  • possibility of reversion (back mutation to wild type)

Question 22

describe acellular and subunit vaccines

Answer 22

• selected antigens from the microbe rather than the whole organism are used (immunodominant protein)
• toxoid vaccines (acellular): formalin treated bacterial toxin
• conjugate vaccines (acellular): encapsulated bacteria (incapable of activating CMI)
• subunit vaccines: viral components

Question 23

describe recombinant vacciens

Answer 23

• recombinant vector vaccines
  
  • selected genes for microbial antigens are cloned into a vector
  • the cloning host will produce the antigen for use in a vaccine
• DNA vaccines
  
  • DNA plasmids encoding antigenic proteins injected into patient
  • expression of foreign proteins in host cells
  • strong humoral and CM response

Question 24

summarize the production, booster requirement, relative stability, type of immunity induced and reversion tendency for attenuated, inactivated and DNA vaccines

Answer 24

Question 25

___ is the only isotype useful in diagnosing infections in neonates

Answer 25

IgM is the only isotype useful in diagnosing infections in neonates